U.S. patent number 3,884,103 [Application Number 05/403,885] was granted by the patent office on 1975-05-20 for paper feeding device for a duplicating machine.
This patent grant is currently assigned to Fuji Xerox Co., Ltd.. Invention is credited to Yoshiharu Namba.
United States Patent |
3,884,103 |
Namba |
May 20, 1975 |
Paper feeding device for a duplicating machine
Abstract
A paper feeding device for a duplicating machine using a rolled
paper as a copying sheet, having a plurality pairs of feed rollers,
said pairs including intermittently paper feeding first rollers,
second rollers rotating at lower speed than the first rollers and
feeding out the paper a predetermined length at a time, third
rollers lower than the second rollers and a cutter synchronously
cutting the paper with said third rollers.
Inventors: |
Namba; Yoshiharu (Webster,
NY) |
Assignee: |
Fuji Xerox Co., Ltd. (Tokyo,
JA)
|
Family
ID: |
14246884 |
Appl.
No.: |
05/403,885 |
Filed: |
October 5, 1973 |
Foreign Application Priority Data
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Oct 5, 1972 [JA] |
|
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47-99417 |
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Current U.S.
Class: |
83/156; 83/205;
83/649; 346/94; 83/63; 83/280; 346/79 |
Current CPC
Class: |
G03G
15/6523 (20130101); Y10T 83/896 (20150401); Y10T
83/464 (20150401); Y10T 83/2196 (20150401); Y10T
83/091 (20150401); Y10T 83/4448 (20150401) |
Current International
Class: |
G03G
15/00 (20060101); B26d 005/20 () |
Field of
Search: |
;83/156,205,203,280,649,63,64 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yost; Frank T.
Attorney, Agent or Firm: Ferguson, Jr.; Gerald J. Baker;
Joseph J.
Claims
What is claimed is:
1. A paper feeding device for a duplicating machine using a paper
roll as a copying sheet, said feeding device comprising first feed
rollers for intermittently feeding said paper roll, second feed
rollers for receiving said paper roll from said first feed rollers
and for delivering a predetermined length of said paper roll, said
second feed rollers rotating at a slower rate than said first feed
rollers, third feed rollers for slackening said roll paper between
said second feed rollers and said third feed rollers by a rotation
rate differential therebetween, said third feed rollers
continuously rotating at a slower rate than said second feed
rollers, and a cutter for cutting said paper roll to a said
predetermined length, said cutter positioned between said second
feed rollers and said third feed rollers, the timing of said
cutting being synchronized to that of movement suspension of said
second feed rollers.
2. A paper feeding device for use in a duplicating machine or the
like, said feeding device comprising
at least one pair of feed rollers for receiving said copy
paper;
means for delivering a predetermined length of copy paper from said
one feed roller pair;
another feed roller pair for receiving the copy paper from the one
feed roller pair, said another feed roller pair continuously
rotating at a speed less than that of said one feed roller pair to
form a loop of said copy paper between said one and another roller
pairs;
cutting means disposed between said one and another feed roller
pairs for cutting said copy paper to said predetermined length;
and
means for stopping said one roller pair after said predetermined
length of copy paper has been delivered thereby and for actuating
said cutting means to cut said predetermined length of copy paper
before another roller pair removes said loop so that said loop
absorbs the impact of said cutting means on the copy paper to
thereby lessen the affect of the cutting step on the operation of
the duplicating machine or the like.
