Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM, METHOD, AND PROGRAM FOR SORTING OBJECTS
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to the field of sorting and handling objects such
as pieces of mail, including parcels, and articles intended for commercial or
industrial
use. More particularly the invention relates to a transfer and sorting system
useful in
such operations as a hub facility of a parcel delivery system, a warehouse or
distribution facility in which products ordered by customers are selected and
packed
for delivery, and similar operations in which items are stored for later use
or
distribution as inventory, raw materials, work in process or parts.
Generally, in a parcel delivery system, packages are picked up from
various locations for ultimate transport to a large number of final
destinations. To
meet a rigorous delivery schedule and provide accurate deliveries, a parcel
delivery
company uses various manual and/or automated sorting and transfer systems to
match
each incoming package with proper transport to the destination of the package.
Simple belt and roller conveyor systems are often used in such parcel
sorting systems to move parcels from incoming loading docks to outgoing
transport.
Typically, conveyors carry parcels unloaded from a truck to a worker who
manually
sorts them by reading address information on shipping labels attached to the
packages. The worker then places the parcels onto receiving conveyors or
chutes
which carry the parcels either to a loading dock for loading onto outgoing
trucks, or to
another sorting station for a narrower breakdown of destinations.
Conveyor diverter assemblies have been developed to automate and
expedite handling of articles in conveyor systems. Examples appear in U.S.
Pats. Nos.
4,798,275 to Leemkuil et al., and 4,174,774 to Bourgeois, both of which are
incorporated herein by reference. However, such diverters are used primarily
to divert
articles from a main linear conveyor. As a result, such systems occupy a
relatively
large amount of space and their throughput is limited by the speed of the
linear
conveyor. Increasing the speed of a linear conveyor often requires the use of
more
expensive equipment and control systems, and such efforts are often limited by
such
factors as the varying inertia of sorted articles, precise timing requirements
and
increased maintenance costs. In some conveyor-based systems, throughput is
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enhanced without increasing conveyor speed by the use of pre-sorting
subsystems
which route an object to one of multiple linear conveyors depending on the
object's
destination. Such pre-sorting subsystems typically occupy substantial
additional
space, however, and often add considerable additional cost to the system.
Throughput
gains resulting from the use of multiple linear conveyors are partly offset by
the
additional time required by the pre-sort operation.
Various other systems have been developed to achieve the triple
objectives of high throughput, compact size and low cost. For example, in the
rotary
sorter system shown in U.S. Pat. No. 5,284,252 to Bonnet, which is
incorporated
herein by reference, destination codes printed on packages are machine-read,
and the
packages are transferred onto powered conveyor modules mowlted on a rotating
distribution assembly. The individual module is then rotated and elevated or
lowered
into aliglunent with one of a plurality of destination conveyors that are
spaced apart
both horizontally and vertically. After such alignment, the modules rollers
are
operated to discharge the package onto the destination conveyor. In the Bonnet
system, packages can be rapidly sorted without human intervention by an
apparatus
that occupies a relatively small amount of floor space. Another example is
shown in
U.S. Pat. No. 6,005,211 to Huang et al., incorporated herein by reference,
which uses
a stationary matrix of mufti-directional conveyor cells to sort objects to a
plurality of
destinations.
Such sorting systems are of varying but limited effectiveness in
achieving high throughput, compact size and low cost, particularly in
circumstances
requiring sortation to thousands of destinations.
SUMMARY OF THE INVENTION
The present invention provides a compact, high-speed and efficient
object sorting system based on a matrix comprising one or a plurality of
closed
ellipses (each an "upper loop") of conveyor cells ("cradle") that circulate
around the
upper loop in steps of a fixed length and duration, each such loop crossing,
in a
different plane, at about four points, each of one or a plurality of other
closed ellipses
(each a "lower loop") of conveyor cells ("cradle") that circulate around the
lower loop
in steps of a fixed length and duration.
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According to one illustrative embodiment of the present disclosure
there is presented a system for sorting objects comprising a control unit, a
first
conveyor sorting matrix and a second conveyor sorting matrix located below
said first
soiting matrix. Wherein said first and second sorting matrices are each
adapted to
receive and transport one or more objects to be sorted. The first matrix
includes one
or more primary discharge apertures for discharging said objects to said
second
matrix. The second matrix includes one or more primary discharge locations for
discharging said obj ects to one or more collection areas.
According to another illustrative embodiment, an apparatus for
receiving and discharging objects to be sorted by a sorting system is
presented,
wherein the apparatus comprises a pair of spaced apart side pieces having a
slanted
floor portion sandwiched therebetween the side pieces. A gate portion is
movably
attached to the floor portion and extends outwardly away therefrom.
According to another illustrative embodiment, a system for sorting
objects is presented, the system comprising an induction assembly adapted to
receive
objects for sorting and an upper sorting circuit adjacent to the induction
assembly and
adapted to receive objects therefrom, wherein a lower sorting circuit crosses
under
said upper sorting circuit and is adapted to receive objects therefrom for
delivery to a
destination assembly adapted for receiving objects from the upper and lower
sorting
circuits. One or more sensor assemblies mounted to gather data on the one or
more
objects provide inputs to a control apparatus connected to the induction
assembly, the
upper sorting circuit, the lower sorting circuit, and the one or more sensor
assemblies.
The control apparatus sends output commands to facilitate the delivery of each
object
to the destination assembly.
According to another illustrative embodiment, a method is presented
for sorting objects comprising the steps of providing a control unit to
control the sort
process of objects in a sorting matrix comprising a first and a second sorting
matrix
and a plurality of collection destinations. The method also provides for
diverting
obj ects. The control unit directs the transferring of an obj ect to be sorted
from the
first matrix to the second matrix and the transfernng of said transferred
object from
the second matrix to one of the collection destinations.:
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The present invention provides an improved object sorting system and
method, particularly fox use in a package sorting and delivery system, and
also for use
in a sorting system in a warehouse or distribution facility.
The present invention provides an object sorting system that can sort to
a large number of sort destinations and yet occupy a comparatively small space
relative to existing sorting systems used for similar purposes.
The present invention provides an object sorting system and method in
which multiple streams of objects may be sorted simultaneously at high
throughput
rates despite relatively low line speeds.
The present invention provides an object sorting system and method in
which an object to be sorted can be routed in advance to its sort destination,
and
subsequently re-routed in certain circumstances, based on the predictable
future
location of such object and of each earlier object.
The present invention provides an object sorting system and method in
which an object to be sorted can be diverted from the sorting system for
recirculation
or manual processing if the object predictably cannot be routed to its sort
destination
without conflicting with the passage of another object through the sorting
system.
The present invention provides an object sorting system and method in
which an object to be sorted can be scanned for identification and then
transported to
its sort destination without the need to re-scan the object.
The present invention provides an object sorting system and method in
which objects sorted to a specific sort destination can be grouped at such
destination
with other objects sorted to the same destination, and thereafter transferred
as such a
group for aggregation with other objects or object groups sorted to different
destinations, when such distinct object groups nevertheless possess one or
more
common characteristics, such as the same delivery vehicle or container.
Other features and advantages of the present invention will become
apparent upon review of the following detailed description of a preferred
embodiment
and the attached drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a top plan view of a system according to one embodiment of
the invention;
Fig. 2 is a side elevational sectional view of the outgoing run of the
upper-loop sorting matrix and an end-on sectional view of the lower-loop
sorting
matrix of the system depicted in Fig. 1 taken generally along the line 2-2 of
Fig. 1;
Fig. 3 is a is a side elevational sectional view of the return run of the
upper-loop sorting matrix and an end-on sectional view of the lower-loop
sorting
matrix of the system depicted in Fig. 1 talcen generally along the line 3-3 of
Fig. l;
Fig. 4 is partial diagrammatic view of the upper-loop sorting matrix
and the lower-loop sorting matrix and a side elevation view of a takeaway
conveyor
of the system of Fig. 1;
Fig. 5 is an enlarged view of a portion of the upper-loop return-run
depicted in Fig. 3;
Fig. 6 is a flow diagram depicting one embodiment of the method of
the present invention; and
Fig. 7 is a block diagram showing the input signals to the control unit
and the control outputs therefrom.
DETAILED DESCRIPTION OF THE DRAWINGS
To promote an understanding of the principles of the invention,
reference will now be made to a number of preferred embodiments illustrated in
the
drawings and specific language will be used to describe the same. It will
nevertheless
be understood that no limitation of the scope of the invention is thereby
intended,
such alterations and further modifications in the illustrated embodiments, and
such
further applications of the principles of the invention as illustrated
therein, being
contemplated as would normally occur to one skilled in the art to which the
invention
relates.
Referring now to Figs.l-4, in which like numerals refer to like parts
throughout the several views, illustrative embodiments of the system and
method
embodying the present invention are shown. A sorting system 100 and method for
sorting objects 110 such as parcels is provided, such system 100 comprising
generally
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a control system 120; an induction area assembly 200; an upper-loop sorting
matrix
300 consisting of longitudinally extending, generally ovate ellipses; a lower-
loop
sorting matrix 400 consisting of transversely extending, generally ovate
ellipses; a
collection-bin loading area assembly 500; a saclc loading area assembly 512,
532; and
a loose object loading area assembly 518, each as further described herein.
Referring to Fig. 4, it can be seen that the illustrative system 100 is a
multi-level system with loading assemblies 512, 518, 532 occupying the lower
levels
of the system 100, with the collection-bin loading assembly 500 elevated above
the
loading assemblies 512, 518, 532, with the lower-loop sorting matrix 400
elevated
above the collection-bin loading assembly 500, with the upper-loop sorting
matrix
300 elevated above the lower-loop sorting matrix 400, and with the induction
area
assembly 200 elevated above the upper-loop sorting matrix 300. It will be
appreciated that the vertical relationship of the different portions of the
system could
be changed if some of such portions also used lift devices. For example, the
induction
line assemblies 200 could be at a lower level relative to the other components
through
the use of one or more conveyors or other lift devices) to elevate the
objects) to be
sorted up to the upper-loop sort matrix 300. As will be explained further
below, a
series of conveyors 506, 526, underlie the collection-bin loading assembly
500, as
does a walkway 600 which lies generally in the middle of the collection-bin
loading
assembly 500 and proceeds from the induction assembly 200 longitudinally away
therefrom toward the far end of the upper-loop sorting matrix 300 in general
alignment with the longitudinal axis of said matrix 300 and perpendicular to
the
longitudinal axis of the lower-loop sorting matrix 400, thereby separating the
collection bins 501 into two sides. A number of walkways 602 extend
longitudinally
between and generally parallel to the conveyors 506. Said conveyors 506
proceed
laterally away from walkway 600 in a first direction indicated by arrow 507,
in order
to serve a first side of collection bins 501, while conveyors 526 proceed
laterally away
from walkway 600 in a second direction directly opposite that of conveyor 506
as
indicated by arrow 527, thereby serving a second side of collection bins 501.
