JPH06312846A - Paper feeder - Google Patents

Abstract

PURPOSE:To prevent paper from being double fed together and deformed by providing a member which makes action of rushing in and waiting in an advancing path while paper is conveyed to pass, and impeding a single sheet of the separately fed paper from being double fed in company with paper in the next position after by the action of rushing in. CONSTITUTION:Since an erection turn angle of an accompaniment double feed impeding member 33 erected to be turned is restricted by a stopper part 22b, a protruding amount of an upper stopper part 33a of the accompaniment double feed impeding member 33 to the upper from an upper surface (b) of a guide member 22 is restricted, and an optimum amount can be always specified. Since a point end part reverse surface of a swivel loading plate 2 is brought into contact with a bottom end contact part 33b of the accompaniment double feed impeding member 33 elastically through an elastic member 35 so that the accompaniment double feed impeding member 33 can be actuated to turn, an error of part dimension, building, etc., is absorbed by elasticity of the elastic member 35. Accordingly, protruding position accuracy of the upper stopper part 33a of the accompaniment double feed impeding member 33 from the upper surface (b) of the guide member 22 is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine and a laser beam printer, and various other types of paper-using equipment, from a paper stacking unit to paper (transfer paper, photosensitive paper, thermal paper, electrostatic recording). The present invention relates to a paper feeding device that separates and feeds one sheet of paper, printing paper, originals, cards, envelopes, and the like.

More specifically, a sheet feeding means, a sheet stacking plate that stacks sheets and causes the stacked sheets to abut against the sheet feeding means with a predetermined pressure, and abuts against the sheet feeding means to feed the sheets. A sheet separating means for separating one sheet of paper on the sheet stacking plate fed by the feeding means, and a sheet feeding direction of the separated and fed sheet from the contact portion of the sheet feeding means and the sheet separating means. The present invention relates to a sheet feeding device that is transported by a downstream transport unit.

[0003]

[Prior art]

(A) FIGS. 15 to 20 show an example of a conventional sheet feeding device of this type. 15 is a partially cutaway cross-sectional side view of a main part of the apparatus, FIG. 16 is a vertical cross-sectional front view taken along line aa of FIG. 15,
17 to 20 are operation process charts of single-sheet separation feeding.

Reference numerals 1 and 2 are a fixed stacking plate and a swinging (elevating) stacking plate as a sheet stacking unit. The fixed stacking plate 1 is arranged so as to be inclined forward and downward. The swingable loading plate 2 is the fixed loading plate 1
Is vertically connected to the front end side of the shaft so as to be vertically swingable around the support shaft 3. The sheets S are stacked and set on the fixed and swinging stacking plates 1 and 2.

The swingable stacking plate 2 is mounted and supported between a pair of left and right support members 4 and 4 whose front end is free to swing up and down around the support shaft 3 at the front end of the fixed stacking plate 1. An elastic member 6 provided between the lower surface of the stacking plate 2 and the immovable member 5 under the stacking plate 2 is constantly biased upward (clockwise in FIG. 15) about the support shaft 3 as a center.

Numeral 7 is a roller as a cam follower, and one end of one of the pair of left and right support members 4, 4 on which the swingable stacking plate 2 is attached and supported is bent upward and the upper end thereof is folded. It is rotatably provided on the upper end of the bent portion.
Reference numeral 7a is a rotation center axis of the roller 7.

During the paper feed standby, the cam 21 to be described later is held in a substantially downward rotation angle posture so that the cam 2
The roller 7 is pushed downward by 1 and the supporting member 4, that is, the swingable stacking plate 2 resists the elastic member 6 and the supporting shaft 3
It is pushed down and rotated around the center and is maintained in a posture of a front downward inclination which is substantially flush with the fixed loading plate 1 having a front downward inclination. Figure 1
5 to 17 show the paper feed standby state.

Reference numeral 10 denotes a paper feed drive shaft disposed in the left-right direction above the front end of the swingable stack plate 2, and supports plate 1
The bearings 1a and 11b are rotatably held by bearings 12a and 12b.

