Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR SORTING MAIL ARTICLES
The present invention relates generally to an article sorting method and
apparatus and,
more particularly, to an article sorting method and apparatus for the
sortation of articles of
mail. The present invention is especially adapted to sort flat mail to a
delivery point
sequence or carrier walk sequence, but may also apply to sort a mix of flat
mail and letter
mail.
to BACKGROUND OF THE 1NVENTTON
Typically, mail is received in a distribution center or warehouse from two
sources.
One source or type is local mail which is to be delivered within the local
area. This is
commonly lmown as turnaround mail. Local mail may also be sorted for delivery
to other
distribution centers. Another source or type of mail is out-of area mail
received from other
i5 distribution centers. Mail which is to be delivered locally must,
ultimately, be sorted to
delivery point sequence, also known as "carrier walk sequence," i.e., the mail
is sorted and
arranged such that the first address stop is followed by the second address
stop, which is
followed by the third address stop, and so on. A Dual Bar Code Sequenced
(DBCS)
machine is capable of achieving delivery point sequence for letter mail.
However, it requires
2o two or more passes of the mail through the same sequence.
A process exists today to delivery point sequence letter sized mail, which
sorts the
mail into a specific mail carrier's route sequence. The approach commonly used
to sequence
the letter mail requires that the mail be processed through a Letter Sorting
Machine (LSM)
twice. Each of these two sort processes is referred to as a pass. The first
pass inducts mail,
25 which arrives in somewhat random order, into an LSM, which arranges it into
groupings of
addresses. The number of discreet addresses (sequences) in each grouping
depends on how
many output bins of the LSM are utilized in the sorting process.
The device used to provide places to hold the mail in order is a sorting
matrix, such as
a grouping of slots, with each slot representing an address in the carrier's
route. This sorting
3o matrix can be as large or as small as necessary or desired. For example, a
larger matrix (or
number of slots) allows for a larger carrier route or more individual smaller
carrier routes to
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be processed at one time. If an LSM contains output bins equal to the number
of stops on the
carrier's route, then mail for each address would be sorted to one bin.
However, to be able to
process more carrier routes at one time, a theoretical grouping of sorting
slots is created using
a specific number of LSM output bins. The number of slots is typically equal
to the number
of bins squared. For example, if an LSM is equipped with 10 output bins, a
matrix of 100
slots can be created.
Therefore, mail for the first Garner route address or sequence may be sorted
to the first
assigned bin, the second address to the second bin, the third sequence to the
third bin and so
on to the tenth bin. The eleventh sequence may then be sorted to the f rst
bin, the twelfth to
l0 the second bin, and so on, up to the twentieth sequence being sorted to the
tenth bin. This
same sorting process is repeated so that the first, eleventh, twenty first,
thirty first and so on,
up to and including the ninety-first sequence, are sorted into the first bin,
while the second,
twelfth, twenty-second, thirty-second, etc. sequences are sorted into the
second bin and so on
for all ten output bins.
Having completed the first sorting pass, mail is usually manually removed from
the
LSM and loaded onto manual carts and/or temporarily stored on shelves in racks
in
preparation for the second pass. The trays are then unloaded from the manual
carts and the
sorted articles in the trays are reprocessed during a second pass. An
alternative to manual
handling of the trays of mail between sort passes is disclosed in U.S. Pat.
No. 5,35,243,
2o which utilizes a storage and retrieval machine to stage the letter trays
for the second pass.
For the second pass, it is absolutely essential that proper order of trays be
maintained.
First pass mail trays from bin number one of the first pass must be inducted
into the LSM
first, followed by the trays of bin number two, three and so on up to bin
number ten. The
current process requires machine operators to properly maintain tlus sequence.
When
inducted for the second pass, the sequences are sorted with address or
sequence 1 being
sorted to bin 1, sequence 11 to bin 2, sequence 21 to bin 3, and so on up to
sequence 91 to bin
10. Trays of mail for the second bin (containing sequences 2, 12, 22, 32, 42,
52, and so on up
to 92) are inducted and sorted such that address or sequence 2 is sorted to
bin 1, sequence 12
to bin 2, sequence 22 to bin 3, etc. When the trays of mail sorted at all ten
bins during the
first sort pass are inducted and sorted during a second sort pass, bin 1 will
contain sequences
1 through 10, bin 2 will contain sequences 11 through 20, and so on.
Accordingly, when the second sort pass is completed and the mail is removed
from
the LSM, it is sorted in Garner route sequence, i.e., first address stop
followed by second
address stop followed by third address stop; etc. The delivery point sequence
sorting matrix
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described above is recognized as the process currently utilized for letter
mail, and can be
adapted to flat mail sequencing. However, as discussed above, this process
requires manual
handling of the trays between sort passes to ensure that the trays are in the
proper order or
sequence for the second sort pass.
Flat mail is mail which ranges in length from approximately 5 inches to
approximately 15 inches, height from approximately 6 inches to approximately
12 inches,
thickness from approximately 0.009 inches to approximately 0.75 inches, and
weight from
approximately 0.01 pound to approximately 1.0 pound. It may include paper
envelopes,
plastic wrappers, bound catalogs, banded newspapers, open mail pieces without
wrappers,
l0 and the like. Such flat mail has traditionally been sorted to the
distribution center level
automatically, such as via a model AFSM 100 flat sorting system manufactured
by
Mannesmann Dematic Postal Automation and marketed in the United States by
Mannesmann
Dematic Rapistan Corp. The sortation from distribution center to carrier walk
sequence has
traditionally been performed manually utilizing pigeon-hole bins. Such manual
sorting of flat
15 mail to the delivery point sequence may take several hours, up to half of
the time available
for a Garner to deliver his/her route.
It would be desirable to provide a carrier walls sequence for mail, especially
for flat
mail. It would be most desirable if the carrier walk sequence depth of sort is
accomplished
automatically. It would also be desirable if the carrier walls sequence of
flat mail is
20 accomplished irrespective of the source or type of the mail. In particular,
it would be
desirable to be able to sort turnaround mail to carrier walk sequence.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus for sorting flat
articles which
is capable of automatically sorting the articles to delivery point sequence.
The method and
25 apparatus may utilize one or more flat sorting machines, whereby multiple
flat sorting
machines may be arranged together with a tray sorting, queuing and handling
system.
According to an aspect of the present invention, an article sortation system
for sorting
articles to a delivery point sequence depth of sort includes at least one
article sorter and a
buffering assembly. The at least one article sorter has an induct and a
discharge, and is
30 operable to sort articles into a plurality of trays and discharge the trays
of sorted articles at the
discharge. The buffering assembly is operable to automatically sort and convey
the trays
containing sorted articles sorted during a first sort of the at least one
article sorter from the
discharge of the at least one article sorter to the induct of the at least one
article sorter. The
buffering assembly is operable to automatically arrange the trays in an
arranged manner and
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convey the arranged trays to the induct of the at least one article sorter for
a second sort of the
articles.
The buffering assembly may include a plurality of conveyors which are
cooperatively
operable to arrange and accumulate trays in the sequenced manner on the
buffering assembly
as the trays are received from the discharge of the at least one article
sorter. In one form, the
plurality of conveyors includes at least one transport conveyor and a
plurality of zone
conveyors connected to the transport conveyor. The zone conveyors and the
transport
conveyor are cooperatively operable to receive trays from the at least one
transport conveyor
and discharge trays to the at least one transport conveyor in an appropriate
order for the
to second sort. The plurality of zone conveyors are positioned along at least
one side of the at
least one transport conveyor. The at least one transport conveyor may include
a plurality of
transfer units, with each of the plurality of transfer units being positioned
at at least one of the
plurality of zone conveyors and being operable to move trays between the at
least one
transport conveyor and a respective at least one of the plurality of zone
conveyors.
In another form, the plurality of conveyors define at least one generally
continuous
loop between the discharge of the at least one article sorter and the induct
of the at least one
article sorter. The buffering assembly is operable to circulate trays in the
at least one
generally continuous loop and input new trays into appropriate spaces between
the circulating
trays in the at least one generally continuous loop as the new trays are
received from the
2o discharge of the at least one article sorter. The at least one generally
continuous loop may
include at least two generally continuous loops. The at least one article
sorter may then
include a plurality of individual article sorting stations, with each of the
at least two
continuous loops being operable to convey trays received from different groups
of individual
sorting stations of the at least one article sorter.
Optionally, the at Ieast one article sorter may include a first article sorter
and a second
article sorter. The buffering assembly may then be positioned along a return
conveyor which
is connected between at least one of a discharge of the first article sorter
and a discharge of
the second article sorter and at least one of an induct of the first article
sorter and an induct of
the second article sorter. The article sortation system may include a second
buffering
assembly connected between a discharge of the second article sorter and an
induct of the
second article sorter. The article sortation system may then include a
connecting conveyor
positioned between the buffering assembly and the second buffering assembly
and between
the discharges of the first and second article sorters. The connecting
conveyor is operable to
convey trays from the discharge of the first article sorter and/or the second
article sorter to an
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appropriate one of the buffering assembly and the second buffering assembly.
The
connecting conveyor may define a generally continuous conveying loop.
Optionally, the at least one article sorter comprises a single article sorter.
The
buffering assembly may be operable to sort and convey the trays containing
sorted articles
sorted during the first sort of the article sorter from the discharge of the
article sorter to the
induct of the article sorter for a second sort of the single article sorter.
Optionally, the buffering assembly is positioned at a Level above the at Least
one
article sorter. The article sortation system may then include elevating
devices which are
operable to convey trays upward from the discharge of the at least one article
sorter to the
to buffering assembly and downward from the buffering assembly to the induct
of the at least
one article sorter.
The first sortation process may resolve the address of each article, apply a
pseudo
identification to the article, which is retained in a control, and sort the
article to trays, bins or
containers. The second sortation process calls for containers from the first
sortation process
in a particular order and carnes out a delivery point sequence sortation on
the articles in those
containers using the information stored in the control by the first sortation
process.
Preferably, the delivery point sequence sortation is to 9 zip code digits and,
most preferably,
to 11 zip code digits.
According to another aspect of the present invention, a method for sorting
articles to a
2o delivery point sequence depth of sort includes providing at Least one
article sorter having an
induct and a discharge. Articles are then sorted in a first sort of the at
least one article sorter
into a plurality of trays. A buffering assembly is provided for automatically
sorting and
conveying trays containing sorted articles sorted during a first sort of the
at least one article
sorter. The trays of sorted articles are conveyed and arranged in an arranged
manner on the
buffering assembly. The arranged trays of sorted articles are conveyed to the
induct of the at
least one article sorter for a second sort of the articles. The articles are
then sorted in a
second sort of the at least one article sorter.
In one form, the method may include conveying each of the trays to an
appropriate
one of a plurality of zone conveyors. The trays may be cooperatively
discharged from the
zone conveyors in an arranged manner.
In another form, the method may include conveying the trays in a continuous
loop.
The trays may be generally continuously conveyed in the continuous loop. The
trays may be
inducted into the generally continuous Loop in an arranged manner.
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Optionally, the method may include providing at least two article sorters and
at least
two buffering assemblies. The trays may be conveyed from the discharge of one
of the at
least two article sorters to one of the at least two buffering assemblies.
Alternately, the
method may include providing a single article sorter.
According to another aspect of the present invention, a method of sorting
articles to a
delivery point sequence depth of sort via a first sort pass and a second sort
pass of at least one
article sortation assembly provides a delivery point sequencing sortation
matrix. The method
includes supplying articles for multiple carrier routes to an induct of the
sortation assembly,
and then sorting articles in a first sort pass to a first set of output bins
of the sortation
to assembly, whereby each output bin of the first set of output bins receives
articles for each of
the multiple carrier routes. The sorted articles are then arranged at the
induct of the sortation
assembly for a second sort pass, and then sorted to a second set of output
bins of the sortation
assembly. The sortation matrix provides that articles from each output bin of
the first set of
output bins are sorted to each output bin of the second set of output bins.
15 The first and second sets of output bins may have a different quantity of
bins
associated therewith. For example, the first set may include 110 of 120 bins
of the sortation
assembly, while the second set may include all 120 bins, in order to maximize
the number of
carrier routes that the sortation matrix may sort. For carrier routes having
approximately 650
stops, the sortation matrix of the present invention is capable of sorting the
articles for 20
2o different routes to a delivery point sequence depth of sort via two sort
passes through a
sortation machine having 120 output bins.
According to another aspect of the present invention, a delivery point
sequencing
system includes a conveying assembly for automatically sorting and conveying
trays
containing sorted articles from a discharge of at least one sorting assembly
to an induct of the
25 at least one sorting assembly. The conveying assembly has a generally
continuous conveying
tracl~ and is operable to automatically provide the trays containing sorted
articles to the induct
of the sorting assembly in a sequenced mamler.
In one form, the at least one sorting assembly includes a single sorting
assembly. The
conveying assembly is operable to sort and convey trays between the discharge
end of the
3o single sorting assembly to the input end of the single sorting assembly.
In another form, the at least one sorting assembly includes a first sorting
assembly and
a second sorting assembly. The conveying assembly is operable to sort and
convey trays
between a discharge end of the first sorting assembly and an induct end of the
second sorting
assembly.
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The conveying assembly preferably includes a plurality of conveyors which are
cooperatively operable to arrange trays in a sequenced manner on the conveying
assembly as
the trays are received from the discharge of the sorting assembly. In one
form, the plurality
of conveyors define at least one continuous loop between the discharge of the
sorting
assembly and the induct of the sorting assembly. The conveying assembly is
then operable to
cycle trays around the at least one continuous loop and input new trays into
appropriate
spaces between the cycling trays in the at least one continuous loop as the
new trays are
received from the discharge of the sorting assembly.
In another form, the conveyors include a plurality of zone conveyors which are
l0 operable to receive trays from and discharge trays to at least one transfer
conveyor which
conveys the trays to the induct of the sorting assembly. The zone conveyors
and the transfer
conveyor are cooperatively operable to arrange the trays in a sequenced manner
on the
transfer conveyor for the second sort pass.
