US3647204A

US3647204A - Paper sheet feed device

Info

Publication number: US3647204A
Application number: US4227A
Authority: US
Inventors: Jiro Sato
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1969-01-28
Filing date: 1970-01-20
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07
Also published as: GB1293746A; DE2003497A1; DE2003497B2; DE2003497C3

Abstract

Paper sheet feed device includes a plurality of paper sheet feed means disposed such that each means can feed paper sheets having a predetermined size. When paper sheets are supplemented or replaced by the sheets of other size, the paper feed means is moved from its operative position to nonoperative position, but the paper sheets have been supplemented or replaced, the paper sheet feed means is automatically returned to its operative position with the aid of pawl members and ladder chain cooperating with feed means.

Description

[ Mar. 7, 1972 United States Patent Sato ...27l/36 X .....27l/36 .....271/36 ....27l/36 Carlson.............................

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Primary Examiner-Joseph Wegbreit Attorney-Ward, McElhannon, Brooks & Fitzpatrick 211 App]. No.: 4,227

[30] Foreign Application Priority Data Jan. 28, 1969 Japan.....................................44/7826 ABSTRACT ,44/15144 Paper sheet feed device includes a plurality of paper sheet feed means disposed such that each means can feed paper Feb. 19, 1969 sheets having a predetermined size. When paper sheets are supplemented or replaced by the sheets of other size, the 271/3637 paper feed means is moved from its operative position to nonoperative position, but the paper sheets have been supplemented or replaced, the paper sheet feed means is automati- [Sl] Int. [58] Field of Search References Cited UNITED STATES PATENTS cally returned to its operative position with the aid of pawl members and ladder chain cooperating with feed means.

3,273,883 Baronnie 5Clairns,5Drawing Figures PAPER SHEET FEED DEVICE The present invention relates to a paper sheet feed device and more particularly a paper sheet feed device of the type in which paper sheets are fed one by one from the uppermost one of a stack of paper sheets.

Rolled or sheet photocopying and printing papers are used for photocopying by electrophotographic copying machines, diazo type copying machines, printing presses and so on. In photocopying machines, the rolled photocopying paper is cut into a predetermined size before or after it is fed into a copying section, while in case of a stack of photocopying paper sheets are used, the sheets are fed one by one from the uppermost one of the stack.

The present invention relates to an improvement of a paper sheet feed device. In the conventional paper sheet feed device, a stack of paper sheets is supported on a paper feed stand and is held in position by use of guide plates which press against the side edges of the paper sheets so that the latter may be aligned. Paper sheet feed means is placed upon the stack of paper sheets whose leading side edges are aligned by means of paper sheet separating pawl members, which apply'a suitable force upon the stack of paper sheets so as to hold them in position. When the paper feed device of the character described above is actuated, the uppermost paper sheet is caused to bend or curve arcuately between said paper feed means and said separating pawl members. When the paper sheet is curved arcuately beyond a predetermined degree, the leading edge of the paper sheet is disengaged from the pawl members and springs out forwardly so as to be fed by the feed rollers into a next processing section. However, said feed means must be readjusted in position depending upon the sizes of paper sheets to be used. This readjustment is very delicate and complex so that even a little misadjustment causes the misfeed of paper sheets. Furthermore, the readjustment takes a relatively long time, thus resulting in a low efficiency of the paper feed operation. When the paper sheets having the same size are supplemented or supplied or when the paper sheets having the different size are used, the paper feed means must be moved away from its paper feed or operative position. In this case, the operator tends to fail to return the paper sheet feed means to its normal or operative position after the paper sheets have been supplemented or replaced. Thus, when a photocopying machine is operated, no photocopying paper is fed into the machine, thus causing much time loss.

Accordingly, the primary object of the present invention is to provide an improved paper sheet feed device which can feed paper sheets one by one securely and effectively.

Another object of the present invention is to provide an improved paper sheet feed device which can feed paper sheets having various sizes without adjustment.

A further object of the present invention is to provide an improved paper sheet feed device in which a paper sheet feed means which has been moved-away from the paper feed or operative position for supplementing or replacing paper sheets may be automatically returned to its normal or operative position.

