JP2001106363A - Sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeder capable of removing a sheet jagged with no trouble without requiring a complex mechanism. SOLUTION: A sheet feeder is provided with a core roll 13 retained so as to be rotated by a conveying of a sheet, a handling member 30 for clamping the paper between the core rolls 13 and preventing an overlapping sending of the sheet, and a support member 34 turnably retained, retaining the handling member 30 and urging the handling member 30 to the core rolls 13. The support member 34 has a projection 33 of which a surface has a lower friction coefficient than that of the handling member 30. In the case where the sheet clamped by the handling member 30 and the core rolls 13 is drawn to a direction opposite to a conveying direction, the support member 34 is turned by a friction force of the sheet and the handling member and the sheet is clamped between the projection 33 and the core roll 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device used in an image forming apparatus such as a copying machine, a facsimile, a printer, and the like, for supplying sheets on which images are fixed one by one.

[0002]

2. Description of the Related Art As shown in FIG.
1 includes a middle plate 62, a separating member 63, a sheet feeding unit 64, and a conveying unit 65. The intermediate plate 62 presses a sheet (not shown in FIG. 14) against the sheet feeding unit 64 and
The paper feeding unit 64 feeds the separated papers one by one by separating and feeding the stacked papers one by one, and the feeding unit 65 includes a feeding roll 66 and a driven roll 67, and further transports the fed sheet by sandwiching it between them. The driven roll 67 includes a pressing arm 68
Urged in the direction of the paper feed roll 66. In addition,
The end on the side where the paper is fed is the plate portion 62 of the intermediate plate 62.
It is loaded on A.

When a sheet is jammed while being sandwiched between the sheet feeding means 64 and the separating member 63 and between the sheet feeding roll 66 and the driven roll 67, when the sheet 62 is separated from the sheet feeding means 64 by a predetermined distance, the sheet Separates the separating member 63 from the sheet feeding means 64, and the separating member 63 pushes down the pressing arm 68, and
6 and the driven roll 67 are separated from each other. As a result, the nip between the paper feeding means 64, the separating member 63 and the conveying means 65 is released, and the jammed paper can be removed.

[0004]

According to the conventional paper feeder described above, the complicated nip must be released as described above in order to remove the jammed paper, which is troublesome. I was Further, since there are many mechanical parts for releasing the nip, the mechanism is complicated and the cost is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding device which does not require a complicated mechanism and can remove a jammed sheet without trouble.

[0006]

In order to achieve the above object, a paper feeder according to the first aspect of the present invention is, for example, as shown in FIG. 13; a separating member 30 for sandwiching the sheet between the core roll 13 and preventing double running of the sheet.
And a supporting member 34 rotatably held, holding the separating member 30 and biasing the separating member 30 toward the core roll 13. The surface of the supporting member 34 is smaller than the friction coefficient of the separating member 30. A projection 33 having a low coefficient of friction; when the sheet sandwiched between the separating member 30 and the core roll 13 is pulled in a direction opposite to the conveying direction, the frictional force between the sheet and the separating member 30 Thus, the support member 34 is rotated, and the paper is sandwiched between the protrusion 33 and the core roll 13.

With this configuration, the paper feeding device includes the separating member and the support member having the protrusion, and when the paper is jammed, if the paper is pulled in the direction opposite to the conveyance direction, the paper is removed by pulling the paper. The frictional force with the separating member applies a rotational force to the supporting member to rotate the supporting member, and shifts from a nip (first nip) formed by the core roll and the separating member to a nip (second nip) formed by the core roll and the protrusion. . Since the surface of the projection has a low coefficient of friction, the sheet can be easily pulled out with a small force without damaging the sheet.

According to a second aspect of the present invention, in the paper feeder according to the first aspect, the support member has a rotation shaft for rotatably holding the support member; When the sheet is sandwiched between the separating member and the core roll, a normal line of the core roll at a contact point between the sheet and the core roll is configured to be located between the protrusion and the rotation axis. It is characterized by having.

