JP2814707B2 - Sheet material feeding device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet material feeding apparatus for sequentially feeding stacked sheet materials to a sheet material receiving portion one by one.

More specifically, a sheet material stacking table for stacking and storing sheet materials, and a sheet material feeding unit for feeding a sheet material to a sheet material receiving unit by applying a feeding force to the stacked storage sheet material on the loading table. By means of a cam that has means and is rotationally controlled,
When the sheet material is not fed, the sheet material stacking table and the sheet material feeding means are relatively moved apart from each other so that the stacked storage sheet material and the sheet material feeding means are kept in a non-contact state. The present invention relates to a sheet material feeding device configured to relatively move the two members closer to each other so as to hold the sheet material feeding means and the stacked storage sheet materials in contact with each other to execute sheet material feeding.

In the above, the sheet material is, for example, a transfer sheet or a photosensitive sheet (electrofax sheet,
Other photosensitive papers), electrostatic recording paper, thermal recording paper, pressure-sensitive recording paper, printing paper, postcards, envelopes, cards, manuscripts, etc. Materials.

The sheet material receiving section is, for example, an image transfer mechanism section, an image forming process mechanism section, a printing mechanism section, a printing section, etc. in the image forming apparatus of the above example, and a sheet material processing mechanism section in various other sheet material processing apparatuses. (For example, a perforation processing mechanism, a coating processing mechanism for a medicine, another sheet material, or the like).

(Prior Art) FIGS. 4 to 6 show a conventional example of a sheet material feeding apparatus having the above-described configuration. FIG. 4 is a partially cutaway perspective view of a main part thereof, FIG. 5 is a longitudinal sectional view, and FIG. 6 is a transverse sectional view.

Reference numeral 1 denotes a paper feed shaft, which is rotatably supported by left and right bearings (not shown) of the apparatus main body.

Reference numeral 2 denotes a paper feed roller made of rubber or the like integrally formed on the outer periphery of the core tube 3. The paper feed shaft 1 is inserted into the core tube 3, and movement along the axis is regulated. It is rotatably fitted on the outside.

Reference numeral 9 denotes a clutch gear 9 which is supported on the right end of the paper feed shaft 1 in the drawing at the right end in the drawing and which is rotatably fitted to the outside while restricting movement along the shaft 1. A drive gear 11 driven by a motor (not shown) meshes. And receives a rotational force in the counterclockwise direction a in FIG. 4 by the drive gear.

Reference numeral 9a denotes a spring winding cylinder concentrically integrated with the clutch gear 9, and 7a denotes a spring winding cylinder fixed coaxially and integrally with the paper feed shaft 1 in the vicinity of the spring winding cylinder 9a, and both spring winding cylinders 9a and 7a are substantially Have the same outer diameter. Reference numeral 19a denotes a coil-wound clutch spring externally fitted over both spring winding cylinders 9a and 7a, and 6a denotes a one-turn control ring loosely fitted outside the clutch spring. One end portion 19 ₁ of the clutch spring 19a is engaged with the spring winding drum 7a, the other end portion 19 ₂
Is locked to the control ring 6a. 6b is a claw provided at one place on the outer surface of the control ring 6a. 12a is the first engaging and disengaging with the claw 6b.
The claw part.

A known one-turn spring clutch (hereinafter referred to as a first spring clutch B) using the above members 9a, 7a, 19a, 6a, 6b, and 12a.
Is configured.

The right end of the core tube 3 of the paper feed roller 2 is extended outward from the right end of the paper feed roller 2 in the drawing, and is brought close to the right end of the extended core tube portion so as to be concentric with the paper feed shaft 1. A spring winding cylinder 7b is provided integrally and fixed. Extension core tube part 3 and spring winding cylinder 7b
Have substantially the same outer diameter. 19b is the extension core 3
A coil-wound clutch spring 8a externally fitted over both the coil spring 7b and the spring cylinder 7b is a control ring loosely fitted outside the clutch spring. One end portion 19 ₁ of the clutch spring 19b is engaged with the extension core tube portion 3, the other end _{19. 2} are engaged with the control ring 8a. Reference numeral 8b denotes a large number of claws formed on the entire outer periphery of the control ring 8 at a fine pitch. Reference numeral 12b denotes a second claw portion which engages with and disengages from the claw portion 8b.

