JP2000302269A - Sheet material feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce costs with the reduced number of bearings and costs for the replacement of a retarding roller. SOLUTION: This feeder has a pair of rollers, a feeding roller 6 and a retarding roller 7. It also has a rotor 201 axially rotated and driven around a retarding roller shaft 16 by a power supply device and a rotor 202 axially rotated and arranged on the outer periphery side via a torque limiter mechanism. The retarding roller 7 is detachably provided on the outer periphery side of the rotor 202 in parallel to the torque limiter mechanism in the radial direction of the retarding roller shaft 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus having a retard separating mechanism, which is used in an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional sheet feeding apparatus 1. The sheet material feeding device 1 supplies a transfer sheet 2 as a sheet material to an image forming apparatus (disposed on the left side of FIG. 3) in the drawing. As shown in FIG. 3, a sheet material feeding device 1 feeds the uppermost transfer paper 2 one by one from a sheet material storage device 3 in which a plurality of transfer papers 2 are stacked and stored on a loading table (not shown). And a feed roller 6 that conveys the transfer paper 2 supplied from the sheet material storage device 3 by the pickup roller 5 into an image forming apparatus main body (not shown) (in the direction of arrow b in the drawing). When there are a plurality of transfer papers 2 provided from the sheet material storage device 3 facing each other, a retard roller 7 for rotating in a direction opposite to the rotation direction of the feed roller 6 to separate the transfer papers 2 into one transfer paper 2. And a pair of transport rollers 9 and 9 disposed in front of the image forming apparatus main body.

A sheet material passage area 1 between a pickup roller 5, a feed roller 6, and a retard roller 7
0, a guide 11 is arranged, and a guide 12 is arranged between the feed roller 6 and the retard roller 7 and the transport roller pair 9, 9 and between the transport roller pair 9, 9 and the image forming apparatus main body. The paper 2 is guided and conveyed.

The feed roller 6 and the retard roller 7 are driven by a drive transmission device 13 shown in FIG.
As shown in FIG. 4, the drive transmission device 13 includes a feed roller shaft 15 that supports the feed roller 6, a retard roller shaft 16 that supports the retard roller 7, and a retard roller that is connected to the retard roller shaft 16. Drive shaft 17
Are provided substantially in parallel.

The retard roller shaft 16 is supported by a swingable support member (not shown) via a bearing 25, so that the retard roller shaft 16 can be brought into contact with and separated from the feed roller shaft 15 in parallel. The bearing 25 has a torque limiter 20 in which the retard roller shaft 16 is fixed without any load.
It is arranged to be able to rotate forward and reverse by the torque of.

[0006] A coupling 19 and a torque limiter 20 are disposed between the retard roller shaft 16 and the retard roller drive shaft 17. Further, at an end of the feed roller shaft 15, there is provided an electromagnetic clutch 22 for transmitting the driving force transmitted from the main drive unit of the image forming apparatus main body (not shown) via the drive input belt 21 to the feed roller shaft 15. I have. Also, the feed roller shaft 15
A retard drive belt 23 that transmits the rotational driving force transmitted to the feed roller shaft 15 to the retard roller drive shaft 17 is wound between the drive roller 17 and the retard roller drive shaft 17.

The coupling 19 is for transmitting the drive from the retard roller driving shaft 17 to the retard roller shaft 16 even when the retard roller 7 is displaced.

The pickup roller 5 causes the transfer paper 2
When one sheet is fed one sheet at a time in the sheet feeding direction (the direction of the arrow b shown in FIGS. 3 and 4), the frictional force between the feed roller 6 and the transfer sheet 2 is smaller than the idling torque of the torque limiter 20. Therefore, the retard roller driving shaft 17 is rotated while the torque limiter 20 is idling.
The rotation follows the feed roller 6 in a direction opposite to the driving rotation direction of the roller.