Since the normal line of the core roll at the point of contact between the sheet and the core roll is located between the projection and the rotation axis, the normal line from the center of the rotation axis to the nip point of the second nip is formed. The distance is longer than the distance from the center of the rotation axis to the nip point of the first nip. Therefore, the rotation torque at which the protrusion pushes the core roll can be made larger than the rotation torque at which the separating member pushes up the core roll,
A smooth transition from the first nip to the second nip can be achieved.

[0010] According to a third aspect of the present invention, in the paper feeder according to the first or second aspect, the separating member has a holding plane for holding the paper between the core roll and the core roll. The projection has a portion in contact with an imaginary plane extending from the holding plane, or a portion of the projection closest to the imaginary plane is located slightly away from the imaginary plane. .

Since the projection has a portion in contact with a virtual plane extending from the holding plane, or the portion of the projection closest to the virtual plane is slightly separated from the virtual plane, the projection becomes an obstacle and the paper runs poorly. , Without causing heavy running
When the support member rotates, the nip smoothly transitions from the first nip to the second nip.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding members are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a perspective view of a main part showing an embodiment of a sheet feeding apparatus according to the present invention. The paper feeder is used in an image forming apparatus such as a copying machine and a printer, and is for supplying paper to the image forming apparatus.

The paper feeder 1 has a shaft 11, which is rotatably supported by a bearing (not shown in FIG. 1) attached to a base (not shown in FIG. 1) of the paper feeder 1. The shaft 11 is provided with two sets of a substantially half-moon-shaped paper feed roll 12 and a disk-shaped core roll 13. The paper feed roll 12 is fixedly mounted on the shaft 11, rotates in synchronization with the shaft 11, and the arc portion 12 A of the paper feed roll 12 having an arc-shaped cross section comes into contact with the sheet 55 (see FIG. 3). The paper 55 is pressed and sent out, and the paper 55 is conveyed. The core roll 13 is freely attached to the rotation of the shaft 11 and is rotated by the fed sheet 55 to prevent the paper 55 from running multiple times (the sheets are conveyed without being overlapped or spaced apart). 55 are surely sent one by one at an interval.

A driven gear 14 is fixed to one end of the shaft 11, and the driven gear 14 has a toothless portion 14A in which teeth are partially missing at one place. Another bearing (not shown in FIG. 1) is attached to the above-described base, and a drive gear 15 is fixed to a shaft (not shown in FIG. 1) rotatably supported by the bearing. Are arranged to mesh with the driven gear 14.

A pin 16 is provided upright on a side surface 14B of the driven gear 14 opposite to the side surface on the shaft 11 side. One end of a tension spring 17 is connected to the pin 16 and the other end of the tension spring 17 is Pins erected on the aforementioned base (not shown in FIG. 1)
It is connected to the. The tension spring 17 urges the pin 16 in the direction of 18 in the figure, and in the state shown in FIG.
However, the tension spring 17 generates a rotational force that attempts to rotate in the direction of arrow A in the figure.

The driving gear 15 rotates in the direction of arrow B, and drives the driven gear 14 when its teeth mesh with the teeth of the driven gear 14. However, the driven gear 14 is rotated by the driving gear 15 and the toothless portion 14A of the driven gear 14
However, when it comes to a position where it should be meshed with the drive gear 15, there is no tooth in the toothless portion 14A, so that the mesh between the drive gear 15 and the driven gear 14 is released.

The driven gear 14 is provided with the boss 1 adjacent in the axial direction.
9, and a locking portion 20 is formed on the boss portion 19. The locking portion 20 is formed such that a part of the circumferential surface of the boss portion 19 is gradually projected in the radial direction (see FIG. 2), and the boss portion 1 is formed.
9 has a flat end face 20A (see FIG. 2) toward the central axis of the shaft 9, that is, the central axis of the shaft 11. A cam 28 is attached to the shaft 11 adjacent to the driven gear side of the boss 19, and a cam 29 is attached to one end of the shaft 11 far from the driven gear 14. The cams 28 and 29 project perpendicularly from the shaft 11 in the same direction.