According to another aspect of the present invention, a method of sorting mail
to a
delivery point sequence depth of sort includes providing at least one article
sorter adapted to
perform at least two sort processes to articles supplied thereto and providing
at least one
y conveyor between a discharge of the at least one article sorter and an input
of the at least one
article sorter. Articles are supplied to the at least one article sortation
assembly and a first
sort pass is performed to sort the articles. Containers of the sorted articles
are substantially
continuously conveyed to arrange the containers in an arranged manner. The
arranged
containers are conveyed to an input of the at least one article sorter and a
second sort pass is
then performed to sort the articles to the delivery point sequence depth of
sort. Preferably,
the method includes buffering the containers on the at least one conveyor.
The at least one conveyor may be operable to automatically convey and arrange
containers from a discharge of the at least one article sorter to the input of
the at least one
article sorter.
In one form, the method may include providing at least one continuous
conveying
loop between the discharge and the input of the at least one article sorter.
The at least one
conveyor may include at least one incoming conveyor leading from the discharge
of the at
least one article sorter to the at least one continuous conveying loop and at
least one outgoing
conveyor leading from the at least one continuous conveying loop to the input
of the at Least
one article sorter. The method may include substantially continuously
circulating containers
around the at least one continuous conveying loop and inducting containers
from the at least
one incoming conveyor at appropriate places between the circulating containers
to arrange
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the containers in the arranged manner. The method may provide at least two
independently
operable continuous loops between the at least one outgoing conveyor and the
at least one
incoming conveyor.
In another form, the method may provide a plurality of zone conveyors which
are
operable to receive containers from and discharge containers to at least one
transport
conveyor which conveys the containers to the input of the at least one article
sorter. The
containers may be cooperatively discharged from the zone conveyors in an
appropriate order
onto the transport conveyor to arrange the containers on the transport
conveyor in the
arranged manner for the second sort pass.
1o Optionally, the method may provide a single auticle sorter and convey
arranged
containers from the discharge of the single article sorter to the input of the
single article
sorter. Alternately, the method may provide first and second article sorters.
Articles may be
supplied to an induct of the first article sorter, and the arranged containers
may be conveyed
to an induct of the second article sorter. The method may provide at least two
of the first
article sorters, where each of the first article sorters has a throughput that
is approximately
one-half the throughput of the second article sorter.
According to yet another aspect of the present invention, an article sortation
system
for sorting articles to a delivery point sequence depth of sort includes at
least two article
sorters and a conveying system. Each of the article sorters includes an induct
and a
2o discharge. The article sorters are operable to sort articles into a
plurality of trays and
discharge the trays of sorted articles at the discharges. The conveying system
is
interconnected between the inducts and the discharges of the article sorters.
The conveying
system is operable to sort and convey trays containing articles sorted during
a first sort pass
of the article sorters. The conveying system is operable to automatically
arrange the trays in
an arranged manner and provide the arranged trays to the inducts of the
article sorters for a
second sort of the articles.
Preferably, the conveying system includes at least two buffering assemblies
connected
to the induct of a respective one of the article sorters and a conveyor
assembly connected
between the discharges of the article sorters and the buffering assemblies.
The conveyor is
selectively operable to convey trays from the discharges to an appropriate one
of the
buffering assemblies, where the trays are arranged and then conveyed to a
respective one of
the article sorters for a second sort pass through the respective one of the
article sorters. The
at least two buffering assemblies include a first buffering assembly connected
to the induct of
a first one of the at least two article sorters and a second buffering
assembly connected to the
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induct of a second one of the at least two article sorters. Each of the first
and second
buffering assemblies preferably includes a plurality of conveyors which are
cooperatively
operable to arrange and accumulate trays in a sequenced manner on the
buffering assemblies
as the trays are received from the conveyor assembly.
W one form, the plua-ality of conveyors define at least one continuous loop
between
the conveyor assembly and the inducts of the first and second article sorters.
The plurality of
conveyors are operable to circulate trays on the at least one continuous loop
and induct trays
into appropriate spaces between the circulating trays in the at least one
continuous loop as the
new trays are received from the conveyor assembly.
l0 In another form, the plurality of conveyors include at least one transport
conveyor and
a plurality of zone conveyors connected to the at least one transport
conveyor. The plurality
of zone conveyors and the at least one transport conveyor are cooperatively
operable to
convey trays from the at least one transport conveyor to the plurality of zone
conveyors, and
to convey trays from the plurality of zone conveyors to the at least one
transport conveyor in
15 an appropriate order for the second sort.
The conveying system may be positioned at a level above the article sorters.
The
article sortation system may then further include elevating devices which are
operable to
convey trays upward from the discharges of the article sorters to the conveyor
assembly and
downward from the conveyor assembly or buffering assemblies to the respective
one of the
2o inducts of the article sorters.
Preferably, the article sortation system further includes a control which is
operable to
determine an appropriate one of the article sorters for a second sort pass for
articles in a
particular tray, whereby the conveying system is operable to convey and
arrange the tray for
induction to the appropriate one of the article sorters in response to the
control.
25 According to yet another aspect of the present invention, a method of
sorting mail to a
delivery point sequence depth of sort includes providing at least two article
sortation
assemblies adapted to perform at Ieast two sort processes to articles supplied
thereto. Articles
are supplied to the at least two article sortation assemblies and a first sort
pass is performed
on the articles. The method includes determining an appropriate one of the at
least two
30 article sortation assemblies for the sorted articles to be inducted into
for a second sort pass.
Trays containing sorted articles sorted by the first sort pass axe conveyed to
arrange the trays
in an arranged mariner. The arranged trays are then conveyed to an input of
the appropriate
one of the at least two sortation assemblies. A second sort pass of the
articles is performed to
sort the articles to a delivery point sequence depth of sort.
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Preferably, the step of conveying trays includes buffering trays of sorted
mail and
arranging the trays in the arranged manner. The step of buffering trays may
include
circulating trays around at least one continuous loop positioned between a
discharge of the
first sortation assembly and an induct of the second sortation assembly, and
inducting
containers at appropriate places between the circulating containers to arrange
the containers
in the arranged manner.
Optionally, the step of conveying trays of sorted articles may include
conveying trays
of sorted articles along at least one transport conveyor, conveying the trays
to a plurality of
zone conveyor connected to the at least one transport conveyor, and
cooperatively
to discharging trays from the plurality of zone conveyors in an appropriate
order onto the at
least one transport conveyor to arrange the trays on the at least one
transport conveyor in an
appropriate order for the second sort pass.
Optionally, the step of conveying the arranged trays may include conveying the
arranged trays from a discharge of the at least two article sortation
assemblies to an induct of
an appropriate one of at least two buffering assemblies. The step of conveying
the arranged
trays may then include conveying the arranged trays along a generally
continuous conveyor
assembly positioned between the discharge of the at least two article
sortation assemblies and
the at least two buffering assemblies.
According to yet anothex aspect of the present invention, an article sortation
system
2o for sorting articles to a delivery point sequence depth of sort includes at
least one article
sorter, a plurality of zone conveyors and at least one transport conveyor. The
at least one
article sorter has an induct and a discharge, and is operable to sort articles
into a plurality of
trays and discharge the trays of sorted articles at the discharge. The at
least one transport
conveyor is operable to convey trays from the discharge of the at least one
article sorter to the
induct of the at least one article sorter. The plurality of zone conveyors are
positioned along
the at least one transport conveyor. The at least one transport conveyor and
the plurality of
zone conveyors are cooperatively operable to arrange and accumulate trays in a
sequenced
manner on the at least one transport conveyor. The at least one transport
conveyor is
operable to discharge the sequenced trays to the induct of the at least one
article sorter.
Preferably, the plurality of zone conveyors are positioned along at least one
side of
the at least one transport conveyor. The at least one transport conveyor may
include a
plurality of transfer units, where each of the plurality of transfer units is
positioned at at least
one of the plurality of zone conveyors and is operable to move trays between
the at least one
transport conveyor and a respective at least one of the plurality of zone
conveyors.
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Optionally, the at least one transport conveyor and the plurality of zone
conveyors axe
positioned at a height above the at least one article sorter. The article
sortation system may
then include a tray elevating device between the discharge of the at least one
article sorter and
the transport conveyor and a tray lowering device between the transport
conveyor and the
induct of the at least one article sorter.
Optionally, the article sortation system may includes a single article sorter.
Alternately, the article sortation system may include at Least two article
sorters.
Therefore, the present invention provides an automatic delivery point sequence
apparatus and process for sequencing flat mail. The present invention provides
an automated
l0 means for sorting, queuing and presenting trays of sorted articles to
inducts of one or more
sortation assemblies for a second sort pass of the articles. The trays may be
automatically
removed from their respective output bins, and automatically identified and
labeled so that
the trays can be provided to the inducts in the proper order. The present
invention thus saves
time, improves accuracy of sorting and more fully utilizes the production
capacity of the flat
sorting machines, especially when two or more machines are coupled together.
These and other objects, advantages, purposes and features of this invention
will
become apparent upon review of the following specification in conjunction with
the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an upper perspective view of a sequencing conveyor and article
sortation
assembly in accordance with the present invention;
FIG. 2 is an upper perspective view from an opposite end of the sequencing
conveyor
and article sortation assembly of FIG. I;
FIG. 3 is a perspective view of a plurality of sorting mechanisms useful with
the
present invention;
FIG. 4 is a top plan view of the sequencing conveyor of FIGS. l and 2;
FIG. 5 is a side elevation of an alternate embodiment of a sequencing conveyor
and
article sortation assembly in accordance with the present invention, with
conveyor ramps
being configured to convey trays from a discharge end of the sortation
assembly to an input
end of the sequencing conveyor;
FIG. 6 is a top plan view of the sequencing conveyor of FIG. 5, with portions
cut
away to show the discharge end of the sortation assembly;
FIG. 7 is a perspective view of a tray handling system useful with the present
invention;
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FIG. 8 is a perspective view of the tray handling system of FIG. 7 from an
opposite
end;
FIG. 9 is a top plan view of an alternate flat article sortation apparatus
according to
the present invention;
FIG. 10 is a top plan view of a sequencing conveyor useful with the sortation
apparatus of FIG. 9;
FIG. 11 is a perspective view taken generally from the direction XI-XI in FIG.
9;
FIG. 12 is the same view as FIG. 9 of an alternate embodiment thereof;
FIG. 13 is the same view as FIG. 9 of another alternate embodiment thereof;
to FIG. 14 is the same view as FIG. 9 of yet another alternate embodiment
thereof;
FIG. 15 is a top plan view of another alternate embodiment of the present
invention,
which utilizes multiple flat sorting machines;
FIG. 16 is an upper perspective view of another sequencing conveyor and
article
sortation assembly in accordance with the present invention;
FIG. 17 is a top plan view of the sequencing conveyor and article sortation
assembly
of FIG. 16;
FIG. 18 is an upper end view of the sequencing conveyor and article sortation
assembly of FIGS. 16 and 17;
FIG. 19 is a lower, opposite end view of the sequencing conveyor and article
sortation
2o assembly of FIGS. 16-18;
FIG. 20 is a view along one side of the sortation assembly and beneath the
sequencing
conveyor of FIGS. 16-19;
FIG. 21 is a perspective view of the discharge end of the sortation assembly
and the
induct end of the sequencing conveyor of FIGS. 16-20;
FIG. 22 is a flow chart of a flat mail sequencing process according to the
present
invention;
FIG. 23 is a schematic of a first sort pass of a sorting matrix useful with
the present
invention;
FIG. 24 is a schematic of a second sort pass of the sorting matrix of FIG. 23;
FIGS. 25A and 25B are schematics of a first sort pass of a sorting matrix of
the
present invention; and
FIGS. 26A and 26B are schematics of a second sort pass of the sorting matrix
of
FIGS. 25A and 25B.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now specifically to the drawings and the illustrative embodiments
depicted
therein, a flat article sortation apparatus or system 10 includes a sorter
unit or assembly 12
and a sort conveyor or buffer assembly 14. Sorter unit 12 includes an induct
end 16 and an
output or discharge end 26 and a sortation mechanism, generally illustrated at
18. Buffer
assembly 14 includes an induct end 20 and an output end 22, and is
cooperatively
interconnected between discharge end 26 and induct end 16 of sorter assembly
12. Buffer
assembly 14 automatically arranges and conveys containers 25 of articles
sorted by an initial
sortation process of sorter assembly 12 from discharge end 26 back to induct
end 16 of sorter
assembly 12 in order to induct the sorted articles for further sortation by
sorter assembly 12,
as discussed in detail below. Accordingly, article sortation system 10 is
operable to provide a
delivery point or carrier route sequence depth of sort via first and second
passes through
sorter units 12 and via buffer 14, which provides trays containing sorted
articles from the first
pass to the induct end 16 of the sorter assembly 12 in a sequenced or arranged
manner.
In the illustrated embodiment, sortation assembly 12 is a flat-sorting system,
such as
the type manufactured and marketed by Alcatel Postal Automation System and/or
Mannesmann Dematic Postal Automation and/or Mannesmann Dematic Rapistan Corp.
and/or Siemens Dematic Corp. under Model AFSM100. Sortation assembly 12 sorts
mail
received at induct end 16. An OCR-Optical Character Reader, VCS-Video Coding
System
(OCR/VCS) attempts to resolve the address to the full 11 digit zip code during
the first pass
on the sorting assembly 12. If the OCR/BCR (BCR-Bar Code Reader) cannot
resolve the
address to 11 digits, the VCS is used to complete the result. The address is
resolved to 11
digits during the first pass. This information is retained by a high level
sortation computer
and used during the first and second pass operations. The OCR/VCS system
connects the
pseudo number with the 11 digit zip code. The sortation assembly 12 uses the
11 digit zip
code to send the mail piece to the correct output during the first pass, so
that it can be fed
back through the second pass to be sorted to the delivery point sequence. The
mail piece
must be sorted correctly (using the 11 digit zip code) each pass to be
properly sorted to the
delivery point sequence.
