JPH0986686A - Sheet material feeder and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet material feeder and an image forming device using this sheet material feeder wherein a sheet material interposed between a rotary feed member and a friction member can be returned back to a sheet material loading member. SOLUTION: A sheet material feeder has sheet material pressure means 6, 10, 12 pressing a sheet material on a sheet material loading member 17 to a rotary feed member 1 and sheet material pressure releasing means 6, 7, 8, 9 for releasing a pressure of the sheet material in the sheet material pressure means 6, 10, 12 at draw out time from a mate side device main unit of the sheet material loading member 17. Means 4, 5 are provided, which rotate the rotary feed member 1 reversely to the feed direction of the sheet material associated with movement of the sheet material pressure releasing means 6, 7, 8, 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a sheet material feeding device for separating and feeding sheet materials one by one by a rotary feeding member, and the sheet material feeding device for a feeding portion to an image forming portion. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, a sheet material feeding device is provided on a sheet material stacking member which is pressed by a sheet material pressing means between a sheet feeding roller as a rotary feeding member and a friction member. There is known a structure in which a sheet material is sandwiched, separated one by one, and fed into the apparatus main body.

A schematic structure of a copying machine as an image forming apparatus equipped with such a conventional sheet material feeding device is shown in FIG.
This will be described with reference to FIG.

In FIG. 7, reference numeral 100 is a copying machine. 1
Reference numeral 01 is a platen glass for placing a document on which a document to be copied is placed. Reference numeral 102 denotes an exposure device which moves in the direction of arrow X and scans the entire surface of the original while irradiating the original placed on the original table glass 101 with light.

The reflected light obtained by illuminating the original with the exposure device 102 is a first mirror group 103.
a, the zoom lens 104, and the second mirror group 103b
An image is formed on the photosensitive drum 105 via the, and an electrostatic latent image is formed.

The photosensitive drum 105 is provided inside a process cartridge 106 equipped with a plurality of process means for contributing to image formation around the photosensitive drum 10.
Around the circumference of 5, a charging means, a developing means, a cleaning means, etc. are arranged. The electrostatic latent image formed on the photosensitive drum 105 is developed by the developing means and visualized.

Next, the sheet material feeding device will be described. Reference numeral 131 denotes a cassette body as a sheet material stacking member for stacking and storing copy paper 132 as a sheet material.
It is detachably mounted on the bottom of the main body of the copying machine 100.

When the cassette body 131 is mounted on the apparatus body, the middle arm 133 on the apparatus body side is rotated in association with the movement of the cassette body 131, and the cassette body 131 is rotated.
Middle plate 13 rotatably provided upward on the bottom front side of the
4 is pushed up, and the copy paper 1 stacked on the middle plate 134
The sheet material pressing unit is configured so that 32 is pressed against the paper feed roller 135 to generate a frictional force between the copy paper 132 and the paper feed roller 135.

Reference numeral 136 is a pad as a friction member, which is urged by a pad spring 137 and is in pressure contact with the paper feed roller 135.

Then, the cassette body 131 is replaced with the copying machine 10.
When pulling out from the apparatus main body of No. 0, the middle arm 133 interlocks and rotates to the bottom side of the cassette body 131, and the middle plate 13
4 is pushed down to release the press of the copy paper 132 against the paper feed roller 135.

On the other hand, when the paper feed roller 135 rotates, the stacked copy papers 132 are fed from the uppermost one and separated one by one when passing between the paper feed roller 135 and the pad 136. Will be delivered. Then, the sheet is conveyed on a reverse conveying path formed between the sheet feeding roller 135 and the reverse guide 111.

Then, it passes through the pre-registration guide 112 and is guided to the pair of registration rollers 113 which is temporarily stopped. The registration roller pair 113 is the photosensitive drum 105.
Synchronized with the developed image formed on the copy paper 132,
To the transfer unit.

A transfer roller 114 is in pressure contact with the photosensitive drum 105. The registration roller pair 11
On the copy paper 132 conveyed by 3, the developed image is transferred when passing between the photosensitive drum 105 and the transfer roller 114.

The copying paper 132 after the image transfer is carried by the conveying device 1.
The transfer image is conveyed by 15, and when passing through the fixing device 116, heat and pressure are applied to fix the transferred image. And
The copy paper 132 on which the image is fixed is discharged from the copying machine 100 by the discharge roller pair 117.