A well-known spring clutch (hereinafter, referred to as a second spring clutch C) is constituted by the above members 3.7b, 19b, 8a, 8b, and 12b.

Reference numeral 4 denotes a cam provided integrally with the paper feed shaft 1 at a position between the first and second spring clutches B and C.

Reference numeral 12 denotes a flapper which is sucked and released by a solenoid 13. A first engaging / disengaging claw portion 12 for the claw portion 6b of the control ring 6a of the first spring clutch B is provided on the tip side of the flapper 12.
a and the claw 8 of the control ring 8a of the second spring clutch C described above.
A second engagement / disengagement claw portion 12b for b is formed.

Reference numeral 14 denotes a sheet material loading table which is disposed below the sheet feeding roller 2 with its leading edge side positioned. The loading table 14 is moved by a push-up spring 16 in a direction in which the leading edge side approaches the lower surface of the sheet feeding roller. Lifted and biased. S indicates a sheet material loaded and stored on the loading table 14.

15 is a friction pad for separating one sheet material,
At a position downstream of the leading edge of the sheet feeding direction and in the vicinity of the leading edge, the lower surface of the paper feed roller 2 is constantly pressed and contacted by a spring 17.

. When the sheet material is not fed, the solenoid 13 is off (non-energized), the flapper 12 is pulled down by a not-shown pull-down spring, and the first and second two claw portions 12a on the leading end side are provided. 12b is engaged with the pawl portions 6b and 8b of the control rings 6a and 8a of the first and second spring clutches B and C, respectively (the state shown by the solid line in FIG. 5). Therefore, both the control rings 6a and 8a are stopped, so that the first and second spring clutches B and C
Are off.

That is, the first spring clutch B holds the clutch spring 19a in a state in which the clutch spring 19a is loosened (clutch-off state) with respect to the spring winding cylinders 9a and 7a.
, But idles on the paper feed shaft 1, no driving force is transmitted to the paper feed shaft 1, and the shaft 1 is kept in a rotation stopped state.

Also in the second spring clutch C, the sheet feeding shaft 1, that is, the spring winding cylinder 7 b is not rotated, and the clutch spring 19 b is loosened with respect to the spring winding cylinder 7 b and the extended core tube portion 3 of the sheet feeding roller 2 (clutch-off state). State), the paper feed roller 2 is kept in a rotation stopped state.

The large diameter portion of the cam 4 is located at the downward rotation angle position, and therefore, the sheet material mounting table 14 has a predetermined downward resistance against the push-up spring 16 when the tip of the downwardly large diameter portion of the cam 4 contacts the upper surface. It is kept in a state of being pushed down to the pushing position (FIG. 5), and the upper surface on the leading edge side of the stacking storage sheet material S on the stacking table 14 is separated from the lower surface of the sheet feeding roller 2 in a non-contact manner. It is in the state that you are doing.

. When the solenoid 13 is turned on (energized) based on the sheet feeding start signal from the sheet non-sheet feeding state, the flapper 12 is turned on.
Is sucked by the solenoid 13 and the first and second
Have first and second spring clutches B and C, respectively.
Escapes from the claw portions 6b and 8b of the control rings 6a and 8a (FIG. 4,
The state shown by the two-dot chain in FIG. 5). Thus, the first and second spring clutches B and C are both turned on by releasing the locking of the control rings 6a and 8a.

That is, in the first spring clutch B, the clutch spring 19a is tightened around the spring winding cylinders 9a and 7a by releasing the detent of the control ring 6a. By being connected to the paper feed shaft 1 via the winding drum 9a, the clutch spring 19a, and the spring winding drum 7a, the paper feeding shaft 1 is integrally rotated with the clutch gear 9 in the a direction.

In the second spring clutch C, when the control ring 8a is released, the clutch spring 19b causes the spring winding cylinder 7b and the paper feed roller 2
7b ・ 3
Is connected via the clutch spring 19b, so that the paper feed roller 2 starts rotating in the direction a in unison with the paper feed shaft 1 that has started to rotate by turning on the first spring clutch B as described above. I do.

Also, the cam 4 integrated with the paper feed shaft 1 rotates with the rotation of the paper feed shaft 1, and its downward large-diameter portion escapes from the upper surface of the sheet loading table 14 in a non-contact manner and rotates. Then, the holding state of the sheet loading table 14 by the cam 4 is released. With this release, the loading table 14 is pushed up by the push-up spring 16 so that the upper surface on the leading edge side of the stacked storage sheet material S on the loading table 14 comes into contact with the lower surface of the sheet feeding roller 2 (FIG. 6). .

