JPH07257765A - Sheet material feed device and image forming device - Google Patents

Abstract

PURPOSE:To surely separate and feed loaded sheet materials one by one into by providing a guide flange section which is formed the same in diameter as a circular part from a position where a rotor and a separating means form a gap to a point where the notched part of the roller and the circular part continue mutually. CONSTITUTION:The separated paper feed of every one sheet of recording paper sheers P is carried out between a paper feed roller 31 and a separating pad 46. The paper feed roller 31 has a roller 56 composed of a notched part 56a and a circular part 56b, and a resin flange part is severally attached to both its ends. In addition, a side roller 42 serving as a pressing member having a diameter slightly smaller than the diameter of the circular part 56b of the roller 56 is severally provided at both the outside ends of the roller 31. The flange part is composed of a part smaller than the diameter r2 of the side roller 42 and a guide flange part L being the same in a diameter as the diameter r 1 of the circular part 56b of the roller 56. The range of the guide flange part L is from a position where a gap is formed with the separating pad 46 to a point where the notched part 56a of the roller 56 and the circular part 56b being a round part at which the separate paper feed is started continue mutually.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an image forming apparatus such as a copying machine, a printer, a facsimile, and a word processor, and various other apparatus using sheet materials, such as sheet material (transfer) A sheet material feeding device for feeding out one sheet at a time, a sheet, a photosensitive sheet, an electrostatic recording sheet, a printing sheet, an OHP sheet, an envelope, etc. .

[0002]

2. Description of the Related Art A conventional sheet material feeding device of this type will be described by taking a laser beam printer (hereinafter, LBP) using electrophotographic recording as an example.

FIG. 7 is a schematic view of a main cross section of a black and white LBP in which the sheet path from the cassette is an S-shaped type. A sheet feeding cassette insertion port 104a and a multi-tray 115 are provided on one side of the apparatus, and the cassette 104 is provided. The whole is removably inserted and stored in the main body of the apparatus (removing operation is indicated by arrows a'and b ').

The recording paper P'as a sheet material sent from the cassette 104 by the paper feed roller 105 is reversed along the transport guides 118 and 119, and the registration roller 1
When it reaches 06, it is conveyed to the image transfer section and the fixing device 108. The recording paper P ′ that has left the fixing device 108 is reversed by the conveyance guides 121 and 122, and the conveyance rollers 123 and
The discharge rollers 109 convey and discharge the sheets to the face-down tray 110 using the top plate of the apparatus. Further, the multi-tray 115 is opened, and the recording paper P ′ loaded on the multi-tray 115 is delivered by the paper feed roller 131 and reaches the registration roller 106 along the transport guides 118 and 125, and thereafter, the same transport as the cassette paper feed is performed. Be done.

In this apparatus, a part 124 of the top plate of the apparatus is opened, from which the process cartridge 103 is attached / detached, g ', h', and the process cartridge 103 is also treated for paper jams inside the apparatus. It will be removed from here. Paper jam after the fixing device 108 is performed by opening the rear cover 126.

In such an apparatus, the separation and feeding of the recording paper P'from the cassette 104 one by one is generally performed by the intermediate plate 11.
1 and the claws 112 provided at both ends of the intermediate plate and the half-moon type paper feed roller 105.

On the other hand, the separate feeding of the recording paper P'from the multi-tray 115 for each sheet is performed by separating the sheet between the feeding roller 131 and the separating pad, which is one of the clawless feeding methods. The so-called Duplo type paper feeding method of feeding is generally used.

For the duplo type paper feed, there are one using a round paper feed roller shown in FIG. 8 and one using a half-moon paper feed roller as shown in FIG.

First, the operation of the round paper feed roller shown in FIG. 8 will be described.

