JPH09183529A - Paper feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish a mechanism of FRR paper feeding device to return to the tray and stack those sheets which remain in the place while they are pinched by a feed roller and separation roller without increasing electric components but using only simple mechanical part items. SOLUTION: An FRR paper feeding device concerned includes a feed roller 1 rotating in the sheet feeding direction, a separation roller 2 contacting with it 1 and rotating in the opposite direction to the sheet feeding direction with torque limiter interposed, a pickup roller 3 to feed sheet to between the two rollers, and a swinging means to contact and separate the pickup roller 3 with/ from the sheet 5. A gear 35 is installed on the drive shaft T of the feed roller 1 so that restraint is made by a pawl 33-1 with possibility of rotating only in the sheet feeding direction. This restraint of the rotating direction is disengaged when a solenoid 13 to swing the pickup roller 3 is actuated so that the drive shaft 7 is put free to rotate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device used in an image forming apparatus such as a copying machine, a facsimile and a printer.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, in order to reliably feed sheets one by one, a feed roller is driven to rotate in the sheet feeding direction, and a feed roller is abutted against the feed roller and fed through a torque limiter. There is an FRR type paper feed device having a separation roller that is driven to rotate in the direction opposite to the paper direction and a pickup roller that feeds the paper between the feed roller and the separation roller. FIG. 4 is a perspective view of a conventional FRR sheet feeding device, and FIG. 5 is a schematic view of a conventional FRR sheet feeding copying machine. In the figure, 1 is a feed roller, 2 is a separation roller,
Reference numeral 3 indicates a pickup roller. The leading end of the bundle of sheets 5 stacked and stored in the tray 4 is located below the pickup roller 3, and the bundle of sheets 5 can be raised in the direction of the pickup roller 3 via the bottom plate 6 by raising means (not shown). It is like this. Further, in the figure, 38 is a paper end filler, and when there is no paper, a notch 6- provided on the bottom plate 6
The filler at the tip has fallen into 1 and sensor 3
The presence / absence of a sheet can be determined by detecting in 9.

The pickup roller 3 is supported rotatably around a shaft 9 fixed to an arm 8 which is swingably supported around a drive shaft 7. A gear portion 3-1 is provided at the end of the pickup roller 3, and the gear portion 1 of the feed roller 1 is provided.
The rotational force is transmitted from -1 through the idler gear 10. The arm 8 is urged by a spring 40, but is pushed down by a lever 12 urged by a stronger spring 11, so that the pickup roller 3 is normally positioned above. When the solenoid 13 is energized, the pressing force of the lever 12 is released, the pickup roller 3 swings down in the direction of the bundle of sheets 5, and the pickup roller 3 is lowered to raise the sheet 5 by an unillustrated raising means. When raising the bundle, arm 8
The optimum height of the paper is detected by the shutter unit 8-1 and the sensor 14 which are fixedly installed at the position, and control is performed to stop the raising means.

The feed roller 1 is a one-way clutch 1-2.
It is supported by the drive shaft 7 via. One way clutch 1-
2 transmits the rotation of the drive shaft 7 in the sheet feeding direction to the feed roller 1, but when the drive shaft 7 is stopped or when a force for rotating the feed roller 1 in the sheet feeding direction acts, the feed roller 2 is provided. It works in the direction that allows rotation of 1. Further, the drive shaft 7 is pivotally supported by a bearing 22 installed on the rear side plate 17. The bearing 22 further includes a one-way clutch 22-1.
Is incorporated to prevent the drive shaft 7 from rotating in the reverse direction of the paper feed direction. An electromagnetic clutch 23 is provided at the shaft end protruding from the rear side plate 17. Since the gear portion of the electromagnetic clutch 23 is constantly rotationally driven from a drive source (not shown) via the timing belt 24 and the gear pulley 25, when the electromagnetic clutch main body is energized, the rotation is transmitted to the drive shaft 7,
The feed roller 1 is rotated in the paper feeding direction via the one-way clutch 1-2.