Sortation mechanism 18 includes a carousel (not shown) which deposits articles
into
particular chutes 24 for depositing in containers 25 positioned under the
chutes (as shown in
FIG. 3). After the containers or trays 25 are at least partially filled with
articles, a tray
handling system, such as tray handling system 110 of FIGS. 7 and 8, discharges
the at least
partially filled trays automatically to output end 26, which, in the
illustrated embodiment, is a
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conveyor, such as a belt conveyor, powered roller conveyor, or the like. A
preferred form of
tray handling system 110 is disclosed in commonly assigned, U.S. pat.
application, Ser. No.
09/629,009, filed July 31, 2000 by Olson et al. for AUTOMATIC TRAY HANDLING
SYSTEM FOR SORTER (Attorney Docket RAP04 P-601), the disclosure of which is
hereby
incorporated herein by reference, and is illustrated in FIGS. 7 and ~ and
discussed briefly
below. In the illustrated embodiment, each induct end 16 includes three induct
lines 16a,
16b, 16c and the sorter unit 12 and tray handling system have 120 bin
positions, but may be
extended up to 240 bins or more, depending on the application. For a 120 bin
system, the
three induct lines 16a, 16b, 16c rnay randomly feed any of three groups of 40
bins during the
to first sort pass operation. The bins may be divided so there are three
groups, such as group A,
having bins 1-40 of the sortation assembly, group B, having bins 41-80 of the
sortation
assembly, and group C, having bins 81-120 of the sortation assembly. Sortation
assembly 12
is preferably capable of sorting up to 10,000 pieces of flat mail per hour
and, most preferably,
approximately 20,000 or more pieces of flat mail per hour.
The first pass through sortation assembly 12 is used by the system to
determine the
address information. The system must learn how many letters are to be sent to
each delivery
point. Note that this first pass preferably has the addresses resolved to the
delivery point
level (11 digits for the U.S.). During the first pass, all of the mail
destined for the first
delivery point of each route is sent to output or bin 1, the second delivery
point to output 2,
2o and the third to output 3, and so on. The mail is inducted into the
sortation assembly by all
three inducts or feeders I6 randomly. A schematic of the first pass sortation
process is shown
generally at 15A in FIG. 23.
After the first pass is concluded, the trays are then swept automatically from
the
sortation assembly 12 and sent to sorter conveyor or buffer assembly 14, and
then to the
induct end 16 of sortation assembly 12, but only when sortation assembly 12
calls for each
particular container. The trays may be swept as disclosed in U.S. pat.
application, Ser. No.
09/629,009, referenced above, or via other means or processes, without
affecting the scope of
the present invention. For correct delivery point sequencing, output 1 is
processed before
output 2, which is processed before output 3, and so on. Therefore, the trays
are arranged in
order by sorter conveyor 14 for induction into the second pass of sorter
assembly 12. During
the second pass, mail for a first Garner route will be sent to bin or output
1, mail for another
carrier route will be sent to output 2, and mail for yet another Garner route
will be sent to
output 3. This pass splits mail from the original output 1 (first delivery
point regardless of
route) between final outputs 1, 2, and 3. The same process is followed fox
original outputs 2
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and 3. The mail is inducted to the sortation assembly by a particular one of
the inducts or
feeders which is dedicated to a particular group of 40 bins. A schematic of
the second sort
pass is shown generally at 15B in FIG. 24. The idea is to ensure that the
delivery points in
the stackers at the end of the first pass are in separate outputs at the end
of the second pass.
Alternately, sortation assembly 12 may comprise a dual carousel system, such
as the
sortation assembly marlceted by Mannesmann Dematic Postal Automation under
Model
TOP2000, the sortation assembly marketed by Lockheed Martin Postal Automation
under
Model FSM 1000 or any other flat mail sortation system. Details of one type of
such
sortation assemblies are disclosed in French Pat. Application Nos. 9908610,
filed July 5,
l0 1999 by Fabrice Darrou, Vincent Grasswill, Alain Danjaume, entitled
DISPOSITIF DE
CONVOYAGE D'OBJETS PLATS AVEC UN SYSTEMS D'AIGUILLAGE; 9909163,
filed July 15, 1999 by Jean-Luc Astier, Pierre Advani, Dino Selva, entitled
DISPOSITIF A
PLUSIEURS CONVOYEURS A GODETS SUPERPOSES POUR LE TRI D'OBJETS
PLATS; and 9907316, filed June 10, 1999 by Fabrice Darrou, Vincent Grasswill,
Robert
Vivant, entitled DISPOSITIF DE CONVOYAGE DE COURRIER AVEC DES ROUES EN
MATIERE ELASTOMERE ELASTIQUEMENT DEFORMABLES; International Pat.
Application published 6 July 2000 by Francois Agier et al. as International
Publication No.
WO 00/39010, entitled DEVICE FOR CONVEYING FLAT OBJECTS BETWEEN
PROCESSING EQUIPMENT ITEMS; and International Patent Application published 6
July
2000 by Francois Agier et al. as International Publication No. WO 00/39012,
entitled
ROUTING DEVICE FOR GROUPING TWO STREAMS OF FLAT OBJECTS, SUCH AS
MAIL ENVELOPES, INTO ONE STREAM, the disclosures of which are hereby
incorporated herein by reference. Alternately, sortation assembly 12 may use
the principles
disclosed in U.S. Pat. No. 5,718,321, the disclosure of which is hereby
incorporated herein by
reference, adapted to flat mail sortation capability.
In the illustrated embodiment, buffer 14 is positioned at a height above
sortation
assembly 12, and thus conveys the containers or trays 30 over top of sort
assembly 12 from
the discharge end 26 back to the induct end 16 of sorter assembly or unit 12.
As seen in FIG.
2, discharge end 26 of sort assembly 12 includes a first sort discharge 26a
and a second sort
3o discharge 26b at each side of sort assembly 12 for discharging the trays
after respective first
and second sort passes, as discussed below. A pair of elevating or lifting
devices 28 are
positioned at the first sort discharge 26a at each side of sort assembly 12.
Each tray lifting
device 28 is operable to raise trays 25 from first sort discharge 26a upward
and onto induct
end 20 of buffer 14. Tray lifting devices 28 may be any known elevating or
lifting device,
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such as a Vertiveyor manufactured and marketed by Vertical Systems, Inc. of
Walton,
Kentucky, or a Mechanical Vertical Lift manufactured and marketed by P-flow
Vertical
Material Handling Systems of Milwaukee, Wisconsin, or any other known vertical
conveying
or lifting device, without affecting the scope of the present invention.
Optionally, as
discussed below, the vertical lifting device 28 may comprise a ramped conveyor
or any other
means of elevating trays from first sort discharge 26a onto induct end 20, as
discussed below.
Lilcewise, one or more tray lowering devices 30 may be positioned at the
discharge
end 22 of buffer 14, to lower the sorted or sequenced trays from discharge end
22 of buffer
14 to the induct end 16 of article sort assembly 12. W the illustrated
embodiment, three
to lowering devices 30a, 30b, 30c are operable to lower trays from a
respective one of three
output conveyors ZZa, 22b, 22c of buffer 14 to a respective one of three
induct stations 16a,
16b, 16c of sort assembly 12, as discussed below. Similar to elevating devices
28, lowering
devices 30 may be any known vertical lowering device or may be a ramped
conveying
surface or the like, without affecting the scope of the present invention.
Although shot~m and
15 described as being positioned generally above sort assembly 12, it is
further envisioned that
the sort conveyor or buffer of the present invention may otherwise be
positioned elsewhere,
such as alongside sort assembly 12, without affecting the scope of the present
invention.
Although shown and described as having three output conveying paths to three
inducts,
clearly, the buffer of the present invention may be adapted to sorter units
having less than or
2o more than three inducts, without affecting the scope of the present
invention.
As best shown in FIG. 4, buffer 14 includes a plurality of conveyors 32
positioned
side by side one another along at least a portion of buffer 14 and between
input end 20 and
discharge end 22 of buffer 14. Conveyors 32 are preferably powered roller
conveyors and are
operable to convey the sorted trays along the conveying portions in a selected
direction.
25 However, other conveying surfaces may be utilized, such as a belt conveying
surface or the
like, without affecting the scope of the present invention. A plurality of 90
degree transfers
or pop-up belt transfer units 34 are preferably positioned at each end of each
of the plurality
of conveyors 32 to change the direction of conveyance of the trays as they are
conveyed
along conveyors 32, as discussed in detail below. Such transfer units are
commercially
30 available and known in the art, such that a detailed discussion will not be
included herein.
Briefly, transfer units 34 are operable to convey a tray in a direction along
the conveyor at
which they are positioned, and may be operable to raise one or more belt
conveyor strips or
the Iike to convey a tray positioned at the transfer unit in a direction which
is generally
transverse or normal to the conveyor direction.
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Conveyors 32 include a feed conveyor portion 32a and an accumulating or
cycling
conveyor portion 32b. In the illustrated embodiment, conveyor portions 32a,
32b provide
three conveying paths from induct end 20 to a respective one of output
conveyors 22a, 22b,
22c at output end 22, as discussed below. Induct end 20 of buffer 14 includes
a pair of
induction conveyors 20a at the tray lifting devices 28 at either side of
buffer 14. Induction
conveyors 20a extend across buffer 14 and are interconnected by a plurality of
second
induction conveyors 20b and 90 degree transfer units 39. Induction conveyors
20a are
operable to convey the trays inducted via the vertical lifting devices 28
across buffer 14 to
align each tray with an appropriate one of the three induct conveyors 20b,
which are
l0 generally aligned with a respective or corresponding one of the feed
conveying portions 32a
of buffer 14. The 90 degree or pop-up transfer units 39 are positioned along
the cross
induction conveying portions 20a and function to convey the trays across the
induction
conveyors 20a or change the direction of conveyance of the trays onto an
appropriate second
induction conveyor 20b and toward the appropriate feed conveying portion 32a,
as discussed
below. A third cross conveyor 20c may extend across buffer 14 at an upstream
end of feed
conveying portions 32a to facilitate additional movement of trays across the
buffer 14 and/or
to facilitate operation of a larger sort loop, as discussed below. Providing
separate cross
conveying portions 20a facilitates generally continuous flow of trays from
both sides of sorter
unit 12 onto both sides of induct end 20 and onto and along the appropriate
conveying path of
buffer assembly 14, as also discussed in detail below.
Each conveying path of buffer 14 has one of the feed conveyor portions 32a
connected to a corresponding one of the induct conveyors 20b, preferably via a
transfer unit
39a. The feed conveyor 32a then conveys or feeds the trays from induct end 20
onto a
respective one of the accumulating conveyor portions 32b via a transfer unit
34a. Each
conveying path of accumulating conveyor portion 32b further includes a first,
input conveyor
33a and a second, return or accumulating conveyor 33b, which conveys the trays
in an
opposite direction from the input conveyor 33a. A pair of transfer traits 34b,
34c and 34d,
34a are positioned at opposite ends of accumulating conveyor portions 32b,
such that the
trays may be conveyed in a generally continuous loop around input conveyor 33a
and
3o accumulating conveyor 33b via 90 degree transfer units 34a, 34b, 34c, 34d.
More
particularly, transfer unit 34a is positioned at an upstream end of input
conveyor 33a and is
operable to convey trays from feed conveyor 32a onto input conveyor 33a or to
transfer trays
from transfer unit 34d onto input conveyor 33a. Additionally, transfer unit
34b is positioned
at a downstream end of input conveyor 33a and is operable either to change the
direction of
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or transfer the tray being conveyed along input conveyor 33a to the transfer
uut 34c at an
upstream end of the accumulating conveyor 33b, or to discharge the tray from
input conveyor
33a onto a respective one of the output or take-away conveyors 22a, 22b, 22c
at discharge
end 22 of buffer 14. The transfer units 34c, 34d at opposite ends of the
second accumulating
conveyor 33b function to change the direction of travel of the trays at each
end.
Buffer 14 is operable to convey the trays in a generally continuous loop via
transfer
unit 34a, first accumulating conveyor 33a, transfer units 34b, 34c, second
accumulating
conveyor 33b and transfer unit 34d. The trays are cycled or circulated in the
loop while new
trays are input into the loop at appropriate spaces between the trays being
cycled. After the
to trays are sorted and positioned in a sequenced manner along accumulating
conveyor portion
32b, the trays are continuously transferred from transfer unit 34b onto the
appropriate
discharge conveyor 22a, 22b or 22c. The discharge or take-away conveyors 22a,
22b, 22c
convey the sorted trays from the accumulating portion 32b to the vertical
lowering devices 30
at the discharge end 22 of buffer I4.
15 Accordingly, buffer 14 receives trays from the vertical lifting devices 28
and arranges
the trays onto appropriate feed and accumulation conveyor portions 32a, 32b,
depending on
the particular sortation station at which the articles were input into the
particular trays.
Preferably, each of the three feed and accumulating conveyor portions 32a, 32b
along buffer
14 are associated with a particular set or group of sortation stations of the
sortation
20 mechanism 18. For example, because each of the induct lines 16a, I6b, 16c
is associated
with and sorts articles for 40 of the 120 tray positions or sortation stations
of sorter trait 12,
the trays associated with a particular group or set of 40 of the sortation
stations are conveyed
to an appropriate path defined by one of the feed and accumulating conveying
portions 32a,
32b and further conveyed onto the appropriate output 22a, 22b, 22c and
lowering device 30a,
25 30b, 30c to provide the appropriate trays in an arranged or sequenced
manner at the
corresponding induct station 16a, I6b or 16c for a second pass or sort of the
articles. This
allows the articles within the containers after the first sortation pass to be
re-input or re-
inducted into an appropriate induct station and in an appropriate sequence for
a second
sortation process to achieve a delivery point sequence depth of sort of the
articles.