[0015]

However, in the above-described sheet material feeding apparatus of the prior art, the copy paper 13 is used.
Since 2 is sandwiched between the paper feed roller 135 and the pad 136 for separate feeding, even after the paper feeding operation is stopped,
The copy paper 132 is still held between the paper feed roller 135 and the pad 136.

Therefore, when the cassette body 131 is pulled out from the apparatus body of the copying machine 100, it is necessary to separate the pad 136 from the paper feed roller 135.
A release means for releasing the pressure applied to the paper feed roller 135 by 36 is required.

Further, the cassette body 131 of the copy paper 132
Since the amount of protrusion from the leading edge is not constant, the leading edge of the copy paper 132 comes into contact with a part of the apparatus main body, and the copy paper 13
There was a problem such as 2 breaking.

The present invention was made in order to solve the above-mentioned problems of the prior art, and its purpose is to:
An object of the present invention is to provide a sheet material feeding device capable of returning a sheet material sandwiched between a rotary feeding member and a friction member to a sheet material stacking member, and an image forming apparatus using the same.

It is another object of the present invention to prevent the sheet material on the sheet material stacking member from being damaged when the sheet material stacking member is pulled out from the apparatus main body.

[0020]

In order to achieve the above object, according to the present invention, a sheet material stacking member on which a sheet material that is detachable from a main body of a counterpart apparatus is stacked, and the sheet material stacking member. A rotary feeding member for feeding the sheet material on the member, a friction member provided to face the rotary feeding member and pressed against the rotary feeding member, and a sheet material on the sheet material stacking member. Sheet material pressing means for applying pressure to the rotary feeding member, and sheet material pressure releasing means for releasing the pressure of the sheet material in the sheet material pressing means when the sheet material stacking member is pulled out from the counterpart apparatus main body. And a means for rotating the rotary feeding member in a direction opposite to the feeding direction of the sheet material in association with the movement of the sheet material pressure releasing means. To do.

The means for rotating the rotary feeding member in the direction opposite to the sheet feeding direction is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack provided with a gear meshable with the gear. It is characterized in that it has a slidable member, and the rack is engaged with the gear by interlocking with the slide member only in accordance with the movement of the sheet material pressure releasing means.

The means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack which can always mesh with the gear. A movable slide member and a clutch member provided on the inner diameter side of the gear, the clutch member not transmitting the rotation of the rotation shaft of the rotary feeding member in the feeding direction to the gear, The rotation opposite to the feeding direction is transmitted to the rotation shaft of the rotary feeding member, and the slide member may be interlocked with the movement of the sheet material pressure releasing means.

Further, the sheet material feeding device having each of the above-mentioned configurations is used as a feeding portion for feeding the sheet material to the image forming portion of the image forming apparatus.

In the sheet material feeding device having the above structure,
When pulling out the sheet material stacking member from the other device,
Since the means for rotating the rotary feeding member in the direction opposite to the feeding direction is provided in association with the movement of the sheet material pressure releasing means for releasing the pressure of the sheet material on the rotary feeding member in the sheet material pressing means. The sheet material that is still sandwiched between the rotary feeding member and the friction member after the feeding operation is completed is returned to the sheet material stacking member by the reverse rotation of the rotary feeding member.

From the above, it is unnecessary to provide the conventional means for releasing the pressure contact of the friction member with the rotary feeding member.
The device configuration can be simplified and the operation can be simplified.

In addition, as described above, since the sheet material is returned to the sheet material stacking member, it is possible to prevent the sheet material from being damaged when the sheet material stacking member is pulled out from the counterpart apparatus main body.

The means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack provided with a rack meshable with the gear. With a slide member capable of moving, the slide member is interlocked only in response to the movement of the sheet material pressure releasing means so that the rack meshes with the gear, so that the sheet material pressing means Since the gear and the rack are not in mesh with each other when the rotary feeding member is pressurized by the drive source, the rotary shaft is driven by the drive source to move the rotary feeding member in the feeding direction. When rotated, the rack does not interfere with the rotation.