Reference numeral 13 denotes a half-moon type paper feed roller made of a friction member, which is fixed to the right end side of the paper feed drive shaft 10. Numerals 14 and 14 are driven rollers disposed on both sides of the paper feed roller 13 so as to be loosely fitted to the drive shaft 10. The driven rollers 14 have a diameter slightly smaller than that of the paper feed roller 13. The paper feeding roller 13 and the driven rollers 14 and 14 described above are the feeding means 15.

Reference numeral 16 designates 1 provided on the left end side of the paper feed drive shaft 10.
It is a rotary spring clutch and is controlled by the solenoid 17.

In the sheet feed standby state shown in FIGS. 15 to 17, the energization of the solenoid 17 is off. In this state, the claw portion 19a of the control ring 19 of the spring clutch 16 is held by the actuator (amateur) 18. The spring clutch 16 is kept off, and the rotational force transmitted from the drive source M to the drive gear 20 of the spring clutch 16 via the power transmission system (not shown) is not transmitted to the paper feed drive shaft 10.
The paper feed drive shaft 10, that is, the paper feed roller 13 of the feeding means 15 is kept in a rotation stopped state.

When the rotation of the sheet feeding roller 13 is stopped, the sheet feeding roller 13 is in a rotation angle posture in which the cutout portion 13a is substantially downward.

Reference numeral 21 denotes a cam fixed to the paper feed drive shaft 10, which is held in a substantially downward rotation angle posture in a paper feed standby state, that is, when the spring clutch 16 is turned off. The roller 7 on the plate 2 side is pushed down, and the swingable stacking plate 2 is kept in a state of being pushed down around the support shaft 3 against the elastic member 6 and rotated.

By pushing down the swingable stacking plate 2, the upper surface of the stacked sheets S on the front end side is fed by the sheet feeding roller 13 of the feeding means 15.
The driven roller 14 is not in contact with any of the driven rollers 14, and the contact pressure of the rocking stack plate 2 with respect to the feeding means 15 is maintained in a released state.

Reference numeral 22 is a paper guide member arranged in front of the swingable stacking plate 2, and 23 is a separating member consisting of a friction member as a paper separating means provided in the paper guide member 22 below the feeding means 15. (Rubbing pad). The separating member 23 is constantly lifted and urged by the elastic member 24 and comes into contact with the lower surface of the driven rollers 14 of the feeding means 15 or the circumferential portion 13b of the rotated paper feeding roller 13 with a predetermined pressure. In the paper feed standby state shown in FIGS. 15 to 17, the paper feed roller 13 of the feeding means 15 has the cutout portion 1 as described above.
Since 3a faces downward, the separating member 23 is in contact with the lower surfaces of the driven rollers 14 on both sides thereof.

Reference numeral 25 denotes a pair of conveying rollers as a sheet conveying means which is arranged on the downstream side of the sheet guide member 22 in the sheet feeding direction, and is rotated by a driving source M in the sheet conveying direction via a power transmission system (not shown). Driven.

When paper is fed, the solenoid 17 is energized with a pulse of 1
When the actuator 18 is rotated once, the control ring 19 of the spring clutch 16 is released from being held as shown in FIG. As a result, the spring clutch 16 is turned on, and the paper feeding drive shaft 10, that is, the paper feeding roller 13 and the cam 21 is rotationally driven in the clockwise direction which is the paper feeding direction.

At the initial stage of this rotational driving, the lower end of the cam 21 escapes from the roller 7 and the pushing down of the roller 7 is released, and the rocking stack plate 2 is lifted clockwise by the elastic member 6 around the support shaft 3. The upper end of the stacked sheets S is rotated and comes into contact with the lower surfaces of the driven rollers 14 of the feeding means 15 at a predetermined pressure.

When the paper feed drive shaft 10 is subsequently driven to rotate, the circumferential portion 13b of the paper feed roller 13 is loaded with the stacked paper S as shown in FIG.
The upper end sheet S ₁ of the stacked sheets S is fed with a feeding force, and the leading end portion of the uppermost sheet S ₁ moves around the circumference of the rotary paper feed roller 13 as shown in FIG. Part 1
One sheet is separated from the next or lower sheet through the sandwiching portion (pressing nip portion) between the sheet 3b and the separating member 23 as the sheet separating means, and the sheet is fed.