3. A paper feeding device for use in a duplicating machine or the
like, said feeding device comprising
first feed rollers for feeding a continuous roll of copy paper;
second feed rollers for receiving said copy paper from said first
rollers;
means for intermittently increasing the speed of said first feed
rollers with respect to said second feed rollers to form a first
loop of said copy paper therebetween to lessen slippage between
said second feed follers and said copy paper;
means for delivering a predetermined length of copy paper from said
second feed rollers;
third feed rollers for receiving the copy paper from the second
feed rollers, said third feed rollers continuously rotating at a
speed less than that of said second feed rollers to form a second
loop of said copy paper between said second and third roller
pairs;
cutting means disposed between said second and third feed rollers
for cutting said copy paper to said predetermined length; and
means for stopping said second roller pair after said predetermined
length of copy paper has been delivered thereby and for actuating
said cutting means to cut said predetermined length of copy paper
before the third roller pair removes said second loop so that said
second loop absorbs the impact of said cutting means on the copy
paper to thereby lessen the affect of the cutting step on the
operation of the duplicating machine or the like.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a paper feeding device for a duplicating
machine, particularly to a paper feeding device wherein a cutter,
operating in synchronization with paper feeding movement of feed
rollers, is positioned between a set of paper feed rollers and a
set of feed rollers for advancing a paper sheet to a copying stage
and said cutter is arranged to cut paper from a roll into a sheet
of predetermined length as the roll paper between the two sets of
feed rollers forms a loop or droop due to rotation rate
differential therebetween, and thereby adverse effects of cutting
that would otherwise be imposed on copying step may be effectively
prevented.
2. Description of the Prior Art
With recent development of high-speed duplicating machines, the
previous practice of using copying papers already cut into a
predetermined size is being gradually replaced by use of rolled
paper to be cut to predetermined size during the copying process.
Use of rolled paper requires that a cutting stage be incorporated
into the apparatus. In the case of prior-art devices wherein a
paper sheet cut in the cutting stage stops momentarily at an
exposing position to receive light rays before entering into a
fixing stage, the momentary halting of the copying sheet for
exposure purposes becomes a bar to obtaining an increased operation
speed of the copying machines. Even when the copying sheet is
exposed to light rays without halting the sheet travel (that is, by
synchronizing the sheet feeding speed with the scanning speed
during exposure), the impact that results from cutting the paper
roll adversely affects the copying step, causing such defects in
the formed image as aberration. One method for preventing this is
to perform cutting of roll paper only after copying, but the
drawback with this method is that it requires an additional device
for detecting or determining the cutting position from the formed
image, making the apparatus too bulky and too costly to suit
practical use.
SUMMARY OF THE INVENTION
The object of the current invention is to overcome such
shortcomings of the prior-art devices as mentioned above and to
provide a suitable device for increasing operation speed of
duplicating machines by positioning a cutter between paper feed
rollers and feed rollers which are adapted to transfer a paper
sheet to a copying stage, operation of the cutter being
synchronized to the paper feeding motion, arranging said cutter to
cut the roll paper into a predetermined size when there is formed a
loop of the roll paper due to the rotation rate differential
between the two sets of feed rollers, thereby absorbing the impact
of cutting at said paper loop to protect the copying step from any
adverse effect of cutting.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic view of the entire duplicating
machine;
FIG. 2 is a perspective view showing in detail a machine portion
for driving the second feed rollers;
FIG. 3 is a side view of the portion in FIG. 2;
FIG. 4 is a perspective view showing in detail a cutter
portion;
FIG. 5 is a side view of the cutter portion in FIG. 4;
FIG. 6 is an electric circuit diagram of a control system;
FIG. 7 is a time chart indicating timing of various parts.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of this invention is hereinafter described
in detail with reference to the drawings.
FIG. 1 shows a xerographic duplicating machine with paper feeding
device A according to this invention. The circumferential surface
of a xerograph drum 1 coated with photoconductive material is
charged by a charger 2, and light rays from the light source 3
reflected from a master sheet 4 to be copied are projected to the
cylindrical surface of the drum 1 to dissipate charges in an image
pattern, thereby forming on the cylindrical surface of the drum 1 a
latent image identical to the master sheet 4. This latent image is
developed in the next developing step to a visible image which is
transferred onto copying sheet a. At the same time, toner remaining
on the cylindrical surface of xerograph drum 1 is removed by a
cleaning device 6 while the copying sheet a with its transferred
image is conveyed by a feeding mechanism 7 to a fixer 8 by which
the image is permanently fixed. The structure of the feeding device
A is as follows. Paper roll 11 is detachably mounted underneath a
main body 10 of the duplicating machine with the leading edge of
the rolled paper 11 inserted through the first feed rollers 12,
through the second feed rollers 13 which are spaced apart from the
first feed rollers 12, and through the third feed rollers 14 which
serve to feed a paper sheet to the xerograph drum 1. Between the
first feed rollers 12 and second feed rollers 13 is positioned a
microswitch 15 for detecting tension of the roll paper 11. The
ON-OFF state of microswitch 15 regulates intermittent rotation of
the first feed rollers 12. In other words, while the roll paper 11
is stretched and tensioned, the microswitch 15 is ON and a clutch
(not shown) of the mechanism (not shown) for driving the first feed
rollers 12 is engaged to rotate the first feed roller 12 at a rate
greater than that of the second feed rollers 13 thereby causing the
roll paper 11 to form a loop or droop between the first feed
rollers 12 and the second feed rollers 13. When the roll paper 11
droops, the microswitch 15 is cut off and rotation of the first
feed rollers 12 halts. By repetition of the above-noted sequence of
operation, slippage between second feed rollers 13 and roll paper
11 is kept at a minimum. Also said second feed rollers 13 are
arranged to be driven through a spring clutch 16 shown in FIG. 2.