When the sheet material stacking member is pulled out,
That is, when the sheet material pressure releasing means is moving, the slide member moves, the gear and the rack first mesh with each other, the movement of the slide member continues, and the rack, the gear,
The rotary feeding member can be rotated in the direction opposite to the feeding direction via the rotary shaft.

In this way, the rotary feeding member can be reliably rotated in the direction opposite to the feeding direction of the sheet material in association with the movement of the sheet material pressure releasing means.

Further, the means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack capable of always meshing with the gear. A movable slide member and a clutch member provided on the inner diameter side of the gear, the clutch member not transmitting the rotation of the rotation shaft of the rotary feeding member in the feeding direction to the gear, In order to convey the rotation opposite to the feeding direction of the sheet to the rotary shaft of the rotary feeding member, and the slide member is interlocked with the movement of the sheet material pressure releasing means, during feeding, The rotating shaft is driven by the drive source,
Even if the rotary feeding member is rotated in the feeding direction, the clutch member provided on the inner diameter side of the gear does not transmit the rotation of the rotation shaft of the rotary feeding member in the feeding direction to the gear, so that the rotation of the rotation member is prevented by the rack. Will not be disturbed.

When the sheet material stacking member is pulled out, the slide member moves to rotate the gear through the rack in the direction opposite to the feeding direction. At this time, the clutch member
Since the rotation opposite to the gear feeding direction is transmitted to the rotating shaft of the rotating feeding member, the rotating feeding member is rotated in the opposite direction to the feeding direction via the rack, the gear, the clutch member and the rotating shaft. Can be made.

In this case, since the rack of the slide member always meshes with the gear, the movement amount of the slide member can be reduced. Thereby, space saving can be achieved.

By using each of the sheet material feeding devices described above in the feeding portion of the image forming apparatus, it is possible to simplify, downsize and reduce the cost of the entire image forming apparatus.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) The present invention will be described below based on the illustrated embodiment. First, a schematic configuration of a copying machine as an image forming apparatus including the sheet material feeding device according to the present invention will be described with reference to FIG.

In FIG. 4, reference numeral 30 is a copying machine. 31
Is a platen glass for placing a document on which a document to be copied is placed. Reference numeral 32 denotes an exposure device which moves in the direction of arrow X while scanning the original placed on the original table glass 31 and scans the entire original surface.

The reflected light obtained by illuminating the original with the exposure device 32 is the first mirror group 33a,
An image is formed on the photosensitive drum 35 via the zoom lens 34 and the second mirror group 33b to form an electrostatic latent image.

The photosensitive drum 35 is provided in a process cartridge 36 equipped with a plurality of process means for contributing to image formation on the periphery thereof, and a charging means, a developing means, a cleaning means and the like are provided around the photosensitive drum 35. It is arranged. The electrostatic latent image formed on the photosensitive drum 35 is developed by the developing means and visualized.

Then, when the sheet material passes between the feed roller 1 which is a rotary feeding member of the sheet material feeding device described later and the friction member 2A, the sheet material is separated and fed one by one. Then, the sheet is conveyed on a reverse conveying path formed between the sheet feeding roller 1 and the reverse guide 41.

Then, it passes through the pre-registration guide 42 and is guided to the pair of registration rollers 43 which is temporarily stopped.
The pair of registration rollers 43 synchronizes with the developed image formed on the photosensitive drum 35 and conveys the sheet material to the transfer portion.

A transfer roller 44 is in pressure contact with the photosensitive drum 35. A developed image is transferred to the sheet material conveyed by the registration roller pair 43 when passing between the photosensitive drum 35 and the transfer roller 44.

The sheet material after the image transfer is carried by the carrying device 45, and when passing through the fixing device 46, heat and pressure are applied to fix the transferred image. Then, the sheet material after the image fixing is processed by the discharge roller pair 47 by the copying machine 30.
Emitted from.

Next, the sheet material feeding device according to the first embodiment of the present invention will be described with reference to FIGS.

1 (a) to 1 (c) are side views of a sheet material feeding apparatus that best shows the features of the present invention. 2 (a) and 2 (b) are plan views of relevant parts, and FIG.
(A), (b) is a principal part sectional drawing.

In the figure, reference numeral 17 denotes a cassette as a sheet stacking member for stacking and storing sheet materials P (copy paper because the apparatus is the copying machine 30) for exchanging the type and size of the sheet materials P. Alternatively, it can be attached to and detached from the bottom of the main body of the copying machine 30 for replenishment, and is mounted from the front side to the back side in FIG. 4 and pulled out in the opposite direction.