As shown in FIG. 2, a solenoid 21 is disposed almost directly below the boss 19 via a housing plate 41 attached to the base. When power is supplied to the solenoid 21, the core rod 21A of the solenoid 21 moves downward (in a direction away from the boss 19, that is, in a direction toward the solenoid 21). The core rod 21A of the solenoid 21 includes:
The movable plate 22 is connected, and the movable plate 22 moves up and down in accordance with the movement of the core rod 21A. The storage plate 41 is composed of two parallel side plates 4.
1A, and the solenoid is disposed between the side plates 41A.

One end of a compression spring 23 is connected to the housing plate 41, and the compression spring 23 is disposed along the side plate 41A between the solenoid 21 and the side plate 41A in the longitudinal direction. The other end of the compression spring 23 is connected to the movable plate 22. The compression spring 23 urges the movable plate 22 upward in the figure,
When the solenoid 21 is not energized, the movable plate 2
2 is at the top. The movable plate 22 is a stopper 22
A, when the movable plate 22 is at the uppermost position and the stopper portion 22A comes into contact with the locking portion end surface 20A of the locking portion 20,
Engage with the locking portion end face 20A. In this state, the movable plate 22
And the locking portion 20 is engaged. The movable plate 22 moves downward by energizing the solenoid 21, and the stopper portion 22A
Is disengaged from the engaging portion end surface 20A of the engaging portion 20. This state is referred to as disengagement between the movable plate 22 and the locking portion 20.

Since the solenoid 21 has a regulating part (not shown in FIG. 2) for regulating the upward movement of the core rod 21A, the upward movement of the movable plate 22 is restricted to the highest position. In other words, the restricted position is the highest position.

The description of the configuration of the paper feeder 1 will be continued with reference to FIG. The sheet feeding device 1 has a sheet stacking plate 24 on which sheets 55 (see FIG. 3) are stacked. The sheet stacking plate 24 includes a seat 25 (shown by a dotted line in FIG. 1) on a lower surface thereof.
One end of a compression spring 35 (see FIG. 4) as an elastic member is connected to the sheet stacking plate 24, and the sheet loading plate 24 receives an urging force acting on the seat 25 from below to above by the compression spring 35.

The sheet stacking plate 2 protrudes upward from the sheet stacking plate 24 on the upper side near the edge 43 in the width direction of the sheet stacking plate 24 and near the longitudinal edge 43 closer to the shaft 11.
Protrusion plates 46 and 47 having surfaces parallel to 4 are provided. The paper stacking plate 24 is located near a longitudinal edge 44 far from the shaft 11 and is configured to be rotatable around a rotation shaft 45 parallel to the shaft 11. Accordingly, the sheet stacking plate 24 is turned around the turning shaft 45 in the direction D in the figure by the urging force of the compression spring 35. The rotation of the paper loading plate 24 in the D direction causes the paper loading plate 24 to rotate.
The upper sheet 55 rises to a position where the upper sheet 55 comes into contact with the circular arc portion 12A of the paper feed roll 12, and lowers to a position separated from the circular arc portion 12A of the paper feed roll 12 by rotation in the direction C in the drawing.

The protruding plates 46 and 47 are pressed against the cams 28 and 29 by the urging force of the compression spring 35 connected to the seat 25 against the paper stacking plate 24, and are vertically moved by the cams 28 and 29 intermittently. I do. Projection plates 46 and 47 and sheet loading plate 2
4 is integrally formed, the projection plates 46 and 47 rotate around the rotation shaft 45 integrally with the sheet stacking plate 24. When the cams 28 and 29 are not in contact with the protruding plates 46 and 47, the sheet stacking plate 24 in the direction in which the protruding plates 46 and 47 rise.
The core roll 13 acts as a stopper for restricting the rotation of the core roll.

