TECHNICAL FIELD
[0001] The present invention relates to a sheet folding device, and more specifically, relates
to a sheet folding device that folds and stacks a sheet on top of a pallet.
BACKGROUND ART
[0002] Fig. 10 is a schematic diagram of a sheet folding device 101. As shown in Fig. 10,
in this device 101, an elongated rubber sheet 111 conveyed by a conveyor 110 passes
through a swinging device 121 swung by a crank mechanism, is discharged from between
a pair of rolls 121a at the exit side end of the swinging device 121, and is folded
to a predetermined length and stacked on top of a pallet 131. The pallet 131 is disposed
on a raising/lowering device 132, and is lowered when the rubber sheet 111 is stacked.
A folding flap 133 holds down the rubber sheet to assist in folding the rubber sheet
(for example, see Patent Literature 1).
CITATION LIST
PATENT LITERATURE
SUMMARY OF INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0004] In a case where a sheet continuous in the longitudinal direction and conveyed in
the longitudinal direction is folded and stacked on top of a pallet as described above,
stacking the sheet higher increases the material length on the pallet, enabling the
placement of an elongated sheet on the pallet. In addition, the increase in the load
capacity on the pallet reduces the frequency of pallet exchange, which increases the
efficiency.
[0005] However, since the height to which a sheet can be stacked without collapsing depends
on, for example, the width dimension of the sheet, it is difficult to reduce the frequency
of pallet exchange to increase the efficiency.
[0006] In addition, after the sheet stacking is completed, it is necessary to take out the
pallet, place another pallet and then, raise the pallet to a predetermined height.
The operation stop time accompanying this pallet exchange contributes to a decrease
in efficiency.
[0007] In view of such circumstances, a problem to be solved by the present invention is
to provide a sheet folding device capable of reducing the frequency of pallet exchange
and shortening the operation stop time accompanying the pallet exchange.
MEANS FOR SOLVING THE PROBLEM
[0008] To solve the above-mentioned problem, the present invention provides a sheet folding
device structured as follows:
[0009] A sheet folding device is provided with: (a) a first movement unit disposed to be
able to be raised/lowered above a placement region; (b) a second movement unit supported
by the first movement unit and reciprocating along the placement region in a first
direction; and (c) a sheet discharge device supported by the second movement unit
and having a sheet discharge port facing the placement region, the sheet discharge
port reciprocating along the placement region in a second direction crossing the first
direction. A sheet continuous in a longitudinal direction is discharged from the sheet
discharge port of the sheet discharge device so that a width direction of the sheet
crosses the second direction.
[0010] With the above-described structure, the sheet discharged from the sheet discharge
port of the sheet discharge device can be folded and stacked while being shifted in
the width direction of the sheet on top of a pallet placed in the placement region.
The first movement unit is raised as appropriate so that the sheet discharge port
of the sheet discharge device is away at an appropriate distance from the sheet folded
and stacked on top of the pallet.
[0011] In the above-described structure, since the sheet can be stacked while being shifted
along the width of the sheet by the second movement unit reciprocating in the first
direction, the overall length of the folded and stacked sheet can be increased to
thereby reduce the frequency of pallet exchange.
[0012] When the stacking of the sheet is completed, it is necessary only to take out the
pallet and place another pallet in the placement region and it is unnecessary to raise
the another pallet to a predetermined height, so that the operation stop time accompanying
the pallet exchange can be shortened.
[0013] Preferably, the second movement unit stops at a plurality of positions at a distance
of not less than a width dimension of the sheet in the first direction. The sheet
discharge port of the sheet discharge device reciprocates along the placement region
in the second direction orthogonal to the first direction, and the sheet is discharged
from the sheet discharge port so that the width direction of the sheet coincides with
the first direction.
