U.S. patent application number 15/755883 was filed with the patent office on 2018-11-01 for underlapping sheet feeders.
The applicant listed for this patent is Vivid Laminating Technologies Limited. Invention is credited to Sebastien de la Hamayde, Gavin Ward.
Application Number | 20180312355 15/755883 |
Document ID | / |
Family ID | 54363038 |
Filed Date | 2018-11-01 |
United States Patent
Application |
20180312355 |
Kind Code |
A1 |
de la Hamayde; Sebastien ;
et al. |
November 1, 2018 |
UNDERLAPPING SHEET FEEDERS
Abstract
A sheet feeder comprises a roller configured to rotate about an
axis and an input drive configured to deliver single sheets to the
roller such that a leading edge of each sheet is substantially
parallel to the axis. The roller comprises a plurality of flexible
fins extending along the axis. As the roller rotates, one of the
sheets can be lifted by the rotating fins to pass over the roller,
while the leading edge of a following sheet is delivered to the
roller in an underlapping relationship with the first sheet.
Inventors: |
de la Hamayde; Sebastien;
(Leicester, GB) ; Ward; Gavin; (Ravenstone,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vivid Laminating Technologies Limited |
Coalville, Leicestershire |
|
GB |
|
|
Family ID: |
54363038 |
Appl. No.: |
15/755883 |
Filed: |
September 9, 2016 |
PCT Filed: |
September 9, 2016 |
PCT NO: |
PCT/GB2016/052798 |
371 Date: |
February 27, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 2404/12 20130101;
B65H 3/042 20130101; B65H 2301/444 20130101; B65H 5/06 20130101;
B65H 5/24 20130101 |
International
Class: |
B65H 5/24 20060101
B65H005/24; B65H 3/04 20060101 B65H003/04; B65H 5/06 20060101
B65H005/06 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 11, 2015 |
GB |
1516132.6 |
Claims
1.-12. (canceled)
13. A sheet feeder comprising: a roller configured to rotate about
an axis; and an input drive configured to deliver single sheets to
the roller along a direction substantially perpendicular to the
axis; wherein the roller comprises a plurality of flexible fins
extending along the axis, whereby as the roller rotates a first one
of the sheets can be lifted by the fins to pass over the roller and
a leading edge of a second one of the sheets can be delivered to
the roller in an underlapping relationship with the first
sheet.
14. A sheet feeder according to claim 13, comprising at least three
fins disposed about the circumference of the roller.
15. A sheet feeder according to claim 13, comprising up to ten fins
disposed about the circumference of the roller.
16. A sheet feeder according to claim 13, wherein the input drive
delivers the sheets along the surface of a platen, an edge of the
platen being positioned to come into contact with the fins during
rotation of the roller.
17. A sheet feeder according to claim 13, further comprising an
output drive configured to withdraw sheets from the roller.
18. A sheet feeder according to claim 13, further comprising a gate
for controlling the withdrawal of sheets from the roller.
19. A method of feeding sheets in an underlapping series,
comprising: delivering a series of single sheets to a roller, the
roller comprising a plurality of flexible fins extending along an
axis of the roller and the sheets being delivered along a direction
substantially perpendicular to the axis; rotating the roller so
that the fins lift a first one of the sheets to pass over the
roller; delivering a second one of the sheets to the roller while
the first sheet remains above the roller; and rotating the roller
so that the fins lift the second sheet to pass over the roller in
an underlapping relationship with the first sheet.
20. A method according to claim 19, comprising rotating the roller
continuously.
21. A method according to claim 20, comprising rotating the roller
at a rate such that a surface speed of the roller is faster than a
delivery speed of the sheets.
22. A method according to claim 19, comprising using a gate
downstream from the roller to maintain the first sheet above the
roller while the second sheet is delivered to the roller.
23. A method according to claim 19, comprising operating an output
drive to withdraw the sheets from the roller.
24. A method according to claim 19, further comprising aligning the
sheets such that they are delivered to the roller with a leading
edge of each sheet substantially parallel to the axis.
Description
TECHNICAL FIELD
[0001] The invention relates to the arrangement of sheets of paper,
card or other thin material into a line in which each sheet
underlaps the preceding sheet. In other words, the leading edge of
each sheet lies underneath the preceding sheet. Typically the
incoming sheets are delivered singly, e.g. from the bottom of a
stack, and the line of outgoing sheets is fed into a machine for
further processes such as folding, printing or laminating to be
carried out.
BACKGROUND OF THE INVENTION
[0002] In the prior art, when it was desired to form a series of
sheets or other thin articles into an underlapping line, this was
typically achieved using suction cups to lift the preceding sheet,
or using complicated reciprocating mechanisms to control the edges
of the sheets. A simpler solution is desirable.
SUMMARY OF THE INVENTION
[0003] The invention provides a sheet feeder as defined in claim
1.