Conveyor 516 is elevated above conveyors 506, 526 and proceeds
laterally away from walkway 600. Conveyors 506, 516, 526 are generally
perpendicular to walkway 600.
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By way of illustration only, the vertical orientation of the system may
be further described as follows. Walkway 600 is generally located at one of
the
lowest points of the system 100. Elevated from inches (centimeters) up to
about sever
feet (meters) above the walkway 600 in the area of the collection bin loading
assembly 500 are the conveyors 506, 526, which then rise a further four to ten
feet
(1.2 m to 3 m) up to their discharge point to the holding assemblies 512, 518,
532.
The collection bins 501 may rise to a level of six feet to ten feet (1.8 m to
3 m) above
the wall~way 600. The lower-loop sorting matrix 400 may rise between four and
six
feet (1 m to 2 m) above the collection bins 501. The upper-loop sorting matrix
300
may in turn rise between four and six above the lower-loop sorting matrix 400.
The
induction assembly 200 may rise between four and six feet (1 m and 2 m) above
the
upper-loop sorting matrix 300, making the total height of the illustrative
embodiment
between 18 and 28 feet (5 m and 9 m). It will be appreciated that the addition
of
further levels of takeaway conveyors 506, 516, 526, or additional levels of
collection
bins 501, or additional levels of sorting matrices 300, 400, or additional
levels of
induction assemblies 200 would raise the overall height of the system 100.
Similarly,
the desire to accommodate larger objects might increase the size of the
collection bins
501 as well as the vertical distance between the upper 300 and lower 400
sorting
matrixes and between multiple levels of induction assemblies 200. In short,
the
vertical dimensions of the system 100 are not a critical aspect of the
invention.
Rather, the size of the largest object 110 to be sorted will be the principal
factor in
determining the principal vertical dimensions of the system 100.
The system 100 has the following structure and, in brief, the system
and method operate as follows. In such a system, the objects 110 are delivered
to the
induction area assembly 200. In the induction area 200, various tasks are
performed
including the scanning of a label attached to each obj ect 110 as directed by
the control
system 120 and as will be described in greater detail below. The control
system 120
will either divert for manual processing or further pre-processing, or advance
to the
upper-loop sorting matrix 300, each object 110 from the induction area 200.
Based on
destination information taken from each object's 110 label and other
information as
will be explained, the control system then directs each advanced object 110 in
turn to
drop to the lower-loop sorting matrix 400 or instead to drop for manual
processing or
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further pre-processing. Similarly, the control system 120 will direct each
object 110
in turn to drop from the lower-loop sorting matrix 400 for manual processing
or
further pre-processing, or to drop to the collection-bin loading assembly S00
for
transport, via conveyors 506, 516, 526, to either the sack loading assembly
512, 532
or the loose-object loading assembly 518, as appropriate. Fully processed
objects 110
will then be loaded onto transportation to each object's destination. While a
section
specifying the detailed operation of the present invention will be presented
below,
further description of the system's 100 structure, with accompanying overview
details
of its operation, will first be presented.
As noted, objects 110 to be sorted to one of a plurality of final sort
destinations enter the system 100 at the induction line assembly 200. Two
induction
line assemblies 200 are depicted in the illustrative embodiment shown in Fig.
1. Each
induction line assembly 200 comprises a pre-induction holding area assembly
206,
which feeds one or more non-merging induction lines 202, 204, and which may
include a powered-roller-conveyor, or may slope down to the intake conveyor
208 in
order to use gravity to move objects 110 along. Each induction line 202, 204
has a
number of processing zones comprising an intake conveyor 208, a pre-scan
accumulation area assembly 210, a scan zone 212, an induction line divert area
assembly 214, a post-divert accumulation area 238, an induction-line-to-upper
loop
discharge 240, and, optionally as in the case of induction line 204, an
induction line
fork 236. Each of processing zones 208, 210, 212, 214, 236, 238, 240 extends
longitudinally toward the sorting matrix 300, 400 and such zones are generally
aligned in spaced succession as shown in Figs. 1 and 2. Although these zones
206,
208, 210, 212, 214, 236, 238, 240 are generally depicted in line with each
other and
with one of a plurality of respective upper-loop, ovate sorting loops 302 in
the
illustrative embodiment, they need not be. For example, each induction line
202, 204
could feed each into its associated upper loop 302 at an oblique angle, and
the
induction line 202, 204 and its associated upper loop 302 could be offset from
each
other.
Each of these processing zones 206, 208, 210, 214, 236, 238, 240
includes one or more conventional powered-roller and/or belt conveyors, with
each
zone configured and controlled as appropriate to perform advancement,
accumulation
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or singulation functions as described below. Scan zone 212 further comprises
scanning, weighing and dimensionng devices, and divert area 214 further
comprises
divert mechanisms, as further described below. It should be noted that
discharge 240
could optionally be a gravity operated set of rollers or a gravity slide, or a
combination of powered rollers and gravity apparatus.
Objects 110 are manually or automatically inducted at the intake 208;
accumulated in the pre-scan accumulation area 210; scanned, weighed and
dimensioned in the scan zone 212; diverted at the divert area 214 for manual
processing or recirculation if so directed by the control system 120; and (if
not
diverted), accumulated in the post-divert accumulation area 238 and then
advanced at
the discharge assembly 240 into a cradle 304 on the upper-loop sorting matrix
300,
which comprises one or a plurality of ovate sorting loops 302.
As just mentioned, the induction assembly 200 is equipped to divert
for special handling objects 110 which are too large or too heavy for the
system's 100
automated sorting, which have unreadable labels, for which an unobstructed
path
through the sorting matrix 300, 400 cannot be plotted, or which otherwise are
unable
to complete automated sorting. In order to accommodate such special-handling
tasks,
as will be further described herein, the induction assembly 200 further
comprises a
no-read diverter 216, a no-read divert conveyor 218, a no-read processing area
assembly 220; a manual processing diverter 222, a manual processing divert
conveyor
224, a manual processing area assembly 226; a recirculation diverter 228, a
recirculation slide 230, a failed-to-drop conveyor 312, a recirculation
conveyor 232
(Fig. 2), and a recirculation to manual processing diverter 234. The divert
mechanisms 216, 222, 228 comprise one or more conventional diverters (not
shown)
such as a pop-up roller. The conveyors 218, 224, 312, 232 may be either a
powered-
roller conveyor or a belt conveyor. It will be noted that recirculation
conveyor 312,
which is located below the induction assembly 200 and the upper-loop sorting
matrix
300, is also served later in the sorting process by recirculation slide 311,
to which
objects 110 are diverted from the upper-loop sorting matrix 300 if they have
failed to
drop where programmed to the lower-loop sorting matrix 400, for recirculation
as will
be described.
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Objects may drop from the induction line assembly 200 to the
conveyors 218, 224, the gravity slide 230, or upper-loop cradles 302, or from
the
gravity slide 230 to the failed-to-drop conveyor 312, by way of gravity slides
(not
shown, except for gravity slide 230); however, other mechanisms, such as
unpowered
or powered rollers, could be used. In addition, the conveyor 218, 224, 312,
232 or
upper loops 300 could also be elevated over the induction line assembly 200,
and if so
elevated, could use further lift mechanisms to raise objects 110 to their
level.
Similarly, the objects 110 drop from the respective conveyor 218, 224, 312 to
the
commanded destination processing area 220, 226 or recirculation conveyor 232
via a
respective gravity slide or conveyor (not shown), or perhaps even in total
free-fall.
h1 the illustrative embodiment, induction line 202 is a straight-through
line feeding a single sorting loop 302. In contrast, induction line 204 is a
bifurcated
line having the induction line fork 236, which allows the line 204 to serve
more than
one sorting loop 302. The illustrative embodiment's three sorting loops 302
could
also be served by three single straight-through lines, or a single induction
line having
two forks. Moreover, single lines and single- or multi-forked lines may be
used alone
or in any combination to induct objects 110 into any number of sorting loops
302 as
desired. Indeed, as will be discussed further, the three-loop system 100
herein
described is illustrative only. A larger system might contain, for example,
twenty to
fifty upper loops and twenty-five or more lower loops served by any
combination of
single- or mufti-forked induction lines.
Objects 110, unless diverted, will move from the induction assembly
200 to the upper-loop sorting matrix 300, which, in the illustrative
embodiment,
comprises three horizontal, longitudinally extending, closed-oval, sorting
loops,
herein referred to as upper loops 302. Each loop 302 has a longitudinal axis
which
extends longitudinally away from and generally in line with its corresponding
induction line 202, 204. Each loop 302 has a plurality of upper-loop cells 304
or
cradles, one or more cradle-gate pull rods 303, a cradle-conveyor chain 716,
an upper-
loop floor 306, a plurality of upper-loop floor apertures 307, a plurality of
upper-loop
drop slides 308, a failed-to-drop slide 311, a plurality of upper loop drop
points 310,
801-808, and a motor and associated drive shafts and gears (not shown).
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The upper-loop floor 306 may be a solid floor having apertures 307
spaced to allow for commanded drops, or it may be in the nature of a rail
system.
Refernng to Fig. 1, each cradle-conveyor chain 716 runs the entire inner
circumference of its respective loop 302. Referring to Fig. 5, the conveyor
chain 716
is conventionally attached to the side of each cradle 304 using one or more
cradle-
conveyor attachments 718. There is a fixed interval between each of the
cradles 304.
Each loop's 302 pull rods 303 run one each down the inner elongated sides of
the
sorting loop 302. The motor (not shown) is attached using conventional gearing
to
each pull rod 303, and to each elongated side of the conveyor chain 716 for
that
particular loop 302. Such conventional gearing may include any combination of
drive
shafts, motor drive wheels, drive shaft wheels, direction-reversing wheels,
Geneva
mechanisms, cams and the like. In addition, separate motors could be used for
the
cradle chain 716 and the pull rods 303. While the cradle-conveyor chain 716
runs
intermittently in a single forwardly direction during normal operation, the
pull rods
303 move intermittently in alternate fashion between a forwardly first
direction and a
backwardly second direction directly opposite the first direction. The
direction of
travel of cradles 304 around each loop 302 will depend on the placement of
such loop
302 with respect to its associated induction line discharge 240. In the
illustrative
embodiment in Fig. 1, for example, where the induction line discharge 240 is
positioned above the left side of the associated upper loop 302, cradles 304
on such
loop 302 circulate in a clockwise direction; where the induction line
discharge 240 is
instead positioned above the right side of the associated upper loop 302,
cradles 304
on such loop 302 circulate in a counterclockwise direction.