[0014] In this case, since the second movement unit stops at a plurality of positions at
a distance of equal to or greater than the width of the sheet, sheet stacked parts
formed while the second movement unit is stopping are formed at a plurality of positions
so as to be adjacent to each other without overlapping. These stacked parts can be
formed higher because they are connected together by the sheet of the part discharged
while the second movement unit is moving and do not readily collapse. By this, the
overall length of the folded and stacked sheet can be further increased to thereby
further reduce the frequency of pallet exchange.
[0015] Preferably, the sheet folding device is further provided with (d) a pressing member
that returnably moves toward the placement region, on each side of the sheet discharge
device in the first direction.
[0016] In this case, for example, when the folded sheet is undulating, the folded sheet
can be smoothed out by pressing the folded sheet by the pressing member. By doing
this, the sheet can be stacked higher to thereby further increase the overall length
of the sheet that can be folded and stacked, so that the frequency of pallet exchange
can be further reduced.
[0017] The pressing member may be provided either in the first movement unit or in the second
movement unit. Since it is necessary for the pressing member not to interfere with
the sheet discharge device, providing the pressing member in the second movement unit
simplifies the structure.
[0018] Preferably, the sheet folding device is further provided with: (e) a track shifter
disposed above the second movement unit, supported to be swingable by the first movement
unit and having a reception roll that receives the sheet and a discharge roll that
discharges the received sheet, the discharge roll reciprocating in the first direction
in conjunction with the reciprocation of the second movement unit in the first direction;
(f) a plurality of first rolls supported by the first movement unit and defining a
first conveyance path where the sheet is conveyed to the reception roll of the track
shifter; and (g) a plurality of second rolls supported by the second movement unit
and defining a second conveyance path where the sheet is conveyed from the discharge
roll of the track shifter to the sheet discharge device.
[0019] In this case, the position where the sheet is fed to the sheet folding device can
be fixed while the increase in the dimensions of the sheet folding device is suppressed.
That is, even if the sheet conveyance direction shifts in the width direction of the
sheet in response to the movement of the second movement unit, the sheet can be stably
conveyed by absorbing the twist of the sheet due to the swinging of the track shifter
by making the first and second conveyance paths sufficiently long. Moreover, by arranging
the first and second rolls so as to bend the first and second conveyance paths, the
first and second conveyance paths can be made sufficiently long while the increase
in dimensions such as the height and width of the sheet folding device is suppressed.
EFFECTS OF THE INVENTION
[0020] According to the present invention, the frequency of pallet exchange can be reduced
to thereby shorten the operation stop time accompanying the pallet exchange.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021]
[Fig. 1] Fig. 1 is a schematic front view of a sheet folding device (first embodiment).
[Fig. 2] Fig. 2 is a schematic side view along the line A-A of Fig. 1 (first embodiment).
[Fig. 3] Fig. 3 is a schematic view along the line B-B of Fig. 2 (first embodiment.
[Fig. 4] Fig. 4 is a schematic top view along the line C-C of Fig. 2 (first embodiment).
[Fig. 5] Fig. 5 is a schematic partial cross-sectional view along the line D-D of
Fig. 4 (first embodiment).
[Fig. 6] Fig. 6 is a schematic relevant part view of the sheet folding device (first
embodiment).
[Fig. 7] Fig. 7 is a schematic relevant part view of the sheet folding device (first
embodiment).
[Fig. 8] Fig. 8 is a timing chart showing the operation of the sheet folding device
(first embodiment).
[Fig. 9] Fig. 9 is schematic views along the line X-X of Fig. 7 (first embodiment).
[Fig. 10] Fig. 10 is a schematic view of the sheet folding device (first conventional
example).
MODE FOR CARRYING OUT THE INVENTION
[0022] Hereinafter, an embodiment of the present invention will be described with reference
to the drawings.
[0023] [First embodiment] A sheet folding device 10 of a first embodiment will be described
with reference to Figs. 1 to 9.
[0024] Fig. 1 is a schematic front view of the sheet folding device 10. Fig. 2 is a schematic
side view along the line A-A of Fig. 1. Fig. 3 is a schematic view along the line
B-B of Fig. 2. Fig. 4 is a schematic top view along the line C-C of Fig. 2, and shows
a track shifter 40 in perspective view. Fig. 5 is a schematic partial cross-sectional
view along the line D-D of Fig. 4. Fig. 6 is a schematic relevant part view of the
sheet folding device 10.