Paper feed gear 1 rotated by drive gear 145
36 tries to rotate the sheet feeding shaft 132 by the one-rotation spring clutch 133 built in the one-rotation control ring 137, but the pawl 137a or 137b of the one-rotation control ring 137 is stopped by the pawl 138a of the flapper 138. It spins because it is there. When the solenoid 135 is activated by an electric signal during paper feeding, the flapper 138 is pulled toward the solenoid 135, so that the claw 138a is the claw 137a or the claw 137.
b and the paper feed shaft 132 by the one-rotation spring clutch 133.
Begins to rotate.

At the same time, the claw 138b of the flapper 138 is disengaged from the claw of the control ring 143, so that the spring clutch 144 built in the control ring 143 receives the rotation of the paper feeding shaft 132 and rotates the round paper feeding roller 131. When the paper feed shaft 132 starts rotating, the cam plate 134 is disengaged from the cam follower 139, and the recording paper P ′ is moved by the middle plate 140 to the round paper feed roller 1.
The recording paper P ′ is pressed against 31 and is fed by the rotation of the round paper feeding roller 131, and is guided between the round paper feeding roller 131 and the separation pad 146.

Here, the recording paper P'is separated, and only the uppermost one sheet is conveyed to the registration roller 106. When the leading edge of the recording paper P ′ reaches the registration roller 106 and forms a loop, the solenoid 135 is cut off, and the claw 1 of the flapper 138 is cut off.
Since 38b is caught by the claw of the control ring 143, the round paper feeding roller 131 is stopped, but the recording paper P ′ is rounded by the round paper feeding roller 1.
Since it is sandwiched between 31 and the separation pad 146, the loop state is maintained. After that, the claw 138a of the flapper 138 is caught by the claw 137a of the rotating one-rotation control ring, and the paper feed shaft 132 stops rotating. At this time, since the cam plate 134 pushes down the middle plate 140 by the cam follower 139, the recording paper P ′ stacked on the middle plate 140 is not conveyed.

Next, when the registration rollers 106 start to convey the recording paper P ', the round paper feeding roller 131 is rotated by the spring clutch 144 with respect to the recording paper P'.

Next, the operation of the half-moon type paper feed roller shown in FIG. 9 will be described.

Similar to the case of using the round paper feed roller, the paper feed gear 136 driven by the drive gear has a pawl 137 of a one-rotation control ring 137 having a one-rotation spring clutch 133 built therein.
Since the a or 137b is stopped by the claw 138a of the flapper 138, it spins with respect to the paper feed shaft 132.

When the solenoid 135 is actuated by an electric signal, the claw 138a of the flapper 138 moves the one-turn control ring 137.
The pawl 137b is disengaged and the one-rotation spring clutch 133 causes the paper feed shaft 132 to start rotating, and the half-moon paper feed roller 131 attached to the paper feed shaft 132 with parallel pins or the like also starts to rotate.

At this time, the cam plate 134 causes the cam follower 13 to move.
The recording paper P ′ lifted up by the middle plate 140 after being separated from 9 comes into pressure contact with the side roller 142 having a diameter smaller than the diameter of the circular portion of the half-moon feeding roller 131, and the half-moon feeding roller 131 is connected to the half-moon feeding roller 131 by the round portion. It is guided between the separation pads 146, and only the topmost sheet is fed to the registration rollers 106.

During this time, the solenoid 135 is cut off, the half-moon paper feed roller 131 stops in one rotation, and the half-moon paper feed roller 131 is separated from the recording paper P'because the rounded portion is located at the top, but the recording paper forms a loop. Since P ′ is sandwiched between the side roller 142 and the separation pad 146, it keeps keeping the loop. When the recording paper P ′ is conveyed by the registration rollers 106, the side rollers 142 rotate following the recording paper P ′.

While the conventional embodiments of the round paper feeding roller and the half-moon paper feeding roller have been described above one by one, some of the round paper feeding rollers use an electromagnetic clutch to simplify the structure.

As described above, by changing the paper feed roller from the round type to the half-moon type, the spring clutch 144 can be omitted and the costly electromagnetic clutch or the like can be omitted, so that the cost can be reduced. Further, since the half-moon paper feeding roller is not always in contact with the recording paper P ', there is an advantage that durability is improved.