As shown in FIG. 3 (partial sectional view perpendicular to the shaft 11 in the paper feed roll 12 shown in FIG. 1), the paper feed device 1
(FIG. 1) is an edge 43 (FIG. 1) of the sheet stacking plate 24 (FIG. 1).
Next to the sheet feed roll 12 / core roll 13,
A support member 34 is provided. The support member 34 includes the paper feed roll 1
The present invention has a plate-shaped separating member 30 housed in a separating supporting portion housing portion 48 facing the second and core rolls 13, and is opposite to a surface of the separating member 30 in contact with the separating member housing portion 48. The surface 30 </ b> A as a holding plane is formed on the core roll 13.
Further, it is intermittently in contact with the paper feed roll 12. The separating member 30 guides the sheets 55 stacked on the sheet stacking plate 24 (see FIG. 1) and conveyed by the sheet feeding roll 12 one by one, sandwiched between the sheet feeding roll 12 and the core roll 13. The separating member 30 may be made of urethane foam or rubber. In FIG. 3, the sheet 55 is slightly lifted in the direction approaching the core roll 13 near the arrow E, but the sheet 55 is typically in contact with the surface 30 </ b> A of the separation member 30. Lies on a plane.

The support member 34 has a substantially semi-cylindrical projection 3.
The protrusions 33 are arranged substantially parallel to the separating member 30 adjacent to the separating member 30, and are disposed on the separating member 30 on the side of the sheet 55 in the feeding direction. When the height of the protrusion 33 is h1 and the thickness of the separating member 30 is h2, it is desirable that h1 be equal to h2 or slightly smaller than h2. In this case, when considering a virtual plane that is in contact with the surface 30A of the separating member 30 and considering a plane that is an extension of this virtual plane, the highest portion 33A of the projection 33 is slightly away from the extended plane toward the support member. In position.

The support member 34 has a rotating shaft 31 and is configured to be able to rotate a predetermined angle about the rotating shaft 31. The support member 34 is urged by a compression spring (not shown in FIG. 3) to rotate counterclockwise in the drawing. Therefore, usually, the separating member 30 is the core roll 1.
3 or intermittently when the sheet feed roll 12 comes into contact with the sheet feed roller 12, the sheet is further pressed against the sheet feed roll 12.

On the side surface of the support member 34 on the side from which the sheet is fed out, and on the side surface below the projection 33 in the figure, the claw part 3 is provided.
7 is attached. The claw part 37 includes a support member 34.
Regulates the angle of rotation that rotates clockwise in the figure. When the support member 34 rotates clockwise the most in the figure, a gap through which one sheet of the maximum thickness paper 55 passes is formed.
It is formed between the paper feed roll 12 and the separating member 30.

Next, the operation of the sheet feeder 1 will be described. The energization / de-energization of the solenoid 21 and the drive gear 15 /
The relationship between the meshing of the driven gear 14, the state of the inclination of the sheet stacking plate 24 in each of these relations, and the state of the state of the paper feed roll 12 will be mainly described. 4A to 8B, FIG. 4A shows the state of engagement between the driving gear 15 and the driven gear 14, and the state of energization of the solenoid 21. (B) is cam 2
(C) shows the state of engagement between the sheet stacking plate 24 and the sheet loading plate 24, and FIG.

First, a description will be given with reference to FIG. FIG.
As shown in (A), it is assumed that the driving gear 15 and the driven gear 14 are not meshed, and that the solenoid 21 is not energized. At this time, the driving gear 15 is in a state of being dropped into the toothless portion 14A of the driven gear 14, and the shaft 11 and the driven gear 14 are stationary without rotating even when the driving gear 15 is rotating. The locking portion end face 20A of the locking portion 20 provided on the boss portion 19 of the driven gear 14 is engaged with the stopper portion 22A of the movable plate 22. The driven gear 14 receives a biasing force in a direction 18 to rotate in the direction A in the state shown in the figure by a tension spring 17 (indicated by a dotted line in the figure, hereinafter the same from FIG. 5 to FIG. 11).