[0025] As shown in Figs. 1 to 6, the sheet folding device 10 is provided with a first movement
unit 20, a second movement unit 30 and a sheet discharge device 32. A pallet placement
device 16 for disposing a pallet 4 in a placement region 6, the first movement unit
20, the second movement unit 30, the sheet discharge device 32 and the like are disposed
inside a main body frame 12 of the sheet folding device 10.
[0026] While details will be provided later, the sheet folding device 10 folds the sheet
discharged from the sheet discharge device 32 and stacks it on top of the pallet 4
disposed in the placement region 6. The pallet placement device 16 conveys the pallet
4 with the sheet stacked thereon from the placement region 6 to a non-illustrated
taking-out position. The placement region 6 is a predetermined region where the pallet
4 is placed when the sheet discharged from the sheet discharge device 32 is folded
and stacked on top of the pallet 4.
[0027] The sheet folding device 10 conveys a sheet 2 continuous in the longitudinal direction,
and folds and stacks the sheet 2 on top of the pallet 4. The sheet 2 is a single or
multiple layer sheet, for example, a multiple layer sheet where a resin sheet having
stretchability is sandwiched between two nonwoven fabric sheets and the resin sheet
and the nonwoven fabric sheets are bonded together.
[0028] The first movement unit 20 is disposed above the placement region 6, and is raised/lowered
along the main body frame 12 in a third direction 83 facing the placement region 6
as indicated by the arrow 83. Specifically, a first screw shaft 14 extending in the
third direction 83 is rotatably supported by the main body frame 12, and a movement
member 22 of the first movement unit 20 engages with the first screw shaft 14. The
first screw shaft 14 is rotated by a first motor 14m, whereby the movement member
22 of the first movement unit 20 moves parallel in the third direction 83. A wheel
23 rotatably supported by the first movement unit 20 engages with a first rail 13
fixed to the main body frame 12 and extending in the third direction 83, and moves
along the first rail 13.
[0029] The track shifter 40 is disposed to be swingable above the first movement unit 20.
The track shifter 40 is disposed above the second movement unit 30. A reception roll
40p that receives the sheet 2 is rotatably supported by one end of a frame 40k of
the track shifter 40 which frame 40k is U-shaped in cross section, and a discharge
roll 40q that discharges the received sheet 2 is rotatably supported by the other
end of the frame 40k.
[0030] The first movement unit 20 supports a plurality of first rolls 21a to 21c. These
first rolls 21a to 21c define a first conveyance path 2p where the sheet 2 guided
by a guide roll 11a supported by the main body frame 12 is conveyed to the reception
roll 40p of the track shifter 40.
[0031] The second movement unit 30 is supported by the first movement unit 20, and reciprocates
along the placement region 6 in a first direction 81 indicated by the arrow 81. Specifically,
as shown in Figs. 2 and 3, a pair of second rails 25 are fixed to an upper surface
22a of the horizontally extending movement member 22 of the first movement unit 20,
and a pair of second screw shafts 26 are rotatably supported by the movement member
22. The second rails 25 and the second screw shafts 26 extend in the first direction
81. A second wheel 37 of the second movement unit 30 engages with the second rails
25, and an engagement part 36 of the second movement unit 30 engages with the second
screw shafts 26. A second motor 26m rotates the second screw shafts 26 to thereby
move the second movement unit 30 in the first direction 81.
[0032] The second movement unit 30 supports an upper part of the sheet discharge device
32 to be swingable. The sheet discharge device 32 swings between a first and second
positions 32p and 32q indicated by broken lines 32p and 32q in Fig. 1 by a third motor
32m. The swinging of the sheet discharge device 32 reciprocates a sheet discharge
port 32t provided in a lower part of the sheet discharge device 32, along the placement
region 6 in a second direction 82 orthogonal to the first direction 81. The sheet
discharge port 32t discharges the sheet 2 toward the placement region 6 in such a
manner that the width direction of the sheet 2 is parallel to the first direction
81.