The principle of paper separation in the duplo type paper feeding will be described here. Whether the round paper feeding roller or the half-moon paper feeding roller is used, the paper feeding roller, the recording paper P ', and the separation pad 146 are used. It is based on the order of friction, and will be explained together below.

In FIG. 10, the separation pad 146 is fixed to the separation pad holder 147.
Is swingably attached by a fulcrum shaft 148 on the tangent line between the paper feed roller 131 and the separation pad 146, and the separation pad 146 is pressed against the paper feed roller 131 by a spring 150.
(Before the paper feed is started, it is pressed against the side rollers 142.) The recording paper P'pressed against the paper feed roller 131 by the intermediate plate 140 and the spring 151 is fed by the frictional force F generated between them by the rotation of the paper feed roller 131. Paper is fed and the paper feed roller 13
1 and the separation pad 146. At this time, when the uppermost recording sheet P1 'is fed, the recording sheets P1' and P2 '
The second and subsequent recording sheets P2 'to P are
Although n'is also fed, the leading end of the recording paper Pn 'first strikes the separation pad holder 147 and is stopped. The recording paper P ′ that cannot be stopped here is further stopped by the separation pad 146, and the several recording papers P ′ that have escaped from it are fed to the paper feed roller 13.
Proceed between 1 and separation pad 146.

The recording paper P ′ other than the uppermost paper P1 ′ between the paper feed roller 131 and the separation pad 146 is stopped by the frictional force H between the recording paper P ′ and the separation pad 146, and the uppermost recording paper P1 ′. Only will be delivered.

Here, in order to perform the above-mentioned paper separation, the following relationships must be established.

The frictional force between the paper feed roller 131 and the recording paper P1 'is F, and the frictional force between the recording paper P1' and the recording paper P2 'is G.
When the frictional force between the recording paper P2 'and the separation pad 146 is H, the friction order is F>H> G.

[0026]

However, as described in the prior art, the advantage of using the half-month paper feed roller is lower in cost and better in durability than the case of using the round paper feed roller. However, there is a drawback in that double feeding due to poor separation occurs more frequently than when a round paper feeding roller is used.

When a (half-moon type) paper feed roller 131 partially having a notch as shown in FIG. 11 is used,
When the recording paper P ′ is guided between the paper feed roller 131 and the separation pad 146 in order to pick a position several millimeters from the front end of the recording paper P ′, the front end of the recording paper P ′ is free. Next, the tip is not handled.

The side rollers 142 are the paper feed rollers 131.
Since the diameter of the round portion is smaller than the diameter of the round portion of the sheet feeding roller 131, when the round portion of the paper feed roller 131 rotates and comes into contact with the separation pad 146, the separation pad 146 is pushed down due to the impact due to this contact, and the side roller 142 and the separation pad 146 are separated from each other. A gap is created between the side rollers 142 and the separation pad 1.
Even during 46, the leading edge of the recording paper P'is not separated.

On the other hand, when the round paper feed roller is used, as shown in FIG. 12, the leading edge of the recording paper P'is picked by the paper feed roller 131 and abutted against the separation pad 146. There is no impact due to contact with the paper feed roller, and at that time, the leading edge of the recording paper P ′ is separated from the leading edge because it is constrained by the paper feed roller 131 and the separation pad 146.

Further, as shown in FIG. 10, the paper feed roller 13
There is also a device provided with an equalizing mechanism aiming to press the 1 and the separation pad 146 uniformly in the axial direction to reduce the skew of the recording paper P ′ at the time of feeding and at the same time reduce the frequency of double feeding. It has the drawback of being complicated and costly.

