U.S. patent application number 11/800820 was filed with the patent office on 2008-09-25 for sheet folding apparatus.
Invention is credited to Katsunori Ishida, Masamichi Kanao, Tomoyuki Shimizu.
Application Number | 20080234118 11/800820 |
Document ID | / |
Family ID | 38457886 |
Filed Date | 2008-09-25 |
United States Patent
Application |
20080234118 |
Kind Code |
A1 |
Ishida; Katsunori ; et
al. |
September 25, 2008 |
Sheet folding apparatus
Abstract
A buckle (3, 4) is provided with a position adjustable stopper
(5, 6) for stopping a sheet (P) by coming into collision with the
leading edge of the sheet (P) so as to position the sheet in a fold
position. In the inlet of the buckle, there are provided a pair of
rotary drive folding rollers (20a, 20b; 20c, 20d) for taking the
sheet in the buckle, and a pair of rotary drive folding rollers
(20b, 20c; 20d, 20e) for folding a portion of the sheet deflecting
from the buckle. A sheet detector (16, 17) is arranged in the
buckle at a predetermined spacing from the stopper. A control
section (29) outputting a signal for deceleration to a driving
source of the roller upon reception of a sheet detection signal
from the sheet detector and stopping output of the signal for
deceleration after elapse of a predetermined time. After the
leading edge of the sheet introduced into the buckle passes through
the sheet detector, the rotational speed of the roller is reduced
to decrease the conveying speed of the sheet, the leading edge of
the sheet collides with the stopper at a sufficiently reduced
speed, thereafter, the rotational speed of the roller is gradually
increased so that the rotational speed before being reduced is
recovered when the next sheet is introduced into the buckle.
Inventors: |
Ishida; Katsunori; (Shiga,
JP) ; Kanao; Masamichi; (Shiga, JP) ; Shimizu;
Tomoyuki; (Shiga, JP) |
Correspondence
Address: |
KIRSCHSTEIN, OTTINGER, ISRAEL;& SCHIFFMILLER, P.C.
425 FIFTH AVENUE, 5TH FLOOR
NEW YORK
NY
10016-2223
US
|
Family ID: |
38457886 |
Appl. No.: |
11/800820 |
Filed: |
May 8, 2007 |
Current U.S.
Class: |
493/23 ; 493/420;
493/476 |
Current CPC
Class: |
B65H 45/141
20130101 |
Class at
Publication: |
493/23 ; 493/420;
493/476 |
International
Class: |
B65H 45/14 20060101
B65H045/14 |
Foreign Application Data
Date |
Code |
Application Number |
May 10, 2006 |
JP |
2006-131239 |
Claims
1. A sheet folding apparatus having: at least one buckle (3, 4) in
which a sheet (P) to be folded is introduced to a length
corresponding to a predetermined fold position, said at least one
buckle (3, 4) being provided with a position adjustable stopper (5,
6) for stopping the introduced sheet (P) by coming into collision
with the leading edge of the sheet (P) so as to position the sheet
(P) in said fold position; a pair of rotating rollers (20a, 20b;
20c, 20d) arranged near the inlet of said buckle (3, 4) and
oppositely to each other for taking the sheet (P) in said buckle
(3, 4); and a pair of rotating rollers (20b, 20c; 20d, 20e)
arranged near the inlet of said buckle (3, 4) and oppositely to
each other for folding a portion of the sheet (P) deflecting from
said buckle (3, 4), the sheet folding apparatus characterized by a
sheet detector (16, 17) arranged at a predetermined spacing from
said stopper (5, 6) of said buckle (3, 4) toward the inlet of said
buckle (3, 4) and detecting passage of the sheet (P); and a control
section (29) outputting a signal for deceleration to a driving
source (23) of said roller (20a to 20e) upon reception of a sheet
detection signal from said sheet detector (16, 17) and stopping
output of said signal for deceleration after elapse of a
predetermined time, whereby, after the leading edge of the sheet
(P) introduced into said buckle (3, 4) passes through said sheet
detector (16, 17), the rotational speed of said rollers (20a to
20e) is reduced to decrease the conveying speed of the sheet (P),
the leading edge of the sheet (P) comes into collision with said
stopper (5, 6) at a sufficiently reduced speed, and thereafter the
rotational speed of said roller (20a to 20e) is gradually increased
so that the rotational speed before being reduced is recovered when
the next sheet (P) is introduced into said buckle (3, 4).