As shown in FIG. 4B, the cams 28 and 29 attached to the shaft 11 are engaged with protrusions 46 and 47 provided on the sheet stacking plate 24. Therefore, as shown in FIG. 4C, the paper stacking plate 24 is located away from and in contact with the core roll 13. Further, the sheet supply roll 12 has a chord portion 12B which is a flat portion in the circumferential direction.
At a position facing the paper stacking plate 24. In the figure, the arc portion 12A of the paper feed roll 12 and the core roll 13 are shown overlapping.

Next, a description will be given with reference to FIG. FIG. 5 (A)
When the solenoid 21 is energized, the movable plate 22 moves downward in the figure (in a direction approaching the solenoid 21) as shown in FIG.
0A is disengaged from the stopper portion 22A of the movable plate 22. Therefore, the driven gear 14 is rotated in the direction A by the tension spring 17 and meshes with the driving gear 15.
Therefore, the rotation of the shaft 11 and the paper feed roll 12 due to the rotation of the driven gear 14 starts.

As shown in FIG. 5B, the cams 28, 29
The projections 46 and 47 are engaged with each other, and as shown in FIG. 5C, the angle of the sheet stacking plate 24 does not change, and the sheet stacking plate 24 is not in contact with the core roll 13.

Next, description will be made with reference to FIG. FIG. 6 (A)
As shown in FIG. 6, when the driving gear 15 rotates the driven gear 14 by a predetermined angle, as shown in FIG.
The paper stacking plate 24 is disengaged from the projection plates 46 and 47 by the urging force of the compression spring 51 so that the paper
6C, the sheet stacking plate 24 comes to the raised position as shown in FIG. 6 (C). At this time, since the arc portion 12A of the paper feed roll 12 is at a position where it comes into contact with the paper 55 (see FIG. 3) on the paper stacking plate 24, the paper 55 (see FIG. , And is pressed by the paper feed roll 12 to start the conveyance of the paper 55. When the paper 55 is transported by the paper feed roll 12, the transported paper 55 rotates the core roll 13.

When the driven gear 14 rotates, the stopper portion 22A
Locking part 20 at a position where it does not interfere with locking part 20 even if
It is preferable to stop the energization of the solenoid 21 and de-energize the solenoid 21 when the time comes. In this case, even if the solenoid 21 is de-energized (not shown in FIG. 6A, see FIG. 7A), the stopper portion 22A
Rises but does not interfere with the locking part 20

Next, a description will be given with reference to FIG. FIG. 7 (A)
As shown in FIG. 7, since the driving gear 15 / the driven gear 14 are meshing, the driven gear 14 further continues to rotate,
As shown in (C), the circular arc portion 12A of the paper feed roll 12
Then, the contact between the sheet 55 and the sheet 55 (see FIG. 3) ends, and the sheet feeding (conveyance) of the sheet 55 by the sheet feed roll 12 ends. The sheet 55 that has been conveyed by the paper feed roll 12 is further conveyed in a subsequent conveyance step 52 (see FIG. 3). FIG.
As shown in (B), the paper loading plate 24 of the cams 28 and 29
Is disengaged, as shown in FIG.
The paper stacking plate 24 is at an ascending position by the urging force of the compression spring 51.

Next, a description will be given with reference to FIG. FIG. 8 (A)
As shown in FIG. 8, since the driving gear 15 / the driven gear 14 are meshing, the driven gear 14 further continues to rotate, and FIG.
As shown in (B), the cams 28 and 29 and the projection plates 46 and 4
7 is resumed, the sheet stacking plate 24 rotates around the rotation shaft 45 in the direction C in the figure, and the sheet stacking plate 24 comes to the lowered position as shown in FIG. 8C. The solenoid 21 is in a non-energized state.