While the paper feed roller 13 makes one revolution, the leading end of the _one- sheet separated feed paper S ₁ is guided by the guide member 22 and the upper guide member 22a thereof and reaches the nip portion of the conveying roller pair 25. As shown in FIG. 20, it is gripped and transferred as a relay.

At the time when the paper feed drive shaft 10 makes one revolution, the solenoid 17 is already off, and the claw portion 19a of the control ring 19 of the spring clutch 16 is re-engaged with the actuator 18 which has been lifted up, as shown in FIG. When the control ring 19 is hooked and locked, the spring clutch 16 is turned off, and the paper feed drive shaft 10, that is, the paper feed roller 13 and the cam 21.
Rotation is stopped.

When the paper feed roller 13 and the cam 21 are in one rotation stop state, the cam 21 returns to a substantially downward rotation angle posture as shown in FIG. Return to the paper feed standby state. Further, the paper feed roller 13 is returned to the rotational angle posture in which the rounded portion 13a is substantially downward so that the paper feed roller 13 is not in contact with the paper S ₁ .

The separated sheet S ₁ is a driven roller 14.1.
4 and the separating member 23. Since the leading end of the sheet S ₁ is already spliced to the conveying roller 25, the sheet S ₁ is continuously pulled and conveyed by the conveying roller 25 even after the end of one rotation of the sheet feeding roller 13, and the driven rollers 14 and 14 and the friction member 23. Passing through the sandwiching part with
It is introduced into the apparatus main body through the sheet path 26.
While the sheet S ₁ is passing through the holding section, the driven roller 14.1
4 is driven to rotate until the trailing edge of the sheet S ₁ is removed.

The above-described operation is repeatedly executed each time pulse energization is input to the solenoid 16 based on the paper feed signal, and the stacked set sheets S on the sheet stacking plates 1 and 2 are repeated.
Are sequentially separated and delivered to one sheet.

(B) FIGS. 21 to 26 show other examples of the sheet feeding device. This feeding device is a device provided with a paper feed multiple feed preventing member 33 as a second separating means.

FIG. 21 is a partially cutaway cross-sectional side view of an essential part of the apparatus, FIG. 22 is a vertical sectional front view taken along line aa of FIG. 21, and FIG.
3 to 26 are operation process charts of single-sheet separation feeding.

The same members and portions as those of the apparatus shown in FIGS. 15 to 20 are designated by the same reference numerals, and their repeated description will be omitted.

In the apparatus of this example, the separating member 23 is interlocked with the vertical swing control of the swing stacking plate 2 described above, and the feeding means 15 is provided.
It is oscillated into a state where it is in contact with and a state where it is released and released from contact.

That is, the separating member 23 is held by a supporting member 32 which is swingable up and down about the supporting shaft 31, and the supporting member 32 is separated by the elastic member 24 about the supporting shaft 31. It is constantly urged to rotate upward (the clockwise direction in FIG. 21), which is the direction in which it contacts the lower surface of the feeding unit 15.

When the swingable stacking plate 2 is held in a depressed state by the cam 21 (FIGS. 21 to 23), the supporting member 32 described above causes the downward protrusion 2 of the swinging stacking plate 2 on the rear surface side of the front end portion thereof.
The a member a is abutted against the elastic member 24, and is pressed downward about the support shaft 31 and held in a rotated state.
Is held in the contact release state separated from the lower surface of the feeding unit 15.

When the spring clutch 16 is turned on, the paper feed drive shaft 1
When 0 starts driving one rotation, the push-down of the rocking stacking plate 2 is released by the escape rotation of the cam 21 and the stacking plate 2 rotates upward, so that the rear surface side of the tip end of the rocking stacking plate 2 is moved. The pressing of the support member 2a by the downward protrusion 2a is released, the support member 32 is pushed up and rotated by the elastic member 24 around the support shaft 31, and the separating member 23 is brought into contact with the lower surface of the feeding means 15. (Figs. 24 and 25).

Reference numeral 33 denotes a paper feed multiple feeding preventing member as a second separating member, which is arranged beside the separating member 23 and at a position where it does not come into contact with the sheet feeding means 15.