3o During operation, articles are originally input at induct stations 16a, 16b
and 16c of
sort assembly 12 in a random manner. The articles are sorted during the first
pass and
discharged into containers positioned at the appropriate sortation station or
bin position via
the carousel and chutes of sort assembly 12. When the trays become filled or
at Ieast partially
filled, they are discharged from their sortation station and conveyed toward
discharge end 26
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of sort assembly 12. The trays are preferably discharged from the sortation
stations and
conveyed along sort assembly 12 via the tray handling system such as discussed
in detailed
below with respect to tray handling system 110. In the illustrated embodiment
of FIGS. 1
and 2, the filled or at least partially filled trays are conveyed along the
conveying paths of the
tray handling system to a labeler station 41, whereby the trays are identified
and labeled prior
to being discharged either at first sort discharge 26a to vertical conveying
devices 28 after the
first sort pass, or at second sort discharge 26b to the takeaway conveyor or
device after the
second sort pass of sort assembly 12.
After a first sort pass of sort assembly 12, the identified containers or
trays are
to discharged at frst sort discharge 26a and lifted upward by lifting device
28 onto induct end
20 of buffer 14. Each of the trays provided at induct end 20 axe then conveyed
across their
respective cross induction conveying portion 20a until they are aligned with
an appropriate
one of the second induction conveyors 20b and feed conveyors 32a corresponding
to their
respective set of initial sortation stations of the sort assembly 12. The
trays are then
i5 conveyed onto and along the appropriate feed conveyor 32a toward the
corresponding
accumulating conveying portion 32b. As trays are initially received by the
accumulating
conveyor portion 32b, the trays are cycled or circulated around a generally
continuous loop
via conveyance along the input conveying portion 33a and the return conveying
portion 33b
and pop-up transfer units 34b and 34c, as indicated by the arrows in FIG. 4.
The trays may
2o initially come to rest at a downstream end 33c of return conveying portion
33b to temporarily
accumulate and/or buffer the trays being sorted and conveyed along buffer 14.
The trays may
remain at the downstream end 33c or elsewhere along accumulating conveying
portion 32b
until a new tray arnves at the respective feed conveyor 32a, whereby the trays
are again
cycled or circulated around the loop.
25 In order to properly sequence or arrange the trays for the second sortation
pass
through sort assembly 12, as additional trays are provided along feed conveyor
portion 32a,
the trays accumulated along second accumulating conveyor 33b are cycled or
conveyed
around the generally continuous loop via the transfer units 34a-d and the
conveyors 33a, 33b
of accumulating conveyor portion 32b. As the trays are conveyed from
accumulating end
30 33c across transfer units 34d, 34a acid onto first accumulating conveyor
33a, one or more of
the trays being conveyed along feed conveyor 32a may be inducted into the loop
of trays via
transfer unit 34a at an appropriate space between adjacent or consecutive
trays being cycled,
such that the trays are sorted into the proper order or sequence as additional
trays are
provided from induct end 20 of buffer 14.
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As additional trays are received and conveyed along feed conveyor 32a, the
trays and
the accumulating conveyor portions 32b may be generally continuously
recirculated around
the continuous loop, whereby the trays along feed conveying portions 32a are
individually
inducted onto accumulating conveyor portion 32b in the appropriate places
between the
circulating trays. This process continues until a sweep process is performed
at the sortation
unit 12 and tray handling system 110, whereby all of the filled or at least
partially filled trays
are removed from the sorter unit 12 and provided to the induct end 20 of
buffer 14. The trays
at accumulating conveying portion 32b are then circulated while the swept
trays are
individually input into the loop at their appropriate location relative to the
other trays. Once
to the trays are fully sorted and accumulated at accumulating portion 32b of
conveyors 32, the
trays are conveyed and discharged along a respective one of the discharge
conveyors 22a,
22b, 22c via transfer units 34b and then lowered to the appropriate induct
station 16a, 16b or
16c via the respective lowering device 30a, 30b, 30c. The articles are then
input into sorter
unit 12 for a second sortation process or pass of sorter unit 12 to sort the
articles to the
delivery point sequence depth of sort. As the articles are sorted for the
second time, they are
again discharged into the trays or containers 25 via chutes 24, whereby the
containers are
again discharged from the sortation stations and conveyed along their
conveying paths via the
tray handling system. The trays are then identified at the scarring station 41
and discharged
to the take-away conveyor or device at second sort discharge 26b.
2o Flat articles that have been sorted to delivery point sequence by sortation
system 10
may be dispatched to a transportation system utilizing the DISPATCH SYSTEM FOR
CONTAINERS OF SORTED MAIL AND METHOD THEREFOR disclosed in U.S. pat.
application, Ser. No. 09/600,204, filed July 12, 2000 (Attorney Docket RAP04 P-
571A) as
the U.S. national phase application for International Application, Ser. No.
PCT/EP99/00317,
filed Jan. 21, 1999, claiming priority from U.S. provisional pat. application,
Ser. No.
60/072,032, filed Jan. 21, 1998, the disclosures of which are hereby
incorporated herein by
reference. Sortation system 10 rnay also utilize the principles of DOCK-TO-
DOCK
RECEIVING AND DISPENSING FOR A POSTAL PROCESSING CENTER disclosed in
commonly assigned International Application, Ser. No. PCT/EP00/04283, filed
May I0, 2000
and published Nov. 16, 2000 as International Publication No. WO 00/67922,
claiming
priority on U.S. provisional pat. application, Ser. No. 60/133,413, filed May
11, 1999
(Attorney Docket RAP04 P-582), the disclosures of which are hereby
incorporated herein by
reference.
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Although shown and described as having the cycling and accumulating conveyor
portion 32b separate and downstream from the feed conveyor portion 32a,
clearly, the feed
conveyor portion 32a may be combined with the sorting and accumulating
conveying portion
32b, such that a larger continuous loop may be defined by the conveying
portions, in order to
accommodate additional trays on the sorting conveyor of the present invention.
Transfer unit
34d then functions to convey trays in the same direction from accumulating
conveyor 33b
onto a third accumulating conveyor 33d alongside feed conveyor 32a, while a
transfer unit
34e is positioned at a downstream end of third accumulating conveyor 33d and
function in
the same manner as transfer unit 34d, as discussed above with respect to the
smaller
l0 continuous loop of sortation station 10. The trays inducted at induct end
16 are then input
into the appropriate space between trays conveyed around the larger continuous
loop at
transfer unit 39a at the upstream end of the feed conveyor 32a.
Referring now to FIGS. 5 and 6, an alternate embodiment of an article
sortation
system 10' in accordance with the present invention includes sorter unit or
sort assembly 12
and a sort conveyor or buffer 14' positioned generally above sorter unit 12.
As discussed
above, sort assembly 12 includes induct stations 16a, 16b, 16c, and discharges
26a, 26b.
Buffer 14' is generally similar to buffer 14, discussed above, and includes an
input or induct
end 20', three sort paths defined by a feed conveyor portion 32a' and an
accumulating
conveyor portion 32b', and a discharge end 22, which further includes three
tray lowering
devices 30a, 30b, 30c for lowering the trays from multiple discharge conveyors
22a, 22b, 22c
to one of induct stations 16a, 16b, 16c, in the same manner as discussed above
with respect to
article sortation system 10.
As best seen in FIG. 5, discharge 26a of sort assembly 12 is connected to a
vertical
lifting or conveying device 28', which comprises a ramped or inclined
conveying surface
which is operable to convey articles upward and along the conveying surface
from discharge
26a onto cross induction conveyors 20a at induct end 20 of buffer 14', similar
to the vertical
lifting devices 28 of sortation system 10~ discussed above. Because the
inclined ramps 28'
extend further from the discharge 26a of sortation assembly 12, buffer 14'
extends further
along above sort assembly 12 than buffer I4, discussed above. However, buffer
14' is
otherwise generally identical to buffer 14, discussed above, such that a
detailed discussion of
the sorter conveyor will not be repeated herein.
Prior to discharging the containers after the first sortation pass onto the
inclined
conveying surface of inclined conveyor 28', discharge 26a of sort assembly 12
may further
include a rotator or rotating device 42, which is operable to rotate the trays
or containers for
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proper orientation with respect to the inclined conveying surface. Preferably,
the trays are
rotated at rotating device 42 so they are conveyed lengthwise upward and along
inclined
conveyor 28'. The trays are then conveyed up the inclined conveying surface
and onto cross
induction conveyors 20a, where they are conveyed across induct end 20 of
buffer 14' and into
alignment with the appropriate feed conveyor portion 32a' and accumulating
conveying
portion 32b' of buffer 14', in the same manner as discussed above with respect
to buffer 14.
The inclined conveyors 28' may comprise any conveying means, such as powered
roller
conveyors, belt conveyors or the lilce, and may include means for limiting
slippage of the
trays as they are conveyed upward, such as ridges, platforms or the like,
which move along or
to with the conveying surface to support the trays as they are conveyed
therealong, without
affecting the scope of the present invention.
Optionally, other buffering assemblies may be implemented to buffer or
temporarily
store trays or containers between sort passes of one or more sorter units, in
order to provide
the trays for the second sort pass in a sequenced or arranged manner. For
example, a vertical
15 carousel buffer or a horizontal carousel buffer may be implemented between
the discharge of
at least one sorter unit and an induct of the sorter unit or another sorter
unit, without affecting
the scope of the present invention.
Therefore, the present invention provides an article sortation apparatus or
system
which is operable to automatically arrange or sequence trays of sorted
material to an
2o appropriate order or sequence for re-induction into the sorter unit for a
second sortation
process or sort pass, in order to achieve a delivery point sequence depth of
sort of the articles.
The present invention provides a buffer assembly which functions as a random
access
accumulator and temporarily stores or accumulates trays and facilitates
providing the trays to
an induct of a sorter in an arranged or sequenced manner. Preferably, the
buffer functions to
25 cycle or circulate trays containing the sorted articles in a generally
continuous loop, while
additional trays are input into appropriate spaces between the trays being
cycled until the
trays cycled and accumulated on the sorter conveyor or buffer are in the
proper order or
sequence. The trays are then automatically conveyed to the appropriate induct
station of the
sorter unit, whereby the articles are re-inducted into the sorter unit for the
second sortation
3o process. Accordingly, trays discharged from the sortation unit following
the second sort
process contain articles which have been twice sorted and are thus sorted to a
delivery point
sequence or carrier walk sequence.
An example of a tray handling system or tray management system 110 that is
useful
with the present invention is illustrated in FIGS. 7 and 8 and disclosed in
commonly assigned
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U.S. pat. application, Sex. No. 09/629,009, filed July 31, 2000 by Olson et
al. for
AUTOMATIC TRAY HANDLING SYSTEM FOR SORTER (Attorney Docket RAP04 P-
601), which is hereby incorporated herein by reference. However, other tray
management
systems, including ones that are manual or semi-automatic, can be used,
without affecting the
scope of the present invention. For example, an automatic tray handling system
which
automatically destaclcs and loads empty trays onto a conveyor to provide empty
trays to the
sorter unit or units may be implemented with the delivery point sequencing
sortation system
of the present invention. Such a tray handling system is disclosed in commonly
assigned
U.S. provisional application, Ser. No. 60/275,789, filed Mar. 14, 2001 by
Schiesser et al. for
io TRAY DESTACKER (Attorney Docket RAP04 P-624), U.S. Provisional Application,
Ser.
No. 60/297,516, filed June 12, 2001 by Schiesser et al. for TRAY DESTACI~ER
(Attorney
Docket RAP04 P-624A), and U.S. pat. application, Ser. No. , filed
by Schiesser et al. for TRAY DESTACKER (Attorney Docket RAP04 P-624B), which
are all
hereby incorporated herein by reference.
Automatic tray handling system I 10 includes a plurality of conveying surfaces
116,
which are operable to move the trays 25 along one or both sides of the sorter
unit or sort
assembly 12. A plurality of tray moving devices I20 are operable at respective
sorter stations
of sort assembly 12 to pull empty trays onto a tray support 172, which
supports the empty
tray while the sort assembly discharges sorted mail into the tray. After the
tray is at least
2o partially filled by the sort assembly, the tray moving device 120 is then
operable to move the
at least partially filled tray back onto the conveying surface. A continuous
supply of empty
trays is provided to the sort assembly 12, and filled or at least partially
filled trays are
automatically discharged from the sorter units onto the conveying surface 116.
An input end 11 I a (FIG. 8) of tray handling system 110 preferably provides
one or
more tray induct stations 138 and 140 for loading or inducting empty trays
onto the tray
handling system, while a discharge end 1 l 1b (FIG. 7) of tray handling system
110 provides a
downstream operation, such as a labeling station 122, which is operable to
label the trays as
they are discharged from tray handling system 110 to output 26. As can be seen
in FIG. 2
and discussed above, the discharge end l l 1b may provide a first pass
discharge 26a to the
induct 20 of the sequencing conveyor of buffer or sequencing assembly 14, and
a second pass
discharge 26b, which discharges trays to a discharge or take-away conveyor or
device (not
shown) after the articles have been sorted to the delivery point sequencing
depth of sort. The
sorter unit 12 may each be arranged in a pair of rows, and the conveying
surfaces 116 of
automatic tray handling system 110 may extend around both sides of the rows of
sorter unit
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12. However, the tray handling system 110 could be used with a single side of
a mail
sortation system which has one or more rows of sorter units. Empty trays 25
are movable in
a continuous loop via conveying surfaces 116 and a pair of vertical tray
moving or tray return
devices 118 at one end of the tray handling system.
Conveying surface 116 includes a plurality of conveying surfaces. More
particularly,
conveying surface 116 preferably includes a pair of opposite upper conveyors
124 and 126, a
pair of opposite lower conveyors 128 and 130 and a pair of tray moving or
return devices,
such as inclined or connecting surfaces or ramps 132 and 134, which are
operable to move
empty trays from lower conveyor 128 to upper conveyor 126 and from Iower
conveyor 130 to
upper conveyor 124, respectively, at input end I l l a. A pop-up transfer unit
or 90 degree
transfer unit 136 is positioned at each end of the incline ramps 132 and 134
to change the
direction of travel of the trays 30 as they move from one of the lower
conveyors to the
respective incline ramp, and from the incline ramp to the respective upper
conveyor.
Transfer units 136 are operable to convey a tray in a direction along the
conveyor at which
they are positioned, and may be operable to raise one or more belt conveyor
strips to convey
a tray positioned at the transfer unit in a direction which is generally
transverse or normal to
the conveyor direction, similar to transfer units 34 and 39, discussed above.