One object 110 alone will drop into a cradle 304 and travel around the
sorting loop 302 in defined movements 50 or steps, each step of the same
specified
length and time. As will be discussed, each step 50 will comprise a series of
substeps
referred to generally as a move substep 55 and a stationary substep 56. At a
pre-
determined step 50 during each object's 110 travel around the loop 302, the
control
system 120 will command each said object 110 to drop from its discrete cradle
304
either down one of the slides 308 to the lower-loop sorting matrix 400 at a
pre-
determined one of the plurality of drop points 801-808, or, in the case of a
location
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conflict as described below, down slide 311 to the upper failed-to-drop
conveyor 312
at the failed-to-drop drop point 310 as depicted in Figs. 2 and 3.
Generalhr, when directed by the control system 120, an object 110 will
drop from the upper-loop sorting matrix 300 to the lower-loop sorting matrix
400,
which illustratively comprises two transversely extending, closed-oval,
sorting loops
402. The lower loops 402 underlie the upper loops 302 and have longitudinal
axes
that are generally perpendicular to the longitudinal axes of the upper loops
302. Each
loop 402 has a cradle conveyor chain 716, one or more cradle-gate pull rods
403, a
plurality of lower-loop cells 404 or cradles, a cradle-conveyor chain 716, a
lower-loop
floor 406, one or a plurality of lower-loop floor apertures 407, a failed-to-
drop drop
point 40~, a loose-object drop point 412, a plurality of collection-bin drop
points (one
above each collection bin), and a motor and gearing (not shown). As noted
previously, the invention is adaptable to the use of any number of upper 302
and
lower 402 loops.
The lower-loop floor 406 may be a solid floor having apertures 407
spaced to allow for commanded drops, or it may be in the nature of a rail
system. The
loop floor 406 could instead have a single aperture comprising substantially
the entire
area of the oval described by the inner circumference of the lower loop 402.
Referring to Fig. 1, each cradle-conveyor chain 716 runs the entire inner
circumference of its respective loop 402. The conveyor chain 716 is
conventionally
attached to the front of each cradle 404 using one or more cradle-conveyor
attachments 71~. There is a fixed distance between each of the cradles 404.
Each
loop's 402 pull rods 403 run one each down the inner elongated sides of the
sorting
loop 402. The motor (not shown) is attached using conventional gearing (not
shown)
to each pull rod 403, and to each elongated side of the conveyor chain 716 for
that
particular loop 402. Such conventional gearing may include any combination of
drive
shafts, motor drive wheels, drive shaft wheels, direction-reversing wheels,
Geneva
mechanisms, cams and the life. In addition, separate motors could be used for
the
cradle chain 716 and the pull rods 403. While the cradle-conveyor chain 716
runs
intermittently in a forwardly direction during normal operation, the pull rods
403
move intermittently in alternate fashion between a forwardly first direction
and in a
bacl~wardly second direction directly opposite the first direction. The
cradles 404
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travel around each loop 402 in a countercloclcwise direction as indicated by
arrows
420, 422. The cradles 404 circulate in steps 50 synchronized with the steps 50
of the
upper cradles 304. Any object 110 received into a lower-loop cradle 404 from
an
upper-loop cradle 304 circulates around its lower loop 402 until the object
110 drops
as programmed by the control system 120 to its sort destination as described
in the
next paragraph. As best shown in Figs. 2-4, the lower loops 402 are elevated
at a
level below the induction line assemblies 200 and the upper loops 302, and
above the
sort destinations.
When directed by the control system 120, an obj ect 110 will drop from
its upper-loop cradle 304 to the pre-programmed lower-loop cradle 404. Each
cradle
304, 404 comprises a bottom piece or floor 704, a gate piece 706, a pair of
spaced-
apart side pieces 720, 721, a cradle-gate cable 710, a cable arc 708, a
manipulation
piece 712, a manipulation piece guide 714, one or more cradle roller wheels
728, and
may include a top piece 702. The cradle floor 704 is sandwiched between the
spaced-
apart side pieces 720, 721 and is slanted at about a 42 to 48 degree angle in
the
illustrative embodiment. A shallower or steeper floor incline, for example
between
about 30 and 60 degrees, could be used. The top piece 702 is connected to and
spans
each of the side pieces 720, 721 at the upper front portion of each cradle
304, 404. In
any one upper loop cradle 304, its top piece 702 is generally slanted to
substantially
the same degree as the floor 704, and is generally aligned with the bottom
portion of
the floor 704 in the cradle 304 ahead of said first mentioned cradle 304. The
maximum size object 110 that a cradle 304 may accommodate will be one that
fits
under the top piece 702 and between the side pieces 720, 721.
As noted, the upper-loop cradles 304 are oriented on the upper loop
302 in a forwardly facing direction as shown in Figs. 2; 3 and 5, such that
objects 110
drop out of the cradle 304 in the same direction as the cradle conveyor chain
716
moves. Each upper-loop cradle 304 has an open back portion 726 behind and
below
the floor 704. This configuration allows for minimal spacing between adjacent
cradles 304 since each object 110 can slide out of the cradle 304 in which it
is riding,
passing underneath that cradle's top piece 702 and underneath and between,
respectively, the floor 704 and spaced-apart sides 720, 721 of the cradle
ahead of that
cradle 304. The cradles 304 could also be configured without the open back
portion
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726; however, such configuration could require greater spacing between the
cradles
depending on the size of the objects 110 to be sorted.
The lower-loop cradles 404 are oriented on their loop 402 in an
inwardly facing manner such that obj ects 110 drop to the inside of the loop
402 in a
direction roughly perpendicular to the forward direction of travel of the
respective
conveyor chain 716. Because the sidewardly moving lower-loop cradles 404 do
not
drop their objects 110 toward adjacent cradles, they do not need an open back
portion
to obtain minimum spacing between cradles 404. Therefore, they may or may not
have an open back portion, irrespective of the desired spacing between
adjacent
cradles 404.
The cradle gate 706 is movably connected to the floor 704 by a hinge
(not shown) or other suitable device, and is generally perpendicular to the
floor in the
illustrative embodiment. One end of the grooved cradle arc 708 is connected to
the
underside of the gate 706, and the other end, which is loose, travels into a
cavity 722
inside floor 704 when the cable 710 is pulled. The cable 710 is connected at
one end
to the underside of the gate 706 just above the cradle arc 708 and at the
opposite end
to the manipulation piece 714. The upper-loop cradles' 304 manipulation piece
714
protrudes outwardly through the side 720, and the lower-loop cradles' 404
manipulation piece 714 protrudes downwardly through the bottom of the cradle
404.
The manipulation piece is disposed within the generally elongated cable guide
714
and is adapted to move back and forth along the guide's 714 length when
actuated by
the upper- or lower-loop pull rod 303, 403. The cradle roller wheels 728 are
conventionally attached to the sides 720, 721 of the upper-loop cradles 304
and to the
front and back sides of the lower-loop cradles 404.
The control system 120 will command an object 110 to drop from its
lower cradle 404 to one of several sort destinations. The object may drop to
one of
the array of collection bins 501 in the collection bin assembly 500, to a
loose-object
conveyor 516, or to a lower-loop failed-to-drop conveyor 410. Each collection
bin
assembly 500 comprises a number of collection bins 501 arranged in double rows
beneath and in the center of their respective lower loops 402 and over their
respective
conveyors 506, 526 as seen in Figs. 2 and 3. Sandwiched between the double
rows
are walkways 602. Walkway 602 access to the bins 501 is provided by a door 504
in
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each bin. A system frame 604 supports the bins 501 and the sorting matrix. A
collection-bin divider 502 divides the bins 501 into the double rows. A sack-
conveyor bifurcator 508 divides the conveyors 506, 526 into two sides
corresponding
to the row of bins 501 over a particular side of the conveyors 506, 526. A
number of
sack-conveyor diverters 510 divert the sacks to one or more destination sack
loading
areas 512, 532. Objects 110 dropped, also referred to herein as diverted, to a
collection bin 501 may thereafter, but need not be, placed in a sack 520 or
otherwise
grouped with other objects 110 sorted to the same collection bin 501.
Alternatively,
an object 110 may be diverted directly from its lower-loop cradle 404 down a
loose-
object slide 514 to the loose-object conveyor 516 for transport to a loose-
object
loading area 518 as shown in Fig. 4. At each sort destination 501, 518 the
correct
sorting of an object 110 may be confirmed by a comparative scaal of the
object's 110
label bar code and a unique bar code assigned to each collection bin 501 or
loose-
object loading area 518. Although only one loose-object loading area 518 and
associated conveyor 516 is shown in Fig. 1, it is possible to have multiple
loose-
object loading areas 518 and associated conveyors 516 on the same side of the
system
and/or one or multiple mirror-image loose-object loading areas and associated
conveyors on the other side of the system 100 opposite the area 518 and
conveyor 516
shown.
After the take-away conveyors 506, 516, 526 have transported objects
110 to their specified loading areas S 12, 518, 532, the objects 110 may be
further
processed according to a common processing characteristic. For example, sacks
520
of sorted objects 110 arriving at a single loading area 512, 532 from multiple
collection bins 501 may be loaded onto the same truck for delivery.
The system 100 has a number of failed-to-drop conveyors 312, 410.
Referring to Figs. 2 and 3, it can be seen that an object 110 may be directed
down
failed-to-drop slide 311, or, as explained above, down recirculation slide
230, to
conveyor 312. Similarly, an object 110 may be directed from its lower cradle
404
through drop point 408 for free fall to, or slide down a gravity slide (not
shown) to,
conveyor 410. Conveyor 312 runs under and generally perpendicular to the
direction
of travel of the upper loops 302 at the end of the upper-loop matrix 300
nearest to the
induction line assembly 200. The conveyor 312 ultimately feeds into the lower-
loop
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failed-to-drop conveyor 410. Lower-loop failed-to-drop conveyor 410 is
disposed
beneath and runs generally perpendicular to the travel of lower loops 402 and
conveyor 312. Conveyor 410 transports the objects 110 deposited thereon to the
recirculation conveyor 232 either for transport to the manual processing
assembly 226
or for recirculation to the induction line assembly 200. In an alternative
embodiment,
conveyor 312 could bypass conveyor 410 and feed directly into recirculation
conveyor 232. An additional lower-loop failed-to-drop conveyor 410 may be
installed to permit diversion of failed-to-drop objects 110 along either side
of the
upper-loops assembly. In such case, the additional conveyor 410 located on the
side
of the upper-loop sort matrix 300 remote from the recirculation conveyor 232
could
feed into the upper-loop failed-to-drop conveyor 312 for transport to conveyor
232, or
a second recirculation conveyor 232 could be installed on the side of the
upper-loop
sort matrix 300 remote from the recirculation conveyor 232 depicted in Fig. 1.