The multi-feed preventing member 33 is freely rotatable about the support shaft 34, has an upper end serving as a stopper portion 33a (paper contact portion) having a plurality of convex portions, and a lower end serving as a swingable stacking plate. 2 as the contact portion 33b for the back surface of the tip end portion of 2,
In conjunction with the vertical swing control of the swingable stacking plate 2, the swingable stacking plate 2 is rotated about the support shaft 34.

That is, when the swingable stacking plate 2 is held in a depressed state by the cam 21 (FIGS. 21 to 23), the lower end contact portion 33b of the double feed preventing member 33 is moved by the swinging stacking plate 2.
Is pressed down by the abutment of the rear surface of the front end portion of the upper end portion and is held in a state of standing upright around the support shaft 34 in the clockwise direction against its own weight, and thus the stopper portion 3 at the upper end portion of the double feed preventing member 33.
3a is held in a state of protruding above the upper surface b of the guide member 22.

When the spring clutch 16 is turned on, the paper feed drive shaft 1
When 0 starts driving one rotation, the push-down of the rocking stack plate 2 is released by the escape rotation of the cam 21, and the stack plate 2 rotates upward, so that the back surface of the tip of the rocking stack plate 2 is moved. The lower end abutting portion 33b of the hanging multi-feed preventing member 33 is released, and the hanging multi-feed preventing member 33 is tilted counterclockwise about its support shaft 34 by its own weight to be rotated and the upper end stopper portion 33a is rotated. The guide member 22 is positioned below the upper surface b (FIGS. 24 and 25).

In the paper feed standby state shown in FIG. 23, the solenoid 17 is energized once based on the paper feed start signal so that the spring clutch 16 is turned on as in the case of the apparatus shown in FIGS. One rotation drive of the paper drive shaft 10 is started, and at the initial stage of the rotation, the cam 21 releases the push-down holding of the rocking stack plate 2 and the rocking stack plate 2 rotates upward, and the upper surface of the stacked paper S on the leading end side. Is brought into contact with the lower surfaces of the driven rollers 14 of the paper feeding means 15 at a predetermined pressure.

The separating member 23 comes into contact with the feeding means 15 in association with the upward rotation of the swingable stacking plate 2,
In addition, the multi-feed preventing member 33 tilts counterclockwise and rotates, and the upper end stopper portion 33a of the double feeding preventing member 33 is rotated on the upper surface b of the guide member 22.
It will be in a state of being located below.

With the subsequent rotation of the paper feed drive shaft 10, the uppermost sheet S ₁ of the stacked sheets S is separated and fed by the same principle and operation as the apparatus shown in FIGS. 25).

When the paper feed drive shaft 10 makes one rotation and the control ring 19a of the spring clutch 16 is re-engaged by the actuator 18 of the solenoid 17 to stop the rotation of the paper feed drive shaft 10 (FIG. 26), the cam is released. Since 21 is returned to the substantially downward rotation angle posture, the swingable stacking plate 2 is pushed down to return to the first paper feed standby state.

Further, in conjunction with the pushing down of the rocking and stacking plate 2, the separating member 23 moves downward and the contact with the feeding means 15 is released. As a result, the multi-feed preventing member 33 is rotated upright, and the upper end stopper portion 33a projects upward from the upper surface b of the guide member 22.

At the time when the paper feed drive shaft 10 makes one rotation and its rotation is stopped, the leading edge of the above-mentioned one-sheet separated feed paper S ₁ has already been conveyed to the conveying roller pair 25 (the apparatus of this example). Then, since the sheet S ₁ is intermediately connected to the skew roller, the sheet S ₁ is continuously pulled and conveyed by the conveying roller pair 25 and introduced into the apparatus main body through the sheet path 26.

At this time, the separating member 2 is separated from the feeding means 15.
Since _No. 3 is separated and is in the contact release state, back tension is not applied to the sheet S ₁ which is continuously conveyed by the pair of conveying rollers 25. Further, since the upper end stopper portion 33a of the overlap feeding prevention member 33 is in a state of projecting above the upper surface b of the guide member 22, the overlap feeding of the second and subsequent sheets is prevented.

[0043]

However, the above-mentioned conventional apparatus has the following problems.

