U.S. patent application number 11/264894 was filed with the patent office on 2007-05-03 for sheet convey apparatus.
Invention is credited to Tetsuo Komori.
Application Number | 20070096382 11/264894 |
Document ID | / |
Family ID | 37995230 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070096382 |
Kind Code |
A1 |
Komori; Tetsuo |
May 3, 2007 |
Sheet convey apparatus
Abstract
A sheet convey apparatus includes first and second conveyor
belts, an air pipe, and a rotary body. The first conveyor belt
conveys a plurality of sheets. The second conveyor belt is provided
downstream of the first conveyor belt in a sheet convey direction
and has a convey speed lower than that of the first conveyor belt.
The air pipe is provided above the first conveyor belt and
discharges air obliquely downward toward a downstream side of the
sheet convey direction to float a trailing edge portion of a sheet.
The rotary body is rotatably supported above the first conveyor
belt and guides the trailing edge portion of the sheet which has
floated with the air from the air pipe.
Inventors: |
Komori; Tetsuo; (Shaumburg,
IL) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN
12400 WILSHIRE BOULEVARD
SEVENTH FLOOR
LOS ANGELES
CA
90025-1030
US
|
Family ID: |
37995230 |
Appl. No.: |
11/264894 |
Filed: |
November 1, 2005 |
Current U.S.
Class: |
271/9.09 |
Current CPC
Class: |
B65H 29/6618 20130101;
B65H 2701/1313 20130101; B65H 2406/122 20130101 |
Class at
Publication: |
271/009.09 |
International
Class: |
B65H 5/26 20060101
B65H005/26; B65H 3/44 20060101 B65H003/44 |
Claims
1. A sheet convey apparatus comprising: first convey means for
conveying a plurality of sheets; second convey means provided
downstream of said sheet convey means in a sheet convey direction
and having a convey speed lower than that of said first convey
means; air discharge means, provided above said first convey means,
for discharging air obliquely downward toward a downstream side of
the sheet convey direction to float a trailing edge portion of a
sheet; and a rotary body which is rotatably supported above said
first convey means and guides the trailing edge portion of the
sheet which has floated with the air from said air discharge
means.
2. An apparatus according to claim 1, wherein said first and second
convey means respectively comprise first and second conveyor belts
arranged on one plane, and when a leading edge portion of the sheet
separates from said first conveyor belt and comes into contact with
said second conveyor belts, the trailing edge portion of the sheet
floats by air.
3. An apparatus according to claim 2, wherein said air discharge
means constantly discharges air, while a sheet is conveyed by said
first conveyor belt, the sheet is pressed against said first
conveyor belt with the air blown to an upper surface thereof, and
when a convey operation of a sheet is switched from said first
conveyor belt to said second conveyor belt, the trailing edge
portion of the sheet is lifted by the air blown between a lower
surface of the trailing edge portion of the sheet and said first
conveyor belt.
4. An apparatus according to claim 2, wherein said rotary body is
provided at a position to correspond to the trailing edge portion
of the sheet the leading edge portion of which has separated from
said first conveyor belt and has come into contact with said second
conveyor belt.
5. An apparatus according to claim 2, wherein each of said first
and second conveyor belts comprises a plurality of narrow belts
divided in a widthwise direction of the sheet.
6. An apparatus according to claim 5, wherein said air discharge
means comprises a plurality of nozzles which are attached to
correspond to every other one of said narrow belts of said first
conveyor belt.
7. An apparatus according to claim 1, further comprising air flow
rate adjusting means for adjusting a flow rate of the air to be
discharged from said air discharge means.
8. An apparatus according to claim 7, wherein said air flow rate
adjusting means has a valve member which adjusts a sectional area
of an air channel to change a discharge speed of the air.
9. An apparatus according to claim 1, wherein said air discharge
means comprises an air pipe which is axially, pivotally supported
and to which air from an air supply source is supplied, and a
nozzle which is attached to said air pipe to discharge the air
supplied to said air pipe, and a discharge direction of the air
from said nozzle is adjusted by pivot adjustment of said air
pipe.