Reference numeral 1 is a paper feed roller as a rotary feeding member for feeding the sheet material from the cassette 17.

Reference numeral 2 denotes a separation pad to which a friction member 2A provided facing the paper feed roller 1 is attached, and the friction member 2A is pressed against the surface of the paper feed roller 1 by being biased by a spring or the like (not shown). The sheet material P is sandwiched together with the sheet feeding roller 1 to separate the sheet materials one by one.

Reference numeral 3 denotes a paper feed shaft for rotating the paper feed roller 1 by a drive source (not shown). Both ends of the paper feed shaft are rotatably held by the main body of the apparatus, though not shown.

A return gear 4 is fixed on the paper feed shaft 3 of the paper feed roller 1.

Reference numeral 5 denotes a slide plate as a slide member, which has a rack 5A capable of meshing with the return gear 4 on its upper surface, is movable in the rotation direction of the return gear 4, and is returned by the slide spring 21. 4 and rack 5A
It is urged in the direction (the right side in FIG. 3) that disengages with.

Reference numeral 6 is a relay plate having a cam-shaped projection 6A for pushing out the slide plate 5. 7 is the front lever, 8
Is a release shaft, 9 is a release arm, and the front lever 7 and the release arm 9 are attached to the release shaft 8 with a certain angle. These constituent parts constitute a sheet material pressure releasing means for releasing the sheet material P pressed by the sheet feeding roller 1 by the sheet material pressing means described later. And the front lever 7
Has a long hole 7A at the end opposite to the release shaft 8 of
A shaft 6B having one end in the longitudinal direction of the relay plate 6 in the elongated hole 7A.
Are engaged.

Similarly, on the right side of the relay plate 6 in FIG.
The middle lever 10 and the pressure arm 12 are attached to both ends of the pressure shaft 11 in the axial direction at a constant angle. These components constitute sheet material pressing means for pressing the sheet material P against the sheet feeding roller 1. Then, the pressure shaft 11 of the middle lever 10
Has an elongated hole 10A at the end opposite to the
A shaft 6C provided at an end portion of the relay plate 6 opposite to the longitudinal sheet material pressure releasing means side is engaged with 0A.

In this way, the front lever 7 and the middle lever 10
Is connected to the relay plate 6 by the long holes 7A and 10A at the tip end and the shafts 6B and 6C, and the relay plate 6 moves in the left-right direction in FIG. 1 as the levers rotate.

Reference numeral 14 is a rear lever, the upper end of which is swingably held by an apparatus main body (not shown), and the pin portion of the lower end is engaged with the cutout portion 17A of the cassette 17, and A pressure spring 13 is provided between the lower end of the rear lever 14 and the tip of the middle lever 10, and the cassette 17 is inserted into the bottom of the main body of the copying machine 30 from left to right in FIG. When mounted, the rear lever 14 swings to pressurize the middle lever 10.

The function of the pressure arm 12 is shown in FIG. A pressing plate 19 is rotatably provided in the cassette 17, and is pushed up by the tip of the pressing arm 12. Reference numeral 20 denotes an intermediate plate that is provided on the front side of the bottom of the cassette 17 so as to be rotatable upward, and is pushed up by the tip of the pressure plate 19.

Since the sheet material P is stacked on the bottom of the cassette 17 including the intermediate plate 20, when the pressure arm 12 is rotated and its tip is lifted, the pressure plate 19 and the intermediate plate 2 are moved.
0 is sequentially lifted, and the front half of the sheet material P stacked in the cassette 17 is lifted and pressed against the paper feed roller 1 (see FIG. 3B).

Reference numeral 15 denotes a cassette handle which is rotatably held by the cassette 17 and which is downward from the rotary shaft 15C required to hang a finger for pre-operation when the cassette 17 is pulled out from the apparatus main body. It has an arm that extends to
It has two arms on the right side in FIG.

One is the arm portion 15A, and the rotary shaft 1
5C extends in the lower right direction in FIG. 1, and the tip end thereof can contact the release arm 9, but the pressing spring 16
Since it is biased in the counterclockwise direction in FIG. 1, it is normally separated from the release arm 9.