(A) In the case of the apparatus as shown in FIGS. 15 to 20, the one-sheet separated feeding sheet S ₁ after one rotation of the sheet feeding drive shaft 10 is driven by the feeding means 15 as described above. Roll 14
It is sandwiched between 14 and the separating member 23 abutting against it, and is continuously pulled and conveyed by the conveying roller pair 25 against the clamping force. At this time, as shown in FIG. At least three sheets of paper S ₁ , S ₂ , S ₃ , and so on are sandwiched between the driven rollers 14 and 14 and the separating member 23.
· If occurs a state of intervention as intermediate sheet S ₂ is in FIG. 27 (b), it is taken to continue pulling the conveyed uppermost sheet S ₁ and the conveying roller pair 25 It is easy to get a double feed through the nip.

(B) Further, in the case of the apparatus as shown in FIGS. 21 to 26, the positional accuracy of the upper end stopper portion 33a of the double feed preventing member 33 is poor, so that the sheet carrying property is deteriorated.

That is, when the paper feed drive shaft 10 makes one rotation and its rotation is stopped, the multi-feed preventing member 33 rises up and the upper end stopper portion 33a thereof protrudes from the upper surface b of the guide member. Is low as shown in FIG. 28 (a),
As a result, the double feed prevention function is lowered, and double feed of sheets S ₂ ...

Further, if the protruding position is high as shown in (b) and (c), the sheet S ₁ is deformed and becomes a conveyance resistance, so that conveyance failure or skewing is likely to occur. Note that FIG. 7C is a sectional view taken along line cc in FIG.

It is an object of the present invention to provide a sheet feeding device of this type that does not have the above problems.

[0049]

According to the present invention, there are provided a sheet feeding unit, a sheet stacking plate for stacking sheets and bringing the stacked sheets into contact with the sheet feeding unit with a predetermined pressure, and the sheet feeding unit. A sheet separating unit that abuts and separates one sheet on the sheet stacking plate fed by the sheet feeding unit, and a contact unit between the sheet feeding unit and the sheet separating unit that separates and feeds one sheet. In a sheet feeding device that is conveyed by a conveying unit on the downstream side of the sheet feeding direction, a contact pressure releasing unit that releases a contact pressure of the sheet stacking plate with respect to the sheet feeding unit, and the sheet feeding unit. Are arranged at positions where they do not come into contact with each other, and have at least one or more convex portions on the surface facing the paper, and they are projected into the traveling path of the paper which is being conveyed between the paper feeding means and the paper separating means. Stand-by operation, and one sheet of paper that is the next or lower than the one-feed sheet fed by rushing A double feed blocking member for preventing double feed, and when the leading edge of the sheet separated and fed one sheet reaches the transport means and the sheet is transported by the transport means, or After the conveyance of the sheet by the means, the contact pressure releasing means interlocks with the contact pressure release of the sheet stacking plate with respect to the sheet feeding means, and the double feed preventing member plunges into the sheet advancing path. A sheet feeding device characterized in that

Further, the above-mentioned double feed preventing member is rotatably supported, and a paper contact portion is provided at one end and a paper stacking plate contact portion is provided at the other end. An elastic member is interposed between the plate contact portion and the sheet stacking plate.

Further, the double feed preventing member is positioned in contact with a guide member forming a sheet advancing path.

Further, the contact pressure of the sheet separating means with respect to the sheet feeding means is released in association with the release of the contact pressure of the sheet stacking plate with respect to the sheet feeding means by the contact pressure releasing means. Characterize.

[0053]

In order to prevent the sheets separated and fed by the pressure contact surface formed by the feeding means and the separating means from being overlapped with the next sheet to be conveyed, the sheet advancing is performed in conjunction with the stacking plate. An elastic member is provided between the multi-feed preventing member protruding to the path and the stacking plate so as to abut and position the guide member forming the paper advancing path.

[0054]

【Example】

<First Embodiment> (FIGS. 1 to 7) FIG. 1 is a partially cutaway cross-sectional side view of an essential part of the apparatus of this embodiment, FIG. 2 is a vertical sectional front view taken along line aa of FIG. FIG. 4 is a side view of a main part, and FIGS. 4 to 7 are operation process charts of sheet separation feeding.

Components and parts common to those of the apparatus shown in FIGS. 15 to 20 or the apparatuses shown in FIGS. 21 to 26 are designated by the same reference numerals and their description will not be repeated.