In brief, in a paper feed device in accordance with the present invention, the adjustment of the paper sheet feed means is not required even when paper sheets having different sizes are fed. For this purpose, a plurality of paper sheet feed means are disposed so that each of paper feed means feeds paper sheets having a predetermined size. When paper sheets are supplemented or replaced, the paper sheet feed means is moved away from its first position or operative position to a second position, but after the paper sheets have been supplemented or replaced, the paper sheet feed means is automatically returned to its first or operative position.

The present invention will become more apparent from the following description of one illustrative embodiment thereof with reference to the accompanying drawing in which:

FIG. I is a perspective view of one embodiment of a paper sheet feed device in accordance with the present invention;

FIG. 2 is a plan view thereof;

FIG. 3 is a schematic side view thereof for explanation of an automatic paper sheet feed roller returning means;

FIG. 4 is a perspective view thereof; and

FIG. 5 is a longitudinal sectional view of a variation of a ladder chain used in said means shown in FIGS. 3 and 4.

Referring to FIGS. 1 and 2, a stack of paper sheets P upon a paper feed stand 1 is applied along both sides thereof with suitable forces from a pair of guide plates 2, and 2 which are adjustably disposed upon the paper feed stand 1, so that a plurality of paper sheets P are correctly stacked with their side edges maintained in alignment. The leading side edges of paper sheets P are adjusted by a pair of paper separating pawl members 4, and 4 each of which is pivotably fixed to each of the guide plates 2, and 2 by a pivot 3, respectively. It is noted that the leading side edge of the uppermost sheet is applied with a suitable pressure from the pair of pawl members 4, and 4 A pair of

feed rollers

5 and 5 are disposed upon the stack of sheets P in such a manner that these

rollers

5, and 5 may press against the stack of sheets P and rotate with a sufficient frictional force between them and the uppermost sheet P so as to feed it. The pair of

feed rollers

5, and 5 are carried by a shaft 7 which in turn is journalled by an arm member 6. A drive shaft 9 is also journalled to the arm member 6 and has a sprocket wheel 10 over which is wrapped a ladder chain or the like 11, which is also wrapped over a sprocket wheel 8 carried by the roller shaft 7. Thus, the rotation of the drive shaft 9 is transmitted to the shaft 7 and the pair of feed rollers S and 5 fixed thereon.

The sheet from the paper feed stand 1 is fed along a sheet insertion guide plate 12 and then into the next section or stage by a pair of feed rollers 13, and 13 When the uppermost sheet is moved by the frictional force by the pair of

feed rollers

5, and 5 its forward movement is temporarily stopped by the pair of sheet separating pawl members 4, and 4 which engage with the leading side edge of the uppermost sheet, so that it is curved arcuately between the pawl members 4. and 4 and the feed rollers'S and 5 When the uppermost sheet is curved in excess of a predetermined degree, the leading side edge is naturally disengaged from the pawl members 4, and 4 and is fed. In this case, it is noted that when a plurality of sheets are stacked at random, the leading side edge of the sheet may be not in parallel with the nip of the feed rollers 13, and I3 or a plurality of sheets may be fed at the same time, thus causing the breakdown of a photocopying machine or the like. For this purpose the pair of guide plates 2, and 2 are disposed upon the paper feed stand as described hereinabove so that they may press against the sides of the stacked sheets P, whereby the sheets may be held in a predetermined position. Thus, the sheets may be fed in correct position. Furthermore, in order that a plurality of sheets may not be fed at the same time, the guide plates 2, and 2 are pressed against the side of the stacked sheets and the sheets are stacked in the waveform as a whole by use of a rod 14.

In a copying machine or the like, the sheets having different sizes are frequently used and depending upon the size of the sheets to be used, the guide plates 2 and 2 must be readjusted in position. In the conventional paper feed device, the feed rollers which are generally carried by the roller shaft for the axial movement thereof must be adjusted depending upon the size or width of the sheets to be used. Since the distance between the sheet separating pawl members and the feed rollers generally much affects the paper sheet feed operation, the adjustment is very complicated, thus reducing the efficiency of the operation.

The present invention contemplates to eliminate such defects described above. For this purpose, the pairs of

feed rollers

5, and 5 and 15, and 15 are fixedly secured to the roller shaft 7 with predetermined distances from the separating pawl members 4, and 4 depending upon the sizes for example Sizes A and B of the sheets to be used. Therefore the pair of feed rollers 15, and 15 are used when the size of the sheets is Size B while the pair of

rollers

5, and 5 are used when the size of sheets to be used is Size A. It will be understood that further pairs of feed rollers may be securely fixed to the roller shaft 7 for the sizes of sheets other than Size A and B of the instant embodiment.