In the illustrative embodiment, each of the surfaces on which objects
110 may slide, such as slides 230, 311, 514, chutes, cradle gates 706 and
cradle floors
704, will be coated with a non-skid surface. The orientation of such surfaces
will
generally be on the order of about 42 to 48 degrees from horizontal, although
shallower or steeper inclines/declines could be used. It should be noted that
the
elevated nature of the illustrative embodiment allows the invention to take
advantage
of gravity.
The operation of the system 100 is controlled by a digital control
system 120, which directs the sorting and transfer process. The control system
120
comprises a processing unit 125 and a number of sensor assemblies 130. The
processing unit 125 receives input data from the sensor assemblies 130
associated
with various conveyors, divert mechanisms, slides, chutes and sort
destinations as
previously described and as further described herein, and it outputs control
signals
instructing such devices to operate to sort and transfer objects 110 in a
selected
direction in order to arrive at their final sort destination 512, 518, 532.
Referring to Fig. 7, the control system 120 can be any conventional
control system. In the illustrative embodiment, the control system 120
comprises a
digital processor 125, such as a personal computer or a work station,
connected to a
plurality of input sensor assemblies 130 and to a number of output devices. As
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depicted in Figs. 1 and 7, and as will be described, the illustrative
embodiment utilizes
the following sensors. Positional sensors 132 are used to confirm the position
of
objects at several points as they are moved, diverted or dropped. Scanners
134, 136
determine and confirm destination information for each obj ect 110. One or
more
dimensioning sensors 138 determine the outer dimensions of each object 110. A
scale
or other weighing device140 determines the weight of each object 140. Based on
such input information, the control system 120 monitors and directs the
movement of
the conveyor belts and rollers, determines whether an object should be
diverted and, if
so, actuates the divert mechanisms, determines drop points and actuates the
pull rods,
directs workers in the loading of sorted sacks 520 and loose objects 110, and
prints
out reports and manifests.
Generally, each positional sensor 132 comprises a conventional photo-
cell transmitter and receiver, though any detection advice could be used. The
sensors
132 generally are placed such that the light path between the transmitter and
receiver
passes at a level slightly above the surface over which an object 110 passes
between
the transmitter and receiver at that location, and generally at a right angle
from the
direction of travel of such object 110. Such sensor assemblies 130 detect and
report
to the control system 120 the passage (or non-passage) of objects 110. The
control
unit 125 processes and applies such positional information as follows.
A sensor 132 placed in the holding area 206 warns of a backlog of
objects 110 in that area. Sensors 132 in the pre-scan accumulation area 210
facilitate
the accumulation and singulation of obj ects 110 for advancement into the scan
zone
212. After an object 110 has been scanned for identification in the scan zone
212, a
sensor 132 mounted at the discharge end of the scan zone 212 detects and
reports to
the control unit 125 the position of such object 110. Based on such positional
information, together with similar positional information recorded for other
objects
110 advancing single-file through the scan zone 212 of the same and other
induction
lines 202, the control system's 120 control unit 125 monitors the object 110's
position
along the remainder of the induction line assembly 200, without further
scanning
being necessary, by reference to the object 110's known sequential position
along its
respective induction line 202, 204. Based on such positional information,
together
with information about the object's 100 weight, size, destination and other
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characteristics determined when the object 110 passes through the scan zone
212, the
control unit 125 either (1) diverts the object 110 from the induction line
202, 204 in
the induction-line divert area 214; or (2) advances the obj ect 110 along its
induction
line 202, 204, 236 to the induction-line discharge 240 and records the initial
position
of such object 110 upon its advancement into an upper-loop cradle 304.
As noted, the sensors 132 also facilitate accumulation and singulation
of objects 110 along the induction line assemblies 200. In each portion of
each
induction line assembly 200, except the scan zone 212, sensors 132 are placed
at
appropriate intervals to detect gaps between objects 110 advancing along the
induction line assembly 200. Such gaps typically result from either: (1)
insufficiently
frequent inductions of obj ects 110 at the induction-line intake 208; or (2)
the
downstream diversion of earlier-inducted objects 110 in the induction-line
divert area
214. To prevent such gaps from diminishing throughput, such gaps are closed by
accumulating objects 110 in single file at each of two points along each
induction line
202, 204: (a) immediately before the intake end of the scan zone 212; and
(b) immediately before the induction-line discharge 240. This accumulation is
accomplished in a conventional manner in the illustrative embodiment by the
coordinated use of multiple zones of conventional powered-roller conveyors. To
facilitate the control system's 120 monitoring of each object's 110 position
along the
induction line assembly 200, accumulated objects 110 are singulated as they
advance
irmnediately past each of such two accumulation points, by use of a
conventional
singulation conveyor immediately downstream from each accumulation point. This
singulation of objects 110 enables the control system 120 to distinguish a
first object
110 from a second object 110 immediately behind such first object.
The control unit 125 from time to time determines that an obj ect 110
must be diverted, as, for example, when an object 100 is determined to be too
big or
too heavy for the sorting matrixes 300, 400, or when the control system 120 is
unable
to plot a route to the obj ect's 110 sort destination that will not result in
a "location
conflict" as described below. In such a case, sensors 132 mounted at each
divert point
in the induction-line divert area 214 will confirm the passage of such a
commanded-
divert object 110. So too, these sensors 132 will warn of the passage of any
object
110 that was diverted not on command but in error.
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As noted, objects 110 that are not diverted in the divert area 214 move
along to the discharge 240, passing a sensor 132 prior to the discharge 240.
Two
other sensors 132 are mounted beneath the chute descending from the induction-
line
discharge 240 at opposite sides of each upper loop 302, to detect the
advancement of
such object 110 into an upper-loop cradle 304 positioned beneath such chute.
In the event of a location conflict resulting from the failure of an earlier
obj ect 110 to drop where programmed from its lower loop cradle to its final
sort
destination, which will be explained below, or an equipment malfunction, an
object
110 may be directed by the control system not to drop, or may fail to drop,
from its
upper-loop cradle 304 to its pre-programmed lower-loop cradle 404. A sensor
132 is
mounted at the drop point 310 on each upper loop 302, to detect the presence
of an
object 110 in an upper-loop cradle 304 positioned at such drop point 310. The
control
unit 125 will command such object 110 to drop to the failed-to-drop conveyor
312 at
that drop point 310. One or more additional sensors 132 are mounted below each
drop point 310 to detect the passage of such an object 110 down the chute 311
leading
from such drop point 310 to the conveyor 312. An additional sensor assembly
130 is
mounted at a point farther along each upper loop 302, between the drop point
310 and
the upper-loop cradle 304 position immediately underneath the induction-line
discharge 240, to confirm that each upper-loop cradle 304 passing by such
sensor
assembly 130 is unoccupied.
Sensor assemblies 130 are similarly used to confirm drops from the
lower loops 402. First, a sensor 132 is mounted at each of drop point 408 and
loose-
object drop point 412 to detect passage of an object 110 to either the lower-
loop
failed-to-drop conveyor 410, or down the chute 514 to the loose-object
conveyor 516,
respectively. Second, a sensor 132 is mounted at the entrance to each
collection bin
501 to confirm the passage of an object 110 into such collection bin 501.
Other sensor assemblies 130 include a number of scanners 134, 136 ,
dimensioners 138, 140, and scales or other weighing devices 140. As will be
described, an object will be scanned at the beginning and, optionally, at the
end of its
flow through the system 100. The initial scan will be accomplished by a
conventional
scanner 134 located in the scan area 212. Also in the scan area 212, each
object 110
will be dimensioned by one or more dimensioning sensors 138 and weighed by a
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conventional scale or other weighing device 140. If an object's 110 sensed
dimensions or weight disqualifies it from automatic processing by the system
100, or
if its label information is determined to be unreadable, or if the object
fails to meet
other criteria programmed into the control system 120 (for example, the object
is
destined for an address to which no delivery will be made), then the control
unit 125
will divert the object 110 as appropriate in the divert area 214. The final
scan,
optionally performed to confirm the correct sorting of an object 110, will be
accomplished in the respective destination areas 501, 518 by another scanner
136. It
will be appreciated that the control system 120 could utilize further sensors
132
throughout the system 100. For example, such sensors 132 could be used at the
begimling and end of every conveyor, at the top and bottom of every slide or
chute, at
each destination, and at various intermediate positions along the way.
Referring now to Figs. 1-8, the operation of the system 100 will be
described in more detail. Objects 110 are inducted one by one, manually or
automatically, at the induction-line intake 208 of each induction line 202,
204. Each
inducted object 110 will have been pre-labeled with an object-identifying bar
code or
other optical code (not shown) that, upon scanning as described herein, can be
linked
to information previously transmitted to the control system 120 when the label
was
created. Such information will include at least the sort destination of the
object 110
within the sorting system 100, but may also include other information about
the object
110. An object 110 should be inducted in an orientation that will permit its
bar code
to be scanned automatically in the scan zone 212. For example, in one
embodiment,
the scanner 134 is a conventional overhead omnidirectional scanning device,
which
necessitates that each object 110 be inducted with its coded label facing
upward in
any horizontal direction.
In the pre-scan accumulation area 210 of each induction line 202, 204,
inducted objects 110 are (1) arranged in single file along the induction line
202, 204,
by using a conventional device such as skewed rollers or pop-up wheels to
align all
obj ects 110 to one side of the line 202, 204 so that the control system 120
can later
record and monitor each object's 110 sequential position once it has been
scanned in
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the scan zone 212 as described above; and (2) to accumulate objects 110 at the
discharge end of the pre-scan accumulation area 210, immediately prior to the
scan
zone 212.
After inducted objects 110 have been accumulated single-file at the
discharge end of the pre-scan accumulation area 210, they are singulated and
advanced, one-by-one, into the scan zone 212, which comprises one or more
segments
of powered conveyor belts. As noted above, obj ects 110 are scanned, weighed
and
dimensioned in the scan zone 212 and then are advanced into the induction-line
divert
area 214. The scanner 134 may be either a conventional laser scaimer or an
over-the-
belt video scanner having a charged coupled device (CCD) sensor. An example of
the
latter system is described in U.S. Pat. No. 5,308,960, which is incorporated
herein by
reference. The obj ect's weight may be obtained by any conventional scale or
other
weighing device. For example, the weighing device 140 may be a conventional in-
motion scale, mounted under the conveyor belt in the scan zone 212, that is
capable of
weighing an object 110 as it passes through the scan zone 212. Any
conventional
dimensioning sensor assembly may be used to dimension the object 110. In one
embodiment, dimensioning is accomplished by using a conventional CCD-based
dimensioning system that is capable of determining all three dimensions of an
object
110 as it moves through the scan zone 212. In another embodiment, dimensioning
is
accomplished by multiple arrays of photo-electric sensor assemblies 130
mounted
alongside, above and/or below the scan zone 212 at intervals sufficiently
close to
measure each dimension with the accuracy required for the application
involved.