Next, description will be made with reference to FIG. Since the driving gear 15 / the driven gear 14 are meshing, the driven gear 14
Continues to rotate further. The solenoid 21 is in a non-energized state. Although not shown in FIG. 9, the cams 28 and 29 and the protruding plates 46 and 47 are engaged, and the sheet stacking plate 24 is at the lowered position.

Next, a description will be given with reference to FIG. The meshing between the driving gear 15 and the driven gear 14 that has continued meshing is released. Due to the tension spring 17, the driven gear 14
In the direction by the urging force of the compression spring 17,
0 and the stopper 22 of the movable plate 22
A engages (see FIG. 4 for the engagement state). The solenoid 21 is in a non-energized state. Although not shown in FIG. 10,
The cams 28 and 29 and the protruding plates 46 and 47 are engaged, and the sheet stacking plate 24 is at the lowered position. This state is the same as the state in FIG.

Next, the operation when the sheet 55 (see FIG. 3) passes through the separating member 30 will be described with reference to FIG. The uppermost sheet 55 among the sheets stacked on the sheet stacking plate 24 comes into contact with the circular arc portion 12A of the sheet feeding roll 12 and the core roll 13 which are further rotated by the rising of the sheet stacking plate 24. The sheet is conveyed by being sandwiched between the paper feed roll 12, the core roll 13, and the separating member 30 (FIG. 3) on the support member 34. When the sheets are conveyed in an overlapping manner, they are loosened by the separating member 30 and only one sheet can pass through the separating member 30.

Next, referring to FIG. 3 and FIG.
The operation of removing the sheet 55 in the case where is jammed between the separating member 30 and the core roll 13 will be described.

In a normal sheet conveyance state, the circular arc portion 1 is formed by rotating the sheet supply roll 12 substantially once.
The sheet 55 sent out by 2A is the core roll 13
While being nipped (first nip) by the separating member 30, it is sent out to the previous transporting step 52. At this time, the separating member 30
Is held away from the core roll 13, the sheet 55 is not nipped at the position of the protrusion 33.

However, as shown in FIG.
Sheet 55 on the wall 36 of the sheet guide member 53 on the downstream side of
The paper 55 that cannot reach the previous transport step 52 due to slippage of the paper feed roll 12 and the paper 55 caused by an increase in transport resistance due to an increase in transport resistance, is jammed, and is pinched by the core roll 13 and the separating member 30. State.

As shown in FIG. 3, when the jammed sheet 55 is pulled in the direction indicated by the arrow E in the figure, the load at which the sheet 55 is nipped by the core roll 13 and the separating member 30 is N, and the friction between the sheet 55 and the separating member 30 is N. Since the core roll 13 is made of a highly slidable resin, the coefficient of friction with the paper 55 is set to 0.
Can be considered. The nip point of the support member 34 (the nip portion is not a point, but has a slight width and a length substantially equal to the width of the sheet, but is referred to as a point in the description because it is discussed on a sectional view). A force F of × N is applied in the drawing direction E of the sheet 55.

The distance between the nip point and the center of the rotation axis 31 of the support member 34 is R, and the angle formed between the straight line connecting the nip point and the center of the rotation axis 31 of the support member 34 and the direction E in which the paper 55 is pulled out. Is θ, the component force of F is F × sin at the nip point.
Since a force of θ is applied, a rotation torque T = F × sin θ × R about the rotation shaft 31 of the support member 34 acts at the nip point.