10. An apparatus according to claim 1, further comprising a cutting
device which sequentially cuts a leading edge of a web that is fed
out and supplies a cut sheet to said first convey means.
11. An apparatus according to claim 1, wherein said first convey
means conveys the plurality of sheets to be separate from each
other.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a sheet convey apparatus
which, when conveying sheets obtained by sequentially cutting a web
which is fed out, conveys the sheets by lapping the leading edge
and trailing edge of two successive sheets.
[0002] As a conventional sheet convey apparatus which conveys
sheets by lapping the leading edge and trailing edge of two
successive sheets, one as shown in U.S. Pat. No. 4,302,001 is
proposed. This apparatus comprises a cutting device which cuts a
paper web, the first feeding device which feeds a cut sheet, the
second feeding device which is located downstream of the first
feeding device in a sheet convey direction and has a sheet feed
speed lower than that of the first feeding device, and a chucking
means for chucking the sheets upward between the first and second
feeding devices within a range where the edges of the sheet are
lapped like fish scales.
[0003] According to another conventional sheet convey apparatus,
one as shown in U.S. Pat. No. 5,275,394 is proposed. This apparatus
comprises a belt device which conveys a sheet obtained by cutting a
paper web by a cutting device, a lifting means for lifting upward
the trailing edge portion of a downstream sheet which is being
conveyed by the belt device, and a pickup means for chucking the
lifted trailing edge portion. The leading edge portion of an
upstream sheet is inserted under the trailing edge portion of the
sheet chucked by the pickup means to lap the edges of the two
sheets.
[0004] According to the former sheet convey apparatus described
above, the sheets are conveyed with the trailing edge portion of
the preceding downstream sheet being chucked by the chucking means.
Thus, the sheet is rubbed by the chucking means and accordingly
damaged.
[0005] According to the latter sheet convey apparatus, if the
rigidity (hardness) of the sheet to be lifted by the lifting means
is relatively low, sometimes the trailing edge portion of the sheet
cannot be lifted to a predetermined height. In this case, the
trailing edge portion of the sheet cannot be chucked by the pickup
means, so the edges of the two sheets cannot be reliably lapped.
Also, adjusting operation is required to adjust the lifting amount
of the lifting means to match the stiffness (hardness) of the
sheet.
[0006] These problems may be solved by a method of blowing
discharge air to the sheet from below so that the trailing edge
portion of the downstream sheet is chucked by the chucking means
reliably. In this case, to reliably lap the sheets, the operation
of adjusting the chucking air discharge timing is necessary so that
only the trailing edge of the downstream sheet may be blown up with
the discharge air but the leading edge of the upstream sheet may
not be blown up. This adjusting operation is cumbersome and
time-consuming because the air discharge on/off timing must be
adjusted in accordance with the sheet convey speed.
[0007] The same problem arises when conveying precut sheets in a
lapped state.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a sheet
convey apparatus that can reliably lap the edges of sheets without
damaging the sheets.
[0009] It is another object of the present invention to provide a
sheet convey apparatus that does not require adjusting
operation.
[0010] According to the present invention, there is provided a
sheet convey apparatus comprising first convey means for conveying
a plurality of sheets, second convey means provided downstream of
the first convey means in a sheet convey direction and having a
convey speed lower than that of the first convey means, air
discharge means, provided above the first convey means, for
discharging air obliquely downward toward a downstream side of the
sheet convey direction to float a trailing edge portion of a sheet,
and a rotary body which is rotatably supported above the first
convey means and guides the trailing edge portion of the sheet
which has floated with the air from the air discharge means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side view of a sheet-fed offset rotary printing
press to which a sheet convey apparatus according to the first
embodiment of the present invention is applied;
[0012] FIG. 2 is a plan view of the sheet convey apparatus shown in
FIG. 1;
[0013] FIG. 3 is a side view of the sheet convey apparatus shown in
FIG. 1;
[0014] FIG. 4 is a partially cutaway plan view of the air flow rate
adjusting device shown in FIG. 2; and
[0015] FIG. 5 is a plan view of a sheet convey apparatus according
to the second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] A case will be described with reference to FIGS. 1 to 4
wherein a sheet convey apparatus according to the first embodiment
of the present invention is applied to a sheet-fed offset rotary
printing press.