Input shaft 17 of the spring clutch 16 always turns in the
direction shown by arrow x, while output shaft 18 is drivingly
linked together with a cam plate 19 having a plurality of equally
spaced apertures 19b to a driving shaft 13a of the second feed
rollers 13. Between the input shaft 17 and output shaft 18 is
linkedly positioned a collar 20 with a lobe (not shown) formed
therearound. When one end of an interposer 21 engages with said
lobe of the collar 20, the spring clutch 16 is disengaged. Likewise
the spring clutch 16 is connectedly engaged when the lobe and
interposer 21 are disengaged. The interposer 21 is held at the mid
portion by a pivot 21a for free rotational movement. The base end
of the interposer 21 is in engagement with one end of a plunger 22a
of a solenoid 22. One end of the interposer 21 is also engaged to
one end of another interposer 23. A central portion of the
interposer 23 is pivotally supported, in a position underneath the
spring clutch 16, by a pivot 24 while the other end of the
interposer 23 engages with one end of rod 27 extending out from the
interposer 26 of the spring clutch 25 for the cutter, spring clutch
16 being positioned on the other side of the interposer 21. The
interposer 26 is pivotally supported at its upper edge portion for
free vibrating motion of the lower edge portion, with the central
portion having an aperture 26a bored through to receive for loose
fitting, base end portion of said rod 27, the pointed end portion
of rod 27 extending out toward the spring clutch 16. At the lower
surface in the mid portion of the rod 27 is formed a recess 27a
which fittingly receives one end of a link 28. The link 28 is
pivotally supported at the mid portion thereof for free rotational
movement. The other end of the link 28 slidingly engages with the
outer surface of said cam plate 19. Rotatingly driven by
projections 19a which are formed at uniform intervals around
prephery of cam plate 19, the link 28 urges said rod 27 to move in
the direction indicated by arrow y. Movement of the rod 27 in the
direction y rotates the lower edge portion of the interposer 26 of
the cutter spring clutch 25 for the cutter, to disengage said
interposer 26 from the collar 29 of the cutter spring clutch 25,
thereby actuating the cutter 30. The cutter 30 is positioned
between the second feed rollers 13 and third feed rollers 14, as
shown in FIG. 1, and is constructed as shown in FIG. 4. At one end
of the output shaft 31 of the cutter clutch 25 is fixedly secured a
disc 32. To an eccentric position thereof is pivotally secured one
end of a link 33. The other end of the link 33 extends slantedly
upward and pivotally couples with an upper end of a substantially
L-shaped crank 34. To the lower end of the crank 34 is fixedly
secured the end portion of the rotary cutter 30a, which is designed
to rotate back and forth around the rotary shaft 30b of the rotary
cutter 30a in response to rotation of said output shaft 31.
Slantingly upward of rotary cutter 30a is provided a fixed cutter
30c with a blade so positioned as to align with the blade of rotary
cutter 30a as rotary cutter 30a moves, severing paper sheet 11 fed
between the two cutters.