Then, a feeding force is applied to the uppermost sheet material of the stacked storage sheet materials S by the paper feed roller 2 which has started to rotate, and only the uppermost sheet material becomes one of the friction pads 15.
One sheet is separated from the next lower sheet material by the sheet separating operation, passes between the sheet feeding roller 2 and the friction pad 15 and passes through the loading table 14.
It is fed from above.

The fed sheet material is relayed by a registration roller 18 and conveyed to a sheet receiving unit such as an image forming unit.
Reference numeral 20 denotes a sheet guide plate between the paper feed roller 2 and the registration roller 18.

. After the sheet material fed by the rotation of the paper feed roller 2 is delivered to the registration roller 18 (1 of the paper feed roller 2)
The solenoid 13 is turned off within the rotation). As a result, the suction of the flapper 12 by the solenoid 13 is released, and the first and second claws 12a and 12b of the flapper 12 are lowered with respect to the control rings 6a and 8a of the first and second spring clutches B and C, respectively. .

As a result, the second spring clutch C
The outer claw 8 of the control ring 8a is immediately
When the control ring is engaged and the control ring is stopped, the clutch is turned off, and the paper feed roller 2 is disconnected from the paper feed shaft 1 to be cut off from the drive. Become.

Further, the first spring clutch B controls the control ring 6a by rotating the control ring 6a one turn from the previous clutch-on, and the claw portion 6b is engaged with the first claw portion 12a of the flapper 12 in the lowered state. Ring 6a
Is stopped, the clutch is turned off, and the rotation of the paper feed shaft 1 is stopped. That is, one rotation drive of the paper feed shaft 1 stops. At the time of this stop, the cam 4 also completes one rotation and returns to the rotation angle position where the large-diameter portion is directed downward, and the sheet material stacking table 14 is kept pressed down against the push-up spring 16 so that the stacking is performed. The sheet material S is separated α from the sheet feed roller 2 in a non-contact manner.

The fed sheet material includes first and second spring clutches B.
-Even after C is turned off, the conveyance is continued by the conveyance force of the registration roller 18. When the second spring clutch C is turned off, the core cylinder 3 is cut off from the edge of the paper feed shaft 1 and is free to rotate around the paper feed shaft 1. The sheet feeding roller 2 and the core tube 3 are rotated on the shaft 1 by the transfer movement force of the registration sheet 18 of the sheet material until the trailing end of the sheet material passes between the friction pad 2 and the friction pad 15.

(Problems to be Solved by the Invention) The above-described sheet material feeding apparatus uses first and second two sets of spring clutch mechanisms B and C. In particular, the sheet material is rotated by rotating the cam 4. The first spring clutch mechanism B for moving the loading table 14 up and down is required to have strict dimensional accuracy of the winding drum and the clutch spring. In addition, application of grease and preparation of play in the thrust direction of the winding drum are required in assembling. However, there are drawbacks such as troublesome work and high cost.

Therefore, the present invention relates to this kind of sheet material feeding device,
At least, a driving mechanism for controlling the rotation of the cam to move the sheet material loading table up and down with a simple configuration and a low-cost mechanism having sufficient control accuracy, and using a spring clutch as described above. The aim is to eliminate the problem.

(Means for Solving the Problems) The present invention is a sheet material feeding device having the following configuration.

(1) The first state in which the sheet material loading table is moved away from the sheet material feeding means by the cam whose rotation is controlled to hold the sheet material and the sheet material feeding means in a non-contact state, A sheet material feeding device for moving the sheet material to a second state in which the sheet material and the sheet material feeding means are kept in contact with each other, and a drive for applying a rotational force to the cam via a toothless gear. In the first state of the gear and the sheet material loading table, the toothless gear is locked and the toothless portion is held at a rotation angle position corresponding to the drive gear at which no rotational force is transmitted from the drive gear to the toothless gear. Engaging and disengaging means for allowing the rotation of the toothless gear by releasing the lock, wherein the toothless gear is driven by the cam by the pressure contact force of the sheet loading table with the cam in the first state of the sheet loading table. Rotation moment in the direction that matches the A sheet feeding device, wherein when the engagement and disengaging means is unlocked, the cam rotates with the rotation moment to rotate the toothless gear and mesh with the drive gear. .