[0017] As shown in FIG. 1, a sheet convey apparatus 1 according to
this embodiment includes a roll 3 around which a web 2 is wound, a
cutting device 4 which feeds separately from each other a plurality
of sheets obtained by cutting the web 2 fed out from the roll 3
into a predetermined size, and a lapping unit 5 which inserts the
leading edge portion of, among two sheets fed from the cutting
device 4, the following sheet under the trailing edge portion of
the preceding sheet and conveys the two sheets with their edges
being lapped. Note that"the trailing edge portion of the preceding
sheet" means"the upstream edge in the sheet convey direction of a
sheet located downstream in the sheet convey direction". Also, "the
leading edge portion of the following sheet" means"the downstream
edge in the sheet convey direction of a sheet located upstream in
the sheet convey direction".
[0018] A known sheet-fed offset rotary printing press 6 includes a
feeder board 8 which feeds one by one the sheets conveyed from the
sheet convey apparatus 1 described above, a printing unit 9 which
prints the sheets fed from the feeder board 8, and a delivery unit
10 which delivers the sheets printed by the printing unit 9. The
printing unit 9 includes two printing units 9A and 9B sequentially
disposed in the sheet convey direction. Each of the printing units
9A and 9B includes a plate cylinder 11 to which ink and water are
supplied from an inking device and dampening device (not shown), a
blanket cylinder 12 which is in contact with the plate cylinder 11,
and an impression cylinder 13 which opposes the blanket cylinder
12. A transfer cylinder 14 is arranged between the impression
cylinders 13 of the printing units 9A and 9B.
[0019] The delivery unit 10 includes a sprocket 15 coaxial with a
delivery cylinder (not shown) which opposes the impression cylinder
13 of the printing unit 9B, a sprocket 16 rotatably supported at
the rear end side of the delivery unit 10, and a delivery chain 17
applied between the sprockets 15 and 16. In this arrangement, a
sheet fed from the feeder board 8 is printed on its obverse surface
with the first color by the printing unit 9A. The sheet is then
conveyed to the printing unit 9B by the transfer cylinder 14, and
its obverse surface is printed with the second color. The printed
sheet is gripping-changed to the delivery pawls (not shown) of the
delivery chain 17 and conveyed as the delivery chain 17 runs. When
the sheet is conveyed to the rear end side of the delivery unit 10,
the delivery pawls release the sheet, so that the sheet drops onto
a pile board (not shown) and is stacked there.
[0020] The lapping unit 5 of the sheet convey apparatus 1 will be
described with reference to FIGS. 2 and 3. The lapping unit 5
includes a first conveyor belt 20 (first convey means) which
conveys a sheet 19 cut by the cutting device 4, and a second
conveyor belt 21 (second convey means) which is arranged downstream
(direction of an arrow A) of the first conveyor belt 20 in the
sheet convey direction. The first and second conveyor belts 20 and
21 are arranged on one plane.
[0021] As shown in FIG. 2, the first conveyor belt 20 is formed of
one endless belt having a width larger than the width (the length
in a direction perpendicular to the sheet convey direction) of the
sheet 19. The endless belt which forms the first conveyor belt 20
is looped between a first driving roller 22 and a driven roller
(not shown) arranged in the vicinity of the cutting device 4 to
extend in the directions of the arrow A and an arrow B. When the
first driving roller 22 is driven to rotate by a first motor 23,
the first conveyor belt 20 travels at a speed V1 in the direction
of the arrow A.
[0022] As shown in FIG. 2, the second conveyor belt 21 is formed of
one endless belt having the same width as that of the first
conveyor belt 20. The endless belt which forms the second conveyor
belt 21 is looped between a second driving roller 24 and a driven
roller (not shown) arranged in the vicinity of the feeder board 8
to extend in the directions of the arrows A and B. When the second
driving roller 24 is driven to rotate by a second motor 25, the
second conveyor belt 21 travels at a speed V2 lower than the
traveling speed V1 of the first conveyor belt 20 in the direction
of the arrow A.