Incline ramp 132 is connected between a pair of 90 degree transfer units 136a
and
136b at a downstream end 128b of lower conveyor 128 and an upstream end 126a
of upper
conveyor 126, respectively. Similarly, incline ramp 134 is connected between a
pair of 90
degree transfer units 136c and 136d at a downstream end 130b of lower conveyor
130 and an
upstream end 124a of upper conveyor 124, respectively.
Lower conveyors 128 and 130 are preferably operable in a reverse direction
from
upper conveyors 124 and 126, to~return the empty trays baclc toward input end
l l la. The 90
degree transfer units 136a and 136c are positioned at downstream ends 128a and
130a of
conveyors 128 and 130, respectively, to move the empty trays onto the
respective incline
ramps 132 and 134 to transport the trays to the upper conveyors 124 and 126,
respectively, at
the other side of the sortation system 12. In order to provide a continuous
loop for the empty
trays about the conveyor surfaces 116, vertical tray moving devices 118 are
positioned at
downstream ends 124b, 126b of upper conveyors 124, 126 and upstream ends 128a,
130a of
lower conveyors 128, 130. Each vertical tray moving device 118 is operable to
move an
empty tray from the respective upper conveyor 124, 126, lower the tray to the
level of the
lower conveyors 128, 130, and then move the tray onto the respective lower
conveyor 128,
130.
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Tray induct stations 138 and I40 are preferably positioned side by side one
another.
Preferably, tray induct stations 138 and 140 preferably include belt
conveyors, which are
operable to transport or convey an empty tray onto a corresponding 90 degree
transfer unit
136a and 136d, respectively. Empty trays may be manually loaded onto the
induct stations to
induct the empty trays into the conveyor system 116 of the automatic tray
handling system
110 or may be automatically fed from a tray return conveyor 125a, I25b.
Preferably, tray
induct station 140 includes an inclined belt conveyor, such that an input end
138a and 140a of
each of the induct stations 138 and 140, respectively, is positioned at
substantially the same
level for easy access and loading of empty trays onto the induct stations 138
and 140.
Trays 25 are conveyed along upper conveying surfaces 124 and 126 toward
downstream ends 124b and 126b, respectively. Vertical tray moving devices 118
are
positioned near or at the downstream ends 124b and 126b to remove empty trays
from the
upper conveyors and move the empty trays onto an upstream end 128a and I30a of
the lower
conveyors 128 and 130, respectively, as discussed in detail below. Labeling
stations 122 may
be positioned at or near a discharge end 124c and I26c of upper conveyors 124
and 126,
respectively, and are operable to label the filled trays as they are conveyed
toward output 26
of automatic tray handling system 110. Optionally, one or both of the upper
conveyor
surfaces included a curved section 127, such that the discharge ends 124c and
I26c of upper
conveyors 124 and 126, respectively, may be in close proximity, in order to
reduce the
manual labor of the system. However, as shown in FIG. 2, the discharge ends of
the upper
conveyors may be positioned at opposite sides of sort assembly 12 for
discharge of trays onto
respective vertical tray lifting devices or the like. A scanner 146 may be
positioned at output
end 26 to verify the information contained on the label applied to the trays.
A pair of reject
conveyors 148 and 150 may be provided adjacent to discharge ends 124c and
126c,
respectively, to allow incorrectly labeled trays to be discharged to a
separate area via
respective 90 degree transfer units I36e and I36f and reject conveyors 148
alld 150.
Referring now to FIGS. 9-11, an article sortation apparatus or system 210
includes
primary sort assemblies 212a and 212b and a delivery point sequence (dps) sort
assembly
213, which is connected to sort assemblies 212a, 2I2b by respective sequencing
or sorting
3o conveyors or buffer assemblies, shown generally at 214 in FIG. 9. Such an
arrangement of
sortation assemblies is disclosed in commonly assigned U.S. pat. application,
Ser. No.
09/629,007, filed July 31, 2000 for DELIVERY POINT SEQUENCING MAIL SORTING
SYSTEM WITH FLAT MAIL CAPABILITY (Attorney Docket RAP04 P-613), which
claims priority on U.S. provisional application, Ser. No. 60/146,689, filed
Aug. 2, 1999, and
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in U.S. provisional applications, Ser. No. 60/289,329, filed May 7, 2001
(Attorney Docket
RAP04 P-613A); Ser. No. 60/302,527, filed June 29, 2001 (Attorney Docket RAP04
P-
629A); and Ser. No. 60/328,160, filed Oct. 10, 2001 (Attorney Docket RAP04 P-
629B),
which are all hereby incorporated herein by reference. Each sort assembly
212a, 212b
includes an induct 216 and a sortation mechanism generally illustrated at 218.
Sort assembly
213 includes an induct 217 and a sortation mechanism 219. Induct 217
preferably includes
four feeder conveyors or spurs 238 with a tray unloader (not shown) at each
induct station
239 at each spur 238. Buffer assemblies 214 interconnect outputs 226 of
sortation assemblies
212a, 212b with induct 217 of sortation assembly 213 via one or more transfer
switches 236
l0 and spurs 238. The purpose of buffer assemblies 214 is to automatically
arrange and convey
containers of articles sorted by initial sortation assemblies 212a, 212b from
discharge 226 of
sort assemblies 212a, 212b to induct 217 of sort assembly 213, in order to
induct the sorted
articles for further sortation by subsequent sortation assembly 213, similar
to buffer 14,
discussed above.
Similar to sort assembly 12 discussed above, sort assemblies 212a and 212b are
operable to sort articles or mail received at induct 216. The sort assemblies
212a, 212b may
be any known sortation unit or system, such as the flat sorting system
maxlceted by Alcatel
Postal Automation System, Mannesmann Dematic Postal Automation, Mannesmann
Dematic
Rapistan Corporation, Solystic and/or Siemens Dematic Corp. under Model
AFSM100 or the
like. Clearly, sort assemblies 212a, 212b may otherwise be any other sortation
assembly,
such as the sortation assembly marketed by Lockheed Martin Postal Automation
under Model
FSM 1000 or any other flat mail sortation system, without affecting the scope
of the present
invention. The sortation assemblies may even be a dual carousel system, such
as the
sortation assembly marketed by Mannesmann Dematic Postal Automation, Solystic
and/or
Siemens Dematic Corp. under Model TOP2000.
Sort assemblies 212a, 212b are operable to resolve the address of the mail to
eleven
digits during the sortation process. Also, similar to sort assembly 12,
discussed above, trays
are discharged in a generally random manner from sort assembly 212a, 212b at
discharge end
226 of sort assembly 212a, 212b. The trays are then conveyed along conveying
portions 227
and onto an induct end 220 of buffer 214 (FIG. 10), where the trays are
arranged or sorted
prior to induction into the second sorter unit 213 in a manner similar to that
discussed above
with respect to sortation apparatus 10.
Preferably, sort assembly 213 is capable of sorting up to 20,000 flat articles
per hour
and, most preferably, up to approximately 40,000 flat articles per hour, or
more. Preferably,
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sort assembly 213 has a sort rate that is approximately double the sort rate
of each sort
assembly 212a, 2I2b for reasons that are set forth in more detail below. For
example, in the
illustrated embodiment, sort assembly 213 is a dual-carousel system having 300
or more bins
marlceted by Mannesmann Dematic Postal Automation under Model TOP2000. Mail
can be
sorted to each of the bins from either of the dual carousels as fed by each of
the spurs 238 and
the dual induct lines 234. Details of sort assembly 213 of the illustrated
embodiment are
disclosed in French Pat. Application Nos. 9908610, filed July 5, 1999 by
Fabrice Darrou,
Vincent Grasswill, Alain Danjaume, entitled DISPOSITIF DE CONVOYAGE D'OBJETS
PLATS AVEC UN SYSTEME D'AIGUILLAGE; 9909163, filed July 15, 1999 by Jean-Luc
l0 Astier, Pierre Advani, Dino Selva, entitled DISPOSITIF A PLUSIEURS
CONVOYEURS A
GODETS SUPERPOSES POUR LE TRI D'OBJETS PLATS; and 9907316, filed June 10,
1999 by Fabrice Darrou, Vincent Grasswill, Robert Vivant, entitled DISPOSITIF
DE
CONVOYAGE DE COURRIER AVEC DES ROUES EN MATIERE ELASTOMERE
ELASTIQUEMENT DEFORMABLES; Published International Pat. Application WO
00/39010, published 6 July 2000 by Francois Agier et al., entitled DEVICE FOR
CONVEYING FLAT OBJECTS BETWEEN PROCESSING EQUIPMENT ITEMS; and
Published International Patent Application WO 00/39012, published 6 July 2000
by Francois
Agier et al., entitled ROUTING DEVICE FOR GROUPING TWO STREAMS OF FLAT
OBJECTS, SUCH AS MAIL ENVELOPES, INTO ONE STREAM, the disclosures of which
are hereby incorporated herein by reference. Alternately, sort assembly 213
may use the
principles disclosed in U.S. Pat. No. 5,718,321 adapted to flat mail sortation
capability, the
disclosure of which is incorporated herein by reference. A tray return
conveyor 225a, 225b
returns empty trays from the dps sortation assembly 213 to a respective
primary sort
assembly 212a, 212b, while full trays containing sorted mail are discharged to
a takeaway
conveyor or the like (not shown), or to a return or loop conveyor 229, as
discussed in detail
below.
As containers or trays are dispatched from sort assemblies 212a and 212b
according
to the sort plan, they are buffered, sorted and discharged by buffer 214
toward induct 217 of
sortation assembly 213. As shown in FIG. 10, buffer 214 may be substantially
similar to
buffer 14, discussed above, and may include one or more circulating and
accumulating
conveying portions or loops 232b for circulating trays therearound.
Alternately, the buffer
assembly may include a vertical carousel buffer or a horizontal carousel
buffer or other
buffering assemblies or systems, without affecting the scope of the present
invention.
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Because buffer 214 is substantially similar to buffer 14, discussed above, a
detailed
description of the buffer will not be repeated herein. Suffice it to say that
the trays are
circulated and sorted about one or more continuous loops at accumulating
conveying portions
232b of buffer 214 until all of the trays have been swept from the sorter
units 212a, 212b and
inducted into buffer 214. The trays are then discharged from accumulating
conveying portion
232b onto a single discharge conveyor or onto two or more discharge conveyors,
such as two
discharge conveyors 222a and 222b, for conveying trays toward the induct of
sortation
assembly 213. Each loop of accumulating conveying portion 232b may
sequentially
discharge all of its trays in order onto discharge conveyors 222a and/or 222b,
such that all of
to the ordered or sequenced trays from one loop are discharged first, all the
trays from another
loop are discharged second and so on. In the illustrated embodiment with three
loops and
two discharge conveyors, all of the trays from one loop may be discharged onto
one
discharge conveyor 222a, all of the trays from another loop may be discharged
onto the other
discharge conveyor 222b, and the trays from the third loop may be split, with
a portion of the
Z5 trays being discharged in an appropriate sequence or order on each of the
discharge
conveyors 222a, 222b before or after the other trays from the other loops. The
trays may then
be conveyed along discharge conveyors 222a, 222b toward a series of transfer
switches 236.
Transfer switches 236 selectively transfer the trays or containers onto spurs
238
leading to induct 217 via induct stations 239. Transfer switches 236 are
operated in
20 coordination with the overall sortation plan in order to stage the
containers at induct stations
239 in a sequence called for by sortation assembly 213. Optionally, other
transfer switches
237a may discharge trays from buffer 214 onto a return or loop conveyor 229,
which conveys
the sorted or sequenced trays back to the induct 216 of sorter units 212a,
212b for a second
sort pass through sorter units 212x, 212b. In the illustrated embodiment,
return conveyor 229
25 conveys trays from transfer switches 237a to transfer switches 237d and
further toward induct
216 of sorter units 212a, 212b. Such a return conveyor facilitates two or more
sort passes
through the first sorter units 212a, 212b and/or one or more sort passes
through the first sorter
units 212x, 212b, followed by a sort pass through the second sorter unit 213.
Optionally, return conveyor 229 may also or otherwise be connected between
transfer
3o switches 237c at the discharge of sorter unit 213 and transfer switches
237b at the induct end
227 of buffers 214, in order to facilitate multiple sort passes of the sorter
unit 213 to further
sort and consolidate the sorted mail. Although shown as having a buffer at the
discharge end
of each sorter unit 212a, 212b, optionally, or additionally, a single buffer
assembly may be
positioned between the discharge of each of the sorter units 212a, 212b and
213 and the
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induct to each of the sorter units 212a, 212b and 213, in order to facilitate
multiple sort passes
through one or more of the sorter units 212a, 212b, 213, without affecting the
scope of the
present invention.
The buffers 214 and/or the return conveyor 229 may be elevated above the level
of
sorter units 212a, 212b, such that one or more tray lowering devices 230 may
be positioned at
inducts 216 of sorter units 212a, 212b to lower the trays from return
conveyors 229 to inducts
216, similar to tray lowering devices 30, discussed above. Additionally, one
or more tray
raising devices 228 may be positioned at the discharge of sorter unit 213 to
raise the trays
upward onto return conveyor 229 via transfer switches 237c. However, clearly,
buffers 214
l0 and/or return conveyors 229 may be positioned elsewhere or at the same
level of sorter units
212a, 212b, 213, such that the tray raising and/or lowering devices are not
required, without
affecting the scope of the present invention. As discussed above with respect
to tray raising
and lowering devices 28, 30, the tray raising and lowering devices 228, 230
may alternately
comprise inclined or ramped conveyors or the lilte, depending on the
application.