The other one is a cassette handle head 15B, which is bent from the rotary shaft 15C in the upper right direction in FIG. 1 and extends, and the tip end is above the upper edge of the cassette 17.

Reference numeral 18 is a positioning block for the cassette 17, which is located above the right end of the cassette 17,
It is provided in the device body. 17B is a stopper,
The cassette 17 is provided so as to slightly project to the upper edge on the right end side.

In FIG. 1, the cassette 17 is replaced by a copying machine 30.
In order to mount it on the bottom of the main body of the device, it is inserted from left to right. In that case, pull the cassette handle 15 with a finger to resist the spring force of the pressure spring 16. ,
Cassette handle head 15 provided on the cassette 17 side
By lowering the tip of B, the positioning block 18
Pass by.

Next, since the stopper 17B of the cassette 17 hits the positioning block 18, if the finger is released from the cassette grip 15 there, the spring force of the pressure spring 16 causes the positioning block 18 to move to the stopper 17B and the cassette grip head. The tip of the portion 15B is sandwiched, and the cassette 17 is held at a predetermined position, so that the sheet material is fed (see FIG. 1A).

The operation of the sheet material feeding device configured as described above will be described. The state in which the sheet material is fed to the photosensitive drum 35 side forming the image forming portion of the copying machine 30 is shown in FIG.
It is shown in (a), FIG. 2 (b), and FIG. 3 (b).

When the cassette 17 is inserted into the bottom of the main body of the copying machine 30 from left to right in FIG.
The rear lever 14 is rotated counterclockwise by hitting the notch 17A of the center lever 1 through the pressure spring 13.
0, the relay plate 6, and the front lever 7 are rotated clockwise in FIG. 1 or moved to the right side in FIG.

At the same time, the pressure arm 12 also rotates clockwise, and the pressure plate 19 and the intermediate plate 20 are sequentially lifted, and the front half of the sheet material P loaded in the cassette 17 is lifted and fed. It is pressed against the roller 1 (Fig. 3
(B)).

At this time, since the slide plate 5 does not come into contact with the cam-shaped projection 6A of the relay plate 6 as shown in FIGS. 2 (b) and 3 (b), the slide spring 21 causes the return gear 4 to move.
And the rack 5A are retracted to a position where they do not mesh with each other.

In this state, the paper feed roller 1 is driven by a motor (not shown) in the main body of the sheet material feeding device to drive the sheet material feeding device 1 as shown in FIG.
(B) Rotate in the counterclockwise direction. As a result, the sheet material P pressed against the sheet feeding roller 1 is transferred to the cassette 17
It is pulled out, separated between the paper feed roller 1 and the separation pad 2, and fed one by one to the registration roller pair 43 of the copying machine 30.

Then, the paper feeding operation is terminated and the cassette 17
The operation when pulling out is explained. This is shown in Fig. 1 (b),
(C), FIG. 2 (a), and FIG. 3 (a).

As a pre-operation for pulling out the cassette 17 from the main body of the apparatus, by pulling the cassette handle 15 with a finger, the arm portion 15A rotates clockwise in FIG.
When is pushed down, the front lever 7, the relay plate 6, and the middle lever 10 are rotated counterclockwise in FIG. 1 or moved to the left side in FIG. 1 against the spring force of the pressure spring 13 accordingly. ,
The pressure arm 12 rotates counterclockwise to move the pressure plate 19,
The intermediate plate 20 is also lowered, and the pressing of the sheet material P against the sheet feeding roller 1 is released.

At the same time, the cam-shaped projection 6 of the relay plate 6
Since A pushes out the slide plate 5, the rack 5A of the slide plate 5 meshes with the return gear 4, and further the return gear 4 is rotated clockwise in FIG. 3 (a). At the same time, since the coaxial paper feed roller 1 is also rotated in the same direction, the sheet material P that remains between the paper feed roller 1 and the separation pad 2 after the paper feed operation is completed is Returned to 17

Further, at the same time as the above operation, the cassette grip head 15B is also rotated to release the positioning and holding of the cassette 17. Therefore, when the cassette 17 is pulled out next time, all the pre-operations are completed.

When the cassette 17 is pulled out, the sheet material is completely stored in the cassette 17, and the sheet material P interferes with a part of the main body of the copying machine 30 and is damaged or broken. Is eliminated.