[0033] As shown in Fig. 6, the sheet discharge device 32 has two conveyors 33a and 33b arranged
in mirror symmetry to each other. The conveyors 33a and 33b each have an endless belt
33v circulating in a direction indicated by the arrow 33x along guide rollers 33p
and 33q and a drive roller 33d. The sheet 2 is conveyed while being sandwiched between
the endless belts 33v of the conveyors 33a and 33b, and is discharged in a direction
indicated by the arrow 2x from the sheet discharge port 32t between end parts, on
the downstream side in the conveyance direction, of facing parts of the endless belts
33v of the conveyors 33a and 33b. The drive rollers 33d of the conveyors 33a and 33b
are rotated by conveyor motors 33m and 33n shown in Fig. 1.
[0034] The second movement unit 30 supports a plurality of second rolls 31a to 31g that
define a second conveyance path 2p where the sheet 2 is conveyed from the discharge
roll 40q of the track shifter 40 to the sheet discharge device 32.
[0035] As shown in Fig. 2, the second movement unit 30 has, on each side of the sheet discharge
device 32 in the first direction 81, a pressing member 34 that returnably moves toward
the placement region 6. For example, the pressing member 34 which is a plate-like
member moves from a standby position 34p to a pressing position 34q as indicated by
the chain lines 34p and 34q in Fig. 1 by the extension and contraction of an air cylinder
35 fixed to the second movement unit 30, and presses a sheet 2s folded on top of the
pallet 4.
[0036] While the pressing members 34 may be provided in the first movement unit 20, providing
them in the second movement unit 30 makes it easy to prevent the pressing member 34
from interfering with the sheet discharge device 32. Pressing members 34 can be omitted.
[0037] When the second movement unit 30 moves in the first direction 81, the conveyance
direction of the sheet 2 shifts in the width direction of the sheet 2. The track shifter
40 swings in response to this shift.
[0038] Specifically, as shown in Figs. 4 and 5, a guide member 42 curved in an arc shape
is fixed to an upper surface 24a of an upper member 24 of the first movement unit
20 through a support member 41, and a third screw shaft 46 is rotatably supported
by the upper member 24. The third screw shaft 46 extends in the first direction 81.
As shown in Fig. 2, an engagement member 47 engages with the third screw shaft 46,
and a protrusion 47a protruding upward is formed on the engagement member 47.
[0039] As shown in Figs. 4 and 5, two pairs of holding rollers 44a and 44b, and 44p and
44q that hold the arc-shaped guide member 42 from inside and outside in a radial direction
are rotatably supported by a lower part on one end side of the frame 40k of the track
shifter 40. As shown in Figs. 2 and 4, block-shaped holding members 48a and 48b that
hold the protrusion 47a of the engagement member 47 from both sides in the first direction
81 are fixed to a lower part on the other end side of the frame 40k of the track shifter
40.
[0040] When the third screw shaft 46 is rotated by the third motor 46m, the engagement member
47 moves along the third screw shaft 46. In response thereto, the track shifter 40
swings as shown by the oblique lines 40a and 40b in Fig. 4, and the discharge roll
40q of the track shifter 40 moves in the first direction 81. At this time, the track
shifter 40 swings about a predetermined position 40x at the center in the width direction
of the reception roll 40p in such a manner that the center line of the sheet 2 that
the reception roll 40p receives does not move, on the upstream side of the reception
roll 40p.
[0041] In tandem with the movement of the second movement unit 30 in the first direction
81, the track shifter 40 swings in such a manner that the discharge roll 40q moves
in the first direction 81. The swinging of the track shifter 40 twists the sheet 2.