2. A sheet folding apparatus having: at least one buckle (3, 4) in
which a sheet (P) to be folded is introduced to a length
corresponding to a predetermined fold position, said at least one
buckle (3, 4) being provided with a position adjustable stopper (5,
6) for stopping the introduced sheet (P) by coming into collision
with the leading edge of the sheet (P) so as to position the sheet
(P) in said fold position; a pair of rotating rollers (20a, 20b;
20c, 20d) arranged near the inlet of said buckle (3, 4) and
oppositely each other for taking the sheet (P) in said buckle (3,
4); and a pair of rotary drive rollers (20b, 20c; 20d, 20e)
arranged near the inlet of said buckle (3, 4) and oppositely to
each other for folding a portion of the sheet (P) deflecting from
said buckle (3, 4), the sheet folding apparatus characterized by a
sheet detector (30) arranged upstream of the pair of rollers (20a,
20b) for taking the sheet (P) in the uppermost stream buckle (3)
for detecting passage of the sheet (P); a rotary encoder (31)
mounted on at least one rotating shaft of said rollers (20a to 20e)
arranged near the inlet of said buckle (3, 4) or at least one
another rotating shaft rotatable in conjunction with said rotating
shaft of said rollers (20a to 20e); and a control section (29)
starting counting the number of pulses outputted from said rotary
encoder (31) upon reception of a sheet detection signal from said
sheet detector (30) to measure the conveying distance of the sheet
(P), outputting a signal for deceleration to a driving source (23)
of said roller (20a to 20e) when the sheet (P) reaches a
predetermined position, and stopping output of said signal for
deceleration when the sheet (P) reaches the next predetermined
position, whereby, after the leading edge of the sheet (P) passes
through said sheet detector (30), the rotational speed of said
roller (20a to 20e) is reduced to decrease the conveying speed of
the sheet (P), the leading edge of the sheet (P) comes into
collision with said stopper (5, 6) at a sufficiently reduced speed,
and, thereafter, the rotational speed of said roller (20a to 20e)
is gradually increased so that the rotational speed before being
reduced is recovered when the next sheet (P) is introduced into
said buckle (3, 4).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sheet folding
apparatus.
[0003] 2. Description of the Related Art
[0004] A conventional sheet folding apparatus has at least one
buckle in which a sheet to be folded is introduced to a length
corresponding to a predetermined fold position. The buckle is
provided with a position adjustable stopper for stopping the
introduced sheet by coming into collision with the leading edge of
the sheet so as to position the sheet in the fold position. Near
the inlet of the buckle, a pair of rotating rollers are arranged
oppositely to each other for taking the sheet in the buckle and a
pair of rotating rollers are arranged oppositely to each other for
folding a portion of the sheet deflecting from the buckle.
[0005] The sheet folding apparatus typically folds 100 or more
sheets per minute. Each of the sheets collides with the stopper of
the buckle at a speed of 900 mm per second, and at the same time,
is deflected in the buckle to contact with the inner wall surface
of the buckle. The noise of the collision and the noise of the
contact of the sheet with the inner wall surface of the buckle
together with the noise of sheet nipping of the rollers cause a
noise problem in the installation location for the sheet folding
apparatus such as an office.
[0006] In order to reduce such noise, there is proposed a method of
attaching an elastic member for relieving any impact at a time of
collision to the front surface of the stopper of the buckle (see
Japanese Laid-Open Patent Publication No. H11-106127). There is
also proposed a method of reducing the speed of a sheet in such a
manner that an elastic slide is arranged ahead of the stopper of
the buckle for coming into collision with the leading edge of the
sheet (see Japanese Laid-Open Patent Publication No.
2004-345773).