Further, with this structure, there is no need for means for releasing the pressure while keeping the separation pad 2 constantly pressurized.

Further, if the paper feed roller is rotated in the reverse direction by an electric means as has been known so far, the motor becomes large and expensive, but by using the mechanical construction like this construction, A sheet material feeding device and a copying machine using the sheet material feeding device for the sheet material feeding portion to the image forming portion can be downsized, and the cost can be reduced.

(Second Embodiment) A sheet material feeding device according to a second embodiment of the present invention will be described with reference to FIGS.

FIGS. 5A to 5C are side views of the sheet material feeding device. 6 (a) and 6 (b) are cross-sectional views of the main part of them.

The same components as those of the first embodiment shown in FIGS. 1 to 3 are designated by the same reference numerals. These have the same operation, and the description thereof will be omitted.

As a new member and a component different from that of the first embodiment, a one-way clutch 4A as a clutch member formed integrally with the inner diameter of the return gear 4 and a rack 22A which is always meshed with the return gear 4 are provided in the vertical direction. A slide plate 22 that is a slide member that is movably held in the apparatus main body, and a relay plate 23 that moves the slide plate 22.

The one-way clutch 4A is the paper feed roller 1
The rotation of the paper feed shaft 3 in the paper feed direction (counterclockwise rotation in FIG. 6B) is not transmitted to the return gear 4, and the return gear 4 rotates in the opposite direction to the paper feed direction (FIG. 6A). (Clockwise rotation) is transmitted to the paper feed shaft 3 of the paper feed roller 1.

The method of connecting the slide plate 22 and the relay plate 23 is as follows. The relay plate 2 is attached to the slide plate 22.
3 has a protruding portion 22B protruding toward 3
The long hole 2 which is diagonally long and engages with the protrusion 22B.
3B is provided, and this elongated hole 23B acts as a cam to convert the lateral movement of the relay plate 23 into the vertical movement of the slide plate 22.

The operation of the second embodiment having the above configuration is as follows.

The state during normal paper feeding is shown in FIGS.
As shown in FIG. 5B, when the cassette 17 is inserted into the bottom of the main body of the copying machine 30 from left to right in FIG. 5, the cassette 17 is abutted against the notch 17A and the rear lever 1
4 rotates counterclockwise in FIG. 5A, and the middle lever 10, the relay plate 23, and the front lever 7 are connected to each other via the pressure spring 13 as shown in FIG.
(A) Rotate in the clockwise direction or move to the right side in FIG. 5 (a).

At the same time, the pressure arm 12 is also rotated clockwise, and the pressure plate 19 and the intermediate plate 20 are sequentially lifted, and the front half of the sheet material P stacked in the cassette 17 is lifted and fed. It is pressed against the roller 1. The process up to this point is the same as in the first embodiment.

At this time, the slide plate 22 has a structure shown in FIG.
As shown in FIG. 6 (b), the return gear 4 and the rack 5 </ b> A mesh with each other even though the return gear 4 is in the lifted position.

In this state, the paper feed roller 1 is driven by a motor (not shown) in the main body of the sheet material feeding device to drive the sheet material feeding device 1 as shown in FIG.
(B) Rotate in the counterclockwise direction. As a result, the sheet material P pressed against the sheet feeding roller 1 is transferred to the cassette 17
The sheet is pulled out, separated between the sheet feed roller 1 and the separation pad 2, and fed one by one into the apparatus main body.

In this case, the return gear 4 and the rack 5A mesh with each other, but the one-way clutch 4A rotates the paper feeding shaft 3 of the paper feeding roller 1 in the paper feeding direction (in the counterclockwise direction in FIG. 5B). (Rotation) is not transmitted to the return gear 4,
And the rack 5A do not interfere with the rotation of the paper feed roller 1.

Then, the paper feeding operation is terminated and the cassette 17
The operation when pulling out is explained. This is shown in FIG.
6 (c) and 6 (a).