In FIG. 10, the separation pad holder 147 is attached to the bracket 152 so as to be swingable about a fulcrum shaft 148, and the bracket 152 is attached to the apparatus main body so as to be rotatable about a shaft 153. In addition to this, a method is devised in which the separation pad 146 is divided into three parts, that is, a part that comes into pressure contact with the sheet feeding roller 131 and a part that comes into contact with both side rollers 142, and springs are provided for each part so that the side roller 142 and the side pad are always in pressure contact. However, it has not been put to practical use because of its complicated structure, high cost, and difficulty in replacing the paper feed roller.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to reliably separate the stacked sheet materials one by one and feed them. To provide.

[0033]

In order to achieve the above object, the present invention provides a sheet material stacking section for stacking sheet materials, and a sheet feeding section for feeding the sheet materials stacked on the sheet material stacking section. In a sheet material feeding device having a feeding means and a separating means that engages with the feeding means and separates a sheet material, the feeding means includes a circular roller having a notch in a part thereof, When the cutout portion of the roller is located on the separating means side, a pressing member for pressing the separating means to form a gap between the roller and the roller and the separating means form a gap. A guide flange portion having the same diameter as the circular portion is provided from the existing position to the point where the cutout portion of the roller and the circular portion are continuous.

The portion of the guide flange portion that comes into contact with the sheet material may be made of a material having a coefficient of friction smaller than that of the sheet materials.

The separating means abuts on the feeding means in a swingable manner, the swinging central axis is on the tangent line at the contact point between the separating means and the feeding means, and the bearing portion of the swinging central axis is the above-mentioned. It is preferable to form an elongated hole in an arc direction centered on the contact.

It is preferable that the width of the swing center axis portion of the separating means is narrower than the width of the separating means.

An elastic member for bringing the separating means into pressure contact with the feeding means may be provided between the contact and the swing center shaft.

[0038]

In the sheet material feeding device constructed as described above, the feeding means is a circular roller having a notch in a part thereof, and when the notch of the roller is located on the separating means side. A pressing member for pressing the separating means to form a gap between the roller and the notch portion and the circular portion of the roller are continuous from the position where the roller and the separating means form the gap. The guide flange portion formed to the point has the same diameter as the circular portion, so that the guide flange portion presses the sheet material before the sheet material abuts the circular portion of the roller and is fed.

Since the portion of the guide flange portion which comes into contact with the sheet material is made of a material having a coefficient of friction smaller than that of the sheet materials, the guide flange portion does not feed the sheet material.

The separating means abuts on the feeding means in a swingable manner, the swinging central axis is on the tangent line at the contact point of the separating means and the feeding means, and the bearing portion of the swinging central axis contacts the contact point. By forming the elongated hole in the arc direction with respect to the center, the swing central axis can be guided by the elongated hole to move.

By making the width of the swinging central axis portion of the separating means narrower than the width of the separating means, the separating means can easily move in the width direction of the sheet material.

By providing an elastic member for pressing the separating means to the feeding means between the contact point and the swing center axis, a pressing force can be constantly applied to both the separating means and the swing center axis.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments.

FIG. 1 is a schematic view of a main cross section of a black and white LBP in which the sheet path from the cassette is an S-shaped type, and the paper feed cassette insertion port 4a and the multi-tray 15 are provided on one side of the apparatus.
Is provided, and the entire cassette 4 is detachably inserted into and housed in the main body of the apparatus (attaching / detaching operation is indicated by arrows a and b).

The recording paper P as a sheet material sent from the cassette 4 by the paper feed roller 5 is conveyed by the guides 18, 1.
It is reversed along 9 and reaches the registration roller 6, and is conveyed to the image transfer section and the fixing device 8.

The recording paper P coming out of the fixing device 8 is conveyed by the conveyance guide 2.
1, 22 to be reversed by the transport roller 23, the discharge roller 9
Is conveyed and discharged to the face down tray 10 using the top plate of the apparatus. Further, the multi-tray 15 is opened, and the recording paper P loaded on the multi-tray 15 is fed by the paper feed roller 3 as a feeding means.
The sheet is sent out by 1 to reach the registration rollers 6 along the conveyance guides 18 and 25, and thereafter, the same conveyance as that of cassette sheet feeding is performed.