Based on the information determined from the scanning, weighing and
dimensioning of an obj ect 110, the control system 120 determines whether such
object 110 will be diverted away from the induction line 202, 204 in the
induction-
line divert area 214 for recirculation, manual processing or other special
handling.
More specifically, if the object's 110 label code cannot be read, the object
110 will be
diverted by a pop-up roller or other conventional diverter at the no-read
divert 216 to
the no-read conveyor 218 for re-scanning, and re-labeling if necessary, at the
no-read
processing area 220, after which it will be either recirculated to the
induction line
assembly 200 or manually transported to one of the sort destinations 501, 512,
518,
532. If the object 110 has dimensions or a weight that makes it unsuitable for
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automated sorting on the sorting matrices 300, 400, based on pre-set standards
resident in the control unit 125, then the control unit 125 will direct that
the obj ect
110 be diverted at the manual-processing divert 222 to the manual processing
conveyor 224 for manual processing in the manual processing area 226, after
which it
will be manually transported to its sort destination 501, 512, 518, 532.
Optionally,
additional or different diverts can be installed in the induction-line divert
area 214 to
route such unsuitable objects 110 directly to one or more loose-object loading
areas
518, without any intermediate manual processing or transportation.
Each object 110 will have four opportunities to drop, drop points 800,
from the object's 110 upper-loop cradle 304 to a lower cradle 404 on the lower
loop
402 that sorts to the obj ect's 110 sort destination. Two such opportunities
occur on
the outgoing run, and two such opportunities occur on the return run, of the
upper
cradle 304 which the object 110 is occupying. If more than one lower loop 402
sorts
to the final sort destination of the object 110 in question, then such object
110 will
have an additional four drop opportunities per such loop 402. For example, in
the
embodiment depicted in Fig. 1, there are two lower loops 402. If an object 110
were
addressed to a certain zip code, and the collection bin 501 for that zip code
were fed
by both lower loops 402 (such configuration not being shown in Fig. 1), then
the
obj ect would have eight drop opportunities to reach a bin destined for that
zip code,
four from each of such two lower loops 402.
A "location conflict" will exist if, but only if, the control system 120 is
unable to plan an unobstructed route for an obj ect 110 through the sorting
matrices
300, 400 because all four (or more) of the object's 110 drop opportunities 800
predictably will be unavailable when the object 110 arrives there. This will
be the
case only if each of the lower cradles 404 predicted to be present beneath
each of such
drop points 800 will then be occupied by an earlier object 110. If a location
conflict
exists, then the control system 120 will direct that the object 110 be
diverted at the
recirculation divert 228, after which it will proceed down the recirculation
slide 230
leading to the upper failed-to-drop conveyor 312, and then to the
recirculation
conveyor 232. The object 110 will then be recirculated for re-induction onto
an
induction line assembly 202, 204, or instead may be diverted at the
recirculation
divert to the manual processing area 226 for manual processing and transport
to one
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of the sort destinations 501, 512, 518, 532 as directed by the control system
after such
object 110 has been re-scanned at such area 226.
The control system 120 uses the following information to determine
whether an object 110 can be routed to its sort destination without a location
conflict,
all of which information will be known to, or determinable by, the control
system 120
once the object 110 has been scanned, weighed and dimensioned in the scan zone
212.
For simplicity, it is assumed in the explanation below that the object 110 in
question
has four drop opportunities from its upper-loop cradle 304 to the lower loop
302 that
feeds its final sort destination:
A. The object's 110 sort destination, which will be either a
collection bin 501 or a drop point to a loose-object conveyor 412, and the
specific
lower loop 402 serving that sort destination, referred to hereinafter as the
"target
lower loop" 402.
B. The number of system steps 50 that will be required for the
object 110 to reach each of the four drop opportunities 800 to its target
lower loop
402. This number of system steps is calculated by the control system 120 based
on
the following data:
The number of other non-diverted obj ects 110 ahead of the
present object 110 on the same induction line 202, 204, which will determine
the
number of steps 50 required for the present object 110 to arrive at the
induction-line
discharge 240. In the case of a bifurcated induction line 204, the control
system 120
may adjust this number of steps 50 if necessary to prevent a location
conflict, as
further explained below, by altering the subsequent distribution of objects
110
between the two forks of such bifurcated induction line 204; and
2. The number of system steps 50 that will be required for the
present object 110 to reach each of its four drop opportunities 800 after the
object 110
has advanced into its upper-loop cradle 304.
C. The predictable presence of an earlier-routed object 110 in the
lower-loop cradle 404 beneath one or more of the object's 110 four drop
opportunities
800 when the present object 110 arrives there, referred to hereinafter as a
"blocking
object" 110. To predict the presence of a blocking object 110, the control
system 120
takes into account the route previously planned for each earlier obj ect 110,
including
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not only earlier objects 110 that are already in lower-loop cradles 404, but
also earlier
objects 110 that are still in upper-loop cradles 304 or on induction lines
202, 204.
If the control system 120 initially determines that only one of the
present object's 110 four drop opportunities 800 will be available, then the
control
system 120 generally will program the object 110 to drop at that drop
opportunity
800. If two, three or four drop opportunities 800 instead will be available to
the
object 110, then the control system 120 will choose among such drop
opporhmities
800 based on pre-established criteria resident in the control system 120.
These
criteria may include, for example, the directness of the route from each drop
opportunity 800 to the object's 110 sort destination, the relative probability
of
location conflicts with later objects 110 posed by each alternate route (which
probability may be based on, among other information, the control system's 120
analysis of historical data concerning the distribution of earlier objects 110
among
sort destinations), and the advantage of maintaining flexibility to reroute
the object
110 later, for reasons described below, wluch may result, for example, in the
object
110 being assigned to drop at the first of such two, three or four drop
opportunities
800 even if a later drop opportunity 800 presents a more direct route.
If the control system 120 initially determines that a location conflict
will exist for the present object 110, i.e., that a blocking object 110 will
be occupying
the lower-loop cradle 404 beneath each of the four drop opportunities 800,
then the
control system 120 nevertheless may be able to avoid such location conflict by
rerouting an earlier-routed obj ect 110. The earlier-routed obj ects 110
considered for
such rerouting will include each of the four blocking objects 110, but may, if
necessary, include additional earlier-routed objects 110, as necessary. For
example,
the control system 120 may evaluate each of the following rerouting
opportunities,
among others:
If any one of the four blocking objects 110 has not yet reached
its lower-loop cradle 404, and at least one alternate drop opportunity 800
remains
available to that blocking object 110, the control system 120 can reprogram
that
blocking object 110 to drop to its target lower loop 400 at a different drop
opportunity
800, thus creating a drop opportunity 800 for the present object 110.
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2. If only its originally programmed drop opportunity 800 remains
available to each of the four blocking objects 110, but one or more of those
blocking
objects 110 has not yet advanced beyond all of its blocked drop opportunities
800,
then the control system 120 may be able to "unblock" one or more of the
blocked
drop opportunities 800 for such blocking obj ect 110 by rerouting one of the
obj ects
110 that would otherwise have blocked that blocking object 110.
3. If the sorting system 100 includes one or more bifurcated
induction lines 204, additional rerouting opportuuties are available to the
control
system 120, even if the present object 110 itself is on a non-bifurcated
induction line
202. For example, if the present object 110 is on a bifurcated induction line
204, the
control system 120 can initially route the object 110 to either of the two
upper loops
302 fed by such bifurcated line 204, effectively making eight, rather than
four, drop
opportunities 800 available for the present object 110. If the present object
110
instead is on a non-bifurcated induction line 202, but one or more blocking
objects
110 are on a bifurcated induction line 204, then the control system 120 may be
able to
reroute such a blocking object 110 to a drop opportunity 800 on the other fork
236 of
such bifurcated induction line 204 if the blocking object 110 has not yet
reached the
fork 236 on its induction line 204.
4. In addition to these rerouting opportunities, the control system
120 may be programmed to override an earlier obj ect 110 routing even if no
alternate
route can be plotted for that earlier object 110. Such a rerouting may be
desirable, for
example, if the present object 110 needs to be sorted promptly but the
blocking object
110 need not be sorted as promptly. In that event, the earlier blocking object
110 will
be reprogrammed to remain in its upper-loop cradle 304 and to drop to the
upper
failed-to-drop conveyor 312 at the end of its circuit around its upper loop
300.
Thus, the crossing-loops configuration of the sorting system 100
reduces the possibility of location conflicts by creating at least four drop
opportunities
800 from each upper loop 302. The statistical possibility of an incurable
location
conflict depends on several factors in addition to those previously described,
principally including the number of lower loops 402, the number of upper loops
302,
and the extent to which obj ects 110 are disproportionately routed among the
lower
loops 402. Although tlus statistical possibility may be extremely low in some
sorting
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system 100 configurations, and may be further reduced by rerouting methods
including but not limited to those described above, the theoretical
possibility of an
incurable location conflict cannot be entirely eliminated. For this reason,
the sorting
system 100 must provide for some method of diverting objects 110 for which an
incurable location conflict exists.
As described above, one such diverting method, which is shown in the
illustrative embodiment depicted in Fig. 1, is to divert an object 110 from
its
induction line 202, 204 before it reaches its upper loop 302, and to reduce or
prevent
any diminution in throughput by closing the resulting gap in object 110 flow
by the
accumulation methods described above. An alternate method, not further
explained
herein, would be simply to advance each "location conflict" object 110 into an
upper-
loop cradle 304 without frst determining whether a location conflict will
exist when
the object 110 arrives at each of its four drop opportunities 800, and then to
use sensor
assemblies 130 to detect the presence or absence of an earlier object 110
beneath each
of such four drop opportunities 800 when the present object 110 arnves there.
Under
such alternate method, any object 110 that is blocked at all four drop
opportunities
800 would be routed to the drop point 310 to conveyor 312 on its upper loop
302, and
then be recirculated or manually processed as described above.
If the control system 120 is able to plot an unobstructed route for an
object 110 as just described, the object 110 will continue through the post-
divert
accumulation area 238, which begins at the discharge end of the scan zone 212
(and
thus includes the divert area 214) and ends at the induction-line discharge
240. The
post-divert accumulation area 238 is devoted to the accumulation of non-
diverted
objects 110 at the induction-line discharge 240, while maintaining the
objects' 110
single-file sequence. Gaps in object 110 flow will have been created by the
diversion
of objects 110 in the divert area 214. On a bifurcated induction line 204
which feeds
two upper loops 302, the control system 120 causes objects 110 to be
distributed to
each fork of the bifurcated induction line 204. This may be accomplished by
the use
of conventional divert devices such as subsurface pop-up wheels mounted
between
rollers on the powered-roller conveyor. As mentioned above, the control system
120
may adjust the distribution of objects 110 between the forks on a bifurcated
induction
line 204 if necessary to resolve a location conflict. For example, if objects
are
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generally alternated between the two forks 236, the control system 120 may
direct
instead that two successive objects 110 be directed to the same fork 236 in
order to
avoid a location conflict that would otherwise exist for the second object
110. As
noted, the sorting system 100 can accommodate trifurcation or even further
division
of a single induction line 200, provided only that (1) the control system 120
is able to
monitor the sequential position of all objects 110 as they are distributed
among the
multiple forks 236; and (2) objects 110 can be advanced quiclcly enough to
ensure that
an object 110 reaches the induction-line discharge 240 at each fork 236 by the
beginning of each system step 50.