In the paper feed device in accordance with the present invention, the roller shaft 7 and associated feed rollers and 15 may be rotated manually by the operator about the drive shaft 9 so as to move these elements away from the paper feed stand 1 to permit the addition or substitution of paper sheets. This is shown in FIG. 3 wherein the feed rollers 5 and 15 moved away from the paper feed stand 1 are shown in chain lines. However, it has been found that the operator forgets, in many instances, to return the feed rollers 5 and 15 to their normal or initial position after the paper sheets have been replaced or supplemented, so that the operation of the paper feed device is interrupted, resulting in low efficiency use of the machine. To eliminate this drawback, the paper feed device of the present invention is constructed to automatically return the feed roller shaft 7 and associated feed rollers 5 and 15 to their initial or normal position after paper sheets have been replaced or supplemented. Specifically, as best shown in FIGS. 3 and 4, a guide plate 12 is disposed above a stationary member 17 and both the guide plate 12 and the stationary member 17 are inclined with respect to the paper feed stand 1 and also with respect to each other. A clearance for the ladder chain 16 is provided on a side of the stationary member 17 to allow the arm member 6 to pivot about the drive shaft 9 and position the roller shaft 7 and associated feed rollers 5 and 15 above the guide plate 12 clear of the paper sheets P positioned in the paper feed stand 1. 'As best shown in FIG. 4, an inclined detent member 18 is provided on the portion of the stationary member 17 which is adjacent this clearance. The detent member 18 is constructed to fit between adjacent bars 16' of the ladder chain 16 and support the roller shaft 7 and associated feed rollers 5 and 15 in a second position clear of the paper feed stand 1, whereby the paper sheets P can be freely substituted or added.

After the paper sheets P have been replenished or replaced, if the operator fails to manually return the roller shaft 7 and associated feed rollers 5 and 15 to the initial or feed position, the sprocket wheel is driven by the drive shaft 9 in the direction indicated by the arrow 0 (FIG. 4), while the detent member 18 engages and holds a bar 16' of the ladder chain 16, whereby the ladder chain 16 is pulled in tension with a tensile force. While the ladder chain 16 is under the resistance of this detent member 18, opposing tensile forces are induced in the parts of the ladder chain 16 on the opposite sides of the sprocket wheel 8. Since the part of the ladder chain 16 between the

sprocket wheels

8 and 10 which contacts the detent member 18 is displaced inwardly (FIG. 3), the directions of the tensile force acting on both sides of the sprocket wheel 8 are not the same, but rather are inclined to one another. Accordingly, the direction and the amount of the resultant or total force of the two forces acting about the sprocket wheel 8 is determined by the so called parallelogram rule used to obtain a total vector of component vectors. It will be appreciated that the direction of the resultant or total force acting about the sprocket wheel 8 extends to the left (FIG. 3) with respect to the centerline' connecting the centers of the

sprocket wheels

8 and 10 because the part of the ladder chain 16 which engages the detent member 18 is displaced to the left. This resultant or total force can be divided into two components, namely a radial component and a tangential component. The direction of the radial component corresponds to that of the centerline connecting the centers of the

sprocket wheels

8 and 10, and the direction of the tangential component is normal to the radial component and acts on the circular locus of the center of the sprocket wheel 8. The radial component is absorbed at the journal between the sprocket wheel 8 and the arm member 6, while the tangential component acts to rotate the feed rollers 5 and and arm member 6 about the drive shaft 9. The feed rollers 5 and 15 are returned to their initial or normal position by this tangential component together with the inertia of the rotating assembly which is sufficient to move the arm member 6 past its upright position so that gravity will carry the arm member 6 and associated feed rollers 5 and 15 downwardly to the initial or normal position. If the arm member 6 and the feed rollers 5 and 15 mounted on the shaft 7 do not provide the necessary inertia to carry the assembly past its upright position (FIG. 3), the detent member 18 must be mounted as shown in FIGS. 3 and 4 to incline relative to the ladder chain 16 so that the intersecting angle formed between the lower surface of the detent member 18 and the linear line of the ladder chain 16 on the part of the detent member 18 being inserted is less than a right angle when the two facing parts of the ladder chain 16 on opposite sides of the

sprocket wheels

8 and 10 are aligned in parallel. In this case. as the drive shaft 9 and the sprocket wheel 10 are being forced to drive the ladder chain 16 in the direction indicated with the arrow a (FIG. 4) the bar 16' contacting the lower surface of the detent member 18 will slide on the surface of the detent member 18 towards the top end, overcoming the frictional force induced at the contact line. After disengaging the bar 16' with the detent member 18, the arm member 6 is pivoted past its upright position to the initial or feed position by the function of the driving force transmitted through the sprocket wheel 10 to the ladder chain 16.