As a pre-operation for pulling out the cassette 17 from the bottom of the main body of the copying machine 30, by pulling the cassette handle 15 with a finger, the arm portion 15A rotates clockwise and the release arm 9 is pushed down. Pressure spring 13
5, the front lever 7, the relay plate 23, and the center lever 10 are rotated counterclockwise in FIG. 5 or moved to the left side in FIG. 5, and the pressure arm 12 is rotated counterclockwise. Move
The pressure plate 19 and the middle plate 20 are also lowered, and the pressing of the sheet material P against the sheet feeding roller 1 is released.

At the same time, the long hole 23B of the relay plate 23
However, as a cam, the protrusion 22B of the slide plate 22 is pushed down, so that the slide plate 22 also moves downward, and the return gear 4 is rotated clockwise through the rack 5A in FIG. 5A.

In this case, since the one-way clutch 4A transmits the rotation of the return gear 4 opposite to the paper feeding direction (clockwise rotation in FIG. 6A) to the paper feeding shaft 3 of the paper feeding roller 1, it is coaxial. The upper sheet feeding roller 1 is also rotated in the same direction, and the sheet material P remaining between the sheet feeding roller 1 and the separation pad 2 after the sheet feeding operation is finished is returned to the cassette 17. Be done.

Further, at the same time as the above operation, the cassette grip head 15B is also rotated to release the positioning and holding of the cassette 17. Therefore, when the cassette 17 is pulled out next time, all the pre-operations are completed.

When the cassette 17 is pulled out, the sheet material is completely stored in the cassette 17, and the sheet material P is prevented from interfering with a part of the apparatus main body and being damaged or broken. .

Further, with this structure, there is no need for means for releasing the pressure while the separation pad 2 is always being pressurized.

Further, by incorporating the one-way clutch 4A as in the present embodiment, the rack 22A of the slide plate 22 can be constantly meshed with the return gear 4, so that further space saving can be realized.

Instead of the separation pad used in each of the above-described embodiments, a friction member is disposed opposite to the paper feed roller to sandwich the sheet material to be fed together with the paper feed roller and separate the sheets one by one. Alternatively, a roller having a high coefficient of friction on the rotating surface may be used.

Further, although the case where the sheet feeding roller is used as the rotary feeding member has been described as an example, it is a belt-like member and can be similarly applied.

Further, the slide member has been described by taking a plate-shaped member as an example, but it may be rod-shaped, and the shape thereof is not particularly limited as long as it has a rack.

[0097]

As described above, according to the present invention,
When pulling out the sheet material stacking member from the other device,
A means for rotating the rotary feeding member in the opposite direction to the feeding direction is provided in association with the movement of the sheet material pressure releasing means for releasing the pressure of the sheet material to the rotary feeding member in the sheet material pressing means. Therefore, the sheet material that is still sandwiched between the rotary feeding member and the friction member after the feeding operation is finished is returned to the sheet material stacking member by the reverse rotation of the rotary feeding member. .

As a result, it is unnecessary to provide the conventional means for releasing the pressure contact of the friction member with the rotary feeding member.
The device configuration can be simplified and the operation can be simplified.

In addition, as described above, since the sheet material is returned to the sheet material stacking member, the problem that the sheet material is damaged when the sheet material stacking member is pulled out from the other side apparatus main body is solved. The effect is obtained.

The means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack capable of meshing with the gear. With a slide member capable of moving, the slide member is interlocked only in response to the movement of the sheet material pressure releasing means, and the rack is engaged with the gear, so that the sheet material pressure releasing means can be reliably operated. The rotary feeding member can be rotated in association with the movement in the direction opposite to the feeding direction of the sheet material.

Further, the means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack capable of always meshing with the gear. A movable slide member and a clutch member provided on the inner diameter side of the gear, the clutch member not transmitting the rotation of the rotation shaft of the rotary feeding member in the feeding direction to the gear, The rotation of the sliding member is transmitted to the rotary shaft of the rotary feeding member in a manner opposite to the feeding direction of the sheet feeding member, and the slide member is configured to interlock with the movement of the sheet material pressure releasing means. Does not affect the feeding operation even if the gear always meshes with the gear. Therefore, the amount of movement of the slide member can be reduced, and space can be saved.

As described above, since the means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material is mechanically constructed without taking electrical means, space saving and cost reduction are achieved. Can be achieved.

By using each of the above-described sheet material feeding devices in the feeding portion of the image forming apparatus, the overall structure of the image forming apparatus can be simplified, downsized, and reduced in cost.