Due to the rotation torque T, the sheet 55 is nipped more strongly by the core roll 13 and the separating member 30 and the friction coefficient μp between the separating member 30 and the sheet 55 is large. In this state, the sheet 55 cannot be easily pulled out. . However, when the sheet 55 is further pulled out in the front E direction, the core roll 13 is pushed up in the G direction by the rotation torque T, the shaft 11 to which the core roll 13 is attached is bent, and the support member 34 is rotated, and the state shown in FIG. become. FIG. 11 shows the shaft 11 before bending by a dotted line.

The nip of the paper 55 is changed from the first nip between the core roll 13 and the separating member 30 having a large friction coefficient to the second nip between the core roll 13 and the projection 33 having a small friction coefficient, so that the paper 55 is easily pulled out. be able to.

At this time, as shown in FIG.
In order to bend the material (for example, steel) into the state shown in FIG. 11, the diameter of the shaft 11 is 8 mm, the thrust distance between the fulcrums 56 of the shaft 11 in the thrust direction is 328 mm, and the core roll closest to one fulcrum 56 of the shaft 11. 13, the distance to the side 13A opposite to the side facing the paper feed roll 12 is 121 mm,
The distance between the side surface 13A of one core roll 13 and the side surface 13A of the other core roll 13 is preferably 86 mm.

As shown in FIG. 3, the projection 33 on the support member 34 holding the separating member 30 is provided on the core roll 13 passing through the contact point between the core roll 13 and the separating member 30.
Is located on the opposite side of the center of the rotation shaft 31 of the support member 34 with respect to the normal line 54. In this case, the distance from the center of the rotating shaft 31 to the nip point (second nip point) of the projection 33 is smaller than the distance from the center of the rotating shaft 31 to the nip point (first nip point) of the separating member 30. It gets farther. Therefore, the separating member 3
Since the rotation torque at which the protrusion 33 pushes up the core roll 13 is larger than the rotation torque at which 0 pushes up the core roll 13, the first nip can be easily changed to the second nip.

Since the coefficient of friction between the sheet 55 and the protrusion 33 is set smaller than the coefficient of friction between the sheet 55 and the separating member 30, the sheet 55 in the second nip state is replaced with the sheet 55 in the first nip state. With a smaller force, the paper 55 can be easily pulled out without being damaged.

In this case, as shown in FIG. 13, when the shaft 11 is not bent, the horizontal coordinate from the center of the rotation shaft 31 of the support member 34 holding the separating member 30 is X,
Assuming that the vertical coordinate is Y, the position coordinates (Xmm, Ymm) with the center of the rotating shaft 31 as the origin are as follows. Center position of shaft 11 to which core roll 13 is attached:
(-2, 34.5) Radius of core roll: 18.1 mm Contact point between core roll 13 and separating member 30: (15.7, 18.1) Current position of point of projection 33 that should be contact point with core roll 13): (10.1, 20)

As shown in FIG. 3, if the height of the projection 33 is h1 (height from the extension plane of the bottom surface of the separating member 30) and the height (thickness) of the separating member 30 is h2, h
Assuming that 1 is greater than h2, the leading end of the fed sheet 55 hits the protruding portion 33 to cause a traveling failure, or even if the fed sheet 55 is conveyed without hitting the protruding portion 33, Is transported while touching the protruding portion 33, a rotational force (counterclockwise in the drawing) is applied to the support member 34 holding the separating member 30, and the angle of the separating member 30 decreases (counterclockwise in the drawing). Direction), the paper 5
5 and heavy running collapse and paper feeding failure occur. Further, when h1 is much smaller than h2, the protruding portion 33 remains in the core roll 1 even when the jammed sheet 55 is pulled out and the shaft 11 is bent.
No contact is made with h3.
Is set to be approximately the same as h2 or slightly lower than h2.

As described above, according to the present invention, when the support member has the protrusions and the support member, and the paper is jammed, the paper is separated from the core roll when the paper is pulled in the reverse feeding direction. Since the transition from the nip (first nip) by the member to the nip (second nip) by the core roll and the projections is performed, the force for pulling the paper can be reduced and the paper can be easily pulled out with a small force. The jammed paper can be removed without the need for any trouble.