[0007] These methods can reduce the noise of collision of the sheet
with the stopper, but cannot reduce the noise of the contact of the
sheet with the inner wall surface of the buckle and the noise of
sheet nipping of the rollers. Consequently, the noise level at
operation cannot be improved much. In addition, the movement of the
stopper provided with the elastic member and the elastic slide is
not smooth, which brings the result that the stop position of the
sheet in the buckle fluctuates, so that the fold position of the
sheet can be easily misaligned.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a sheet
folding apparatus capable of achieving considerably low level of
the noise at operation thereof and ensuring a stable fold position
of a sheet.
[0009] In order to achieve the object, in accordance with the
present invention, there is provided a sheet folding apparatus
having: at least one buckle in which a sheet to be folded is
introduced to a length corresponding to a predetermined fold
position, the at least one buckle being provided with a position
adjustable stopper for stopping the introduced sheet by coming into
collision with the leading edge of the sheet so as to position the
sheet in the fold position; a pair of rotating rollers arranged
near the inlet of the buckle and oppositely to each other for
taking the sheet in the buckle; and a pair of rotating rollers
arranged near the inlet of the buckle and oppositely to each other
for folding a portion of the sheet deflecting from the buckle, the
sheet folding apparatus characterized by a sheet detector arranged
at a predetermined spacing from the stopper of the buckle toward
the inlet of the buckle and detecting passage of the sheet; and a
control section outputting a signal for deceleration to a driving
source of the roller upon reception of a sheet detection signal
from the sheet detector and stopping output of the signal for
deceleration after elapse of a predetermined time, whereby, after
the leading edge of the sheet introduced into the buckle passes
through the sheet detector, the rotational speed of the rollers is
reduced to decrease the conveying speed of the sheet, the leading
edge of the sheet comes into collision with the stopper at a
sufficiently reduced speed, and thereafter the rotational speed of
the roller is gradually increased so that the rotational speed
before being reduced is recovered when the next sheet is introduced
into the buckle.
[0010] Alternatively, in order to achieve the object, in accordance
with the present invention, there is provided a sheet folding
apparatus having: at least one buckle in which a sheet to be folded
is introduced to a length corresponding to a predetermined fold
position, the at least one buckle being provided with a position
adjustable stopper for stopping the introduced sheet by coming into
collision with the leading edge of the sheet so as to position the
sheet in the fold position; a pair of rotating rollers arranged
near the inlet of the buckle and oppositely each other for taking
the sheet in the buckle; and a pair of rotary drive rollers
arranged near the inlet of the buckle and oppositely to each other
for folding a portion of the sheet deflecting from the buckle, the
sheet folding apparatus characterized by a sheet detector arranged
upstream of the pair of rollers for taking the sheet in the
uppermost stream buckle for detecting passage of the sheet; a
rotary encoder mounted on at least one rotating shaft of the
rollers arranged near the inlet of the buckle or at least one
another rotating shaft rotatable in conjunction with the rotating
shaft of the rollers; and a control section starting counting the
number of pulses outputted from the rotary encoder upon reception
of a sheet detection signal from the sheet detector to measure the
conveying distance of the sheet, outputting a signal for
deceleration to a driving source of the roller when the sheet
reaches a predetermined position, and stopping output of the signal
for deceleration when the sheet reaches the next predetermined
position, whereby, after the leading edge of the sheet passes
through the sheet detector, the rotational speed of the roller is
reduced to decrease the conveying speed of the sheet, the leading
edge of the sheet comes into collision with the stopper at a
sufficiently reduced speed, and, thereafter, the rotational speed
of the roller is gradually increased so that the rotational speed
before being reduced is recovered when the next sheet is introduced
into the buckle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side view illustrating the configuration of a
sheet folding apparatus according to a first embodiment of the
present invention;
[0012] FIG. 2 is an enlarged side view illustrating the
configuration around a buckle of the sheet folding apparatus of
FIG. 1;
[0013] FIG. 3(A) is a timing diagram of control of rotational speed
of a motor by a control section;
[0014] FIG. 3(B) is a diagram illustrating sheet positions at
points (i) and (ii) of the timing diagram of FIG. 3(A);
[0015] FIG. 4 is a side view illustrating the configuration of the
sheet folding apparatus according to another embodiment of the
present invention;
[0016] FIG. 5(A) is a timing diagram of control of rotational speed
of a motor by a control section; and
[0017] FIG. 5(B) is a diagram illustrating sheet positions at
points (i) and (ii) of the timing diagram of FIG. 5(A).