As shown in FIG. 6, the separation roller 2 is fixed to a shaft 16 via a torque limiter 15. The shaft 16 includes a bearing 18 installed on the rear side plate 17 and the shaft 1
A slide bearing 20 slidably inserted in a guide 19 for guiding 6 in the direction of the feed roller 1 is pivotally supported. The lower surface of the slide bearing 20 is pressed by a compression spring 21, so that the separation roller 2 is pressed against the feed roller 1 with a predetermined pressing force. Further, the shaft 16 is a gear group 26, 2
Rotational force is always transmitted from the gear portion of the electromagnetic clutch 23 in the direction opposite to the sheet feeding direction by the reference numerals 7 and 28.

Reference numerals 29, 30, and 31 in FIG. 6 denote a pair of transport rollers, and 29 is a drive-side transport roller, whose rotational drive and stop can be arbitrarily controlled by an electromagnetic clutch 32.
Reference numerals 0 and 31 denote driven-side conveying rollers, which are pressed against the conveying roller 29 with a predetermined pressure by a pressing means (not shown).
These conveying roller pairs 29, 30, 31 send out the sheets 5 separated one by one in the paper feeding section to the vertical conveying path and further convey them to the registration roller pair 32. The pair of registration rollers 32 can be rotated and stopped by clutch means (not shown) in order to convey the paper in accordance with the image forming process.

Now, the solenoid 13 and the electromagnetic clutch 2
When electricity is applied to the motors 3, 32, as shown in FIG. 3a, the feed roller 1, the pickup roller 3, and the transport rollers 29, 3
0 and 31 rotate in the paper feed direction, and the roller 3 is the top paper 5
a is fed between the feed roller 1 and the separation roller 2. When the sheet 5a enters between the rollers 1 and 2, the state shown in FIG.
As shown in b, when the solenoid 13 is de-energized, the pickup roller 3 is separated from the upper surface of the bundle of sheets 5, and the uppermost sheet 5a is conveyed by the feeding action of only the feed roller 1. At this time, the separation roller 2 is biased in the opposite direction.
A frictional force that exceeds the torque of the torque limiter 15 acts on the sheet and rotates with the sheet 5a. When the fed-out sheet 5a starts being conveyed by the pair of conveying rollers 29 and 30, the electromagnetic clutch 23 is de-energized, but the feed roller 1 advances by the action of the one-way clutch 1-2 as shown in FIG. 3d. The paper 5a is rotated.

Further, the pair of conveying rollers 29 and 31 are shown in FIG.
The sheet 5a is conveyed to the registration roller pair 32 as indicated by e. Since the registration roller pair 32 is stopped to match the timing of the image forming unit, the driving of the conveying roller 29 is stopped after the sheet 5a hits the registration roller pair 32, and the sheet 5a is temporarily stopped. Then, as shown in FIG. 3e, even when the next paper 5b is called from the tray 4 in the above-described procedure, in order to avoid collision between the papers,
The drive of the feed roller 1 is stopped. At that time, the conveying force of the second-order sheet 5b is applied from the separation roller 2 in the direction opposite to the sheet feeding direction. Instead, it remains stopped. If this one-way clutch 22
If there is not -1, the feed roller 1 and the drive shaft 7 are integrally rotated in the reverse direction by the urging force from the separation roller 2 in the direction opposite to the sheet feeding direction, and the next sheet 5b is returned to the nip of the separation roller 2. As a result, the interval between sheets becomes wider than a predetermined value, and the conveyance timing becomes incorrect.