In this apparatus, a part 24 of the apparatus top plate is opened, from which the process cartridge 3 is attached / detached operation g, h.
In addition, the process cartridge 3 is removed from the apparatus to treat paper jams inside the apparatus. still,
Paper jam after the fixing device 8 is performed by opening the rear cover 26.

In such an apparatus, in order to separate and feed the recording paper P from the cassette 4 one by one, the middle plate 11 and the claws 12 provided at both ends of the middle plate and the half-moon type paper feed roller are generally used. It is carried out by 5.

On the other hand, the separation and feeding of the recording paper P from the multi-tray 15 one by one is performed by separating the paper one by one between the paper feed roller and the separation pad, which is one of the clawless paper feeding methods. The so-called Duplo type paper feeding method is applied.

FIG. 2 and FIG. 3 show a sheet material feeding device using a (half-moon type) sheet feeding roller partially having a cutout according to the present invention.

FIG. 2 shows a state before the start of sheet feeding, and FIG. 3 is a view of FIG. 2 seen from the upstream side in the carrying direction. In FIGS. 2 and 3, reference numeral 31 denotes a paper feed roller as a feeding means, which is formed by a notch portion 56a and a circular portion 56b, and is cut into a part on which a material having a large friction coefficient such as rubber is attached to the surface. A (half-moon shaped) roller 56 having a cutout portion is provided, and the recording paper P is provided at both ends thereof.
The flanges 55a and 55b made of resin such as POM having a smaller friction coefficient than each other are attached, and the rotatably provided circularly-shaped press having a diameter slightly smaller than the diameter of the circle 56b of the roller 56 at both outer ends. A side roller 42 that is a member is provided. And, the flange portions 55a and 5
5b includes a portion smaller than the diameter r2 of the side roller 42 and a guide flange portion L having the same diameter as the diameter r1 of the circular portion 56b of the roller 56.

As shown in FIG. 2, the range of the guide flange L is separated from the separation pad 46 as a separating means from the position where a gap is formed and the cutout portion 56a of the roller 56 in the sheet feeding roller 31 and the separation sheet feeding. It is up to a point (intersection point) where the circular portion 56b which is a rounded portion to be started is continuous.

Here, the separation pad 46 and the separation pad holder 47 will be described in detail.

The separation pad 46 is longer than the paper feed roller 31 in the axial direction and is fixed to a separation pad holder 47 having a substantially L-shaped cross section. The separation pad holder 47 has the paper feed roller 31 or the side rollers 42 and the separation pad 46. Contact point 5
A fulcrum shaft 48 as a swing center axis on the tangent line in FIG.
A spring 50, which is an elastic member that is swingably attached about the center of the separation pad 46 and presses the separation pad 46 against the paper feed roller 31 or the side roller 42, is provided between the contact 54 and the fulcrum shaft 48. By this swinging, the contact pressure between the separation pad 46 and the paper feed roller 31 is adjusted, and an appropriate feeding force can be given to the recording paper P.

The fulcrum shafts 48 are provided at both ends of the separation pad holder 47 in the axial direction, and are fitted in elongated bearing holes 57a opened in a wall 57 rising from the main body of the apparatus.

The slot 57a is a slot in the circumferential direction having a radius R from the contact point 54 of the sheet feed roller 31 and the separation pad 46 to the fulcrum shaft 48.
As a result, even if the paper feed roller 31 tilts with respect to the separation pad 46, the fulcrum shaft 48 fitted in the long hole 57a moves along the long hole 57a, so that the separation pad 46 is moved to the paper feed roller 3.
It is possible to follow 1.

With this structure, the paper feed roller 3
The contact state between 1 and the separation pad 46 is always stable, and partial contact or the like does not occur, so that separation failure or skewing can be prevented.