Accordingly, return conveyor 229 may convey full or at least partially filled
trays
being discharged from sorter unit 213 to buffers 214 via tray raising devices
228, and transfer
switches 237c, 237b. The partially filled and sorted trays may then be
inducted to sorter unit
213 for a second sort pass therethrough. Additionally, return or loop conveyor
229 may
convey at least partially filled trays from buffers 214 to the induction 216
of sorter units
212a, 212b via transfer switches 237a and tray lowering devices 230. The at
least partially
filled trays from either sorter units 212a, 212b and/or sorter unit 213 may
thus be sorted and
sequenced by buffers 214 and then inducted into one of the sorter units 212a,
212b or 213 for
an additional sort pass, depending on the application. This allows for
multiple sort passes
through one of the sorter units or through a combination of two or more of the
sorter units, in
order to automatically further sort the mail after a first sort pass through
one of sorter units
212a, 212b or even sorter unit 213.
In the illustrated embodiment of FIG. 9, the first pass primary sortation
assembly
212a, 212b is used by the system to determine the address information. The
system
determines how many letters are to be sent to each delivery point. The first
machine, in
addition to discovering address and mail piece information, starts the sorting
process. Note
that the address is resolved to the delivery point level (11 digits for the
U.S.) for the first pass.
During the first pass, all of the mail destined for the first delivery point
of each route is sent
to output 1, the second delivery point to output 2, and the third to output 3,
etc. After the first
pass is concluded, the trays are then swept automatically from the sort
assembly 212x, 212b
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and sent to sort assembly 213 via buffer 214, but only when sort assembly 213
calls for each
particular container. For correct delivery point sequencing, output 1 is
processed before
output 2, which is processed before output 3, and so on. Therefore, the trays
are arranged in
order by buffer 214 for induction into second sorter assembly 213. During tlus
second pass,
mail for a first carrier route is sent to output 1, mail for another carrier
route is sent to output
2, and mail for yet another carrier route is sent to output 3, and so on. This
pass splits mail
from the original output 1 (first delivery point regardless of route) between
final outputs 1, 2,
and 3. The same process is followed for original outputs 2 and 3. The idea is
to ensure that
the delivery points in the stackers at the end of the first pass are in
separate outputs at the end
to of the second pass.
As would be apparent to the skilled artisan, article sortation system 210 is
capable of
sorting turnaround mail, which is mail collected in a local area in which
sortation system 210
is located, and sorting the mail to the delivery point sequence at the output
of sort assembly
213. Additionally, mail received in the mail preparation area may be placed in
one or more
compartments in trays 25 and conveyed in the rigid plastic containers or trays
25 to the
inducts 216 of sort assemblies 212a, 212b for an initial sort pass of the mail
through the sort
units or assemblies.
Each piece of mail is identified efficiently (to 11 digits) on the first pass,
such as by
using OCR/VCS and a spray-on PSEUDO m# (or other means of application as may
be
2o more technically prudent, such as a printed and applied label, an RF tag,
or the like). Each of
the sort assemblies 212a, 212b sorts the mail in an efficiently balanced
throughput scenario of
approximately 17,000 pieces/hr (in balance with spray-on system and OCR/VCS
delay).
Buffer 214 then automatically arranges or sorts or sequences the containers
into an
appropriate order or sequence for induction into the second sorter 2I3 for the
second sort pass
of the articles or back to the first sorter units 212a, 212b via return
conveyors 229 for a
second pass therethrough. The product can now be called for in sequence (and
processed) at
a higher speed in the second pass (40,000 pieces/ hr). This allows for
substantial reduction in
labor and utilizes mail containers or cartridges that allow the efficient and
timely input of dps
sort assembly 213. The system maximizes, optimizes and balances the various
levels of
technology (for product m, software and VCS delay) and captures the savings by
allowing
use of a high speed second pass. Various levels of technology may be
integrated in an
efficient (time-balanced) scenario, which addresses a complex series of
process constraints to
capture saving previously achievable. The present invention thus
advantageously utilizes the
extremely fast sortation capacity of sort assembly 213 by supplying articles
initially sorted by
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sort assemblies 212a and 212b, each of which has a lower capacity than sort
assembly 213,
but, when combined, are capable of supplying containers of first-pass sorted
flat articles at a
rate that utilizes the capacity of sort assembly 213. Multiple sort passes may
be performed on
the mail through the sort assemblies 212a, 212b and/or 213 to further
consolidate the sorted
mail into delivery point sequence.
An alternate article sortation apparatus or system 210' (FIG. 12) includes an
input/output assembly 240 for conveyor 227, which conveys sorted trays from
buffer 214 or
directly from sort assemblies 212a, 212b. Input/output assembly 240 includes
one or more
lanes 242 which may transfer containers from an exterior source, such as a
transportation
1o system (not shown) or from a buffer assembly 214a (if additional buffering
capacity is
desired or required) to feed the containers to induct 217 of sortation system
213. Alternately,
input/output section 240 may transfer containers of articles that have been
sorted by sort
assemblies 212a and 212b to a transportation system (not shown). This allows
sortation
system 210' to dispatch to the transportation system trays of articles sorted
by sort assemblies
212a and 212b to the level of dispatch to other distribution/sortation
centers. Accordingly,
mail received at the distribution center in which sortation system 210' is
located can be
inducted at induct 216 on each sort assembly 212a and 212b and sorted to other
distribution
centers, as will be understood by the skilled artisan. This could be done
either separate from
or in combination with sorting turnaround mail to delivery point sequence with
sort assembly
213.
Input/output 240 could additionally be utilized to input trays or containers
of flat
articles received from other distribution centers to be combined with trays of
flat articles
initially sorted by sort assemblies 212a and 212b and finally sorted by sort
assembly 213 to
delivery point sequence. This allows the output of sort assembly 213 to handle
both
turnaround mail and mail originating from other distribution centers. The mail
from other
distribution centers could be sorted separately or in combination with locally
collected mail
in the area surrounding the distribution center in which sortation system 210'
is located. In
sortation system 210', the conveying assembly 227 would utilize bi-directional
transfer
switches 236' in order to provide transferring of articles to either induct
217 or to input/output
240 and vice veYSa. Transfer switches 236, 236' are preferably of the type
disclosed in
commonly assigned U.S. pat. application, Ser. No. 09/831,210, filed May 7,
2001 by Craig J.
M. Stephen for CONVEYOR TRANSFER ASSEMBLY (Attorney Docket RAP04 P-581A),
which is the U.S. National application for International Application No.
PCT/EP00/04995,
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filed May 31, 2000, claiming priority on U.S. provisional application, Ser.
No. 60/137,785,
filed June 4, 1999, the disclosures of which are hereby incorporated herein by
reference.
Preferably, dps sort assembly 213 is capable of handling both flat articles,
such as flat
mail, and the smaller letter mail. With such capacity, it may be possible to
merge not only
flat mail from distribution centers remote from the distribution center in
which sortation
system 210' is located, but also to insert letters such as from other such
distribution centers or
from other sorters such as a sorter dedicated to sorting letter mail. As such,
the mail
dispatched from the output of sort assembly 213 may be integrated into
individual bundles of
both flat mail and letter mail for each household in order to further maximize
the efficiency
of each mail carrier while walking the mail route.
Additionally, similar to sortation system 210, sortation system 210' may
include one
or more return conveyors (not shown in FIG. 12) between transfer switches
positioned along
the conveyors and inducts 216 or sorter units or sort assemblies 212a, 212b
and/or between
the transfer switches and the discharge of sorter unit or sort assembly 213,
in order to
facilitate multiple sort passes of sorter units 212a, 212b and/or 213.
Optionally, buffers 214
may be replaced with a single buffer (not shown) positioned along the return
or loop
conveyor, without affecting the scope of the present invention.
Another alternate embodiment of an article sortation apparatus or system 210"
(FIG.
13) in accordance with the present invention is similar to sortation system
210, except that it
includes a dps sortation assembly 213' with an induct 217' having only two
induct lines 238.
By using rigid containers capable of automatic unloading, sortation assembly
213' can be
supplied with a sufficient quantity of articles utilizing only two induct
lines. Similar to
sortation systems 210 and 210', sortation system 210" may also include one or
more return
conveyors (not shown in FIG. 13) which may convey trays between one or more
transfer
switches and the inducts 216 of the sort assemblies 212a, 212b and/or the
discharge of the
sortation assembly 213', in order to facilitate multiple sort passes through
sort assemblies
212x, 212b and/or 213'.
Another alternate auticle sortation apparatus or system 210"' (FIG. 14) is
shown
having a single initial sort assembly 212 for conducting an initial sort plan
on the flat articles
3o and a buffer 214 for sorting and supplying the containers of initially
sorted flat articles from
sort assembly 212 to dps sort assembly 213. In the illustrated embodiment,
primary sort
assembly 212 has a capacity that is similar to that of subsequent sort
assembly 213. Because
the capacities of sort assemblies 212 and 213 are relatively closely matched,
only one
primary sort assembly 212 is provided in article sortation system 210"'.
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Optionally, sortation system 210"' may include a return or loop conveyor (not
shown
in FIG. 14) which connects between one or more transfer switches along
conveyors 222a,
222b and the induct 216 of sort assembly 212 to facilitate multiple sort
passes through the
initial sort assembly 212 if desired. The return conveyor may also be
connected between the
discharge of the second sort assembly 213 and one or more transfer switches
along conveyor
227 to facilitate multiple sort passes of either of the sort assemblies 212
and/or 213.
Referring now to FIG. 15, a sortation system 310 includes multiple sortation
assemblies or machines, such as three sortation assemblies 312a, 312b and
312c. Each
sortation assembly 312a, 312b, 312c is connected to a conveying assembly or
system 315,
1o which is operable to sort, arrange, sequence and convey trays from a
discharge conveyor 326
of each sortation assembly 312a, 312b, 312c to an induct 316 of an appropriate
one of the
sortation assemblies 312a, 312b, 312c. The conveyor system 315 includes a
buffer or sorter
314a, 314b, 314c positioned at a level generally above or adjacent to a
respective sortation
assembly 312a, 312b, 312c. Sortation assemblies 312a, 312b, 312c and buffers
314a, 314b,
314c are substantially similar to sortation assembly 12 and buffer 14,
discussed above, such
that a detailed discussion of these assemblies and buffers will not be
repeated herein. In the
illustrated embodiment, sortation assemblies 312a, 312b, 312c are flat-sorting
machines, such
as the type marketed by Alcatel Postal Automation System and/or Mannesmann
Dematic
Postal Automation and/or Mannesmann Dematic Rapistan Corp, and/or Siemens
Dematic
Corp. under Model AFSM100. Alternately, however, the sortation assemblies may
be any
other type of sortation assembly, such as a dual carousel system, such as the
sortation
assembly marketed by Mannesmann Dematic Postal Automation under Model TOP2000,
the
sortation assembly marketed by Lockheed Martin Postal Automation under Model
FSM 1000
or any other flat mail sortation system, without affecting the scope of the
present invention.
Similar to sortation assembly 12, discussed above, each sortation assembly
312a,
312b, 312c includes three inducts 316 adjacent to three tray lowering devices
330 of the
respective buffer 314a, 314b, 314c. Inducts 316 receive the articles from
trays or bins
lowered by lowering devices 330 and are operable to induct the articles into
the respective
sortation assembly 312a, 312b, 312c, where the articles are sorted and
discharged into the
bins or trays at the appropriate sortation station, as discussed above with
respect to sortation
assembly 12. The trays are preferably conveyed along the sortation assemblies
via a tray
handling system, such as tray handling system 110, which is operable to
automatically
remove partially filled trays from the sortation stations and convey the trays
to a labeling
station (not shown in FIG. 15) and onto discharge conveyor 326 of the
respective sortation
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assembly. Similar to buffer 14, buffers 314a, 314b, 314c include at least one,
and preferably
three, conveyor loops 332 between an induct end 320 and a discharge end 322.
Trays of
sorted articles are received at induct end 320, and buffers 314a, 314b, 314c
are operable to
sort, stage and accumulate the trays as the trays are conveyed around the
continuous loops
332 to arrange and sequence the trays in an arranged manner prior to
discharging the
arranged trays at discharge end 322. The trays are then lowered via lowering
devices 330 to
inducts 316 of the respective sortation assembly 312a, 312b, 312c.
Conveyor system 315 further includes a conveyor loop 327, which is preferably
elevated and positioned at and interconnected between the discharge conveyor
or conveyors
l0 326 of each sortation assembly 312a, 312b, 312c and the induct end 320 of
each buffer 314a,
314b, 314c. A tray elevating device 328 is positioned at a discharge end 326a
of each
discharge conveyor 326 and is operable to elevate or raise trays upward and
onto the elevated
conveyor Loop 327.
Conveyor loop 327 provides a generally continuous conveying loop for trays to
be
conveyed around, such as in the counterclockwise direction as shown in FIG.
15. Conveyor
loop 327 includes a plurality of transfer units 337a, 337b positioned
therearound for changing
the direction of travel of the trays, similar to transfer units 237, discussed
above. For
example, a transfer unit 337a is positioned adjacent to each tray elevating
device 328 and is
operable to receive the trays from the elevating device 328 and redirect or
transfer the trays
2o onto the conveying loop 327. Similarly, a transfer unit 337b is positioned
at each induct 320
of buffers 314a, 314b, 314c, and is operable to transfer the appropriate trays
onto the
appropriate induct 320 of the appropriate buffer 314a, 314b or 314c for
sorting and arranging
the trays prior to the second sort pass through the sortation assemblies.
Buffers 314a, 314b,
314c then automatically sort, accumulate and arrange the trays, and discharge
the arranged
trays at tray Lowering devices 330 for induction of the articles for the
second sort pass, in a
similar mamler as discussed above.