In the apparatus of this embodiment, the separating member 23 for the feeding means 15 is constantly brought into contact with the lower surface of the feeding means 15 at a predetermined pressure by the elastic member 24 as in the apparatus shown in FIGS. There is.

Further, similarly to the apparatus shown in FIGS. 21 to 26, a paper feed double feed preventing member 33 as a second separating means is provided.

An elastic member (leaf spring piece) 35 is provided on the rear surface of the front end portion of the swingable stacking plate 2, and the double feed preventing member 33 is connected to the rear surface of the front end portion of the swingable stacking plate 2 via the elastic member 35.
The lower end abutting portion 33b is elastically brought into contact with the lower end abutting portion 33b so that the double feed preventing member 33 is rotated about the support shaft 34 in conjunction with the vertical swing control of the swing stacking plate 2. Is done.

Further, the stopper portion 2 which receives the double-feeding prevention member 33 which is rotated upright and regulates the upright rotation angle.
2b is provided on the guide member 22.

Since the standing rotation angle of the double feed preventing member 33 that has been rotated upright as described above is defined by the stopper portion 22b, the upper end stopper portion 33 of the double feed preventing member 33 is set.
The amount of protrusion of a above the upper surface b of the guide member 22 is regulated, so that it can always be regulated to the optimum amount.

Further, the rear surface of the tip end of the swingable stacking plate 2 and the lower end contact portion 33b of the double feed preventing member 33 are elastically brought into contact with each other via the elastic member 35 to rotate the double feed preventing member 33. By the operation, the elasticity of the elastic member 35 absorbs the error of the component size and assembly.

Therefore, the accuracy of the position of the upper end stopper portion 33a of the double feed preventing member 33 protruding from the upper surface b of the guide member 22 is improved.

The separation and feeding of the stacked sheets S one by one is described with reference to FIGS.
The same operation as that of the apparatus of FIG. 20 is performed by the cooperation of the feeding means 15, the separating member 23, and the conveying means 25.

When the spring clutch 16 completes one rotation, the rocking stacking plate 2 is pushed down and rotated by the cam 21, and in conjunction with this, the double feed preventing member 33 stands up and rotates, and the upper end stopper portion 33a thereof is guided. It projects above the upper surface b of the member 22 (FIGS. 3 and 7).

The uppermost sheet S _{1 which} has been separated and fed by _one sheet is nipped between the driven rollers 14 of the feeding means 15 and the separating member 23 which abuts on it, and is conveyed against the holding force. The roller pair 25 continues to pull and convey.

At this time, as shown in FIG. 3, the driven roller 14.1
Even if a plurality of sheets S ₂ · S ₃ ··· of the next order or less intervene in the sandwiching portion between the sheet 4 and the separating member 23, the intervening sheets S ₂ · S ₃ ··· Double feeding prevention member 3
Since it is stopped by the upper end stopper portion 33a of the sheet 3, the feeding roller pair 25 prevents the overlapped feeding with the uppermost sheet S ₁ which is continuously pulled and conveyed.

The position where the upper end stopper portion 33a of the double feed preventing member 33 protrudes from the upper surface b of the guide member 22 is positioned at the optimum position as described above, so that the position accuracy may be low or high. 28 due to the badness of
There is no deterioration in the sheet transportability as described in the above.

<Second Embodiment> (FIGS. 8 to 13) FIG. 8 is a partially cutaway cross sectional front view of a main part of the apparatus of this embodiment, and FIG. 9 is a vertical sectional front view taken along line aa of FIG. 10 to 13
FIG. 4 is an operation process chart of single-sheet separation feeding.

The same members and portions as those of the apparatus shown in FIGS. 21 to 26 are designated by the same reference numerals and their repeated explanation is omitted.

In the apparatus of this embodiment, as in the apparatus of the first embodiment, an elastic member (leaf spring piece) is provided on the back surface of the tip end of the rocking stack plate 2.
35, and the lower end contact portion 3 of the double feed blocking member 33 with the back surface of the tip end portion of the swingable stacking plate 2 via the elastic member 35.
3b and 3b are elastically brought into contact with each other so that the double feed preventing member 33 is rotated about the support shaft 34 in conjunction with the vertical swing control of the swing stacking plate 2.