On the other hand, as shown in FIG. 3c, when the feeding roller 1 and the separation roller 2 sandwich the next sheet 5b by being dragged by the advancing uppermost sheet 5a, the separation roller 2 moves in the feeding direction. Paper 5b rotated in the opposite direction
Send back. This is because the rotation of the separation roller 2 is set so that the torque of the torque limiter 15 is larger than the frictional force between the sheets. The leading end of the fed-back paper 5b is located at the nip of the separation roller 2,
If the trailing edge of the preceding paper 5a passes through the nip between the rollers 1 and 3 while the paper 5b is being fed back to the separation roller 2, the paper 5b is no longer returned. That is, if there is a sheet of paper between the feed roller 1 and the separation roller 2 that have been prevented from rotating around the paper, the separation roller 2 cannot rotate in the biased direction. Therefore, if the paper feed operation ends with the paper being sandwiched between the rollers 1 and 2,
When the tray 4 is pulled out, there is a problem that paper is left behind in the paper feeding device.

[0010]

[Patent Document 2] Japanese Patent Publication No. 2-58
Paper feeders such as those disclosed in Japanese Patent No. 17 and Japanese Utility Model Laid-Open No. 62-128040 have been proposed. In these paper feeding devices, a one-way clutch that regulates the rotation direction of the drive shaft of the feed roller is arranged to be swingable by a predetermined angle, so that the paper left between the feed roller and the separation roller is returned by a predetermined distance. Is able to.

However, with such a configuration,
When the power supply to the clutch that controls the feed roller is cut off, the paper always returns a predetermined distance. That is, when the clutch is de-energized in the state as shown in FIG. 3e, the next sheet is returned in the tray direction and the interval between the sheets is widened, which causes a problem that the conveyance timing is misaligned. Further, the return distance is determined by the radius of the feed roller and the swing angle θ of the drive shaft, and the maximum value of the return distance is when θ = 360 °, and the paper can be returned only for one rotation of the feed roller. Therefore, there is also a problem that the paper that is deeply caught cannot be completely returned.

Therefore, Japanese Patent Laid-Open No. 63-12545 and
A paper feeder as disclosed in Japanese Utility Model Publication No. 2-29064 has been proposed. The device disclosed in Japanese Patent Laid-Open No. 63-12545 has two paths, a path for connecting drive transmission of a separation roller via a torque limiter and a path for connecting via an electromagnetic clutch, and a drive shaft for a feed roller. It has an electromagnetic solenoid that can release and connect the regulation force of the one-way clutch that regulates the rotation direction in a timely manner.When the paper remains in the nip of the roller, the electromagnetic clutch and electromagnetic solenoid are activated to operate the feed roller. Can be reversed by a required distance at a predetermined timing.
The defect in the paper feeding device of 128040 publication has been resolved.

However, if such a configuration is adopted,
In addition to the electric parts required for the FRR sheet feeding device, two electric parts, an electromagnetic solenoid and an electromagnetic clutch, are required, which not only increases the cost but also increases the size of the entire device due to the processing of the harness and the expansion of the control board. Occurs.

In the apparatus of Japanese Utility Model Publication No. 2-29064, an electromagnetic brake is arranged in place of the one-way clutch that regulates the rotation direction of the drive shaft of the feed roller, and the sheet remains in the nip of the roller. At this time, by releasing the braking of the electromagnetic brake, the feed roller can be reversed by a required distance at a predetermined timing, which is also disclosed in Japanese Examined Patent Publication No. 2-5817 and Japanese Utility Model Laid-Open No. 62-1280.
The problem in the paper feeding device of Japanese Patent No. 40 has been solved.

However, with such a configuration,
Since an electromagnetic brake will be used instead of the one-way clutch installed in the FRR sheet feeding device, not only will the cost increase, but the sheet feeding device will also become large due to harness processing and expansion of the control board. Similar problems arise.

In view of the above conventional problems, the present invention is FR
In addition to providing a new mechanism to return the remaining paper sandwiched between the feed roller and the separation roller in the direction of the tray in the R paper feeding device, the electric parts are provided in the same amount as the conventional FRR paper feeding device. It is another object of the present invention to provide a paper feeding device that does not need to be added.