[0023] Above the first conveyor belt 20, an air pipe 26 is arranged
upstream (the direction of the arrow B) of a rotary body 30 (to be
described later) in the sheet convey direction. The air pipe 26
extends in the widthwise direction of the sheet 19, i.e., the first
conveyor belt 20, and is connected to an air supply source (not
shown) such as a compressor through a pipe 27A. The air pipe 26 has
air nozzles 28 (air discharge means) that line up equidistantly on
one straight line in the axial direction. As shown in FIG. 3, the
air nozzles 28 are arranged such that their distal ends are
directed obliquely downward toward the downstream side of the sheet
convey direction (the direction of the arrow A). Air 29 discharged
from the air nozzles 28 is blown to a portion between the first
driving belt 20 and the rotary body 30. The air pipe 26 is
pivotally supported by a pair of frames 31 (FIG. 2) which oppose
each other at a predetermined gap. A blowing angle a of the air 29
discharged from the air nozzles 28 is adjusted by a stepping motor
32 (FIG. 2). The discharge speed of the air 29 is adjusted by an
air flow rate adjusting device 34 (to be described later).
[0024] A gear 32a axially mounted on the output shaft of the
stepping motor 32 meshes with gears 26a and 33a, as shown in FIG.
2. The gear 26a is axially mounted on an end shaft 26b of the air
pipe 26. The gear 33a is axially mounted on the rotating shaft of
an encoder 33. In this arrangement, when the stepping motor 32 is
driven, the air pipe 26 pivots through the gears 32a and 26a. The
pivot amount of the air pipe 26 is detected by the encoder 33
through the gears 32a and 33a. When the blowing angle .alpha. of
the air 29 reaches a predetermined value, the stepping motor 32
stops driving to fix the blowing angle .alpha. of the air 29.
[0025] As shown in FIG. 4, the air flow rate adjusting device 34
includes an electromagnetic valve 35 having an actuator 35a which
can advance/retreat, and a valve 36 having one end pivotally
mounted on the actuator 35a and the other end biased by a coil
spring 37 in a direction to separate from the actuator 35a. When
driven by the electromagnetic valve 35, the valve 36 moves across
the boundary portion of the pipe 27A and a hose 27B in a direction
perpendicular to an air channel to open/close the sectional area of
the air channel. The valve 36 has an air passage 36a through which
the pipe 27A communicates with the hose 27B, and an exhaust passage
36b through which the pipe 27A communicates with outer air. In this
arrangement, when the electromagnetic valve 35 is driven to change
the advancing/retreating amount of the actuator 35a, the opening
amount between the pipe 27A and hose 27B is adjusted to adjust the
discharge speed of the air 29 to be discharged from the air nozzles
28.
[0026] Above the first driving belt 20, as shown in FIG. 3, the
rotary body 30 is arranged upstream of the first driving roller 22
in the sheet convey direction to be parallel to the first driving
roller 22. The rotary body 30 is rotatably supported by the pair of
frames 31 so as to extend in the widthwise direction of the sheet
19 under conveyance. The rotary body 30 is arranged to correspond
to the position of a trailing edge portion 19a of a sheet 19A when
a leading edge portion 19b of the sheet 19A conveyed by the first
conveyor belt 20 separates from the first conveyor belt 20 and
starts to come into contact with the second conveyor belt 21. In
this arrangement, the trailing edge portion 19a of the sheet 19A
which floats with the air 29 discharged from the air nozzles 28
comes into contact with the rotary body 30, so that the floating
sheet 19A is guided.
[0027] The sheet convey operation of the sheet convey apparatus
with the above arrangement will be described. Air has been supplied
to the air pipe 26 in advance from an air supply source (not shown)
through the pipe 27A and hose 27B, and the air nozzles 28
constantly discharge the air 29. In this state, in FIG. 1, the web
2 fed out from the roll 3 is cut by the cutting device 4 into
sheets each having a predetermined size. The cut sheets are
sequentially fed onto the first conveyor belt 20 of the lapping
unit 5. The fed sheet 19A is conveyed by the first conveyor belt 20
at the convey speed V1 in the direction of the arrow A.