DETAILED EXPLANATION OF PREFERRED EMBODIMENTS
[0018] Preferred embodiments of the present invention will be
described below with reference to the accompanying drawings. FIG. 1
is a side view illustrating the configuration of a sheet folding
apparatus according to a first embodiment of the present invention,
and FIG. 2 is an enlarged side view illustrating the configuration
around a buckle of the sheet folding apparatus of FIG. 1.
[0019] Referring to FIGS. 1 and 2, the sheet folding apparatus of
the present invention has a sheet supply table 1 arranged for
up-and-down movement and supporting a sheet bundle of sheets P to
be folded thereon, a vertical plate 1a disposed ahead of the sheet
supply table 1 and aligning the leading edge of the sheet bundle on
the sheet supply table 1, and a sheet feed roller 2 sequentially
feeding the uppermost sheet P of the sheet bundle on the sheet
supply table 1.
[0020] The sheet folding apparatus also has first and second
buckles 3 and 4 in which the sheet P is introduced to a length
corresponding to a predetermined fold position. As illustrated, the
first and second buckles 3 and 4 have a pair of plates 3a, 3b; 4a,
4b arranged oppositely to each other at a small spacing
therebetween.
[0021] The first and second buckles 3 and 4 have stoppers 5 and 6
bringing the leading edge of the sheet P introduced to stop the
sheet for positioning the sheet to a fold position, and sheet
detectors 16 and 17 detecting passage of the sheet in the positions
at a predetermined spacing from the stoppers 5 and 6 toward the
inlets of the buckles 3 and 4.
[0022] The stoppers 5 and 6 are attached to belt driving mechanisms
7 and 8 arranged along the first and second buckles 3 and 4. The
position of each of the stoppers 5 and 6 is adjustable along a
direction of the length of the first and second buckles 3 and 4.
The belt driving mechanisms 7 and 8 comprise a pair of horizontal
rollers 9a, 9b; 10a, 10b are arranged at a spacing therebetween in
a direction of the length of the buckles 3 and 4 and each extending
in a direction of the width of the buckles, endless belts 12 and 13
extended through a pulley 11 between the pair of rollers 9a, 9b;
10a, 10b, and motors 14 and 15 driving one of the rollers 9a;
10a.
[0023] The stoppers 5 and 6 are attached to the endless belts 12
and 13. With the rotational motion of the endless belts 12 and 13
by driving of the motors 14 and 15, the stoppers 5 and 6 can be
moved in the direction of the length of the buckles 3 and 4.
[0024] The sheet detectors 16 and 17 are connected to the
associated stoppers 5 and 6 through support members 18 and 19 and
arranged ahead of the stoppers 5 and 6 in such a manner that the
sheet detectors 16 and 17 can be moved together with the associated
stoppers 5 and 6. In this case, the sheet detectors 16 and 17 nay
be arranged separately from the stoppers 5 and 6.
[0025] Five folding rollers 20a to 20e are arranged one above the
other near the inlets of the first and second buckles 3 and 4 for
rotation round horizontal axes extending in a direction of the
width of the buckles 3 and 4 in such a manner that the adjacent
rollers are contacted with each other. The folding rollers 20a to
20e have the same diameter. Among them, the three middle folding
rollers 20b, 20c, and 20d are formed as an idle roller. The
uppermost folding roller 20a and the lowermost folding roller 20e
are formed as a driving roller.
[0026] A motor 23 is arranged for driving the uppermost folding
roller 20a and the lowermost folding roller 20e. A pulley 24 is
fixed to the driving shaft of the motor 23. Pulleys 21a and 21b are
fixed to the rotational axes of the folding rollers 20a and 20e. An
endless belt 22 is extended between the pulleys 21a and 21b and the
pulley 24. The motor 23 drives the folding rollers 20a and 20e,
whereby the middle folding rollers 20b to 20d are driven. In this
embodiment, the folding rollers 20a to 20e are driven by the single
motor 23. The folding rollers 20a to 20e may be driven by plural
motors, or, alternatively, the folding rollers 20a to 20e may be
driven by independent motors, respectively.