(2) A first state in which the sheet material loading table is moved away from the sheet material feeding means by the rotation-controlled cam to hold the sheet material and the sheet material feeding means in a non-contact state, A sheet material feeding device for moving the sheet material to a second state in which the sheet material and the sheet material feeding means are kept in contact with each other, and a drive for applying a rotational force to the cam via a toothless gear. A gear, a one-turn control ring that rotates integrally with the toothless gear, and a toothless portion of the toothless gear that locks the one-rotation control ring when the sheet loading table is in the first state. One-rotation control corresponding to the gear, allowing the rotation of the sheet loading table to the second state by releasing the locking of the one-rotation control ring by holding the rotation at a rotational angle position at which no rotational force is transmitted from the driving gear to the toothless gear. And a ring engaging / disengaging member, wherein the first position of the sheet material loading table is A rotation moment in a direction coinciding with a direction in which the toothless gear is driven acts on the cam by the pressing force of the sheet material loading table against the cam, and when the lock of the one-rotation control ring is released. A sheet material feeding device, wherein the toothless gear is rotated by the rotation of the cam by the rotation moment to be in mesh with the drive gear.

(3) The sheet feeding device according to (1) or (2), wherein the toothless gear is pivotally supported on the same shaft as the sheet feeding means.

(Operation) That is, when the sheet material is not fed, the sheet material feeding means and the sheet material loading table are relatively separated and held, and each time the sheet material is fed, the two are relatively moved close to each other. The cam rotation control means for bringing the sheet material feeding means into contact with the sheet material on the sheet material mounting table is a driving means including gears with some of the teeth notched, so that the structure and assembly are smaller than those of the spring clutch. A cam rotation drive control mechanism that is simple and has excellent control accuracy is configured, and simplification of the apparatus and cost reduction can be achieved.

(Embodiment) Figs. 1 to 3 show a sheet feeding apparatus according to an embodiment of the present invention. 1 is a partially cutaway perspective view of a main part, FIG. 2 is a longitudinal sectional view, and FIG. 3 is a transverse sectional view. 4th to above
Components and parts common to those of the apparatus shown in FIG. 6 are denoted by the same reference numerals, and the description thereof will not be repeated.

The clutch gear 9 which receives the rotational force from the drive gear 11 includes a spring clutch A including a spring winding cylinder 9a concentrically integrated with the clutch 9, a spring winding cylinder 7 integrated with the paper feed shaft 1, a clutch spring 19, a control ring 8, and the like. Is connected to and disconnected from the paper feed shaft 1. A claw portion 8b is formed on the entire outer circumferential surface of the control ring 8 at a fine pitch, and the first claw portion 12a of the flapper 12 is disengaged.

Numeral 5 denotes a gear with a part of teeth cut out, a one-turn control ring 6 provided with a claw portion 6b at one place on the outer periphery, and a cam for moving the sheet material mounting table 14 up and down on both sides of the gear. And 4 are integrally formed.

The integrally formed product of the toothless gear 5, the control ring 6, and the cam 4 is rotatably fitted to the paper feed shaft 1 so as to restrict the movement thereof along the longitudinal direction of the feed shaft. The second claw portion 12b of the flapper 12 is disengaged from the claw portion 6b of the control ring 6.

Reference numeral 10 denotes a drive gear that meshes with the toothless gear 5 and is driven by a motor (not shown).

The paper feed roller 2 is integrally supported on the paper feed shaft 1 via a core tube 3 and a ratchet (one-way clutch) 3a.

. Therefore, when the sheet material is not fed, the solenoid 13 is off (non-energized), the flapper 12 is pulled down, and the first and second claws 12a and 12b are controlled by the control ring of the spring clutch A, respectively. 8 is engaged with the claw portion 6b of the one-turn control ring 6 integrated with the toothless gear 5 (the state shown by the solid line in FIG. 2).

Therefore, the spring clutch A is off, the clutch gear 9 idles on the paper feed shaft 1 and no driving force is transmitted to the paper feed shaft 1, and the shaft 1, that is, the paper feed roller 2 is kept in a rotation stopped state. I have.