[0004] The invention further provide a method of feeding sheets in
an underlapping series as defined in claim 7.
[0005] Other features of the invention that are preferred but not
essential are defined in the dependent claims.
[0006] THE DRAWINGS
[0007] FIG. 1 is a vertical cross section through a sheet feeder
according to an embodiment of the invention.
[0008] FIG. 2 is a series of schematic drawings showing the
sequence of steps as sheets pass through a feeder according to the
invention.
[0009] FIG. 1 shows a sheet feeder that draws sheets from the
underside of a stack 2 of paper, card or other thin material to be
processed. The stack 2 rests on a feed deck 4. The feed deck 4 is
preferably inclined from the horizontal and the stack 2 is
restrained from moving under gravity by a feed block 6, against
which the leading face of the stack 2 rests. A small gap between
the feed block 6 and the feed deck 4 permits one sheet at a time to
be withdrawn from the bottom of the stack 2 and to pass through the
gap. A moving belt 8 set into the feed deck 4 frictionally engages
the underside of the bottom sheet and drives it through the gap
towards a roller 10.
[0010] The details of the feed deck 4, feed block 6 and drive belt
8 are conventional and do not form part of the present invention.
Alternative means for supplying the sheets could be used; all that
is important is that single sheets are driven one at a time towards
the roller 10 along a direction that is substantially perpendicular
to the axis. Note that this does not mean that the delivery
direction necessarily points directly towards the axis; preferably
it is aligned above the axis. In the typical case of rectangular
sheets, the leading edge of each sheet will be aligned
substantially parallel to the axis of the roller.
[0011] The roller 10 is mounted for rotation about a horizontal
axis. A number of fins 12 are spaced equally about the
circumference of the roller. There are five of the fins 12 in this
example. The fins 12 extend along the roller 10, generally parallel
to its axis, and radiate out from the surface of the roller. Each
fin 12 preferably curves backwards with respect to the direction of
rotation of the roller 10. It is not essential that the roller 10
or the fins 12 should extend across the whole width of the feeder.
Two or more rollers 10 of reduced width, each with its own set of
fins 12, could be spaced along a single axle. Alternatively, a
single, full-width roller 10 could support two or more sets of fins
12 of reduced width. The fins 12 may be formed integrally with the
roller 10 or they may be attached to it. The latter option gives
the advantage of an independent choice of their material at the
expense of a more complex manufacturing process. The fins 12 are
flexible and yielding to avoid damage to the sheets and to permit
the "flicking" action described below. They may be made of a
material such as rubber that can grip the sheets and help to guide
them over the roller 10 as it rotates.
[0012] Downstream from the roller 10 is an output platen 14 for
receiving the underlapping series of sheets. As shown, the output
platen 14 is not necessarily aligned with the input feed deck 4 and
preferably it extends beneath the roller 10. The platen 14 may be
the table of a laminator or other machine supplied by the sheet
feeder. A gate 18 is provided to act as a barrier that selectively
blocks the movement of a sheet away from the roller 10 as explained
below. The gate 18 may comprise one or more teeth that can be
raised through slots in the platen 14. Other known forms of gate
may be used with the invention.
[0013] An output drive 16 may be associated with the output platen
14 for drawing the series of sheets away from the roller 10 and
along the output platen 14 towards the next stage of the process,
such as a laminating machine. In the illustrated embodiment the
output drive comprises a pair of spaced rollers 16,17. When the
gate 18 is lowered to allow a sheet to pass, the upper roller 16 is
simultaneously lowered so that the sheet becomes sandwiched between
the upper and rollers 16,17. At least one roller of the pair is
driven so that the sheet is urged downstream between the
counter-rotating rollers 16,17. Other forms of output drive
synchronized with the gate 18 are possible. In some applications,
an inclined output platen 14 may be sufficient to move the outgoing
sheets under the influence of gravity, without any additional
output drive.
[0014] FIG. 2 illustrates the operation of the invention. In this
case, successive sheets 21,22,23 are shown advancing singly along
the feed deck 4 instead of being withdrawn from the underside of a
stack. This is for ease of understanding but is also a possibility
falling within the scope of the invention. For simplicity, the
input and output drives are not shown in the diagrams of FIG.
2.
[0015] FIG. 2(a) shows a first sheet 21 advancing along the feed
deck 4 towards the roller 10.
[0016] The first sheet 21 is followed, after a small gap, by a
second sheet 22. The gap is determined by the timing of the
upstream supply mechanism and is not essential. The plane of the
feed deck 4 is preferably aligned just above the axis of the roller
10 so that the leading edge of the first sheet 21 is directed
towards the upper half of the roller 10. As shown, the leading edge
enters the space between two of the fins 12.