Further, according to the present invention, each time the paper feeding operation is completed,
An object of the present invention is to provide a paper feeding device that improves the performance of adding paper to a user by returning the paper that is still sandwiched between the feed roller and the separation roller toward the tray.

Further, the present invention provides a paper feeding apparatus for improving the jammed paper removing performance of the user by returning the paper, which is still sandwiched between the feed roller and the separate roller, in the tray direction when the paper is jammed. The purpose is to

Further, according to the present invention, the FRR sheet feeding device has a mechanism not only for returning the sheet left between the feed roller and the separation roller in the direction of the tray but also for reliably stacking the sheet in the tray. Another object of the present invention is to provide a paper feeding device in which simple mechanical parts can be installed without increasing the number of electric parts other than that required for conventional FRR paper feeding.

[0020]

According to a first aspect of the present invention, there is provided a sheet feeding device including: a feed roller which is rotationally driven in a sheet feeding direction; A separation roller that contacts the rollers and is driven to rotate in the opposite direction to the paper feed direction via a torque limiter, a pickup roller that feeds the paper between these feed rollers and the separation roller, and a pickup roller that contacts the paper. In a sheet feeding device having a swinging means for contacting or disengaging, a means for regulating the drive shaft of the feed roller so as to be rotatable only in the sheet feeding direction, and a rotation direction regulating means for synchronizing with the swinging means for the pickup roller. And a means for releasing.

In order to achieve the second object, the paper feeding device according to the second aspect of the present invention has a control means for operating the rotation direction restriction releasing means of the feed roller for a predetermined time at the end of the paper feeding operation. Characterize.

In order to achieve the third object, the paper feeding device according to the third aspect of the present invention comprises a control means for operating the rotation direction restriction releasing means of the feed roller for a predetermined time when a paper jam is detected. It is characterized by having.

In order to achieve the fourth object, the sheet feeding device according to the fourth aspect is such that the pickup roller has a drive member having a drive clutch cylinder made of a cylindrical outer peripheral portion, and is adjacent to the drive clutch cylinder. And a driven member having a driven clutch cylinder formed of a cylindrical outer peripheral portion and a support portion supporting a rubber elastic wheel for feeding a sheet, and the drive mounted on the outer periphery of the drive clutch cylinder and the driven clutch cylinder. It is characterized by having a cylindrical coil spring wound in a direction opposite to the paper feeding direction when viewed from the clutch cylinder side.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following, portions common to the related art are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a perspective view of an embodiment of a sheet feeding device according to the present invention, and FIG. 2 is a sectional view of a drive connecting portion near a pickup roller. Boss part 3-2 of pickup roller 3
Comprises a gear portion 3-1 and a drive side clutch body portion 3-4 adjacent to the gear 3-1 and to which approximately half of the coil spring 3-3 is mounted. The housing portion 3-5 has a space for accommodating the coil spring 3-3 inside, a driven side clutch body portion 3-6 in which approximately half of the coil spring 3-3 is mounted, and elastic rubber rings at both ends of the outer peripheral portion. 3 to 7 and a pair of flanges for positioning. As for the boss portion 3-2 and the housing portion 3-5, the housing portion 3-5 is attached to the small diameter portion at the tip of the boss portion 3-2, and the tip portion of the boss portion 3-2 protruding from the housing portion 3-5 is attached. Stop by the snap ring 3-8 and combine.

The winding direction of the coil spring 3-3 is opposite to the paper feeding direction when viewed from the direction of arrow A in FIG. 2, and therefore when the gear portion 3-1 rotates in the paper feeding direction, the spring 3 is rotated. -3 acts in the tightening direction to transmit the drive, and the gear portion 3-1 and the rubber ring 3-7 rotate together. When the gear portion 3-1 rotates in the direction opposite to the sheet feeding direction, the spring 3-3 acts in the loosening direction,
Only the idling torque is transmitted to the rubber ring 3-7, and the rubber ring 3-7
When the load exceeds the idling torque of the coil spring 3-3, the coil spring 3-3 slips, so that the rotation of the pickup roller 3 is stopped.