During operation, trays are f lied or at least partially filled at their
respective stations
and then conveyed along the tray handling system 110 toward discharge end 326a
of
discharge conveyor 326. As trays containing articles sorted during the first
pass are
3o conveyed along the tray handling system 110 of each sortation assembly, the
trays are
identified and labeled at the labeling station, as discussed above with
respect to sortation
system 10. The trays are then moved to conveyor loop 327, such as via
discharge conveyors
326 and elevating devices 328. Conveyor loop 327 is operable to identify, such
as via a laser
scanner or the Like (also not shown), the trays and direct the trays to the
appropriate sortation
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assembly in preparation for the second sort pass. Sortation system 310 thus
further includes a
control (not shown) which is operable to identify the trays and determine and
select the
appropriate sortation assembly for the second sort pass. The conveyor loop 327
may then be
operable in response to the control to selectively convey trays from any one
of the sortation
S assemblies 312a, 312b, 312c back to the induct of the same sortation
assembly or to the
induct of any of the other sortation assemblies to which conveyor loop 327 is
connected. For
example, the conveyor loop may convey a group of trays from sortation assembly
312a to the
induct 320 of buffering assembly 314b at sortation assembly 312b. The
buffering assembly
is then operable to sort and arrange the trays and to discharge the arranged
trays to the induct
l0 end of the respective sortation assembly for the second sort pass.
Because the sortation assemblies 312a, 312b, 312c are connected together via
conveyor loop 327, the sortation system 310 may accommodate a greater
sequencing matrix
than a single or double assembly system. For example, if each sortation
assembly 312, 312b,
312c provides 120 output bins (such as three 40 output bins at each assembly),
and the
15 sequencing matrix of FIGS. 23 and 24 is implemented, the second pass
through the
assemblies allows all 120 bins of each assembly or machine to be dedicated to
a 120x120
sequencing matrix, so that each of the three sortation assemblies is able to
sequence 4800
addresses for a total of 14,400 addresses. For example, during the first pass,
each sortation
assembly may sort articles to three groups of 40 bins (e.g., sortation
assembly 312a may sort
2o sequences 1, 41, 81, up to 1600 to one bin of a group of 40 bins, and sort
sequences 2, 42, 82,
up to 1582 to a second bin and so on, while sortation assembly 312b may sort
sequences
1601, 1641, 1681 up to 3200 to one bin of a group of 40 bins, and sort
sequences 1602, 1642
etc. to a second bin of that group and so on, with sortation assembly 312c
sorting sequences
3201 to 4800 in a similar manner). The second set or group of 40 bins for each
machine is
25 similarly processed for sequences 4801 to 9600, while the tlurd group of 40
bins for each
sortation assembly is likewise processed for sequences 9601 to 14400.
After the first pass, the overhead conveyor loop 327 and buffer systems 314a,
314b,
314c sequence and arrange the trays for the second sort pass, such as by
queuing all trays
discharged from one group of 40 bins on the three assemblies at a selected one
of the
3o assemblies, while the trays for each of the other groups of 40 bins are
similarly assigned and
queued at a selected one of the other assemblies. The first sortation assembly
may, for
example, then process sequences 1 to 4800 in its 120 bins, while the second
and third
assemblies then process sequences 4801 to 9600 and 9601 to 14,400,
respectively.
Alternately, however, other sequencing matrices may be implemented, such as
the
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sequencing matrix shown in FIGS. 25A, 25B and 26A, 26B and discussed below, or
other
sequencing matrices, without affecting the scope of the present invention.
The conveyor loop 327 is operable to connect the multiple sortation assemblies
in
such a way as to route trays from and to the same sortation assembly or to any
of the other
sortation assemblies, depending on the sequencing matrix and sequences
associated with the
trays or bins. Although shown as having three sortation assemblies, sortation
system 310
may include more or less sortation assemblies, whereby the conveyor loop 327
may be
adapted to convey trays to one or multiple sortation assembly arrangements,
without affecting
the scope of the present invention. Also, although shown as being an overhead
conveyor
to connected.to overhead buffers, the conveyor system, including the conveyor
loop and/or
buffers, may be at a lower level, with the buffers positioned to one side or
end or otherwise
near their respective sortation assembly, without affecting the scope of the
present invention.
Referring now to FIGS. 16-21, a sortation system 410 includes a buffer or
sequencing
conveying assembly or system 414, which is operable to sort, arrange and
convey trays from
a discharge conveyor 426 (FIGS. 19-21) of a sort assembly 412 to induct
stations 416a, 416b,
416c of the sort assembly 412. The buffer conveyor system 414 is preferably
positioned at a
level generally above or adjacent to sort assembly 412. Sort assembly 412 is
substantially
similar to sort assembly 12, discussed above, such that a detailed discussion
of the assembly
will not be repeated herein. Similar to sort assembly 12, sort assembly 412
may have 120 bin
2o positions (as shown), or may be extended up to 240 bins or more, or any
other number of
bins, depending on the application. Providing additional bin positions
facilitates
implementation of a substantially larger sequencing or sortation matrix with
the sortation
system. In the illustrated embodiment, sort assembly 412 is a flats sorting
machine, such as
the type marketed by Alcatel Postal Automation System and/or Mannesmann
Dematic Postal
Automation, Mannesmann Dematic Rapistan Corp., Solystic and/or Siemens Dematic
Corp.
under Model AFSM 100. Alternately, however, the sort assembly may be any other
type of
sortation assembly, such as a dual carousel system, such as the sortation
assembly marketed
by Mannesmann Dematic Postal Automation, Solystic and/or Siemens Dematic Corp.
under
Model TOP2000, the sortation assembly marketed by Lockheed Martin Postal
Automation
3o under Model FSM 1000, or any other flat mail sortation system, without
affecting the scope
of the present invention.
Similar to sort assembly 12, discussed above, sort assembly 412 includes three
inducts
416a, 416b, 416c adjacent to three tray lowering devices 430a, 430b, 430c
(such as the three
generally vertical lowering devices shown in FIGS. 16 and 18 or the three
spiral incline
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conveyors shown in FIG. 17 or any other lowering means) of buffer 414. Inducts
416a, 416b,
416c receive the articles from trays or bins lowered by lowering devices 430a,
430b, 430c
and induct the articles into the sort assembly 412, where the articles are
sorted and discharged
into the bins or trays at the sortation stations, as discussed above with
respect to sort
assembly 12. The trays are conveyed along the sort assembly via a tray
handling system,
such as tray handling system 110, which is operable to automatically remove
partially filled
trays from the sortation stations and convey the trays to a labeling station
(not shown in
FIGS. 16-21) and onto discharge conveyor 426. The labeled trays are then
conveyed to
buffer or sequencing conveyor 414, such as via an inclined ramp conveyor 428
or other tray
moving device which is operable to transfer trays from the sort assembly to
the sequencing
conveyor. Although described as having a labeling station at the end of the
tray handling
system, it is envisioned that the labeling station may be positioned elsewhere
along the sort
assembly and tray handling system, such as at the beginning or upstream end of
the tray
handling system, without affecting the scope of the present invention.
Buffer 414 includes an induct transportation conveyor 421 at an induct end 420
and a
discharge transportation conveyor 423 at a discharge end 422, with a pair of
generally
parallel transportation conveyors 432a, 432b extending therebetween. A pair of
90 degree
transfer units 431 are located at a junction of incline ramp conveyors 428 and
induct
transportation conveyor 421. Also, a pair of 90 degree transfer units 425 are
located at the
junctions of the induct conveyor 421 and transportation conveyors 432a, 432b,
while a
corresponding pair of 90 degree transfer units 427 are located at the
junctions of
transportation conveyors 432a, 432b and discharge transportation conveyor 423.
Transfer
units 427 are operable to move the trays or containers onto discharge
transportation conveyor
423 for conveying the trays to the inducts of the sortation assembly for the
second sort pass,
as discussed below, or to move the trays onto a pair of takeaway conveyors 436
for
discharging the trays after the delivery point sequencing process is
completed, as also
discussed below.
The transportation conveyors 432a, 432b include a plurality of temporary
storage or
sort location fingers, slots or zones 434 extending laterally therefrom at
either side of each of
the parallel conveyors 432a, 432b. A plurality of 90 degree transfer units 429
(FIG. 17) are
positioned along conveyors 432a, 432b and are operable to convey trays either
along
conveyors 432a, 432b or laterally to either side of conveyors 432a, 432b to
direct the trays
into and out from a targeted one of the sort location zones 434. Each of the
zones 434
includes a motorized roller conveyor or the like and is operable to receive
and discharge one
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or more trays from and to a respective one of transportation conveyors 432a,
432b. In the
illustrated embodiment, each slot 434 is capable of temporarily storing or
staging up to four
trays. However, the zones may be configured to receive more or less trays, in
order to adapt
the system to the applicable mailstreams, without affecting the scope of the
present invention.
Trays of sorted articles are received at induct end 420, and buffer 414 is
operable to
sort, stage and accumulate the trays as the trays are conveyed along a
respective one of the
conveyors 432a, 432b and onto an appropriate one of the zones 434. After the
trays are
arranged in their appropriate zones and the first sort pass is completed,
buffer 414 is operable
to discharge the trays from their zones 434 and to convey the discharged trays
along
conveyors 432a, 432b to arrange the trays in an arranged manner prior to
conveying or
transferring the arranged trays onto discharge transportation conveyor 423 at
discharge end
422. A plurality of 90 degree transfer units 433 (FIG. 17) are positioned
along discharge
transportation conveyor 423 and are operable to move the trays onto one of
three discharge
conveyors 435a, 435b, 435c, which then conveys the trays to the tray lowering
devices 43a,
430b, 430c, respectively. The trays are then lowered via lowering devices
430a, 430b, 430c
to inducts 416a, 416b, 416c of the sort assembly 412. As best shown in FIGS.
16 and 17,
buffer 414 includes enough storage zones 434 so that each zone may be
designated to a
particular output bin of the sort assembly 412. Extra zones are preferably
provided for
situations where a particular sort station may provide more than four
containers of sorted mail
to buffer 414, and thus exceeds the space allotted for that station at its
four station storage
zone. In the illustrated embodiment, buffer 414 includes 142 sort location
zones, such that
120 of these are designated for a particular one of the 120 output bins of
sort assembly 412,
and the remaining zones are designated for excess or overflow trays.
Although shown and described as a pair of transportation conveyors having a
plurality
of zones connected thereto, it is further envisioned that the sequencing
buffer of the present
invention may otherwise include multiple transportation conveyors with zones
extending
from each conveyor, such as three pairs of transportation conveyors with zones
extending
from one or both sides of each conveyor, without affecting the scope of the
present invention.
Varying the number of transportation conveyors allows for variation in the
overall
dimensions of the sequencing buffer to adapt the sequencing buffer of the
present invention
to various applications.
The delivery point sequencing process initially begins with the use of the
sortation
machine or sort assembly in conjunction with a tray handling system, which
preferably
automates the flow of trays and mail through the flat sorter. A system of
flats tub or
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container storage and tracking is implemented to again sort the mail and
sequence it into its
numerical order by the address on the mail item. The particular sort process
depends on the
sequencing matrix that is implemented with sortation system 410.
The containers may be stored in a designated zone or accumulation conveyor 434
(such as a four zone accumulation conveyor, as shown in FIG. 17) while mail
sorting is being
conducted. Each sort location of the sortation machine may have its own
designated sort
location zone.
The process of delivery point sequencing is a two step process. The articles
begin the
sequencing process by being delivered to the feeders of the sortation machine
where
l0 operators feed the articles into the machine. Once the articles are fed
into the machine, they
are sorted by the sortation machine according to their zip code or other
identification and
placed into corresponding tubs,.trays or containers, which are located in pre-
designated sort
locations or stations on the sorter.
When a container becomes full, a bin full sensor temporarily halts sorting of
mail to
15 that sort location and triggers the tray handling system to remove the full
container and
release it to the motorized roller take away conveyor 116 (FIGS. 19-21) of the
tray handling
system. An empty container is then delivered to the open sort location and
automatically
placed there in order to allow sorting to continue at that location.
The full or at least partially filled containers removed by the tray handling
system
2o proceed along the motorized roller conveyor 116 until they reach the end,
where they may be
rotated 90 degrees by a tray rotator (not shown in FIGS. 16-21). The
containers then feed
onto incline conveyor 428, which transports them to an overhead height, such
as a height of
approximately 12 feet, and to transfer unit 431 (FIG. 17). The transfer unit
431 then moves
the containers onto the induct transportation conveyor 421. Containers that
came from the
25 rej ect bins (normally one or more of the later bins of the sortation
machine, such as bins 119
and 120) and containers with unreadable labels remain at floor level and are
diverted to a
reject conveyor (not shovm in FIGS. 16-21).
The containers are then transported to one of the two transfer units 425
located at each
end of the induct transportation conveyor 421. Each of the transfer units 425
moves the
3o containers onto a corresponding one of the pair of generally parallel
motorized roller
accumulation conveyors 432a, 432b. The containers may then be scanned as they
are
conveyed along transportation conveyor 432a, 432b to a series of bi-
directional transfer units
429. The information on each container bar code label is used to determine
which one of the
transfer units 429 will actuate for that tray as it is conveyed along the
appropriate
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transportation conveyor 432a or 432b. As the containers continue down the
transportation
conveyor, their transfer information is retained. When the container reaches
its designated
location, the assigned transfer 429 is actuated to move the tray onto the
appropriate storage
slot or sort location zone 434.
The slots or sort location zones 434 preferably correspond to the numerical
order in
which the sort bins are arranged on the sortation machine 412. For example,
sort location
zones 1 thru 60 may be located directly above the sort bins 1 thru 60 of the
sortation machine,
while sort location zones 61 thru 120 may be located on the opposite side.
Sort location
zones l and 2 may be located closest to the charge or induct end of the
accumulation or
to sequencing or buffer conveyor where the containers are scanned. The
numerical order
preferably continues right to left with odd numbers on one side and even on
the other. The
same order system preferably is maintained for the sort location zones 61 thru
120 on the
opposite side. The containers are kept in their respective slots or sort
location zone until the
second sort pass is initiated.
15 This same operation is repeated for every sort location or station of the
sort assembly
412. Delivery point sequencing system 410 includes enough locations to
accommodate the
full or at least partially filled containers and store them separately by
their designated
sequence group and sort location. If additional storage locations are required
for a particular
grouping of delivery sequences or sort location, the containers may be
directed to one of
20 several overflow accumulation zone conveyors, such as to one of the twenty-
two extra zones
shown in the illustrated embodiment. These overflow zones are assigned to the
respective
sequencing group or sort location. The overflow zones can be assigned
dynamically based on
the actual outputs from each sort plan.