[Brief description of drawings]

FIG. 1 is a side view of a sheet material feeding device according to a first embodiment of the present invention. FIG. 1 (a) is a sheet material feeding state, and FIG. 1 (b) is a sheet material feeding apparatus. The state in the middle of releasing the pressure on the paper roller, FIG. 7C shows the state where the release of the pressure on the sheet feeding roller of the sheet material is completed.

FIG. 2A is a plan view of relevant parts showing a state in which the pressure applied to the sheet feeding roller by the sheet material feeding device according to the first embodiment of the present invention is released, and FIG. FIG. 3B is a plan view of a main part of the sheet material in a fed state.

FIG. 3A is a cross-sectional view of relevant parts showing a state in which the pressure applied to the sheet feeding roller by the sheet material feeding device according to the first embodiment of the present invention is released. FIG. 3B is a sectional view of a main part of the sheet material in a fed state.

FIG. 4 is a schematic configuration diagram of a copying machine as an image forming apparatus in which the sheet material feeding device according to the present invention is used.

5A and 5B are side views of a sheet material feeding device according to a second embodiment of the present invention. FIG. 5A is a sheet material feeding state, and FIG. 5B is a sheet material feeding apparatus. The state in the middle of releasing the pressure on the paper roller, FIG. 7C shows the state where the release of the pressure on the sheet feeding roller of the sheet material is completed.

FIG. 6A is a cross-sectional view of essential parts showing a state in which the pressure applied to the sheet feeding roller by the sheet material feeding device according to the second embodiment of the present invention is released. FIG. 3B is a sectional view of a main part of the sheet material in a fed state.

FIG. 7 is a schematic configuration diagram of a copying machine as an image forming apparatus using a conventional sheet material feeding device.

[Explanation of reference numerals] 1 paper feed roller (rotary feeding member) 2 separation pad 2A friction member 3 paper feeding shaft (rotating shaft) 4 return gear 4A one-way clutch (clutch member) 5, 22 slide plate (slide member) 5A rack 6, 23 Relay plate (sheet material pressing means, sheet material pressure releasing means) 6A Protrusion (sheet material pressure releasing means) 7 Front lever (sheet material pressure releasing means) 8 Release shaft (sheet material pressure releasing means) ) 9 release arm (sheet material pressure release means) 10 middle lever (sheet material pressure means) 12 pressure arm (sheet material pressure means) 15 cassette grip 15A arm portion 15B cassette grip head 17 cassette (sheet material stacking) Member) 17B Stopper 18 Positioning block 19 Pressure plate 20 Middle plate 23B Long hole

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Claims (4)

[Claims] 1. A sheet material stacking member on which a sheet material that is detachable from a main body of a counterpart device is stacked, a rotary feeding member for feeding the sheet material on the sheet material stacking member, and the rotation. A friction member provided to face the feeding member and pressed against the rotary feeding member, a sheet material pressurizing unit for pressing the sheet material on the sheet material stacking member to the rotary feeding member, and a sheet material stacking member In a sheet material feeding device having a sheet material pressure releasing means for releasing the pressure of the sheet material in the sheet material pressing means at the time of pulling out from the counterpart apparatus main body, the movement of the sheet material pressure releasing means A sheet material feeding device comprising means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material in association with the above. 2. The means for rotating the rotary feeding member in the direction opposite to the sheet feeding direction is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack capable of meshing with the gear. A movable slide member is provided, and the rack is engaged with the gear by interlocking with the slide member only in response to the movement of the sheet material pressure releasing means. Sheet material feeding device. 3. The means for rotating the rotary feeding member in the direction opposite to the feeding direction of the sheet material is provided with a gear fixed on the rotary shaft of the rotary feeding member and a rack capable of always meshing with the gear. A movable slide member and a clutch member provided on the inner diameter side of the gear, wherein the clutch member does not transmit the rotation of the rotation shaft of the rotary feeding member in the feeding direction to the gear, 7. The rotation of the sheet feeding means is transmitted to the rotary shaft of the rotary feeding member, and the slide member is interlocked with the movement of the sheet material pressure releasing means. The sheet material feeding device according to 1. 4. An image forming apparatus, wherein the sheet material feeding device according to claim 1, 2, or 3 is used in a feeding portion for feeding a sheet material to an image forming portion.