The pitch of the bar 16' of the ladder chain 16, or its distance between the bars 16, is so determined that the detent member 18 does not affect the movement of the ladder chain 16 as described hereinabove. Furthermore, the mounted angle of the detent member 18 is established considering the interrelation between the detent member 18 and the ladder chain 16.

Although a ladder chain 16 has been utilized as a transmitting means in the embodiment of FIGS. 1 through 4, it will be appreciated by those skilled in the art, that alternatively, as shown in FIG. 5, a belt 19 having a plurality of teeth 20 on its underside surface may be used as the transmitting means.

What is claimed is:

1. A paper sheet feed device comprising:

a. support means for supporting a stack of paper sheets,

b. drive means fixedly mounted in said sheet device for supplying a drive force,

c. paper sheet feed means,

d. means for pivotally mounting said paper sheet feed means with respect to said drive means for movement between a first position at said support means for feeding paper sheets and a second position remote from said support means permitting change or addition to said stack of paper sheets,

e. transmitting means for transmitting said drive force from said drive means to said paper sheet feed means, and

f. holding means at said second position for holding said transmitting means and opposing said drive force to induce in said transmitting means a rotating force in said paper sheet feed means and pivot said paper sheet feed means about said drive means to said first position at said support means.

2. A paper sheet feed device as in claim 1, wherein said paper sheet feed means includes feed rollers mounted on a common rotatable shaft and wherein said transmitting means transmits said drive force from said drive means to said rotating shaft.

3. A paper sheet feed device as in claim 2, wherein a first sprocket wheel is coupled to said drive means and a second sprocket wheel is mounted for rotation about said common shaft, and wherein said transmitting means includes a ladder chain carried by said first and second sprocket wheels and wherein said holding means includes a detent member engaging said ladder chain at said second position.

4. A paper sheet feed device as in claim 2, wherein a first belt-driving means is provided on said common shaft and a second belt-driving means is provided on said drive means, and wherein said transmitting means includes a belt carried by said first and second belt-driving means, said belt having a plurality of recesses, and said holding means including means for engaging one of said recesses at said second position.

5. A paper sheet feed device comprising means for supporting a stack of paper sheets, adjustable guide plate means disposed to feed said paper sheets of said second width, means for mounting said plurality of feed rollers to be selectively switched between a first position for feeding paper sheets and a second position moved away from said first position, and means for driving said plurality of feed rollers to feed paper sheets from said stack.

Claims

1. A paper sheet feed device comprising: a. support means for supporting a stack of paper sheets, b. drive means fixedly mounted in said sheet device for supplying a drive force, c. paper sheet feed means, d. means for pivotally mounting said paper sheet feed means with respect to said drive means for movement between a first position at said support means for feeding paper sheets and a second position remote from said support means permitting change or addition to said stack of paper sheets, e. transmitting means for transmitting said drive force from said drive means to said paper sheet feed means, and f. holding means at said second position for holding said transmitting means and opposing said drive force to induce in said transmitting means a rotating force in said paper sheet feed means and pivot said paper sheet feed means about said drive means to said first position at said support means.

5. A paper sheet feed device comprising means for supporting a stack of paper sheets, adjustable guide plate means disposed on said supporting means and adjustable to engage the sides of paper sheets of at least first and second widths, a plurality of feed rollers carried by a common shaft and in spaced-apart relation with each other for feeding paper sheets from said stack of paper sheets, some of said plurality of feed rollers being disposed to feed only said paper sheets of said first width and said some of said plurality of feed rollers together with other of said plurality of feed rollers being disposed to feed said paper sheets of said second width, means for mounting said plurality of feed rollers to be selectively switched between a first position for feeding paper sheets and a second position moved away from said first position, and means for driving said plurality of feed rollers to feed paper sheets from said stack.