Once all of the allotted articles for the first sort pass has been initially
sorted through
25 the sortation machine, a sweep of the sort assembly 412 is conducted and
all partially full
containers are removed and transported in a similar manner as the full
containers or trays
were during the first sort pass. The trays then proceed to the inclined ramp
428 and follow
the same path as the full containers before them.
Once the sort assembly 412 is cleared and an empty container is placed in each
sort
30 location, delivery point sequencing system 410 begins to transport the
stored, full or partially
filled containers from their designated storage locations in the reverse order
they were
received for storage. Using the accumulation zones 434, which initially stored
the containers,
and the transfer units 429 and transportation conveyors 432a, 432b, the
containers are moved
to the transfer units 427 at the opposite, discharge end of the system.
Transfer units 427 then
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move the containers onto the motorized roller discharge transportation
conveyor 423, where
more transfer waits 433 are used to evenly distribute the trays or containers
onto one of the
motorized roller discharge conveyors 435a, 435b, 435c. All of the trays that
came from a
specific bin are preferably distributed evenly to all three of the discharge
conveyors. If there
are more or less than three containers per sort location, the trays preferably
are alternated
through the feeders throughout the sort operation to equalize the feeder
routine. The
accumulation or buffer conveyor system 414 delivers the containers, in order,
to the tray
lowering devices 430a, 430b, 430c, which may be any tray lowering means, such
as a
generally vertical lowering device, such as shown in FIG. 16, or a spiral
chute such as shown
1 o in FIG. 17. The tray lowering devices then return the trays to the floor
level at the feeder area
of the sortation machine. Preferably, each of the three feeder stations 416a,
416b, 416c only
receives the full containers from a specific sort location zone at any given
time. All three
operators at the feeder stations then only sort mail that came from a single
location at any
time. If an operator runs out of mail before the others, that operator and
station may remain
idle until the others are completed. Generally, an operator that runs out of
mail first will not
have to wait more than the time it takes for one or both of the other
operators to complete one
tray of articles. The full containers for the next sort bin location are then
staged to be
immediately ready for processing once all three feeders are cleared of the
articles from the
previous bin.
2o When the articles are fed back into the sort assembly 412 it is stored in
the moving
buckets and dropped in sequence into the appropriate route designated sort
locations. When
the containers become full, they are again removed by the tray handling system
and conveyed
to the inclined ramps 428. The trays are then further conveyed to the
appropriate slot or zone
434 for storage in their proper order, where they are retained in the zone
until they are ready
for delivery. Again, overflow zones are preferably available for storing
containers from bins
receiving a large supply of articles or items.
Once all of the articles have been re-sorted and sequenced by the second sort
pass, the
containers are transported, grouped by sort location, to a remote location,
via takeaway
conveyors 436, where they may be brought down to floor level for loading into
the
3o corresponding delivery vehicles.
Although shown as having a single sortation assembly, sequencing, accumulating
or
buffering conveyor system 414 may be implemented with two or more sortation
assemblies,
whereby a conveyor loop may be adapted to convey trays to another or multiple
sortation
assembly arrangements, similar to sortation assembly 310, discussed above,
without affecting
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the scope of the present invention. Also, although shown as being an overhead
conveyor
connected to overhead conveyors and zones, the buffer conveyor system 414 may
be located
at a lower level, such as to one side or end or otherwise near the respective
sortation
assembly, without affecting the scope of the present invention.
Refernng now to FIG. 22, a flat mail processing flow process 500 is shown for
a
typical processing and distribution center. Process 500 illustrates that a two
pass delivery
point sequencing process can be accomplished on flat sorting machines with 120
bins for
multiple carrier routes in a given timeframe. Process starts at 505 at a
primary processing
stage, where mail is collected at 510 and outgoing mail is zone sorted to 3
digits at 515 and
to the targeted mail is also zone sorted to 3-digits at 520. A first pass
delivery point sequencing
process 525 sorts the mail to the desired bins, depending on the sort plan or
sort matrix.
Incoming mail, contract mail and periodicals are input into the sortation
assembly or machine
at 530, 535 and 540, respectively. The containers containing the mail sorted
in the first pass
are conveyed by a tray handling system to the delivery point sequencing
conveyor at 545.
15 After the trays are sequenced by the delivery point sequencing conveyor,
the trays are input
into the sortation machine at 550 for the second pass through the sortation
machine. The
sequenced carrier route mail is then dispatched at 555. The process 500 may
then be repeated
for new mail being received and collected. Process 500 is not shown with what
typically is
called the first processing of collected outgoing mail or the processing of
incoming and
2o contracted presorted mail. Process 500 also is not shown with the process
involving zoning
mail by carrier nor does it consider specific arrival times of various mail
streams. However,
these processes clearly may be included in process 500, without affecting the
scope of the
present invention.
The number of bins required for each carrier depends on the number of
sequences
25 (addresses) in a particular letter Garner walk (LCW). Typically, a flat
sorting machine with
120 output bins is divided into three groups of bins, each having 40 bins. In
such an
example, it is possible to create a sequencing matrix of 1600 slots (40 rows x
40 columns).
Such a sequencing matrix is depicted in FIG. 23 (first pass) and FIG. 24
(second pass). If
each LCW consists of 650 sequences, then 2.46 LCWs x 3 or 7.3~ LCWs could be
30 sequenced at a time on each 120 bin flat sorting machine.
Referring now to FIGS. 25A, 25B, 26A and 26B, a sortation or sequencing matrix
600
of the present invention provides a matrix for processing and sequencing
significantly more
LCWs during a given time period. This sequencing matrix may be implemented in
connection with any of the sortation systems discussed above, or with other
sortation and
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sequencing systems, without affecting the scope of the present invention. As
shown in FIGS.
25A, 25B, a first sort pass 600A is performed with a total of 660 sequences
per Garner, using
110 outputs of the sortation machine and six sequences per bin or output. The
remaining 10
bins (120 bins - 110 bins or outputs) are preferably reserved for hold out
mail and rejects and
the like.
As shown in FIGS. 25A and 25B, six rows of the sequencing matrix 600 are
assigned
to each carrier. For example, in the illustrated embodiment, rows 1 through 6
are assigned to
LCW #1, rows 7 through 12 are assigned to LCW #2, rows 13 through 18 are
assigned to
LCW # 3, and so on, up to row 120 rows for a total of 20 carriers.
to The number of LCWs able to be processed on any given machine depends on the
number of output bins utilized for the second pass. The example of bin
assignments shown in
FIG. 26B indicates that using 120 output bins permits 20 LCWs to be processed
concurrently
for the first and second passes on a single 120 bin machine (with 6 rows per
carrier). More or
less rows can be assigned depending on the number of sequences required for
each LCW. If
i5 fewer rows are used in the first pass, then fewer rows are required for the
second pass, such
that more LCWs can be processed at a time.
Assuming that each LCW has 1,000 flat mail pieces distributed to 650
sequences,
then, on average, each address receives 1.54 pieces of mail. With 120
sequences assigned to
each bin, each bin could receive 120 x 1.54 or 185 pieces of mail. Using an
average of 70
20 mail pieces per mail tray, an average of 2.6 trays may be discharged from
each bin.
The sequencing system used with sortation matrix 600 may be a sequencing
conveyor
of one of the types discussed above and may be a system of conveyors installed
over the
sortation machine or machines, and is thus able to sort and queue trays for
the second pass.
The tray handling system selected for use with sortation matrix 600 is
preferably capable of
25 handling variances in the number of trays discharged, so that the specific
number of
discharged trays will not hamper performance. The tray handling system
preferably provides
significant flexibility and is adaptable to a variety of site configurations
and sortation
machine layouts.
For the second sort pass through the sortation machine, trays of mail are sent
to the
30 three feeders in the appropriate order or sequence, as performed by the
sequencing conveyor
or the like. For example, the process may sort mail into the carriers' trays
in a last in, first out
(LIFO) order. Therefore, first pass trays from bin 120, or the last sequences
in the LCW, are
delivered first to the feeders by the sequencing conveyor or system. However,
the order of
tray delivery does not matter and may be altered depending on the layout of
the sort scheme
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for the first sort pass. Recall that six sequences of mail for 20 LCWs are
mixed in the
delivered trays during the first sort pass. The order doesn't matter and the
sequencing
conveyor or system preferably distributes trays in a round robin fashion to
all three feeders.
Preferably, in order to ensure that articles are not inadvertently mixed, the
feeder control,
upon recognition of a following address sequence, will not allow mail past the
buffer until all
mail from the previous sequence group is inducted into the carrousel from the
other one or
two feeders.
As shown in FIGS. 26A and 26B, the second sort pass 600B through the sortation
machine sorts the mail sorted during the first pass into an appropriate one of
the output bins
to of the sortation machine, where each Garner is assigned a particular block
or group of bins,
such as six bins in the illustrated embodiment. As the mail from bin 1 of the
first pass (which
includes mail for all six carriers) is sorted during the second pass, the mail
is sorted into an
appropriate bin corresponding to a particular sequence or sequences of a
particular Garner.
For example, bin 1 from the first sort pass includes mail pieces 1, 111, 221,
331, 441 and 551
for each carrier, as shown generally in FIGS. 25A and 25B. During the second
sort pass, the
mail is sorted such that mail piece 1 for carrier 1 is sorted to bin 1, while
mail piece 111 for
carrier 1 is sorted to bin 2, and so on, up to mail piece 551 for carrier 20
being sorted to bin
120, as shown generally in FIGS. 26A and 26B.
Once all of the mail has been fed and inducted, the trays are automatically
swept
(discharged) and labeled by the tray handling system prior to being
dispatched. If a tray
becomes full before the sweep can occur, the tray handling system preferably
removes the
full tray, automatically applies the destination label and replaces it with an
empty tray.
Once the second sort pass is complete and the sortation machine is swept, a
new
scheme or sort plan can be loaded while the sortation machine is being
replenished with
empty trays. Typically, loading a new scheme may take approximately 20
minutes, while
replenishing with empty trays can be done concurrently and well within this
timeframe.
The present invention thus provides a sortation and sequencing matrix which
allows
for significantly more LCWs to be processed at a time. For example, for routes
having 650
sequences, as discussed above, the sequencing matrix of the present invention
allows for
3o sortation and sequencing of 20 different carrier routes. Also, net
throughput of the sortation
system is enhanced. The sortation matrix of the present invention is flexible
and adapts to
varying requirements. The sortation matrix of the present invention also
allows for all three
inducts or feeders of the sortation machine to be used for all of the output
bins during both
sort passes.
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Therefore, the present invention provides an article sortation apparatus which
is
operable to provide two sort processes or passes of articles through one or
two sortation units
in order to achieve the delivery point sequence or carrier walk sequence sort
of the articles.
The buffer of the present invention is operable to automatically sort the
containers or trays
containing articles from a first sort process, such that the articles are
inducted into a sortation
unit in a proper sequence or order for a second sort process or pass. The
buffer of the present
invention may convey the trays containing the first sorted articles in a
generally continuous
loop, whereby additional trays are input into the loop at appropriate spaces
between trays
being cycled around the loop, until all the trays have been accounted for and
are being cycled
to or accumulated around the generally continuous loop in the proper order or
sequence.
Alternately, the buffer may provide a plurality of temporary storage zones or
conveyors,
where the trays are temporarily stored until the first sort pass is completed,
and then
automatically discharged in an appropriate order for the second sort pass. The
ordered trays
are then discharged from the loop conveying portion to the induct of the
sortation unit,
whereby the articles are re-inducted into the sorter unit for the second sort
process. The
present invention thus provides an automatic and efficient system for
automatically sorting
flat mail to the delivery point sequence. The articles are sorted to the
delivery point sequence
without temporary storage of the trays in bins or racks or the lilce, and
without'transporting
the trays via manual processes or via carts or robotic devices or the like.
The trays are
conveyed along interconnected conveying portions in order to provide
continuous sorting and
conveying of the trays, which further expedites the sortation process.
Additionally, mail may be transferred between sortation assemblies or the
input and
output of a single sortation assembly in a highly automated manner. This
avoids the
necessity for loading mail into standard trays and loading the trays on manual
carts, also
knoum as Eastern Regional Mail Containers (ERMC). Advantageously, the present
invention
may utilize containers that are of rigid construction such as rigid molded
plastic or the like,
and bearing a permanent identification number which may be encoded by a plate
attached to
the container, which may be a bar code, radio frequency tag, or the like. This
eliminates the
necessity for applying temporary labels to each container dispatched from the
sortation
3o assembly as would be done if the containers were being dispatched to the
transportation
system. Rigid containers are feasible because the containers may be retained
totally within
the sortation assembly and not utilized to ship mail to other distribution
centers. Mail may be
prepared at a common mail preparation location or station and loaded into the
rigid containers
and then conveyed to the inducts of the sorter units. The utilization of rigid
containers
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advantageously facilitates automatic transfer of flat articles from the
containers at the inducts
to thereby further reduce manual processing of the flat articles to be sorted.
The present invention thus provides automated means for sorting, queuing,
sequencing and presenting trays of sorted articles to the inducts of the
sortation assemblies
for the second sort pass. The trays may be automatically removed from their
respective
output bins, and automatically identified and labeled so that the trays may be
provided in the
proper order. The present invention also provides for automatic delivery point
sequencing for
a larger sequencing matrix via utilization of two or more sortation assemblies
or machines. A
conveyor loop may be implemented to connect each sortation assembly with each
buffer or
to tray sorter to facilitate sortation of a greater number of addresses or
sequences with a single
system.
The present invention also provides for an improved sequencing matrix for
sequencing the articles in appropriate output bins for multiple Garners. The
sequencing
matrix of the present invention provides significantly more carrier routes to
be processed at a
15 given time, while increasing the net throughput of the system. The
sequencing matrix of the
present invention also is flexible and adapts to varying requirements of the
sortation machine
or machines and the desired sequences of the articles or mail.
Changes and modifications in the specifically described embodiments can be
carried
out without departing from the principles of the present invention, which is
intended to be
20 limited only by the scope of the appended claims, as according to the
principles of patent law.
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