Further, the double feed preventing member 33 which is rotated upright.
It receives and defines the standing rotation angle. The stopper portion 22b is provided on the guide member 22.

The separation and feeding of the stacked sheets S by one sheet is described with reference to FIGS.
The same operation as that of the apparatus of FIG. 26 is performed by the cooperation of the feeding means 15, the separating member 23, the conveying means 25 (skew rollers), and the double feed blocking member 33.

When the spring clutch 16 completes one rotation, the rocking stacking plate 2 is pushed down and rotated by the cam 21, and in conjunction with this, the separating member 23 separates from the feeding means 15 and the double feed preventing member 33 moves. When it is rotated upright, its upper end stopper portion 33a projects above the upper surface b of the guide member 22 (FIG. 13). As a result, the double feed of the paper of the second order and below is prevented.

In this case, the projecting position of the upper end stopper portion 33a of the double feed preventing member 33 from the upper surface b of the guide member 22 is set to the optimum position by the elastic member 35 / stopper portion 22b as in the first embodiment. Since the accuracy is obtained, there is no decrease in the sheet transportability as described with reference to FIG. 28 due to the poor position accuracy such as low or high.

<Third Embodiment> (FIG. 14) In the present embodiment, the paper-sheet overlap feed preventing member 33 is composed of a paper-contact member 33A and a rocking stacking plate-contact member 33B, each of which is supported by a support shaft 33C. It is rotatably supported by a torsion coil spring 33D. The support shaft 33C is disposed between the support shaft portions 22c and 22c provided on the guide member 22.

FIG. 14A shows a state in which the spring clutch 16 has completed one rotation and the rocking stacking plate 2 is pushed down and rotated by the cam 21. The rocking stack plate contact member 33B is pressed to support the spindle 3
3C is rotated clockwise against the torsion coil spring 33D.

Due to the reaction force of the torsion coil spring 33D accompanying the rotation of the member 33B, the paper contact member 33A is also interlocked with the support shaft 33C and is rotated clockwise upright until it is received by the stopper portion 22a. Paper S _{2 or} smaller
It functions to prevent double feeding.

Since the rotation angle of the sheet contact member 33A when it is rotated upright is defined by the stopper portion 22a, and the elasticity of the torsion coil spring 33D absorbs errors such as component size and assembly, the sheet contact member 33A absorbs the sheet. The accuracy of the protruding position of the contact member 33A from the upper surface b of the guide member 22 is improved.

In the apparatus of the above-mentioned first to third embodiments, the feeding means 15 has the half-moon type paper feed roller 13 and the driven roller 1.
However, a cam fixed to the drive shaft 10 may be used instead of the driven roller. Further, it may be a combination of a one-way clutch with a round paper feeding roller.

Although the solenoid 17 and the spring clutch 16 are used as the drive control mechanism, for example, an electromagnetic clutch or a clutch using a solenoid and a missing tooth gear may be used.

[0081]

As described above, according to the paper feeding apparatus of the present invention, the positional accuracy of the paper contact surface of the paper overlap multi-feed preventing member is improved, so that the paper overlap multi-feed is reliably prevented. It becomes possible to do. Further, the deformation of the paper can be prevented, and the resistance at the time of carrying the paper is reduced, so that the carrying property is improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway cross-sectional view of a main part of a sheet feeding device according to a first embodiment.

FIG. 2 is a vertical sectional front view taken along the line aa in FIG.

[Fig. 3] Side view of essential parts

FIG. 4 is an operation process diagram of single-sheet feeding and feeding (during sheet feeding standby state)

FIG. 5 is an operation process diagram of single-sheet feeding (when the spring clutch is on)

FIG. 6 is a diagram showing an operation process of separating and feeding one sheet of paper (when one sheet of paper is separated)

FIG. 7 is an operation process diagram of single-sheet feeding of paper (at the end of one rotation of the spring clutch)

FIG. 8 is a partially cutaway cross-sectional view of a main part of a sheet feeding device according to a second embodiment.

9 is a vertical sectional front view taken along the line aa in FIG.

FIG. 10 is a diagram showing an operation process of feeding and separating one sheet of paper (during a paper feed standby state)

FIG. 11 is a diagram showing an operation process of feeding and separating one sheet of paper (when the spring clutch is on).