Also, the cam 4 has a large-diameter portion at a downward turning angle position,
The sheet material mounting table 14 is pushed down to a predetermined pushing position against the push-up spring 16 when the tip of the large-diameter portion facing downward of the cam 4 contacts the upper surface (FIGS. 2.3). In this case, the cam 4 moves the shaft 1 with the reaction force F of pressing down the sheet material loading table 14.
The rotation moment Fa acts in the direction of the arrow a in FIG. 3 to naturally escape from the loading table 14 and rotate, but the second claw portion 12b of the flapper 12 is attached to the claw portion 6b of the control ring 6. Since the cam 4 is engaged, the escape rotation of the cam 4 is prevented, and the sheet material loading table 14 is stably held at the predetermined depressed position.
The upper surface of the stacked sheet material S of the stacking table 14 is kept in a separated state α (FIG. 2) that is not in contact with the paper feed roller 2.

In this rotation angle position of the cam 4, the toothless gear 5 has the toothless portion 5a corresponding to the drive gear 10 (FIG. 3).
It is in a non-meshing state with the drive gear 10, and does not receive the transmission of the driving force.

. When the solenoid 13 is turned on (energized) based on the sheet feeding start signal from the sheet non-sheet feeding state, the flapper 12 is turned on.
Is sucked by the solenoid 13 and the first claw portion 12 of the flapper 12 is
a is disengaged from the claw 8b of the control ring 8 of the spring clutch A, the spring clutch A is clutch-on, and the second claw 12
b is the claw portion 6 of the one-turn control ring 6 integrated with the toothless gear 5 and the cam 4
Deviate from b.

When the spring clutch A is in the clutch-on state, the paper feed shaft 1 is rotated integrally with the clutch gear 9 in the direction a.

The cam 4 is rotated in the direction a around the shaft 1 by the rotation moment Fa received by the reaction force F of pressing down the sheet material loading table 14 by releasing the locking of the one-rotation control ring 6. The toothless gear 5/1 rotation control ring 6, which is integral with the other, also rotates around the shaft 1 in the direction a. Then, the push-up and holding state of the sheet material loading table 14 by the cam 4 is released.

With this release, the loading table 14 is pushed up by the push-up spring 16, and the upper surface on the leading edge side of the stacked storage sheet material S on the loading table 14 comes into contact with the lower surface of the sheet feeding roller 2.

In addition, the rotation of the cam 4 in the direction a along with the escape of the cam 4 causes the gear 5 to be meshed with the drive gear 10, and thereafter the drive gear 10 causes the gear 5 and the The cam 4 and the control ring 6 are driven to rotate in the direction a.

Then, with respect to the lower surface of the paper feed roller 1 that is rotationally driven,
As described above, the feeding force acts on the upper surface of the stacked storage sheet material S brought into contact with the rise of the sheet material loading table 14 due to the lifting of the sheet material loading table 14 and only the uppermost sheet material is in contact with the friction pad 15. One sheet is separated and fed by cooperation, is relayed by a registration roller (18), and is conveyed to a sheet material receiving section such as an image forming section.

. When the sheet material fed by the rotation of the supply roller 2 is delivered to the registration roller (18), the solenoid 13
Is turned off.

As a result, the first claw portion 12a of the flapper 12 engages with the claw portion 8b of the control ring 8 of the spring clutch A to stop the control ring 8, whereby the spring clutch A is disengaged and the paper feed shaft 1 rotates. The drive is locked.

The fed sheet material continues to be transported by the resist roller (18) even after the spring clutch A is turned off. The sheet feeding roller 2 is stopped rotating by the transfer movement force of the registration roller of the sheet material until the trailing end of the fed sheet material passes between the feeding roller 2 and the friction pad 15 even if the spring clutch A is turned off. On the paper feed shaft 1 via the ratchet 3a.

On the other hand, even after the rotation of the feed shaft 1 is stopped due to the turning off of the spring clutch A, the toothless gear 5 remains on the shaft 1 due to the engagement with the drive gear 10.
The cam 4 and the control ring 6 are rotated integrally with each other in the direction, and the large diameter portion of the cam 4 is turned downward again by being driven substantially one rotation, so that the sheet material loading table 14 is pushed down against the spring 16 to lower the table 14. The upper stacking storage sheet material S is separated from the sheet feed roller 2 by non-contact α (FIG. 2).