With reference to FIG. 6 the electric circuit of the duplicating
machine with above-described construction is now explained in
connection with the machine's operation. The light rays from the
light source 3 reflected from master sheet 4 charges and produces a
latent image on the outer cylindrical surface of the xerograph drum
1 as the drum 1 rotates, which latent image is subsequently
developed in a developing section into a visible image.
Simultaneously, the leading edge of the roll paper 11 travels,
driven by the rotation of the first feed rollers 12 from the paper
feeding device A to the second feed rollers 13 and to the third
feed rollers 14, in the order just mentioned, and then to the lower
part of the xerograph drum 1. The third feed rollers 14 always
revolve at a lower rate than the second feed rollers 13, causing
the roll paper 11 to sag in the form of a loop between the second
feed rollers 13 and third feed rollers 14 as indicated by a broken
line in FIG. 1, which loop absorbs the impact which is imposed on
the roll paper 11 by the cutter 30, to be described next, to
prevent adverse effects on copying. The cutter 30 is controlled in
the following manner to cut the roll paper 11 for supplying copying
paper a of a predetermined length.
When a print switch SW1 is turned on, a signal is produced at the
output terminal 40 of NAND gate I to set the terminal 41 of NAND
gate II at the level 1 or in the 1 state. The terminal 42 of the
NAND gate II is for reset purposes. When power supply (not shown)
is switched on, a negative pulse is dispatched from the terminal 42
through the NAND gate II and inverter IIIb to reset flip-flop
counters IV-VIII. The terminal 43, for synchronizing timing, drops
to the level 0 or the 0 state only when a predetermined count,
i.e., a number of apertures formed on disc the 19 is counted, and
is otherwise set at the 1 level. Before the print switch SW1 is
switched on, the terminals 42, 43 of the NAND gate II are at the
level 1, and when print switch SW1 is turned on a signal of the
level 1 is received by terminal 41 to set the output terminal 44 at
the level 0. Then the level is reversed by an inverter IIIb to
actuate a thyristor (SCR) and to energize the solenoid 22. With
energization of the solenoid 22, the plunger 22a is withdrawn to
rotate the interposer 21 around the axial shaft 21a, which
disengages interposer 21 from the lobe around the collar 20 of the
spring clutch 16 whereupon cam plate 19 starts rotation along with
the second feed rollers 13. Simultaneously the interposer 23 is set
in rotation by the interposer 21 to upwardly press one end of the
rod 27. This causes the rod 27 to disengage from the link 28, a
follower of the cam plate 19. Also a photocell or a similar
detector PC (see FIG. 6) which is closely positioned to the cam
plate 19 counts apertures 19b formed through the cam plate 19.
Signals from the detector PC pass throuogh the transistor Tr2 to
one-shot multivibrator O.M.V., actuating the same to produce a
single pulse. The pulse in turn actuates flip-flop counters
IV-VIII. The flip-flop counters IV-VIII in response to signals of
2.sup.0 to 2.sup.4 respectively emit signals of the level 1, which
in combination with selection of the switches SW2, SW3 and SW4 act
to set the output of one of the NAND gates IXa-IXc at the level 0.
For example, if the switch SW2 for A4 size copies is selected, only
the terminal 2 of the NAND gate IXa is held at the level 1 while
the terminals 5 and 10 of the NAND gates IXb and IXc are held at
the level 0 potential. As the cam plate 19 continues to rotate and
when it has completed 2.25 revolutions, i.e., when the second feed
rollers 13 have advanced roll paper 11 by a length corresponding to
the A4 size, the one-shot multivibrator O.M.V. emits a ninth pulse
and the flip-flop counter IV for 2.sup.0 and the flip-flop counter
VII for 2.sup.3 respectively send the level 1 signals to set the
potential of the input terminals 1 and 13 of the NAND gate IXa at
the level 1, whereupon all input terminals of the NAND gate IXa
become the level 1 to set the output terminal 12 at the 0 level.