Further, the relationship between the flange portions 55a and 55b and the elongated hole 57a will be described. When a dimensional error occurs between the two flange portions 55a and 55b,
One of the flange portions comes into contact with the separation pad 46 to cause skew, but as described above, the fulcrum shaft 48 moves along the elongated hole 57a, so that the separation pad 46 is separated into the two flange portions 55a. , 55b can be followed.

With this structure, the separation pad 46 surely abuts the two flange portions 55a and 55b, so that the recording paper P is formed by the two flange portions 55a and 55b.
Can be satisfactorily handled. Further, it is not necessary to strictly control the processing accuracy and the mounting accuracy of the two flange portions 55a and 55b, and there is an effect that the cost can be reduced.

Although the elastic member is a coil spring in this embodiment, it may be a leaf spring, a rubber-like elastic body, a sponge or the like.

With the above-described structure, the separation pad 46 can be uniformly pressed against the paper feed roller 31 or the side rollers 42 at both ends in the axial direction without any one-sided contact.

The sheet feeding roller 31 rotates in the direction of the arrow from the no sheet feeding state in FIG. 2 to the state immediately before the start of the separated sheet feeding in FIG.

In FIG. 4, the separation pad 46 is brought into a state in which it is pressed against the side roller 42 in FIG. 2 and is slightly depressed by the guide flange portion L. Guide flange part L
Of the guide flange portion L has a smooth curved surface so that it can be smoothly inserted into the separation pad 46. In this embodiment, the diameter difference from the side roller 42 is 0.5 m.
It is about m.

When the guide flange portion L and the separation pad 46 are in contact with each other, the intermediate plate 40, which is a sheet material stacking portion, holds the recording paper P.
Is pushed up and brought into contact with the guide flange portion L.

After that, the roller 56 on the paper feed roller 31
The circular portion 56b of the recording paper P rotates to feed the recording paper P.
And the separation pad 46.

At this time, the recording paper P is separated from the leading end portion like the conventional paper feeding roller 131 shown in FIG. Only picked.

In FIG. 5, the guide flange portion L is separated from the separation pad 46 and is conveyed to the registration roller 6 by the circular portion 56b of the roller 56 in the paper feed roller 31.

When the paper feed roller 31 makes one rotation and the leading edge of the recording paper P hits the registration roller 6 to form a loop and returns to the state of FIG. 2, the paper feed roller 31 stops rotating and the recording paper P is not conveyed thereafter. This is performed by the registration roller 6.

At this time, the trailing edge of the recording paper P is only sandwiched between the separation pad 46 and the side roller 42, and the side roller 42 is driven and rotated by the recording paper P.

(Other Embodiments) FIG. 6 shows another embodiment of the present invention.

In FIG. 6, the paper feed roller 31 is divided into two parts, and guide flange portions L are provided at both ends of each. As a result, the variation in the separation pressure due to the axial warp of the separation pad 46 can be reduced. Further, by making the width L1 of the fulcrum shaft portion of the separation pad holder 47 narrower than the width L2 of the separation pad portion, it is possible to provide the equalizing function only by the axial play.

[0072]

According to the present invention having the above-described structure and operation, the feeding means has a circular roller partially having a notch, and the notch of the roller is located on the separating means side. At this time, the pressing member for pressing the separating means to form a gap between the roller and the notch portion and the circular portion of the roller are continuous from the position where the roller and the separating means form the gap. Since it has a guide flange portion formed with the same diameter as the circular portion up to the point, the guide flange portion presses the sheet material before the sheet material abuts the circular portion of the roller and is fed. Since the contact is made in substantially the same manner as the conventional round-shaped sheet feeding roller, the sheet material is separated from the leading end portion of the sheet material, and reliable separation and feeding are performed.

Since the portion of the guide flange portion that comes into contact with the sheet material is made of a material having a coefficient of friction smaller than that of the sheet materials, the guide flange portion does not feed the sheet material, and the circular portion of the roller forms the sheet. Press the sheet material until it reaches the material.