The inner diameter of the coil spring 3-3, the outer diameter of the clutch body 3-4, and the number of turns of the coil spring 3-3 are appropriately determined in consideration of the idling torque of the coil spring 3-3 in the loosening direction. It The setting of the idling torque will be described later.

The arm 8 is biased by a spring 40, but is pushed down by a lever 33 biased by a stronger spring 11. That is, the pickup roller 3 is usually located above. When the solenoid 13 is energized, the pressing force of the lever 33 is released, and the pickup roller 3 swings in the stacking direction of the sheets 5. In addition, a claw portion 33-1 that can be sandwiched by a gear 35 that has a built-in one-way clutch 34 that prevents the drive shaft 7 that drives the feed roller 1 from rotating in the direction opposite to the paper feed direction is fixed to the lever 33. There is. That is, pickup roller 3
When the solenoid 13 for swinging the drive shaft is off, the rotation direction of the drive shaft 7 is restricted, and when it is on, the rotation direction restriction is released to make the drive shaft 7 free to rotate.

The drive shaft 7 for supporting the feed roller 1 is rotatably supported by a bearing 36 provided on the rear side plate 17, and
An electromagnetic clutch 23 is provided at the shaft end projecting from the shaft. The gear portion of the electromagnetic clutch 23 is constantly rotating from a drive source (not shown) via the timing belt 24 and the gear pulley 25. Therefore, when the electromagnetic clutch main body is energized, the rotation is transmitted to the drive shaft 7 and the one-way clutch. The feed roller 1 is configured to rotate in the sheet feeding direction via 1-2.

Now, the solenoid 13 and the electromagnetic clutch 2
When electricity is applied to the motors 3, 32, as shown in FIG. 3a, the feed roller 1, the pickup roller 3, and the transport rollers 29, 3
0 and 31 rotate in the paper feed direction, and the roller 3 is the top paper 5
a is fed between the feed roller 1 and the separation roller 2. At this time, the gear 3 with the built-in one-way clutch 34
Since the claw portion 33-1 is separated from 5, the rotation direction of the drive shaft 7 is not regulated. However, the electromagnetic clutch 23
Is operating, the drive shaft 7 has a separation roller 2
It overcomes the urging force in the direction opposite to the sheet feeding direction and rotates in the sheet conveying direction.

When the sheet 5a enters between the rollers 1 and 2,
As shown in FIG. 3b, when the solenoid 13 is de-energized, the pickup roller 3 is separated from the upper surface of the bundle of sheets 5, and the uppermost sheet 5a is conveyed by the feeding action of only the feed roller 1. At this time, the gear 3 with the built-in one-way clutch 34
Since the claw portion 33-1 is sandwiched between the five, the rotation direction of the drive shaft 7 is restricted only to the paper feeding direction. However, since the electromagnetic clutch 23 is operating, the drive shaft 7 rotates in the paper transport direction. When the fed-out sheet 5a starts being conveyed by the pair of conveying rollers 29, 30, the electromagnetic clutch 2
Although the energization of No. 3 is stopped, as shown in FIG. 3d, the feed roller 1 is rotated along with the sheet 5a which advances by the action of the one-way clutch 1-2. Also, separation roller 2
Causes a frictional force exceeding the torque of the torque limiter 15 to act, and rotates with the sheet 5a.

At this time, since the claw portion 33-1 is sandwiched by the gear 35 having the one-way clutch 34 built therein, the rotation direction of the drive shaft 7 is restricted only to the sheet feeding direction. Therefore, when the trailing edge of the sheet sandwiched between the transport rollers 29 and 30 passes through the nip of the feed roller 1, the feed roller 1 is urged by the separation roller 2 in the direction opposite to the sheet feeding direction, but the one-way clutch. By the action of 34, it does not rotate in the reverse direction and remains stopped.