[0017] The roller 10 is continuously rotated at a rate such that a
surface speed of the roller 10 is faster than the speed at which
the sheet 21 is delivered. Thus the fins 12 move faster than the
leading edge of the sheet 21 and do not block the forward progress
of the sheet. The front edge 24 of the feed deck 4 preferably lies
just within the sweep of the fins 12 so that as the roller 10
rotates, the outer ends of the fins 12 catch against the edge 24.
Being flexible, each fin 12 is then bent backwards until its tip
has passed the edge 24 and, being resilient, the fin 12 then flicks
forwards to resume its original shape. This arrangement closes the
gap between the edge 24 of the feed deck and the fins 12 most of
the time and thus prevents the leading edge of the sheet 21 passing
below the roller 10. It also imparts a rapid, upward movement to
the tip of the fin 12 as it flicks forwards, which helps to lift
the sheet 21 over the roller 10 as discussed below.
[0018] FIG. 2(b) shows an instant shortly after FIG. 2(a), when the
continuing rotation of the roller 10 has brought one of the fins 12
past the edge 24 of the feed deck, into contact with the underside
of the first sheet 21, and the fin has lifted the sheet 21 clear of
the top of the roller 10. The sheet 21 is still moving forwards at
the speed determined by the input drive, which continues to act on
the rear part of the sheet 21 on the feed deck 4. Meanwhile, the
roller 10 is rotating at a sufficiently high speed such that
successive fins 12 sweep past the underside of the sheet 21 and
maintain its elevated position.
[0019] FIG. 2(c) shows a further progression, as the first sheet 21
has moved further across the top of the roller 10 until its
trailing edge ceases to be acted on by the input drive and its
leading edge begins to be acted on by the output drive. Friction
between the rotating fins 12 and the underside of the sheet 21 can
help to keep the sheet moving forwards during this transition.
[0020] In FIG. 2(d), the further progress of the first sheet 21
away from the roller 10 is blocked by the gate 18, which obstructs
its leading edge. Alternatively (or additionally) the movement of
the sheet 21 may be stopped by interrupting the operation of the
output drive. Thus the first sheet 21 is stationary above the
roller 10, supported on the rotating fins 12. Meanwhile, the second
sheet 22 has advanced to the position that the first sheet 21
adopted in FIG. 2(a), with its leading edge approaching the roller
10 and penetrating the space between two of the fins 12. A third
sheet 23 now follows the second sheet 22 along the feed deck 4.
[0021] In FIG. 2(e), a few moments later, the second sheet 22 has
been lifted by the continuing rotation of the fins 12 to be
supported on the rotating fins above the top of the roller 10. The
position of the second sheet 22 in FIG. 2(e) is the same as the
position of the first sheet 21 in FIG. 2(b), except that the first
sheet 21 is already present. Thus the leading edge of the second
sheet 22 now lies below the trailing part of the first sheet 21 in
an underlapping relationship. The system may determine when a
sufficient degree of underlap has been achieved either by the time
that has passed since the first sheet 21 was stopped by the gate 18
or, preferably, by using a sensor (not shown) to detect that the
second sheet 22 has reached the desired position. The gate 18 can
then be de-activated and/or the output drive can be restarted to
drive the first sheet 21 away from the roller 10 at the same speed
as the second sheet 22 is driven towards it, thus maintaining the
desired amount of underlap.
[0022] It should be evident that the cycle of steps illustrated and
described with respect to FIGS. 2(c)-(e) can be repeated
indefinitely, to underlap the third sheet 23 with the second sheet
22 and so on.
[0023] Instead of operating the output drive at the same speed as
the input drive, but intermittently, it is also possible to operate
the output drive continuously at a slower speed, which will be
equal to its average speed in the first embodiment of the invention
just described. In the first embodiment, the first sheet 21 stops
to wait for the second sheet 22 to catch up. In this alternative
embodiment the second sheet 22 will overtake (and underlap) the
first sheet 21 more gradually, based on the difference in speed
between them, but the outcome will be the same. It will in any case
be necessary that the output series of overlapping sheets should
move at this slower speed by the time it reaches the input of the
following process if it is a continuous one.
[0024] The number of fins 12 may be selected depending on the
application, the nature of the sheets to be processed and the speed
of the roller 10. With fewer fins 12, it is likely that the roller
10 will need to be rotated faster to achieve the desired effect. As
discussed above, the minimum rate of rotation is determined by the
need for the surface speed of the roller to exceed the delivery
speed of the sheets. Thus at least three fins are likely to be
required for the roller to be effective. There is unlikely to be
any benefit in the number of fins exceeding ten; a larger number of
fins will allow less time for the leading edge of a sheet to
penetrate between them before the next fin contacts the sheet and
lifts it.
[0025] The roller 10 may be independently driven by its own motor
(not shown). Preferably it is driven at an appropriate speed by
gearing linking it to the input drive. The roller 10 will normally
rotate continuously, as previously described but intermittent
operation of the roller, timed in relation to the operation of the
gate 18 and/or the drive means 8, may also be possible.
* * * * *