The separating means abuts on the feeding means in a swingable manner, the swinging central axis is on the tangent line at the contact point of the separating means and the feeding means, and the bearing portion of the swinging central axis connects the contact point. By forming the elongated hole in the arc direction with respect to the center, the swing center axis can be guided and moved by the elongated hole, and the pressing force of the separating means with respect to the feeding means can be adjusted.

By making the swinging central axis portion of the separating means narrower than the width of the separating means, the separating means can easily move in the width direction of the sheet material, and the pressing force of the separating means against the feeding means is increased. Easy to adjust.

By providing an elastic member for pressing the separating means to the feeding means between the contact point and the swing center axis, a pressing force is constantly applied to both the separating means and the swing center axis, so that the separating means operates. It becomes easy to swing.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an image forming apparatus to which a sheet material feeding device according to an embodiment of the present invention is applied.

FIG. 2 is a side view of essential parts showing a sheet material feeding device according to an embodiment of the present invention.

FIG. 3 is a diagram of FIG. 2 viewed from the upstream side in the transport direction.

FIG. 4 is a side view of essential parts showing a process in which recording paper is separated and fed from the state of FIG.

FIG. 5 is a side view of essential parts showing a process in which recording paper is further separated and fed from the state of FIG.

FIG. 6 is a schematic view showing a sheet material feeding device according to another embodiment of the present invention.

FIG. 7 is a schematic view showing an image forming apparatus to which a conventional sheet material feeding device is applied.

FIG. 8 is a perspective view showing a conventional sheet material feeding device.

FIG. 9 is a perspective view showing a conventional sheet material feeding device.

FIG. 10 is a side view of essential parts showing a conventional sheet material feeding device.

FIG. 11 is a diagram showing a recording paper separation state of a (half-moon type) paper feed roller having a notch in a part, which is applied to a conventional sheet material feeding device.

FIG. 12 is a diagram showing a recording paper separation state of a round paper feed roller applied to a conventional sheet material feeding device.

[Explanation of symbols]

 P, P'Recording paper (sheet material) L Guide flange portion 31,131 Paper feed roller (feeding means) 40,140 Middle plate (sheet material stacking portion) 42,142 Side roller (pressing member) 46,146 Separation pad ( Separation means) 47,147 Separation pad holder 48,148 Support shaft (swing center shaft) 50 Spring (elastic member) 54 Contact points 55a, 55b Flange portion 56 Roller 56a Cutout portion 56b Circular portion 57a Oval hole

Claims (6)

[Claims] 1. A sheet material stacking unit for stacking sheet materials,
A sheet material feeding device comprising: a feeding means for feeding a sheet material stacked on the sheet material stacking portion; and a separating means for engaging with the feeding means and separating the sheet material. Is a circular roller having a notch in part, and for forming a gap between the roller by pressing the separating means when the notch of the roller is located on the separating means side. A pressing member, and a guide flange portion formed with the same diameter as the circular portion from the position where the roller and the separating means form a gap to the point where the cutout portion of the roller and the circular portion are continuous. A sheet material feeding device characterized by the above. 2. The sheet material feeding device according to claim 1, wherein a portion of the guide flange portion which comes into contact with the sheet material is made of a material having a coefficient of friction smaller than that of the sheet materials. 3. The separating means abuts on the feeding means in a swingable manner, and the swinging central axis is on a tangent line at a contact point between the separating means and the feeding means, and a bearing portion of the swinging central axis. 3. The sheet material feeding device according to claim 1, wherein the sheet material feeding device is configured to have a long hole in an arc direction centered on the contact point. 4. The sheet material feeding device according to claim 3, wherein a width of a swinging central axis portion of the separating means is narrower than a width of the separating means. 5. The sheet material feeding apparatus according to claim 3, wherein an elastic member for pressing the separating means to the feeding means is provided between the contact point and the swing center axis. apparatus. 6. A sheet material feeding device according to any one of claims 1 to 5, and an image forming means for forming an image on the sheet material fed by the sheet material feeding device. Image forming apparatus.