This sets the input terminals 43 of the NAND gate II to the level 0
and hence the output terminal 44 to the level 1. The signal is
inverted to the level 0 passing through the inverter IIIa, which
turns off SCR to de-energize the solenoid 22. A level 1 signal from
the output terminal 44 becomes a level 0 signal passing through
inverter IIIb to reset the flip-flop counters IV-VIII. With
de-energization of the solenoid 22, the interposer 21 engages with
the lobe around collar 20 to disengage the spring clutch 16, and
thereby to halt rotation of the second feed rollers 13 and thus
feeding of the roll paper 11. After the plunger 22a is released
from solenoid 22 and the interposer 21 is brought in contact with
the surface of the collar 20, the cam 19 continues to rotate a
while until the interposer 21 actually engages with the lobe of the
collar 20. With release of the plunger 22a, on the other hand, the
link 28 is returned to the original position to engage with the rod
27. Under these conditions, the link 28, by the urge of the
projection 19a formed around the cam 19, presses the rod 27 to move
in the direction of arrow Y. This movement of the rod 27 releases
the interposer 25 of the cutter spring clutch 25 from the lobe (not
shown) formed around the collar 29 of said spring clutch 25 to
actuate the cutter 30. That is, by engagement of the cutter spring
clutch 25, the disc 32 through the link 33 drivingly rotate the
rotary cutter 30a back and forth in the direction of the arrow
shown in FIG. 4 to cut in a predetermined size with the fixed
cutter 30c the roll paper 11 positioned between the two cutters. On
the collar 29 of the cutter spring clutch 25 is formed a lobe. As
soon as the rod 27 is pressed to move in the direction of the arrow
Y by the link 28 shown in FIG. 2 and the interposer 26 is released
from engagement, rotation of the cam 19 stops and the rod 27
becomes free, released from the link 28. Under these conditions,
the interposer 26 is urged by the spring (not shown) to pressingly
contact with the surface of the collar 29 of the cutter spring
clutch 25, thereby reengaging with the lobe 29 of said collar 29
after one revolution of collar 29 to disengage clutch 25. Thus
reciprocating rotation of the rotary cutter 30a of the cutter 30
terminates after one cycle and preparation is made for cutting the
next paper sheet.
The operation thus described is illustrated in the time chart of
FIG. 7. Taking an actual case of operation for simplicity of
description, the number of lobes around the collar 20 of the spring
clutch 16 and the number of projections 19a of the cam plate 19,
the number of apertures 19b formed on the cam plate 19 are assumed
to be four, respectively. Thus at the ninth lobe, i.e., 2.25
revolutions, second feed rollers 13 advance the paper sheet by a
distance corresponding to the A4 size. Now supposing that selection
was made to feed A4 paper, after passing the eighth lobe, the
circuit to be described later emits a signal at the ninth aperture
19b on cam plate 19 to de-energize the solenoid 22. By the time an
approximately 20.degree. revolution was made after emission of the
signal, the solenoid 22 is de-energized. Then after a further
rotation of 60.degree., the interposer 21 engages with the ninth
lobe and second feed rollers 13 stops and so does roll paper 11.
Slightly before engagement of the interposer 21 to the ninth lobe
of collar 20, the cutter spring clutch 25 engages to actuate the
rotary cutter 30a of the cutter 30. After the second feed roller 13
stops, the roll paper 11 is kept feeding by the third feed rollers
14 thereby reducing the loop of the roll paper 11 between the third
feed rollers 14 and the second feed rollers 13. Before the loop
fully disappears, however, cutting of the paper sheet
completes.
Description given so far assumes selection of A4 size paper, but by
making proper selections of the number of the apertures 19b on the
cam 19 and the number of counters, many sizes of copy paper may be
provided, with accordingly varied widths of the roll paper 11.
As heretofore described in detail adverse effects of cutting on
copying step such as aberration of formed image are reliably
prevented by causing roll paper to form a loop between the second
feed rollers and the third feed rollers by a rotation rate
differential therebetween, cutting the paper to yield a copying
sheet of predetermined size by a cutter positioned between the
second and the third feed rollers, and thereby absorbing the impact
of cutting on the paper by said loop. Also utilization of rolled
paper facilitates speed-up of duplicating machine operation, and
simultaneous cutting of the paper during copying eliminates the
need for a bulky apparatus for determing cutting positions as
required for those which cut the paper after copying, making it
possible to supply small and low priced duplicating machines.
* * * * *