The objects 110 proceed from the post-divert area 23~ to the induction-
line discharge 240. The objects 110 are accumulated at the induction-line
discharge
240 and are then singulated and advanced, one at a time, into one of the
stationary
upper-loop cradles 304. Only one object 110 occupies any one upper-loop cradle
304
at a time. One obj ect 110 is advanced in this manner from each induction line
202,
204 during the stationary substep 56 of each system step 50. The timing of
system
steps, and of the stationary substep 56 and the move substep 55, is described
further
below. Thus, the cradles 304 are not moving when objects 110 are deposited
therein.
The object's 110 target cradle 304 will have been moved into position during
the
preceding move substep 55. In the preferred embodiment shown in the drawings
(see
Figs. 2-4), the object 110 is first advanced past the induction-line discharge
240, then
down a gravity slide, and finally onto the slanted cradle floor 704, where its
motion is
stopped by the cradle gate 706. In the preferred embodiment, the gate 705
protrudes
outwardly from the slanted floor of the upper-loop cradle 304 at approximately
a right
angle. It is movably attached to the upper-loop cradle 304 by a hinge 709 (not
shown)
on the bottom edge of the gate 706. This hinged attachment permits the gate
706 later
to be pulled down during a stationary substep 56, as described below, so that
the
cradle floor 704 and the lowered gate 706 form a continuous slanted surface
leading
from the top to the bottom of the cradle 304, thus enabling an object 110 to
slide
down into a lower-loop cradle 404 as described below. Unless the cradle gate
706 is
pulled down, its "default" up position is maintained either by some bias such
as
spring-loading or by a latch mechanism (not shown), with sufficient resistance
to stop
the motion of an object 110 sliding into the cradle 304. Each cradle's 304,
404 side
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pieces 720, 721 prevent an object 110 from escaping at either side of the
cradle 304,
404. If the cradle 304 includes a top piece 702, such top piece 702 will
prevent the
object 110 from passing over the cradle gate 706 as the object 110 drops into
its
upper-loop cradle 304, and such top piece 702 will later ensure that the
object 110
does not contact the cradle 304 ahead of it when the object 110 drops into a
lower-
loop cradle 404.
The cradles 304, 404 are carried on their respective sorting loops 302,
402. As previously described above, the illustrative sorting matrices 300, 400
comprise three horizontal, longitudinally extending, closed-oval sorting loops
302
elevated above two horizontal, transversely extending, closed-oval sorting
loops 402.
On each matrix 300, 400 level, cradles 304, 404 are attached to the conveyor
chain
716 by conventional attachments 718. It will be appreciated that a power-
driven
cable, shaft or other mechanism instead of the power-driven chain 716 may be
used to
drive the cradles 304, 404 around the loops 302, 402. On both loop levels 300,
400,
the cradles 304, 404 are attached to the conveyor chain 716 at intervals
around their
respective loops 302, 402. The interval between each cradle 304 on an upper
loop
will be the same distance (or an exact multiple of such distance), and the
interval
between each cradle 404 on a lower loop will likewise be the same distance (or
an
exact multiple of such distance). Generally the interval between cradles 304
on each
upper loop 302 will be the same, and the interval between cradles 404 on each
lower
loop 402 will be the same. The uniform interval between upper-loop cradles 304
need
not be the same, however, as the uniform interval between lower-loop cradles
404.
The system 100 will operate equally well regardless of the interval between
cradles
304, 404, as long as (1) the interval between any two cradles 304, 404 on a
given loop
302, 402, is the same distance (or an exact multiple of such distance), and
(2) in the
case of upper loops 302, the interval between the upper cradles 304 is not so
close as
to obstruct an object's drop. By way of example only, the interval between all
cradles
304 on the upper loops 302 might be about 48 inches (I.2 m), and the interval
between all cradles 404 on the lower loops 402 might be about 30 inches (76
cm).
Similarly, the cradles 304, 404 may be of almost any size, depending on the
maximum size of the objects 110 to be sorted.
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In the illustrative embodiment depicted in the drawings, each cradle's
304, 404 weight is supported by roller wheels 728 attached to the cradles 304,
404,
though other methods of supporting and guiding the cradles, such as a rail
system, can
instead be used. As has been explained, the front, or open side, of each upper-
loop
cradle 304 faces in the direction of travel of the upper loop 302, and an
object 110
dropping from its cradle 304 to a lower-loop cradle 404 drops through an
aperture 307
in the upper-loop floor 306 located in front of the upper-loop cradle 304. In
contrast,
the open side, or front, of each lower-loop cradle 404 faces toward the inside
of the
ellipse formed by the lower loop 402, which is perpendicular to the direction
of travel
of the lower loops 402, and each object 110 dropping from its lower-loop
cradle 404
to a collection bin 501 or a drop point 412 passes in such inward direction.
Each upper loop 302 and each lower loop 402 circulates in timed
system steps 50. Each step 50 comprises a move substep 55 and a stationary
substep
56. The time-length of each system step 50 is the same on both loops 302, 402,
and
will have been pre-set by the control system 120 based principally on the
length of
time determined to be necessary for each of the two substeps 55, 56 to be
reliably
completed.
During the move substep 55, the cradles 304, 404 advance around their
respective loops 302, 402 by a distance equal to the spacing between the
cradles 304,
404 on such loop 302, 402. During the stationary substep 56, the cradles 304,
404
remain stationary. If, however, a cradle 304, 404 contains an object 110 that
has been
programmed to drop at that stationary location, then its cradle gate 706 will
be pulled
down (as described in detail below) at the beginning of the stationary substep
56 and
will be maintained in such down position long enough for the object 110 to
slide out
of its cradle 304, 404. The gate 706 will then be released to return to its
default up
position.
As noted, the duration of a system step 50 is the same on both loop
matrices 300, 400. This duration need not, however, be allocated equally
between the
two substeps 55, 56, and the time allocation between substeps 55, 56 may be
different
on each of the two loop matrices 300, 400. Nor is it necessary that a step 50
begin at
exactly the same moment on each loop matrix 300, 400. Nevertheless, it is
necessary
that steps 50 on both matrices 300, 400 be synchronized sufficiently that a
lower-loop
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cradle 404 is stationary beneath a drop opportunity 800 whenever an object 110
may
be dropping from its upper-loop cradle 304 into such lower-loop cradle 404. In
a
typical embodiment of the system 100, this will require that substeps 55, 56
on each
loop 302, 402 be of approximately the same duration, and that system steps 50
begin
at approximately the same time on each loop 302, 402, or slightly later on the
lower
loops 402 than on the upper loops 302. While any one substep 55, 56 may be
completed early, the succeeding substep 55, 56 may never begin early.
By way of example only, the duration of the system step 50 in the
preferred embodiment may be on the order of five seconds, with approximately
one-
half of such duration being allocated to each substep 55, 56. As noted above,
however, a system step 50 may be of any duration, and that duration may be
allocated
in any maimer between the move substep 55 and the stationary substep 56 (and
may
be allocated differently between such two substeps on each of the two sorting
matrices
300, 400), provided only that the system step 50 duration is the same on both
sorting
matrices 300, 400 and that sufficient time is allocated to each system step
50, and to
each substep 55, 56, to accomplish the actions required to be taken during
each such
step 50 and substep 55, 56.
Thus it can be seen that the system 100 operates in steps 50 of defined
duration, and, in the case of the move substep 55, defined duration and
distance of
movement, which enables the control system 120 to predict the location of each
object
110 at each future step 50 as the object 110 moves through the system 100.
Although
the system 100 generally will operate with all upper loops 302 and lower loops
402
advancing during each system step 50, the system 100 can operate normally if
one or
more upper loops 302 and/or one or more lower loops 402 either remain
stationary
during a move substep 55 or are entirely disengaged from the operation of the
remainder of the sorting system 100, provided in each case that the control
system
120 records such non-movement of such loop 302, 402 and reroutes objects 110
as
may thereby become necessary.
As noted, objects 110 will drop from upper cradles 304 to lower
cradles 404 during a stationary substep 56. In the preferred embodiment
illustrated in
the drawings, such transfer of an object 110 as prograrmned by the control
system 120
is accomplished by lowering the cradle gate 706 of the cradle 304 to create a
gravity
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slide leading to the target lower-loop cradle 404. Because this drop occurs
during a
stationary substep 56, the cradles 304, 404 and their associated loops 302,
402 will
remain stationary while each such object 110 is dropping out of the one or
more of
upper-loop cradles 304 and into the one or more target lower-loop cradles 404.
As illustrated in Figs. 2, 3, and 5, the slide thus created comprises
(1) the cradle floor 704; (2) the cradle gate 706; and (3) the respective
upper-loop
drop slide 308, which is incorporated into the system frame 604 beneath the
upper-
loop floor 306 and which extends downwardly toward the target lower-loop
cradle
404. In sliding down the slide 308, the object will follow one of two slide
paths,
depending on the orientation of the cradles 304, 404 at the time of the
particular drop.
A first slide path 812 is defined by an object 110 sliding down the slide 308
and
continuing its slide down the cradle floor 704 of the target lower-loop cradle
404.
When following this slide path 812, the motion of the sliding obj ect 110 is
stopped by
the cradle-gate 706 of the target lower-loop cradle 404. A second slide path
814 is
defined by an object 110 sliding down the slide 308 and continuing its slide
down the
cradle gate 706 of the target lower-loop cradle 404, in which case the motion
of the
sliding object 110 is stopped by the cradle floor 704 of the target lower-loop
cradle
404. Although the illustrative system 100 configuration thus permits two slide
paths
812, 814, a system 100 may instead be configured to include only one or the
other of
such two slide paths 812, 814.
In the illustrative embodiment shown in Fig. 5, an object 110 drops
from its upper-loop cradle 304 to its target lower-loop cradle 404 (not shown
in Fig.
5) immediately after the cradle gate 706 of the cradle 304 is pulled down
during a
stationary substep 56. The cradle gate 706 is pulled down by the cradle-gate
cable 710
attached to the bottom of the gate 706. The cable 710 passes through an
aperture (not
shown) in the floor 704 and attaches at its other end to the rigid
manipulation piece
712 that protrudes from the side 720 of the upper-loop cradle 304. During each
stationary substep 56, the maupulation piece 712 of each upper-loop cradle 304
positioned above a drop opportunity 800 will be positioned directly opposite a
manipulation-piece puller (not shown) attached to the pull rod 303 mechanism,
which
mechanism 303 is supported by the frame 604 and driven by a motor and
associated
gearing (not shown).In the illustrative embodiment shown in Fig. 5, the puller
is a
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pneumatically-powered device by a solenoid valve (not shown) that is
controlled, in
turn, by a signal received from the control system 120. Any other type of
connection
between the cradle gate 706 and the manipulation piece (in lieu of the cable
710
illustrated in Fig. 5), manipulation piece, actuator and/or pulley device may
instead be
used, provided only that, when used in combination, they cause the cradle gate
706 to
be pulled down in response to one or more signals received from the control
system
120, thus enabling an object 110 in such cradle 304, 404 to slide down and out
of such
cradle 304, 404 as programmed by the control system 120.
In response to a signal from the control system 120, the solenoid (not
shown), or other actuating mechanism will move the pulley so that it engages
the
manipulation piece 712 as the motor and associated gearing (not shown) are
moving
the pull rod 303 forwardly far enough that the cradle-gate cable 710 will pull
down
the cradle gate 706, thus enabling the object 110 to slide down and out of the
cradle
304, through an upper-loop floor aperture 307, onto the slide 308, and finally
into its
target lower-loop cradle 404. In Fig. 5, the manipulation piece 712, when
pulled, will
move within its cable guide 714 in the direction that the cradle 302 has been
moving.
It is possible, however, for the piece 712 to move in the opposite direction,
or in any
other direction, in an alternate embodiment, provided only that the
manipulation piece
is moved a sufficient distance to cause the cable 710 to pull down the gate
706. After
the object 110 has dropped to its target cradle 404, the pulley will retract,
thereby
releasing the manipulation piece 712 and allowing the spring-loaded cradle
gate 706
to return to its default "up" position, thus returning the manipulation piece
712 to its
original position as well. In Fig. 5, retraction of the manipulation piece 712
will also
occur as the result of the cradle 304 advancing during the next move substep,
as the
manipulation piece 712 will move away from the pulley when this advancement
occurs. All drops from a cradle 304, 404 will occur substantially as just
described,
with some differences in drops from lower-loop cradles 403 as will be
described.
As described above, an object 110 typically will have been diverted in
the induction-line divert area 214 if an incurable location conflict prevented
the
control system 120 from plotting an unobstructed route to the object's 100
sort
destination 501, 518. For this reason, an object 110 in an upper-loop cradle
304
ordinarily will have dropped to a lower-loop cradle 404 before it reaches the
drop
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point 310 to the upper-failed-to-drop conveyor 312. That drop point 310 is
located
beyond all viable drop opportunities 800 on an upper loop 302. An object 110
that
has failed, for any reason, to drop out of its upper-loop cradle 304 before
reaching that
drop point.310 will be commanded by the control system 120 to drop there 310,
during a stationary substep 56. As described above, possible reasons for such
a
required drop to the failed-to-drop conveyor 312 include instances where (1)
the
object 110 has failed to drop from its upper-loop cradle 304 for some
unprogrammed
reason, such as a mechanical failure; (2) the control system 120 has
determined that
the obj ect's 110 planned route will be blocked by the failure of an earlier
obj ect 110
to drop as programmed from its lower-loop cradle 404 to its sort destination;
or
(3) the control system 120 has rerouted such object 110 to drop at such drop
point 310
to permit a later object I IO to be routed through the sorting system 100
because the
later object 110 is required to be sorted more promptly. There may be
additional
reasons for such a drop.
As illustrated in Fig. l, each induction line discharge 240 is located
near the end of the upper loops 300 matrix nearest to the induction line
assembly 200
illustrated in Fig.l, and the upper failed-to-drop conveyor 312 is located
outside of the
periphery of the lower loops matrix 400 nearest to the induction line assembly
200. A
system 100 may instead be configured such that part or all of the induction
line
assembly 200 is positioned above the sorting matrices 300, 400, with each
induction
line discharge 240 thus being positioned farther forward over the sorting
matrices 300,
400 rather than at or near their periphery as shown in Fig. 1. In such an
alternative
configuration, because the upper failed-to-drop conveyor 312 will ordinarily
occupy
substantially the same position relative to the induction line discharge 240,
the upper
failed-to-drop conveyor 312 would also be positioned farther forward in the
area of
the sorting matrices 300, 400, rather than at or near their periphery. For
example, the
upper failed-to-drop conveyor 312 in such an alternative configuration might
be
located above one of the walkways 602, described below, sandwiched between,
and
running parallel to, two adjacent double-rows of collection bins 501.
Similarly,
although in the illustrative example in Fig. 1 the lower loop failed-to-drop
conveyor
4I0, described below, is located outside the periphery of the upper loops
sorting
matrix 300, a system 100 may instead be configured with the lower loop failed-
to-
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drop conveyor 410 located within the periphery of the upper loops sorting
matrix 300.
For example, the lower loop failed-to-drop conveyor 410 could be located above
the
walkway 600, described below, which separates the two sides of the collection
bin
501 assembly.
The drop of an object 110 from its upper-loop cradle 304 at a drop
point 310 will occur as follows. Sensor assemblies 130 are positioned at the
drop
point 310, along the upper-loop fail-to-drop slide 31 l, and at one or more
points along
the upper loop 302 after the drop point 310 and prior to the induction-line
discharge
240 of the associated induction line 202, 204. These sensor assemblies 130
detect the
presence, and confirm the drop, of each object 110 that reaches such drop
point 310,
thus enabling the control system 120 to monitor the location of such object
110 and
ensuring that each upper-loop cradle 304 arriving beneath the induction-line
discharge
240 of the associated induction line 202, 204 is unoccupied so that a new
object 110
can be advanced into such upper-loop cradle 304. Each drop of an object 110 at
a
drop point 310 is accomplished in the same manner as described above for a
drop
occurring at a drop point 800. Sensors 132 will confirm the drop of such
failed-to-
drop object 110 onto the drop slide 311 leading to the upper failed-to-drop
conveyor
312. The drop will be further verified by upper-loop sensors 132 located along
the
upper loop 302 downstream of the drop point 310 but prior to the discharge 240
feeding such loop 302. Once the object 110 has reached the failed-to-drop
conveyor
312, it will be advanced to the recirculation conveyor 232 for recirculation
to the
induction line assembly 200 or manual processing.
If the control system 120 determines that an upper-loop cradle 304 is
occupied when it arrives beneath the induction-line discharge 240, then the
control
system 120 will shut down that particular induction line 202, 204 for one
system step
50 to prevent the next new object 110 in line from dropping into the still-
occupied
upper-loop cradle 304. At the next system step 50 after the induction line
202, 204
shut-down, the still-occupied upper-loop cradle 304 will have advanced one
position
beyond the induction-line discharge 240 and an unoccupied cradle 304 should be
positioned below the discharge 240 such that the induction line assembly 202
may be
restarted. The failed-to-drop object 110 may then be reprogrammed to drop at
one of
the potential drop opportunities 800 on its second circuit around the upper
loop 302.
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If the object 110 fails to drop as programmed on its second circuit around the
upper
loop 302 (for example, because its failure to drop has resulted from a
mechanical
malfunction or because the object has become jammed or is otherwise unable to
slide
freely out of its cradle 304), then it may be manually removed. It may be
necessary
that the upper loop 300 be stopped to permit such manual removal. In each
event
requiring a shut-down of the upper loop 300, the control system 120 will
adjust the
routing of objects 110 on the affected upper loop 302 as necessary.
Similarly, each lower loop 402 has one or more drop points 408 to the
lower failed-to-drop conveyor 410 from which an object 110 may be programmed
to
drop if it has passed its predetermined sort destination without dropping as
programmed from its lower-loop cradle 404. A sensor assembly 130 positioned at
the
entrance to each sort destination 501, 518, 532 will detect and report to the
control
system 120 each drop of an object 110 to that sort destination. If the control
system
120 fails to receive a report of a programmed drop to a sort destination, then
the
control system 120 will (1) reroute the failed-to-drop object 110 to the
nearest drop
point 408 to the lower failed-to-drop conveyor 410, which in turn will convey
the
object 110 to the recirculation conveyor 232; and (2) reroute any later object
110 for
which an unanticipated location conflict has been created by the failed-to-
drop object
110. It should be noted that an object's 110 failure to drop where programmed
from
its lower-loop cradle 404 can create a location conflict only for a later
object 110 that
has not yet reached its own lower-loop cradle 404; i.e., an object 110 that is
still in its
upper-loop cradle 304 or on its induction line 202, 204. If an unobstructed
alternate
route cannot be plotted for such a later object 110, then the control system
120 will
instead reprogram that later object 110 to remain in its upper-loop cradle 304
until it
has reached the drop point 310 to the upper failed-to-drop conveyor 312, where
the
object 110 will drop for recirculation or manual processing as described
above.
If the sorting system 100 is not malfunctioning, it will ordinarily never
be necessary to reroute an object 110 to the lower failed-to-drop conveyor
410. The
control system 120 may, however, employ sensor assemblies mounted at the
entrance
to each collection bin 501 or drop point 412 to a loose-object slide 514 to
detect a
"full" condition (or other obstruction) at such entrance, in which event the
control
system 120 may reroute an object 110 destined for such sort destination to the
lower
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failed-to-drop conveyor 410. For either or both of such reasons, the sorting
system
100 normally will include at least one such drop point 408 to the lower failed-
to-drop
conveyor 410, and may include multiple drop points 408 - for example, one at
each
side of the lower loops 402 - to remove objects 110 which have not dropped
where
programmed from the lower loops 402.
As described above, an object 110 may be routed to the recirculation
conveyor 232 from one of three sources: the induction-line divert area 214,
any upper-
loop cradle 304, or any lower-loop cradle 404. Objects 110 that reach the
recirculation conveyor 232 ordinarily are recirculated, without further manual
handling, back to the pre-induction holding area 206 for re-induction.
Optionally, as
previously stated, the control unit 125 may position the recirculation divert
234 to
divert such objects 110 from the recirculation conveyor 232 into the manual
processing area 226 for re-scanning and manual transportation to their
respective sort
destinations. This may be done, for example, near the end of a sort, when the
final
objects 110 passing along the recirculation conveyor 232 are likely to reach
their sort
destinations more quickly if manually processed.