To absorb the twist of the sheet 2, the first conveyance path 2p upstream of the track
shifter 40 is bent by use of the first rolls 21a to 21c supported by the first movement
unit 20, thereby making the first conveyance path 2p sufficiently long. The second
conveyance path 2q from the track shifter 40 to the sheet discharge device 32 is bent
by use of the second rolls 31a to 31g supported by the second movement unit 30, thereby
making the second conveyance path 2q sufficiently long. By doing this, the sheet 2
can be stably conveyed even though the second movement unit 30 moves.
[0042] Bending the first and second conveyance paths 2p and 2q makes it possible to make
the first and second conveyance paths 2p and 2q sufficiently long while the increase
in dimensions such as the height and width of the sheet folding device 10 is suppressed.
[0043] Next, the operation of the sheet folding device 10 will be described with reference
to Figs. 7 through Fig. 9.
[0044] Fig. 7 is a schematic relevant part view showing the operation of the sheet folding
device 10. As shown in Fig. 7, when the operation is started, the sheet discharge
device 32 repeatedly swigs between the position indicated by the solid line and the
position indicated by the chain line. The sheet 2 which is conveyed in the direction
indicated by the arrow 2i in the sheet folding device 10 passes through the sheet
discharge device 32, and is discharged from the sheet discharge port 32t reciprocating
in the second direction 82. By doing this, the sheet 2s is folded and stacked on top
of the pallet 4 placed on the pallet placement device 16.
[0045] The first movement unit 20 is raised as appropriate so that the sheet discharge port
32t of the sheet discharge device 32 is away at an appropriate distance from the sheet
2s folded and stacked on top of the pallet 4. The pressing member 34 presses the sheet
2s folded and stacked on top of the pallet 4.
[0046] Fig. 8 is a timing chart showing an example of the operation of the sheet folding
device 10. As shown by reference numeral 50 in Fig. 8, the sheet discharge device
32 repeats a regular cycle of swinging. As shown by reference numeral 51, the second
motor 26m rotates in one direction, so that the second movement unit 30 moves in the
first direction 81.
[0047] Then, as shown by reference numeral 52, the second motor 26m stops rotating in one
direction, so that the second movement unit 30 stops at a first position. When the
sheet discharge device 32 completes N1 cycles of swinging (N1=8 in Fig. 8) while the
second movement unit 30 is stopping, as shown by reference numeral 54, the second
motor 26m rotates in the reverse direction, so that the second movement unit 30 moves
from the first position.
[0048] When the sheet discharge device 32 completes K1 cycles of swinging (K1=2 in Fig.
8) while the second movement unit 30 is moving, as shown by reference numeral 56,
the second motor 26m stops rotating in the reverse direction, so that the second movement
unit 30 stops at a second position. When the sheet discharge device 32 completes N2
cycles of swinging (N2=8 in Fig. 8) while the second movement unit 30 is stopping,
as shown by reference numeral 58, the second motor 26m rotates in one direction, so
that the second movement unit 30 moves from the second position.
[0049] Then, when the sheet discharge device 32 completes K2 cycles of swinging (K2=2 in
Fig. 8) while the second movement unit 30 is moving, as shown by reference numeral
59, the second motor 26m stops rotating in one direction, so that the second movement
unit 30 stops at the first position. Similar operations are repeated thereafter.
[0050] N1, N2, K1 and K2 may be either natural numbers or positive real numbers. N1 and
N2 may be not equal to each other, and K1 and K2 may be not equal to each other.
[0051] It is preferable that N1 and N2 are large because the movement of the second movement
unit 30 can be reduced. For example, when N1 is equal to or greater than 2 and N2
is equal to or greater than 2, the number of times of reciprocation of the sheet discharge
port 32t of the sheet discharge device 32 in the second direction 82 along the placement
region 6 while the second movement unit 30 is stopping at one position is two or more,
so that the movement of the second movement unit 30 can be reduced.