[0028] When the leading edge portion 19b of the sheet 19A separates
from the first conveyor belt 20 and comes into contact with the
second conveyor belt 21, as the traveling speed V2 of the second
conveyor belt 21 is lower than the traveling speed V1 of the first
conveyor belt 20, the convey speed of the sheet 19A also decreases.
At this time, the trailing edge portion 19a of the sheet 19A is
located under the rotary body 30. The air nozzles 28 arranged
upstream of the rotary body 30 in the sheet convey direction
discharge the air 29 obliquely downward toward the downstream side
of the sheet convey direction (direction of the arrow A).
[0029] Therefore, the air 29 enters under the trailing edge portion
19a of the preceding sheet 19A to float the trailing edge portion
19a. Thus, a leading edge portion 19b of a following sheet 19B
which has been conveyed by the first conveyor belt 20 at the speed
V1 higher than the speed V2 is inserted under the trailing edge
portion 19a of the preceding sheet 19A. The air 29 from the air
nozzles 28 urges the leading edge portion 19b of the upstream sheet
19B against the first conveyor belt 20. Thus, the leading edge
portion 19b of the sheet 19B is reliably inserted under the
trailing edge portion 19a of the preceding sheet 19A.
[0030] The air nozzles 28 are arranged, above the first conveyor
belt 20, upstream of the rotary body 30 in the sheet convey
direction. Hence, even if the air 29 is constantly discharged, the
upper surface of the sheet 19 on the first conveyor belt 20 is
blown with air. This urges the sheet 19 against the first conveyor
belt 20 so the sheet convey operation is not influenced. After
that, when the sheet 19 moves to the second conveyor belt 21 and
its trailing edge portion 19a is positioned below the rotary body
30, the air 29 is blown between the lower surface of the trailing
edge portion 19a and the first conveyor belt 20 to lift up the
trailing edge portion 19a.
[0031] More specifically, even if the air 29 is discharged
constantly, when the trailing edge portion 19a of the preceding
sheet 19A is positioned below the rotary body 30, the trailing edge
portion 19a floats by the air 29. The leading edge portion 19b of
the following sheet 19B is conveyed as it is pressed (urged) with
the air 29 against the first conveyor belt 20. In this manner, even
if the air 29 is discharged constantly, the edges of the sheets
that travel continuously can be lapped reliably. Thus, the
discharge timing of the air 29 need not be adjusted.
[0032] The floating trailing edge portion 19a of the sheet 19A
comes into contact with the rotary body 30 and is conveyed in the
direction of the arrow A as it is guided by the rotary body 30. In
this manner, as the trailing edge portion 19a of the preceding
sheet 19A is guided by the rotary body 30, it will not flutter or
waves, so that uncontrolled movement of the sheet is regulated. As
the rotary body 30 is rotatably supported, it is rotated in an
interlocked manner by the friction generated between the outer
surface of the rotary body 30 and the trailing edge portion 19a of
the sheet 19A which is in contact with the outer surface of the
conveyor belt 20. Therefore, no rubbing occurs between the sheet
19A and rotary body 30, and the trailing edge portion 19a will not
be damaged. Even when the gap between the cutting device 4 and
sheet-fed offset rotary printing press 6 is large, the two, first
and second conveyor belts 20 and 21 as the sheet convey means can
form the sheet convey path, so that the number of components
decreases and the structure is simplified.
[0033] In the state wherein the trailing edge portion 19a of the
sheet 19A is guided by the rotary body 30, when the sheet 19A is
further conveyed in the direction of the arrow A by the second
conveyor belt 21, the trailing edge portion 19a of the sheet 19A
separates from the rotary body 30. Then, the trailing edge portion
19a of the sheet 19A drops onto the leading edge portion 19b of the
following sheet 19B to lap it.
[0034] In this case, depending on the weight, size, or stiffness
(hardness) of the sheet, if the floating amount of the trailing
edge portion 19a of the sheet 19A is not sufficient, the discharge
speed of the air 29 is adjusted by the blowing angle .alpha. of the
air 29 discharged from the air nozzles 28 or by the air flow rate
adjusting device 34. As a result, the quantity of air 29 to be
supplied under the trailing edge portion 19a of the preceding sheet
19A increases to complement the insufficient floating amount of the
trailing edge portion 19a . Thus, the edges of the two sheets lap
reliably.