FIG. 12 is a diagram showing an operation process of separating and feeding one sheet (sheet 1
(When separating sheets)

FIG. 13 is an operation process chart of single-sheet feeding of paper (at the end of one rotation of the spring clutch)

FIG. 14A is a side view of an essential part of the paper feeding device according to the third embodiment, and FIG. 14B is a front view of a paper feed double feed preventing member.

FIG. 15 is a partially cutaway cross-sectional view of a main part of a conventional sheet feeding device example.

16 is a vertical sectional front view taken along the line aa in FIG.

FIG. 17 is a diagram showing an operation process of feeding and separating one sheet of paper (during a paper feed standby state)

FIG. 18 is an operation process diagram of single sheet feeding (when the spring clutch is on)

FIG. 19 is an operation process diagram of sheet separation feeding (sheet 1
(When separating sheets)

FIG. 20 is an operation process chart of single-sheet feeding of paper (at the end of one rotation of the spring clutch)

FIG. 21 is a partially cutaway horizontal cross-sectional view of a main part of another example of a conventional sheet feeding device.

22 is a vertical sectional front view taken along the line aa of FIG.

FIG. 23 is a diagram showing an operation process of feeding and separating one sheet of paper (during a paper feed standby state)

FIG. 24 is a diagram showing an operation process of feeding and separating one sheet of paper (when the spring clutch is on).

FIG. 25 is an operation process diagram of single-sheet feeding (sheet 1
(When separating sheets)

FIG. 26 is an operation process diagram of single-sheet separation feeding (after completion of one rotation of the spring clutch).

27 (a) and (b) are explanatory views of occurrence of double feeding in the apparatus of FIGS. 15 to 20. FIG.

28 (a), (b), and (c) are shown in FIGS.
Illustration of deterioration of paper transportability in other devices

[Explanation of symbols]

 1 Paper fixed stacking plate 2 Paper swinging stacking plate 13 Half-moon type paper feeding roller 14 Driven roller 15 Paper feeding means 16 Spring clutch 17 Solenoid 23 Separation member (friction pad) 25 Conveying means (conveying roller) 33 Paper feeding double feeding Blocking member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Ishii 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (3)

[Claims] 1. A sheet feeding unit, a sheet stacking plate that stacks sheets and causes the stacked sheets to abut against the sheet feeding unit with a predetermined pressure, and abuts on the sheet feeding unit, and the sheet feeding unit. And a sheet separating means for separating one sheet on the sheet stacking plate fed out by the sheet feeding means and a sheet separating and feeding the sheet separated and fed one sheet in the sheet feeding direction downstream of the contact portion between the sheet feeding means and the sheet separating means. In the sheet feeding device to be conveyed by the conveying means, the contact pressure releasing means for releasing the contact pressure of the sheet stacking plate with respect to the sheet feeding means and the contact pressure releasing means arranged at a position not facing and contacting the sheet feeding means. ,
Has at least one or more protrusions on the surface facing the paper,
As the paper feed-in means and the paper-separating means are rushed into the traveling path of the paper which is being passed and stand-by, and the rushing-in prevents the double-feeding of the second and lower sheets of the separated-single-feeding paper. A double feed preventing member, and when the leading edge of the sheet separated and fed one sheet reaches the conveying means and the sheet is conveyed by the conveying means, or the sheet is conveyed by the conveying means. After that, the contact pressure release means interlocks with the contact pressure release of the sheet stacking plate with respect to the sheet feeding means to cause the double feed prevention member to rush into the paper advancing path, and the double feed A sheet feeding device, wherein the blocking member is positioned in contact with a guide member forming a sheet advancing path. 2. The double stacking prevention member is rotatably supported, and has a sheet contact portion at one end and a sheet stacking plate contact portion at the other end. The sheet feeding device according to claim 1, wherein an elastic member is interposed between the plate contact portion and the sheet stacking plate. 3. The release of the contact pressure of the paper separating means with respect to the paper feeding means is interlocked with the release of the contact pressure of the paper stacking plate with respect to the paper feeding means by the contact pressure releasing means. The sheet feeding device according to claim 1, wherein the sheet feeding device is a sheet feeding device.