[0052] In conjunction with the operation of the second movement unit 30, the first movement
unit 20 is raised and the pressing member 34 operates as follows:
[0053] When the second movement unit 30 moves and stops at the first position, as shown
by reference numeral 60, the air cylinder 35 is turned on, so that the pressing member
34 is lowered. Then, as shown by reference numeral 62, the air cylinder 35 is turned
off, so that the pressing member 34 is raised to return to the original position.
[0054] Moreover, as shown by reference numeral 70, when the air cylinder 35 switches from
on to off while the second movement unit 30 moves and stops at the first position,
the first motor 14m is turned on, so that the first movement unit 20 is raised. Then,
as shown by reference numeral 72, the first motor 14m is turned off, so that the first
movement unit 20 stops.
[0055] When the second movement unit 30 moves and stops at the second position, as shown
by reference numeral 64, the air cylinder 35 is turned on, so that the pressing member
34 is lowered. Then, as shown by reference numeral 66, the air cylinder is turned
off, so that the pressing member 34 is raised.
[0056] Similarly, when the second movement unit 30 stops, the pressing member 34 is lowered.
Moreover, each time the second movement unit 30 reciprocates between the first and
second positions, the first movement unit 20 is raised.
[0057] Fig. 9 which is schematic view along the line X-X of Fig. 7 schematically showes
a bent part 2v of the sheet 2s folded and stacked on top of the pallet 4, by the solid
lines 2a to 2d.
[0058] As shown in Fig. 9(a), when the sheet discharge device 32 swings while the second
movement unit 30 is stopping at the first position, a first folded part 2a where the
sheet is newly folded is formed on one side of the pallet 4 in the first direction
81.
[0059] Then, as shown in Fig. 9(b), the sheet discharge device 32 swings while moving in
the direction indicated by the arrow 32x while the second movement unit 30 is moving
from the first position to the second position, whereby first intermediate folded
parts 2b and 2c where the sheet is newly folded are formed.
[0060] Then, as shown in Fig. 9(c), when the second movement unit 30 stops at the second
position, the pressing member 34 is lowered, so that the first folded part 2a is pressed
to be compressed. For example, an undulating part 2k between opposing folded parts
2u and 2v of the sheet 2 shown in Fig. 7 is pressed to be flattened. Although not
shown in Fig. 9(c), while this is being done, the sheet is newly folded on the other
side of the pallet 4 in the first direction 81.
[0061] As shown in Fig. 9(d), the sheet discharge device 32 swings while the second movement
unit 30 is stopping at the second position, whereby a second folded part 2d where
the sheet is newly folded is formed on the other side of the pallet 4 in the first
direction 81.
[0062] Although not shown, thereafter, second intermediate folded parts where the sheet
is folded are similarly formed while the second movement unit 30 is moving from the
second position to the first position. Then, when the second movement unit 30 stops
at the first position, the pressing member 34 is lowered, so that the second folded
part 2d is pressed to be compressed.
[0063] The second movement unit 30 stops at the first position and the second position in
such a manner that the first folded part 2a and the second folded part 2d are adjacent
to each other without overlapping. That is, the second movement unit 30 stops at a
plurality of positions, that is, at the first position and the second position at
a distance of not less than the width dimension W of the sheet 2 in the first direction
81.
[0064] When the width W of the sheet 2 is not more than half of the dimension T of the
pallet 4 in the first direction 81, the parts 2a and 2d where the sheet is folded
while the second movement unit 30 is stopping can be formed at a plurality of positions
4a and 4b on the pallet 4. The parts 2a and 2d where the sheet is folded while the
second movement unit 30 is stopping are connected together through the parts 2b and
2c where the sheet is folded while the second movement unit 30 is moving, so that
the sheet can be stacked higher than when the sheet is folded only at one position
on the pallet 4. Therefore, by folding and stacking the sheet 2s at a plurality of
positions 4a and 4b on the pallet 4, the frequency of exchanging the pallet 4 can
be reduced more than when the sheet 2s is folded and stacked only at one position
on the pallet 4.
[0065] For example, when the folded sheet 2s is undulating, the sheet 2s can be smoothed
out by pressing the folded sheet 2s by the pressing member 34. By doing this, the
sheet 2s can be stacked higher to thereby further increase the overall length of the
sheet 2s that can be folded and stacked, so that the frequency of pallet exchange
can be further reduced.
[0066] When the stacking of the sheet 2s is completed, the pallet 4 is taken out, and another
pallet 4 is placed on the pallet placement device 16. Since it is unnecessary to raise
the another pallet 4 placed on the pallet placement device 16 up to a predetermined
height, the operation stop time accompanying the pallet exchange can be shortened.
[0067] When the width W of the sheet 2 is shorter, by stopping the second movement unit
30 at three or more positions, the part where the sheet is folded while the second
movement unit 30 is stopping can be formed at three or more positions on the pallet
4. In this case, the second movement unit 30 also stops at a plurality of positions
at a distance of not less than the width dimension W of the sheet in the first direction
81.
[0068] While in the first embodiment, a case is shown where the second direction 82 is orthogonal
to the first direction 81, the sheet folding device 10 may have a structure where
the second direction 82 is a direction crossing the first direction 81 which direction
is other than a direction orthogonal to the first direction 81. While in the first
embodiment, a case is shown where the sheet 2 is discharged from the sheet discharge
port 32t of the sheet discharge device 32 in such a manner that the width direction
of the sheet 2 coincides with the first direction 81, the sheet folding device 10
may have a structure where the sheet 2 is discharged from the sheet discharge port
32t in such a manner that the width direction of the sheet 2 crosses the second direction
82 without coinciding with the first direction 81.
[0069] Moreover, the sheet discharge port 32t of the sheet discharge device 32 may be made
to reciprocate in the second direction 82 without the sheet discharge device 32 swinging,
for example, by the sheet discharge device 32 moving parallel in the second direction
82.
[0070] [Summary] As described above, the sheet folding device 10 reduces the frequency of
exchanging the pallet 4 and shortens the operation stop time accompanying the pallet
exchange.
[0071] The present invention is not limited to the above-described embodiment but may be
carried out with various modifications being added.
[0072] For example, the sheet folding device may be operated in various modes. For example,
the first movement unit may continuously move instead of repeating the cycle of moving
and stopping. Moreover, the moving and stopping of the second movement unit and the
reciprocation of the sheet discharge port may be linked together in various modes.
[0073] The pallet placement device 16 may be designed to guide the pallet 4 to an appropriate
position by a non-illustrated device such as a position measurement device, a controller
or a driver. Specifically, the position of the pallet placement device 16 may be automatically
adjusted in each of the first direction 81 and the second direction 82 so that the
region (not shown) where the sheet 2s is discharged by the sheet discharge device
32 is within the placement region 6 of the pallet placement device 16. Moreover, the
position of the pallet 4 may be automatically adjusted in each of the first direction
81 and the second direction 82 so that the pallet 4 is disposed within the placement
region 6.
[0074] Lastly, technical ideas grasped from the above-described embodiment and other examples
(modifications) will be added in the following:
[0075] A sheet folding device according to a first aspect of the present invention is provided
with: a first movement unit disposed to be able to be raised/lowered above a placement
region; a second movement unit supported by the first movement unit and reciprocating
along the placement region in a first direction; and a sheet discharge device supported
by the second movement unit and having a sheet discharge port facing the placement
region, the sheet discharge port reciprocating along the placement region in a second
direction crossing the first direction. A sheet continuous in a longitudinal direction
is discharged from the sheet discharge port of the sheet discharge device so that
a width direction of the sheet crosses the second direction.
[0076] With the sheet folding device of the first aspect, the sheet discharged from the
sheet discharge port of the sheet discharge device can be folded and stacked while
being shifted in the width direction of the sheet on top of a pallet placed in the
placement region. The first movement unit is raised as appropriate so that the sheet
discharge port of the sheet discharge device is away at an appropriate distance from
the sheet folded and stacked on top of the pallet.