[0027] The folding rollers 20a and 20b function as a pair of
rollers for nipping the sheet P so as to introduce it into the
first buckle 3. The folding rollers 20b and 20c function as a pair
of rollers for nipping a portion of the sheet P deflecting from the
first buckle 3 so as to fold it. The folding rollers 20c and 20d
function as a pair of rollers for introducing the folded sheet P
received from the folding rollers 20b and 20c into the second
buckle 4 with the folded portion in the lead. The folding rollers
20d and 20e function as a pair of rollers for nipping a portion of
the sheet P deflecting from the second buckle 4 so as to it.
[0028] A feed roller 25 is arranged for rotation round a horizontal
axis. The feed roller 25 is contacted with the uppermost folding
roller 20a so as to be rotated with the rotation of the folding
roller 20a.
[0029] The positions of the stoppers 5 and 6 are adjusted according
to the fold position of the sheet P. For instance, when the sheet P
is folded into three equal parts in its longitudinal direction, the
stopper 5 is adjusted by actuating the belt driving mechanism 7 in
such a manner that two-thirds of the length of the sheet P is
introduced into the first buckle 3. In addition, the stopper 6 is
adjusted by actuating the belt driving mechanism 8 in such a manner
that one-half of the length of the sheet P folded once by the first
buckle 3 is introduced into the second buckle 4.
[0030] The uppermost sheet P of the sheet bundle placed on the
sheet supply table 1 is fed by the sheet feed roller 2 one by one,
nipped between the feed roller 25 and the folding roller 20a and
conveyed, and then nipped between the folding rollers 20a and 20b
and introduced into the first buckle 3. The sheet P is stopped by
the leading edge thereof coming into collision with the stopper 5.
The one-third length of the rear of the sleet P is still nipped
between the folding rollers 20a and 20b so as to be conveyed to the
first buckle 3, so that the sheet P is deflected from the first
buckle 3. The top of the deflected portion of the sheet P is nipped
between the folding rollers 20b and 20c and folded by them.
[0031] After the sheet P is folded once, the folded sheet P is
discharged from between the folding rollers 20b and 20c. When the
sheet P is folded twice, the sheet P folded by the folding rollers
20b and 20c is delivered between the folding rollers 20c and 20d
and introduced into the second buckle 4 with the folded portion in
the lead. The introduced sheet P is stopped by the leading edge
thereof coming into collision with the stopper 6. The one-third
length of the rear of the sheet P is still nipped between the
folding rollers 20c and 20d so as to be conveyed to the second
buckle 4, so that the sheet P is deflected from the second buckle
4. The top of the deflected portion of the sheet P is nipped
between the folding rollers 20d and 20e and folded by them. The
folded sheet P is conveyed from the folding rollers 20d and 20e
through a discharge belt 26 and a discharge roller 27 to a
discharge tray 28.
[0032] According to the present invention, the sheet folding
apparatus has a control section 29 outputting a signal for
deceleration to the motor 23 upon reception of a sheet detection
signal from the sheet detectors 16 and 17 and stopping output of
the signal for deceleration after elapse of a predetermined
time.
[0033] FIG. 3(A) is a timing diagram of control of the rotational
speed of the motor by the control section, and FIG. 3(B) is a
diagram illustrating sheet positions at points (i) and (ii) of the
timing diagram of FIG. 3(A). Referring to FIGS. 3(A) and 3(B), when
the leading edge of the sheet P introduced into the first and
second buckles 3 and 4 passes through the sheet detectors 16 and 17
(point (i)), the sheet detection signal is outputted from the sheet
detectors 16 and 17 and received by the control section 29. The
control section 29 outputs the signal for deceleration to the motor
23 upon reception of the sheet detection signal. The rotational
speed of the folding rollers 20a to 20e is gradually reduced to
decrease the conveying speed of the sheet P. When the leading edge
of the sheet P passes through the sheet detectors 16 and 17 and the
predetermined time elapses, the control section 29 stops output of
the signal for deceleration. In this embodiment, time from the
start to stop of output of the signal for deceleration is set in
such a manner that the rotational speed of the folding rollers 20a
to 20e is the lowest when the leading edge of the sheet P collides
with the stoppers 5 and 6 of the first and second buckles 3 and 4
(point (ii)), that is, that the speed of the motor 23 is the lowest
immediately before the leading edge of the sheet P collides the
stoppers 5 and 6.