[Brief description of the drawings]

FIG. 1 is a perspective view of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a schematic longitudinal sectional view around a boss portion of a driven gear of the sheet feeding device of FIG.

FIG. 3 is a longitudinal sectional view around a core roll of the sheet feeding device of FIG. 1;

FIG. 4 is a schematic diagram for explaining the operation of the sheet feeding device of FIG. 1;

FIG. 5 is a schematic diagram for explaining the operation of the sheet feeding device of FIG. 1;

FIG. 6 is a schematic diagram for explaining the operation of the sheet feeding device of FIG. 1;

FIG. 7 is a schematic diagram for explaining the operation of the sheet feeding device of FIG. 1;

FIG. 8 is a schematic diagram for explaining the operation of the sheet feeding device of FIG. 1;

FIG. 9 is a schematic diagram for explaining the operation of the sheet feeding device of FIG. 1;

FIG. 10 is a schematic diagram for explaining the operation of the sheet feeding device of FIG. 1;

FIG. 11 is a diagram for explaining an operation when a jammed sheet is pulled out.

FIG. 12 is a diagram in which a paper feed roll and a core roll are incorporated in a shaft.

FIG. 13 is a diagram showing the coordinates of the center of the shaft, the contact point between the core roll and the separating member, the center of the rotating shaft, and the point of the projection member that should be the contact point with the core roll.

FIG. 14 is a partial schematic view showing a conventional sheet feeding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feeder 11 Axis 12 Paper feed roll 13 Core roll 14 Driven gear 15 Drive gear 16 Pin 17 Tension spring 18 Direction 19 Boss part 20 Locking part 21 Solenoid 22 Movable plate 23 Compression spring 24 Paper loading plate 25 Seat 26, 27 Edge 28, 29 Cam 30 Separating member 30A surface 31 Rotating shaft 33 Projecting portion 34 Supporting member 35 Compression spring 45 Rotating shaft 46, 47 Projecting plate 53 Paper guide member 54 Normal line 55 Paper

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toru Ozawa 3-7-1, Funai, Iwatsuki-shi, Saitama Prefecture Fuji Xerox Co., Ltd. Iwatsuki Office (72) Inventor Kenji Okane 3-7-1, Funai, Iwatsuki-shi, Saitama Prefecture No. 1 Fuji Xerox Co., Ltd. Iwatsuki Office F-term (reference) 3F343 FA02 FB02 FB03 FB04 FC01 FC10 GA02 GB01 GC01 GD01 HA12 HB01 HD09 HD10 HD17 JA16 JD03 JD08 JD33 LA04 LA15 LC06 LC22 LD12

Claims (3)

[Claims] A core roll that is held so as to rotate by transporting the sheet; a separating member that sandwiches the sheet between the core roll and prevents double running of the sheet; A support member that holds the separating member and urges the separating member toward the core roll;
The support member has a projection having a surface having a lower coefficient of friction than the coefficient of friction of the separating member; the sheet sandwiched between the separating member and the core roll is moved in a direction opposite to the direction of conveyance. When pulled, the support member is rotated by a frictional force between the sheet and the separating member, and the sheet is sandwiched between the protrusion and the core roll. Paper feeder. 2. The paper sheet and the core roll when the paper is sandwiched between the separating member and the core roll, wherein the support member has a rotation shaft for rotatably holding the support member. 2. The sheet feeding device according to claim 1, wherein a normal line of the core roll at a contact point with the core roller is configured to be located between the protrusion and the rotation shaft. 3. 3. The separation member has a holding plane for holding the sheet between the separation member and the core roll;
3. The device according to claim 1, wherein the holding portion has a portion in contact with an imaginary plane that is extended, or a portion of the protrusion that is closest to the imaginary plane is located slightly away from the imaginary plane. 3. The paper feeding device according to 2.