When the toothless portion 5a of the toothless gear 5 reaches the rotation angle facing the drive gear 10, the cutting gear 5 is cut off from the edge of the drive gear 20 and cannot be driven for rotation. The cam 4, the toothless gear 5, and the control ring 6, which are integral with each other, continue to rotate in the a direction by receiving the turning moment Fa in the a direction by the downward reaction force F, and the one rotation control is performed in the rotating process. When the claw portion 6b of the ring 6 reaches and engages with the second claw portion 12b of the flapper 12, which has already been lowered, the rotation of the control ring 6 is stopped.

That is, further rotation of the cam 4, the toothless gear 5, and the control ring 6 which are integral with each other is prevented, and the cam 4 of the sheet
A predetermined pressing state (FIGS. 2 and 3) is stably maintained.

The above-described operation cycle is repeated for each sheet feeding start signal, and the separation and feeding of one sheet material is sequentially performed.

(Effects of the Invention) As described above, the rotation control of the cam for moving the sheet feeding means and the sheet loading table close to and away from each other at the time of paper feeding is performed by controlling the drive including the gears with some of the teeth notched. By doing so, the spring clutch mechanism for controlling the rotation of the cam can be eliminated, so that there is an effect that the troublesome labor for assembling the spring clutch can be eliminated and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a main part of an apparatus according to an embodiment. Second
The figure is the longitudinal section. FIG. 3 is a cross-sectional view thereof. FIG. 4 is a partially cutaway perspective view of a main part of a conventional device example. FIG. 5 is a longitudinal sectional view thereof. FIG. 6 is a cross-sectional view thereof. 1 is a paper feed shaft, 2 is a paper feed roller, A, B, and C are spring clutches, 4 is a cam, 5 is a toothless gear, 9 is a clutch gear, and 10 is a clutch gear.
11 is a drive gear, 12 is a flapper, 13 is a solenoid, 14 is a sheet material loading table, S is a sheet material, 15 is a friction pad, 16 and 17
Is a push-up spring, and 18 is a registration roller.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65H 1/00-1/30 B65H 3/00-3/68

Claims (3)

(57) [Claims] A first rotating member that moves the sheet material loading table away from the sheet material feeding means by a rotation-controlled cam to hold the sheet material and the sheet material feeding means in a non-contact state;
A sheet material feeding device that changes between a state and a second state in which the sheet material and the sheet material feeding means are kept in contact by moving the sheet material close to each other; A driving gear for applying a force, and a rotation angle at which the missing tooth portion is locked in the first state of the sheet loading table and the missing tooth portion corresponds to the driving gear, and the rotational force is not transmitted from the driving gear to the missing tooth gear. And an engagement / disengagement means for allowing the missing tooth gear to rotate by releasing the lock, and in the first state of the sheet material loading table, the cam is released by the pressure contact force of the sheet material loading table against the cam. A rotating moment in the direction corresponding to the direction in which the tooth gear is driven acts, and when the engagement / disengagement means is unlocked, the cam rotates with the rotating moment to rotate the toothless gear. And it is engaged with the drive gear Over door material feeding apparatus. 2. A first member in which a sheet material loading table is moved apart from a sheet material feeding means by a rotation-controlled cam to hold the sheet material and the sheet material feeding means in a non-contact state.
A sheet material feeding device that changes between a state and a second state in which the sheet material and the sheet material feeding means are kept in contact by moving the sheet material close to each other; A drive gear for applying force; a one-rotation control ring that rotates integrally with the toothless gear; and a first rotation control ring that locks the toothless gear when the sheet material loading table is in the first state. The tooth portion corresponds to the drive gear and is held at a rotational angle position at which no rotational force is transmitted from the drive gear to the toothless gear, and the one-turn control ring is unlocked to allow the sheet material loading table to be switched to the second state. A rotation control ring engaging and disengaging member, wherein in the first state of the sheet material loading table, the cam member is pressed against the cam by the pressing force of the sheet material loading table in the direction corresponding to the direction in which the toothless gear is driven. It is configured so that a turning moment acts, A sheet material feeding device, wherein when the cam is rotated by the rotation moment, the toothless gear rotates to be in a meshing state with the drive gear. 3. The sheet feeding device according to claim 1, wherein the toothless gear is supported on the same shaft as the sheet feeding means.