[0034] When output of the signal for deceleration is stopped, the
motor 23 gradually increases the rotational speed. When the next
sheet is introduced into the first and second buckles 3 and 4, the
rotational speed before being reduced is recovered. Along with it,
the rotational speed of the rollers 20a to 20e is gradually
increased. When the next sheet is introduced into the buckles, the
rotational speed before being reduced is recovered.
[0035] The conveying speed of the sheet P introduced into the first
and second buckles 3 and 4 is gradually reduced. When it is
sufficiently reduced, the sheet P is stopped by the leading edge
thereof coming into collision with the stoppers 5 and 6. It is
possible to greatly reduce not only the noise of collision of the
sheet with the stopper but also the noise of the contact of the
sheet with the inner wall surface of the buckle and the noise of
sheet nipping of the rollers. The noise level at operation of the
sheet folding apparatus is considerably lowered. In addition, the
fold position of the sheet is hardly fluctuated.
[0036] FIG. 4 is a side view illustrating the configuration of the
sheet folding apparatus according to another embodiment of the
present invention and is similar to FIG. 1. The embodiment of FIG.
4 is different from the embodiment of FIG. 1 in timing of
rotational speed control of the motor. The same constituent
elements in FIG. 4 as those shown in FIG. 1 are indicated by
similar numerals and the detailed description is omitted.
[0037] In this embodiment, as shown in FIG. 4, a sheet detector 30
is arranged in the sheet conveying passage between the sheet feed
roller 2 and the feed roller 25. A rotary encoder 31 is mounted on
the rotating shaft of the uppermost folding roller 20a. In this
case, the rotary encoder 31 may be mounted on any one of the
rotating shafts of the folding rollers 20b through 20e, or,
alternatively, the rotary encoder 31 may be mounted on the drive
shaft of the motor 23 or the rotating shaft of the feed roller 25.
The control section 29 starts counting the number of pulses
outputted from the rotary encoder 31 upon reception of the sheet
detection signal from the sheet detector 30 to measure the
conveying distance of the sheet P. The control section 29 outputs
the signal for deceleration to the motor 23 when the sheet P
reaches a predetermined position, and stops output of the signal
for deceleration when the sheet reaches the next predetermined
position.
[0038] FIG. 5(A) is a timing diagram of control of the rotational
speed of the motor by the control section 29, and FIG. 5(B) is a
diagram illustrating sheet positions at points (i) and (ii) of the
timing diagram of FIG. 5(A). Referring to FIGS. 5(A) and 5(B), when
the leading edge of the sheet P fed from the sheet feed roller 2
passes through the sheet detector 30, the sheet detection signal is
outputted from the sheet detector 30 and received by the control
section 29. The control section 29 starts counting the number of
pulses outputted from the rotary encoder 31 upon reception of the
sheet detection signal to measure the conveying distance of the
sheet. The control section 29 outputs the signal for deceleration
to the motor 23 when the leading edge of the sheet P reaches a
predetermined position (point (i)) ahead of the stoppers 5 and 6 of
the buckles 3 and 4. Thereafter, the control section 29 stops
output of the signal for deceleration when the sheet P reaches the
next predetermined position (point (ii)), in this embodiment, the
position in which the leading edge of the sheet P collides with the
stoppers 5 and 6. After the sheet P is introduced into the buckles
3 and 4 to pass through the predetermined position, the rotational
speed of the rollers 20a to 20e is gradually reduced to decrease
the conveying speed of the sheet P. The leading edge of the sheet P
collides with the stoppers 5 and 6 at a sufficiently reduced speed
and the sheet P is stopped. Thereafter the rotational speed of the
rollers 20a to 20e is gradually increased. The rotational speed
before being reduced is recovered when the next sheet P is
introduced into the buckles 3 and 4. This embodiment can bring
about the same effect as that of the embodiment of FIG. 1.
* * * * *