Further, the pair of conveying rollers 29 and 31 are shown in FIG.
The sheet 5a is conveyed to the registration roller pair 32 as indicated by e. Since the registration roller pair 32 is stopped to match the timing of the image forming unit, the drive of the conveyance roller 29 is stopped (the energization of the electromagnetic clutch 32 is turned off) after the sheet 5a hits the registration roller pair 32, and the sheet 5a
Stop once. Then, as shown in FIG. 3e, even when the next paper 5b is called from the tray 4 by the above-described procedure, the drive of the feed roller 1 is stopped (the electromagnetic clutch 23 is energized in order to avoid collision between the papers). At the same time, the power supply to the solenoid 13 is stopped. At that time, the conveying force of the second-order sheet 5b is urged from the separation roller 2 in the direction opposite to the sheet feeding direction, but since the claw portion 33-1 is sandwiched by the gear 35 having the one-way clutch 34 built therein, the feeding of Due to the action of the one-way clutch 34 that prevents the drive shaft 7 from rotating in the reverse direction, the drive shaft 7 remains stopped without being reversely conveyed.

Then, at the same time that the conveyance of the preceding sheet 5a is restarted (the clutch means of the registration roller pair 32 is energized and the electromagnetic clutch 32 is energized), the conveyance of the next sheet 5b is restarted (solenoid 13). And energization of the electromagnetic clutch 23 is also started). That is, during the continuous paper feeding operation, a smooth paper feeding operation can be achieved without increasing the distance between the paper sheets.

When the paper feeding operation is completed, the solenoid 13 is not operated and the solenoid 13 is operated for a predetermined time.
Energize. Then, as shown in FIG. 3f, the action of the one-way clutch 34 is released, so that the feed roller 1 starts reverse rotation together with the drive shaft 7 by the urging force from the separation roller 2 in the direction opposite to the sheet feeding direction. At the same time, the pickup roller 3 descends to the upper surface of the sheet and starts reverse rotation in the opposite sheet feeding direction. That is, the residual paper sandwiched by the nip of the feed roller 1 is returned to the tray 4. If the paper return force of the pickup roller 3 is too strong, the paper 5b will buckle between the pickup roller 3 and the back fence 37 that regulates the position of the trailing edge of the paper in the tray 4 as shown by the dotted line in FIG. 3g. Will end up.
Therefore, by setting the idling torque of the coil spring 3 built in the pickup roller 3 lower than the buckling force of the paper, the buckling of the paper is prevented and the remaining paper is surely returned to the tray 4. To do. The actual idling torque may be set so that the reverse conveying force of the pickup roller can be generated at about 30 to 50 gf.

Similarly, even if a paper jam occurs somewhere in the machine during the paper feeding operation, the paper may remain sandwiched between the rollers 1 and 2. At that time, the drive source and the solenoid 13 may be stopped after the solenoid 13 is energized for a predetermined time in a state where the electromagnetic clutch 23 is not operated to return the remaining paper without immediately disconnecting the drive source (not shown). .

The operating time for returning the remaining paper as described above is
Can be set freely. However, the remaining paper return time when the normal paper feeding operation is completed is set so that at least the distance from the leading edge of the bundle of papers 5 to the nip of the feed roller 1 can be conveyed in reverse, and the remaining paper when a paper jam occurs. It is preferable that the returning time is set so that at least the distance from the front edge of the bundle of sheets 5 to the nip between the grip rollers 29 and 30 can be conveyed in the reverse direction.

[0038]

As described above, in the paper feeding device according to the first aspect of the present invention, since the swinging means can release the restriction of the rotation direction of the feed roller driving shaft, the remaining paper is returned by the biasing force of the separation roller. Moreover, since the swinging work of the pickup roller and the work of releasing the regulation of the rotation direction of the feed roller driving shaft can be performed at the same time, the electric parts can be replaced by the conventional FR.
There is an effect that the cost is improved and the operability is improved without increasing the amount other than that required by the R paper feeding method.