[0077] In the sheet folding device of the first aspect, since the sheet can be stacked while
being shifted along the width of the sheet by the second movement unit reciprocating
in the first direction, the overall length of the folded and stacked sheet can be
increased to thereby reduce the frequency of pallet exchange.
[0078] When the stacking of the sheet is completed, it is necessary only to take out the
pallet and place another pallet in the placement region and it is unnecessary to raise
the another pallet to a predetermined height, so that the operation stop time accompanying
the pallet exchange can be shortened.
[0079] A sheet folding device according to a second aspect of the present invention is the
sheet folding device of the first aspect in which the second movement unit stops at
a plurality of positions at a distance of not less than a width dimension of the sheet
in the first direction, the sheet discharge port of the sheet discharge device reciprocates
along the placement region in the second direction orthogonal to the first direction
and the sheet is discharged from the sheet discharge port so that the width direction
of the sheet coincides with the first direction.
[0080] With the sheet folding device of the second aspect, since the second movement unit
stops at a plurality of positions at a distance of equal to or greater than the width
of the sheet, sheet stacked parts formed while the second movement unit is stopping
are formed at a plurality of positions so as to be adjacent to each other without
overlapping. These stacked parts can be formed higher because they are connected together
by the sheet of the part discharged while the second movement unit is moving and do
not readily collapse. By this, the overall length of the folded and stacked sheet
can be further increased to thereby further reduce the frequency of pallet exchange.
[0081] A sheet folding device according to a third aspect of the present invention is the
sheet folding device of the first or the second aspect, further provided with a pressing
member that returnably moves toward the placement region, on each side of the sheet
discharge device in the first direction.
[0082] With the sheet folding device of the third aspect, for example, when the folded sheet
is undulating, the folded sheet can be smoothed out by pressing the folded sheet by
the pressing member. By doing this, the sheet can be stacked higher to thereby further
increase the overall length of the sheet that can be folded and stacked, so that the
frequency of pallet exchange can be further reduced.
[0083] The pressing member may be provided either in the first movement unit or in the second
movement unit. Since it is necessary for the pressing member not to interfere with
the sheet discharge device, providing the pressing member in the second movement unit
simplifies the structure.
[0084] A sheet folding device according to a fourth aspect of the present invention is the
sheet folding device of any of the first to third aspects, further provided with:
a track shifter disposed above the second movement unit, supported to be swingable
by the first movement unit and having a reception roll that receives the sheet and
a discharge roll that discharges the received sheet, the discharge roll reciprocating
in the first direction in conjunction with the reciprocation of the second movement
unit in the first direction; a plurality of first rolls supported by the first movement
unit and defining a first conveyance path where the sheet is conveyed to the reception
roll of the track shifter; and a plurality of second rolls supported by the second
movement unit and defining a second conveyance path where the sheet is conveyed from
the discharge roll of the track shifter to the sheet discharge device.
[0085] With the sheet folding device of the fourth aspect, the position where the sheet
is fed to the sheet folding device can be fixed while the increase in the dimensions
of the sheet folding device is suppressed. That is, even if the sheet conveyance direction
shifts in the width direction of the sheet in response to the movement of the second
movement unit, the sheet can be stably conveyed by absorbing the twist of the sheet
due to the swinging of the track shifter by making the first and second conveyance
paths sufficiently long. Moreover, by arranging the first and second rolls so as to
bend the first and second conveyance paths, the first and second conveyance paths
can be made sufficiently long while the increase in dimensions such as the height
and width of the sheet folding device is suppressed.
DESCRIPTION OF REFERENCE NUMERALS
[0086]
2, 2s Sheet
2p First conveyance path
2p Second conveyance path
4 Pallet
6 Placement region
10 Sheet folding device
20 First movement unit
21a to 21c First rolls
30 Second movement unit
31a to 31g Second rolls
32 Sheet discharge device
32t Sheet discharge port
34 Pressing member
40 Track shifter
40p Reception roll
40q Discharge roll
81 First direction
82 Second direction
W Width (width dimension)