[0035] The second embodiment of the present invention will be
described with reference to FIG. 5. The second embodiment is
different from the first embodiment described above in that the
first convey means is formed of a plurality of first conveyor belts
40 and that the second convey means is formed of a plurality of
second conveyor belts 41. The first and second conveyor belts 40
and 41 are formed of narrow endless belts obtained by dividing the
conveyor belts 20 and 21 of the first embodiment each into a
plurality of portions in the widthwise direction of the sheet to be
conveyed. The first conveyor belts 40 line up equidistantly in the
widthwise direction of the sheet to be conveyed, and are looped
between a first driving roller 22 and a driven roller (not shown)
to extend in the directions of arrows A and B.
[0036] The second conveyor belts 41 having the same total width as
that of the first conveyor belts 40 line up equidistantly in the
widthwise direction of the sheet to be conveyed to correspond to
the first conveyor belts 40, and are looped between a second
driving roller 24 and a driven roller 42 provided in the vicinity
of a feeder board 8 to extend in the directions of the arrows A and
B.
[0037] A plurality of air nozzles 43 formed in an air pipe 26
correspond to every other one of the first conveyor belts 40. Air
discharged from the nozzles 43 is blown to diffuse in the widthwise
direction of the first conveyor belts 40.
[0038] In this arrangement, when the leading edge portion of a
sheet which is being conveyed by the first conveyor belts 40 in the
direction of the arrow A comes into contact of the second conveyor
belts 41, the convey speed of the sheet decreases. Simultaneously,
the air blown from the air nozzles 43 floats the trailing edge
portion of the sheet. Thus, the leading edge portion of a following
sheet which is being conveyed by the first conveyor belts 40 in the
direction of the arrow A is inserted under the trailing edge
portion of the preceding sheet which floats. Hence, in the same
manner as in the first embodiment, the two successive sheets are
conveyed in the direction of the arrow A with the leading edge
portion of the upstream sheet underlapping the trailing edge
portion of the downstream sheet.
[0039] While belts are used in this embodiment as a means for
conveying the sheet 19, the sheet may be alternatively conveyed by
a rotary roller. While the air 29 is discharged constantly from the
air nozzles 28, it may be alternatively discharged intermittently.
While a case has been described wherein the air flow rate adjusting
device 34 is used as a means for adjusting the discharge speed of
the air to be discharged from the nozzles 28, the adjusting means
is not limited to this. For example, when a DC motor is used as the
motor of a blower that constitutes an air supply source which
supplies air to the air pipe 26, the DC power supply voltage to be
supplied to the motor may be adjusted. When an AC motor is used as
the blower motor, the AC power supply frequency may be adjusted.
Alternatively, a regulator or relief valve may be disposed midway
along the pipe 27A.
[0040] In the above embodiment, the roll-type sheet is cut by the
cutting device and pre cut sheets are supplied at a predetermined
interval. The present invention can also naturally be applied to a
case wherein pre cut sheets are conveyed in a lapping manner. The
sheet to be conveyed is not limited to a paper sheet, but can be
any sheet-type object, e.g., a plastic sheet or film, which can be
printed on its obverse surface.
[0041] As has been described above, according to the present
invention, the leading edge portion of an upstream sheet can be
reliably inserted under the trailing edge portion of a downstream
sheet. Therefore, the edges of two successive sheets can be lapped
reliably. While the air is constantly discharged, the edges of the
two sheets can be lapped reliably. Thus, the air discharge timing
need not be adjusted. As the trailing edge portion of the floating
sheet is guided by the rotary body, the sheet will not be
damaged.
[0042] Even when the sheets are to be conveyed at a relatively long
interval, this can be coped with by two sets of belts. Thus, the
number of components decreases and the structure is simplified. If
the floating amount of the trailing edge portion of the sheet is
not sufficient, the air speed or air blowing angle may be adjusted
to increase the quantity of air to be supplied under the trailing
edge portion of the sheet, so that the edges of the two sheets can
be lapped reliably.
* * * * *