As described above, in the paper feeding device according to the second aspect, the control means can return the remaining paper at the end of the paper feeding operation. Even if the paper tray is pulled out, the paper is not left in the paper feeding device, and good operability can be provided.

As described above, in the paper feeding device according to the third aspect of the present invention, the control means can return the remaining paper when the paper jam occurs. Even if the paper feed tray is pulled out, it is possible to provide good operability in which the paper is not left in the paper feed device.

As described above, in the sheet feeding device according to the fourth aspect, the cylindrical coil spring can surely return the remaining sheet to the inside of the tray. Even if the paper tray is pulled out, there is no paper protruding from the bundle or paper buckling, and there is an effect that replenishment can be easily performed.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a drive connecting portion near a pickup roller of the apparatus shown in FIG.

FIG. 3 is a side view conceptually showing the paper feeding operation of the paper feeding device adopting the FRR method.

FIG. 4 is a perspective view of a sheet feeding device adopting a conventional FRR method.

FIG. 5 is a schematic view of a copying machine adopting a conventional FRR paper feeding method.

6 is a perspective view showing a drive system of a separation roller and a conveyance roller pair of the apparatus shown in FIG.

[Explanation of symbols]

 1 Feed roller 1-1 Gear section 1-2 One-way clutch 2 Separation roller 3 Pickup roller 3-1 Gear section 3-2 Boss section 3-3 Coil spring 3-4 Drive side clutch body section 3-5 Housing section 3- 6 Driven side clutch body 3-7 Elastic rubber ring 3-8 Retaining ring 4 Tray 5 Paper 5a Top-level paper 5b Next-order paper 6 Bottom plate 6-1 Notch 7 Drive shaft 8 Arm 8-1 Shutter 9 Shaft 10 Idler gear 11 Spring 12 Lever 13 Solenoid 14 Sensor 15 Torque limiter 16 Shaft 17 Rear plate 18 Bearing 19 Guide 20 Slide bearing 21 Compression spring 22 Bearing 22-1 One-way clutch 23 Electromagnetic clutch 24 Timing belt 25 Gear pulley 26, 27, 28 Gears 29, 30, 31 Transport roller pair 33 Bar 33-1 Claw 34 One-way clutch 35 Gear 36 Bearing 37 Back fence 38 Paper end filler 39 Sensor 40 Spring

Claims (4)

[Claims] 1. A feed roller which is rotationally driven in a sheet feeding direction, a separation roller which is in contact with the feed roller and is rotationally driven in a direction opposite to the sheet feeding direction via a torque limiter, and the feed roller and the separation roller. In a sheet feeding device having a pickup roller for feeding a sheet between the rollers and a swinging means for bringing the pickup roller into contact with or out of the sheet, the drive shaft of the feed roller is restricted to be rotatable only in the sheet feeding direction. And a means for releasing the rotation direction regulating means in synchronism with the swinging means of the pickup roller. 2. The paper feeding apparatus according to claim 1, further comprising control means for activating the rotation direction restriction releasing means of the feed roller for a predetermined time when the paper feeding operation is completed. 3. The paper feeding apparatus according to claim 1, further comprising control means for activating the rotation direction restriction releasing means of the feed roller for a predetermined time when a paper jam is detected. 4. A drive member, wherein the pickup roller has a drive clutch cylinder having a cylindrical outer peripheral portion, a driven clutch cylinder having a cylindrical outer peripheral portion provided adjacent to the drive clutch cylinder, and a rubber elastic member for feeding a sheet. A driven member having a support portion for supporting a wheel, and a cylindrical coil spring wound in a direction opposite to the sheet feeding direction when viewed from the side of the drive clutch cylinder mounted on the outer periphery of the drive clutch cylinder and the driven clutch cylinder. The sheet feeding device according to claim 1, further comprising: