Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS
FOR ~ALF FOLDING PAPER S~EETS
Back~round of the Invention
The instant invention relates to folding sheets oE paper
with buckle chutes, and more particularly to sequential
folding in half by a buckle chute of a plurality of sheets
of paper and the subsequent nesting of the folded sheets of
paper into a packet and the insertion of the packet into an
envelope.
There presently exists a need in the area of folding of
paper sheets by means of buckle chute folders to be able to
fold together a relatively large number, such as 10, 20, 30
or more, of paper sheets or documents. This requirement
comes about by virtue of businesses, such as utilities or
banks or retail stores, having large statements or bills
which in many cases may exceed 30 more sheets of paper, most
or all of which may need to be folded in order to be
inserted into an envelope for mailing to a customer.
Typically, the feeding of the sheets of paper, the folding
of the sheets of paper, and the insertion of the folded
sheets of paper into the envelope are effected by an
inserting system comprising documents feeders, conveyors,
buckle chute~folders and envelope feeders.
A critical limitation with the aforesaid state of the
art inserting system is the inability to fold a large number
of sheets together simultaneously, in large part due to the
high speed of these systems. Some of the most critical
limitations are the noise of the sheets of paper entering
and leaving the folding rollers and the tremendous force
required to maintain pressure of the folding rollers
relative to each other as they separate to accept a large
number of sheets together.
It is therefor extremely desirable to have a practical
solution to the foregoing problem of folding a large number
of sheets simultaneously. The instant invention provides
such a solution by providing apparatus and a method for half-
folding a plurality of paper sheets sequentially and
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subsequently nesting the half-folded sheets and thereby
attaining a result which in terms of quality of fold is
superior to simultaneous ~olding of the same large number
of sheets.
Summary of the Inven~ion
The instant invention accordingly provides apparatus
and a method for half-folding sequentially and nesting a
plurality of paper sheets. The apparatus includes a buckle
chute folder having a pair of feed rollers rotating at a
given velocity, the rollers forming an entrance nip to the
buckle chute folder. Means for feeding the plurality of
paper sheets seriatim along a path towards the feed rollers
at a second velocity greater than the first velocity are
provided. Also, means are situated within the path for
causing a succeeding paper sheet of the plurality to become
shingled relative to a preceding paper sheet of the
plurality prior to the succeeding paper sheet entering the
nip of the feed rollers. This forms a shingled stream
entering the entrance nip to the buckle chute holder~
whereby any desired number of the sheets may be folded in
half and nested one inside the other sequentially. The
method of the present invention includes the step of
feeding, at a given velocity, the plurality of paper sheets
seriatim along a path toward a buckle chute folder having
a pair of feed rollers rotating at a second velocity less
than the given velocity. The rollers from an entrance nip
to the buckle chute folder. A succeeding paper sheet of the
plurality is caused to become shingled relative to a
preceding paper sheet of the plurality prior to the
succeeding paper sheet entering the nip of the feed rollers.
The shingled paper sheets are continuously fed into the
buckle chute folder at the second velocity, thereby forming
a shingled stream entering the entrance nip to the buckle
chute folder. The half folded sheets are collected in
nested relationship, whereby any desired number of the
sheets may be folded in half and nested one inside the other
sequentially.
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Brief Description of the Drawings
Fig. 1 is a perspective view of a shingling conveyor
in combination with a buckle chute folder in accordance with
the instant invention;
Fig. 2 is a top plan view of the apparatus seen in
Fig. l;
Fig. 3 is a side elevational view of the apparatus
seen in Figs. 1 and 2;
Fig. 4 is a side alevational view of the buckle chute
folder seen in Fig. 1 showing a first, second and third
sheet of paper in progressive stages preparatory to half-
folding;
Fig. 5 is similar to Fig. 2 except that the first
sheet of paper has been half-folded and a second sheet of
paper is about to be half-folded while the third sheet of
paper is still entering the buckle chute;
Fig. 6 is similar to Fig. 3 except that a collecting
bin is shown beneath the buckle chute for receiving the
half-folded and nesting sheets of paper;
Fig. 7 is similar to Fig. 4 except that the half-
folded sheets of paper are shown as having been completely
nested and assembled into a packet of sheets.
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Detailed Description
In describing the preferred embodiment of the instant
invention, reference is made to the drawings wherein there
is seen in Figs. 1-3 a conveyor--accumulator 10 consisting of
three upper belts 12, 14 and 16 mounted on driven pulleys
18, 20 and 22 respectively and on idler pulleys ~4, 26 and
28 respectively. The driven pulleys 18, 20 and 22 are
fixedly mounted on a drive shaft 30 which is driven by a
motor (not shown). The idler pulleys 24, 26 and 28 are
rotatably mounted on a shaft 32 journalled in the frame (not
shown) of the conveyor-accumulator 10. The conveyor-
accumulator 10 typically is part of a total folding and
inserting system.
The conveyor-accumulator 10 further includes immediately
below the upper belts 12, 14 and 16 a pair of lower belts 34
and 36 mounted on driven pulleys 38 and 40 respectively and
on idler pulleys 42 and 44 respectively. The belts 12, 14,
16, 34 and 36 are preferably "0" ring belts. The driven
pulleys 38 and 40 are fixedly mounted on a drive shaft 46
which is driven by a motor (not shown) and the idler pulleys
42 and 44 are rotatably mounted on a shaft 48. As best seen
in Fig. 3, the upper reaches 50 and 52 of the lower belts 34
and 36 respectively are situated immediately below the lower
reaches 54, 56 and 58 of the upper belts 12, 14 and 16
respectively. As best seen in Fig. 2, a plan view, the
lower belt 34 is si-tua-ted between the upper belts 12 and 14
and the lower belt 36 is situated between the upper belts 14
and 16.
Three sheet elevating ramps 60, 62 and 64 are rigidly
suspended below the lower reaches 54, 56 and 58 of the upper
belts 12, 14 and 16 respectively along a conveying path
moving in the direction of the arrows seen in Figs. 1-3.
The functioning of the ramps 60, 62 and 64 and of the entire
conveyor-accumulator 10 will be explained in additional
detail hereinbelow.
Located downstream of the accumulator-conveyor 10 is a
conventional buckle chute folder generally designated 66
consisting of a first pair of feed rollers 68 and 70 and a
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third feed roller 72 which cooperates with the roller 70 to
form a second pair of feed rollers. The buckle chute folder
66 also includes a conventional buckle chute 74 having a
stopping bar 76 therein (see Figs. 4-6).
In operation, thP conveyor-accumulator 10 ~eeds
seriatim a stream of sheets 78 which have been separated
from a stack (not shown) of sheets upstream by a singulating
device (not shown) between the lower reaches 54, 56 and 58
of the upper belts 12, 14 and 16 respectively and the upper
reaches 50 and 52 o~ the lower belts 34 and 36 respectively
at a desired velocity consistent with the overall folding
and inserting system of which the conveyor-accumulator 10
is a component. The sheets 78, as they are fed seriatim by
the conveyor-accumulator 10, encounter the three sheet
elavating ramps 60, 62 and 64 whose upstream portions
intercept the leading end 80 of the sheet 78 (see Fig. 1)
to thereby cause the sheets 78 to become slightl~ elevated.
This slight elevation results in each sheet 78 being
deposited upon the preceding sheet 78 downstream of the
ramps 60, 62 and 64 and upstream of the feed rollers 68 and
70 which function similar to a registration device in that
their slow speed results in the sheets 78 belng slowed
considerably after leaving the conveyor-accumulator 10. The
buckle chute ~older 66 has its stopping bar 76 positioned
so that the sheets 78 are folded in half, and in order to
achieve this half fold, it is necessary that the sheets 78
have a shingled relationship to each other prior to entering
the feed rollers 68 and 70. A shingled relationship is
defined to mean a plurality of sheets whose leading or
downstream ends are offset from one another, so that their
leading or downstream ends are not aligned to form a
vertical plane. It has been found that in creating the half
fold, a shingled relationship in which the overlap of one
sheet to the adjacent sheet is at least one half of the
length of the sheet required. Achieving this overlap is
effected by having the sheets 78 moved through feed rollers
68 and 70 at a speed between about 5 to 40% that o~ the
speed the sheets 78 are moved by the
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conveyor-accumulator 10, the preferred range being between
about 10 and 20~. For example, if the accumulator-conveyor
10 is moving the sheets 78 at the speed of 100 inches per
second, then the rollers 68 and 70 should move -the sheets 78
at a speed o~ about 5 to 40 inches ~er second (preferably
between about 10 to 20 inches per second) to produce
overlapping of the sheets prior to their entry into the nip
of the rollers 68 and 70 of between about~ ~ sand
one half of their length. It should be noted that
sufficient shingling can be effected by almost any
differences in speed between the conveyor-accumulator 10 and
the roller 68 and 70; e.g. a 1% difference in speed can work
although such a small differential may not be commercially
feasible.
The result of the sheets 78 being shingled as described
above prior to entry into the nip of the feed rollers 68 and
70 is illustrated in Figs. 4-7. The pressure of the feed
rollers 68 and 70 feeds the sheets 78 into the buckle chute
66 toward the stopping bar 76. As the leading edge 80a of
the sheet 78a is stopped by the buckle chute stopping bar
76, as seen in Fig. 4, a buckle 82 is formed in the middle
of the sheet 78a towards the nip of the rollers 70 and 72.
The succeeding sheets 78b, 78c, 78d, etc. continue to enter
the buckle chute 66 and are not affected by the buckling and
folding of the sheet 78a.
As seen in Fig. 5, continued feeding of the sheet 78a by
the roller pair 70 and 72 causes a fold 84 to be formed in
the location of the buckle 82 once the buckle area 82 exits
the nip of the rollers 70 and 72. Simultaneously, as seen
in Fig. 5, a buckle 86 is being formed in the succeeding
sheet 78b so that sheet 78b is being folded inside preceding
sheet 78a as the sheet 78a exits the rollers 70 and 72. As
clearly seen in Figs. 4-7, only one sheet at a time is being
folded, and as best seen in Fig. 6, after the sheets 78 exit
the rollers 70 and 72 they nest inside one another, as they
enter a guide platform 88 which holds the nested packet of
sheets 78, which in the case seen in the drawings, consists
of four sheets 78 a-d. As seen in Fig. 7, once the four
sheets 78 a-d have exited the nip of the rollers 70 and 72,
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all oE the four sheets 78 a-d rest against the platform 88
remote from the rollers 70 and 72.
Once the sheets 78 a-d are accumulated on the platEorm
88, they are removed by conventional means and may be
inserted into an envelope (not shown). It can be
appreciated that there is virtually no limit to the number
of sheets 78 which may be folded and nested inside each
other, but there is a practical limitation imposed by the
thickness of the envelope.
Although the invention has been described in conjunction
with ~he Eoregoing specific embodiment, many alternatives,
variations and modifications will be apparent to those of
ordinarily skill in the art. Those alternatives, variations
and modifications are intended to fall within the spirit and
scope of the appended claims.