More typically, though, objects 110 will arrive at their sort destinations
as follows. An object 110 that drops as programmed into its target lower-loop
cradle
404 will proceed in system steps 50 around its lower loop 402 until it reaches
its
programmed sort destination, which will be either one of the collection bins
501 or
one of the drop points 412 to a loose-object slide 514, as depicted in Fig. 4,
for
delivery to the loose-object holding area 518 as will be described.
The object 110 will drop into its sort destination 501, 412 during a
stationary substep 56. If the object 110 fails to drop where programmed, it
will be
rerouted by the control system 120, as described above, to drop instead at a
drop point
408 to the lower failed-to-drop conveyor 410, where it will be routed to the
recirculation conveyor 232 for re-induction or diversion to the manual
processing
area.
In the illustrative embodiments depicted in the drawings, a drop from a
lower-loop cradle 404 to its sort destination is accomplished in the same
manner as
described above for the drops of an object 110 from an upper-loop cradle 304
to a
lower-loop cradle 404, except that, because of the inward-facing orientation
of cradles
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404 on the lower loops 302 (1) an object 110 drops inwardly in a direction
perpendicular to the direction of travel of the Iower loop 402; and (2) the
cradle-gate
manipulation piece 712 protrudes from the bottom or from the back of each
lower-
loop cradle 404, rather than from the side as on an upper-loop cradle 304, and
the
associated pulling mechanisms are accordingly positioned beneath or behind the
lower-loop cradles 404.
An object 110 that drops from its lower-loop cradle 404 to a loose-
object conveyors) 516 will be conveyed to a loose-object holding area 518. As
noted, the invention will accommodate additional loose object conveyors 516
and
associated loose-object holding areas 518. For example, a mirror-image loose-
object
area assembly could be added to the opposite side of the illustrative system
100.
Also, since commercial embodiments likely will have a greater number of upper
and
lower loops 302, 402, there will be a corresponding increase in the possible
number of
loose-object area assemblies.
An object 110 that drops instead to a collection bin 501 generally will
be manually removed from the collection bin 501, then grouped, as for example
in a
sack 520, with one or more other objects 110 that have been sorted to the same
collection bin 501, and then transported in such grouping to a sack loading
area 512,
532, either manually or by placing such a sack 520 onto one of the sack
conveyors
506, 526 leading to such saclc loading area 512, 532. The correct sortation of
an
object 110 to its sort destination may be confirmed by a re-scanning of the
object's
label-code 110 once it has reached a collection bin 501 or a loose-object
loading axea
518. Such re-scanning will be accomplished by a scanner 136, which may be a
hand-
held manual scanner or a mounted automatic scanner.
Such a mounted or hand-held scanner 136 may also be used to scan
sacks at any of a number of locations. In the illustrative embodiments in the
drawings, Figs. 1-4, each sack conveyor 506, 526 is functionally bifurcated by
a sack-
conveyor bifurcator 508 suspended from the system frame 604 above the sack
conveyor 506, 526. This bifurcation enables a single saclc conveyor 506, 526
to serve
two adjacent rows of collection bins 501 destined for two different respective
sack
loading areas 512, 532. A sack-conveyor diverter 510, 530 positioned near the
end of
each bifurcated portion of such a respective sack conveyor 506, 526 diverts
sacks 520
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to the correct sack loading area 512, 532. Each sack 520 will have been
labeled to
identify the collection bin 501 from which it has been filled, to distinguish
it from
other sacks 520, if any, that may be routed to the same saclc loading area
512, 532
from other collection bins 500. The correct routing of such sacks 520 may be
confirmed by scanners 136 if the sack 520 labels include optically-readable
code, or
instead by visual inspection.
As previously described in detail, the control system 120 monitors the
status of the objects 110 from induction to discharge using logic circuitry.
The
general configuration of the control system 120 and its attendant logic
functions can
be summarized with reference to Figs. 6 and 7. At step 1, each object 110 is
inducted
at the induction line assembly 200 and scanned, weighed and dimensioned in the
scan
zone 212 of said assembly 200. If the scanner 134 can read the object's 110
label at
step 2, and if the weight or the dimensions of the object 110 are not out of
automatic
processing parameters at step 3, then the control unit 125 will project at
step 4
whether all of the drop opportunities will be predictably blocked. If a drop
opportunity can be found at step four, then the control unit will advance the
object to
the next cradle 303 on the upper loop 304 at step 5. If at step 6 the control
unit 125
does not predict any unscheduled failures of any earlier object 110 to drop,
and if at
step 7 the control unit has not elevated over the present object's 110
priority the
priority of any later object 110 requiring an unscheduled reroute of the
present object
110, then the present object 110 will be commanded to drop as scheduled to the
target
lower-loop cradle 404 at step 8. If the object successfully dropped to the
lower loop,
and if at step 9 it did not fail to drop from the lower loop 404 on command,
then it
will be routed at step 10 to either the proper collection bin 501, or to the
loose-object
loading area 518, as appropriate. If the object 110 was routed to the
collection bin
501, then at step 11, then the control unit 125 will output a control signal
commanding actuation of the solenoid to pull down the gate 706 over the
appropriate
drop point to the appropriate collection bin 501. Then, the dropped object 110
will be
scanned with scanner 136 and the control unit 125 will provide information to
the
scanner pertinent to which sack 520 it should be placed in, if any. The object
110 will
be placed in the appropriate sack at step 12 and placed on the conveyor 506,
527 for
delivery to the sack loading area 512, 532 as ordered in step 13. If the
object 110 was
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directed to the loose-object loading area 518, then it will proceed down the
loose-
object slide 514 to the loose-object conveyor 516 at step 14 for transport to
the
loading area 518 and final scanning with scanner 136 at step 17.
Returning to step 2, if the label is unreadable, then the object 110 will
be diverted at the divert assembly 214 to the no-read processing area 220. If
at step
the control unit 125 determines that it is at the end of the sort, then a
control signal
will direct the object to the manual processing area 226 for manual re-
scanning with a
scanner 136 at step 16 and manual transport to either its assigned collection
bin 501 at
step 11 fox sacking at step 12 and delivery to the sack loading axea 512, 532
at step
10 13, or to the loose-object loading area 518 at step 17 as the control unit
signal
transmitted to the scanner 136 dictates. If the at step 3, the object 110 is
not
dimensionally suitable for automatic processing, then a control signal will
divert the
object at the divert area 214 to the manual processing conveyor 224 for
delivery to the
manual processing area 226 at step 16. Then it will proceed to either the
either the
15 loose-object loading area 518 via steps 16 and 17, or to the sack loading
area 512, 532
via steps 16, 11, 12, and 13 as previously described. If all drop
opportunities are
blocked at step 4, then the control unit 12S will determine at step 18 if a
downstream
object can be rerouted, and if so, the object 110 will proceed to step 5 and
then as
described above; but if not, then the object 110 will be directed to the
recirculation
conveyor 232 via the recirculation slide 230 or the failed-to-drop conveyor
312 and
then to its final destination via the step 15 through 17 or 13 as described
above. If at
step 6, the drop point 800 is predictably blocked, and if at step 19 a
rerouting is
feasible, then the object 110 will be rerouted by the control unit 125 at step
22, and
the object 110 will proceed to its destination via step 9 and succeeding steps
as
previously described. If a downstream reroute request is received at step 7,
then the
control unit 125 will determined the feasability of such request at step 21
and if
possible, the object 110 will be reassigned at step 22 and then routed to its
final
destination at step 9 and succeeding steps as previously described. If not
possible,
then the object 110 will proceed at step 8 to its originally assigned cradle
404 and then
via step 9 and succeeding steps as previously described to its destination.
Finally, if
at step 9, the object 110 failed to drop from its lower loop 404, then the
control unit
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will route it to the recirculation conveyor at step 20 and then onward to its
final
destination via succeeding steps as previously described.
As depicted in Fig. 7 and described above, the control system 120 as a
number of inputs and outputs. The sensor assemblies provide inputs to the
control
unit 125. More specifically, information is gathered on each object 110 that
enters the
system 110. Initially, the scanner 134 obtains the destination information
from the
object's 110 label. Such information may contain a discrete destination code,
for
example. This information is sent to the control unit 125. In addition, the
dimensioner 138 and scale 140 gather physical data on each object 125,
including
outer dimensions annd weight. The dimensioner 138 and scale 140 deliver this
data to
the control unit 125. The sensors 132 are suitably positioned around the
sorting
system 100 wherever it is desirable to track passage of objects thereby to
confirm
proper operation. Such sensors report such passage or non-passage to the
control unit
125. The control unit may receive other input information, including but not
limited
to the status of the conveyors, motors, and cradle-assemblies.
The control unit 125 processes the various inputs amd controls the
operation of the system 100 based on such information and the logic routines
described herein. Outputs from the control unit include outputs to the
induction
assembly 200, to the upper-loop sorting matrix 300, to the lower-loop sorting
matrix
400, to the destination assembly 500, and to the scanner 136. More
specifically, the
control unit 125 has any number of outputs M, where M is any positive integer,
wherein M generally will be the number of mechanisms that the control unit 125
sends output signals to on the induction assembly 200. Examples of such
mechansms include but are not limited to the divert mechanisms 216, 222, 228,
234,
the singulation mechanisms (not shown), and the discharge mechanisms.
Similarly,
the control unit 125 has any number of outputs N, where N is any positive
integer,
wherein N generally will be the number of mechanisms that the control unit 125
controls on the upper-loop sorting matrix 300. Examples of such mechanisms
include
but are not limited to the pull rod 303 solenoids which actuate the
manipulation piece
712 puller, the motors and the divert mechanisms. While the operation of the
pull
rods themselves, and the conveyors is generally a function of the conventional
gearing
connecting the motor to such devices, it is within the teaching of the
invention for the
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control unit to control the movements directly. In any event, the controller
can stop
the motor as in the case of a second fail-to-drop. Turning to the outputs to
the lower-
loop sorting matrix, the control unit 125 has any number of outputs L, where L
is any
positive integex, wherein L generally will be the number of mechanisms that
the
control unit 125 controls on the lower-loop sorting matrix 400. Examples of
such
mechanisms include but are not limited to the pull rod 403 solenoids which
actuate
the manipulation piece 712 pulley, the motors and the divert mechanisms. So
too, the
control unit 125 has any number of outputs K, where K is any positive integer,
wherein K generally will be the number of mechanisms that the control unit 125
controls on the destination assembly 500. Examples of such mechanisms include
but
are not limited to the diverters 510, 530 and one or more inforniation
displays (not
shown) located around the collection bins 501. Finally, the control unit 125
sends
output signals to the scanner 136 in order to provide feedback or instructions
to the
workers who perform the final scan.
While the invention has been illustrated and described in detail in the
foregoing drawings and description, the same is to be considered as
illustrative and
not restrictive in character, it being understood that only preferred
embodiments
thereof have been shown and described and that all changes and modifications
that
come within the spirit of the invention are desired to be protected.