Further, when a plurality of transfer papers 2 are supplied, the idling torque of the torque limiter 20 is set to be large with respect to the frictional force between the plurality of transfer papers 2, so that the retard roller 7 is provided. Rotates in the same direction as the rotational drive direction of the retard roller drive shaft 17, and sequentially transports the transfer paper 2 except the uppermost transfer paper 2 from the lowermost layer in a direction opposite to the supply direction. The transfer paper 2 of the uppermost layer is conveyed into the image forming apparatus main body (not shown) by the idle rotation of the torque limiter 20 in the same manner as when the transfer paper 2 is fed one by one.

The arrangement of the torque limiter 20 in the sheet feeding apparatus 1 will be described with reference to FIGS. 4, 5, 6, and 8. FIG.

In the torque limiter 20 of the sheet feeding apparatus 1, the feed roller 6 and the retard roller 7 are formed of a rubber material or a porous resin. As shown in FIG. 6, it is arranged separately via a coupling 19 for displacement. Further, as shown in FIG. 4, it is disposed on the retard roller drive shaft 17 via a coupling 19, or as shown in FIG. However, in any arrangement, the rotational load on the forward or reverse rotating retard roller shaft 16 or the retard roller 7 is reduced so that the idling torque determined by the torque limiter 20 is reliably transmitted without fluctuation. Bearing 25 for
Is arranged.

[0012]

As described above, in the above-mentioned conventional example, it is necessary to stabilize the torque value of the torque limiter in order to cope with all kinds of sheet materials with sufficient margin. In order to stably and effectively transmit the idling torque of the torque limiter, it is necessary to arrange bearings.

This is achieved by arranging the bearings.
This is to stabilize the idling torque of the torque limiter by not sliding the retard roller that rotates forward and backward or the retard roller shaft to which the retard roller is fixed, respectively. However, it has been desired to provide a simple and low-cost sheet material feeding device omitting such bearings.

To solve the above problem, FIG.
, The retard roller 7 and the torque limiter 20
Is proposed in Japanese Patent Application Laid-Open No. Hei 8-59005, but when the retard roller is replaced, the torque limiter integrated with the retard roller is also replaced, so that a costly sheet material feeding device cannot be obtained. Did not get. Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to simplify and reduce the cost by omitting members such as bearings as much as possible, and to perform replacement of the retard roller at a low cost. It is to provide a sheet material feeding device.

[0015]

According to the present invention, there is provided a feed roller and a retard roller forming a pair of rollers, a feed roller driving means for driving the feed roller, and a retard roller for driving the retard roller. A roller driving unit, wherein the sheet material supplied to the roller pair is fed one by one in a predetermined feeding direction. It has a supply device and a power transmission device,
The power transmission device is disposed via a drive member that is rotatable about the rotation axis by the power supply device and a torque limiter mechanism on an outer peripheral side of the drive member, and is rotatable about the rotation shaft. And the retard roller is detachably provided on the outer peripheral side of the driven member in a form in which the retard roller is arranged in line with the torque limiter mechanism in a radial direction from the rotation shaft. Sheet feeding device.

[Operation] According to the above configuration, the driven member side of the power transmission device does not need to be supported by bearings as in the related art, so that the conventionally required bearings can be reduced. The retard roller is detachable (separate type) from the torque limiter side.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sheet feeding apparatus to which the present invention is applied will be described below with reference to FIGS. 1 to 3 (FIG. 3 shows the present embodiment and a conventional one). Is a view showing a similar part.) FIG. 1 is a sectional view of a sheet feeding apparatus provided with a retard separating mechanism according to the present invention.

The sheet feeding device 1 shown in FIG. 3 feeds the uppermost transfer paper 2 one by one from a sheet storage device 3 in which a plurality of transfer papers 2 are stacked and stored on a loading table (not shown). A pickup roller 5; a feed roller 6 for conveying the transfer paper 2 supplied from the sheet material storage device 3 by the pickup roller 5 into an image forming apparatus main body (not shown) (in the direction of arrow b in the drawing); When a plurality of transfer papers 2 are arranged and supplied from the sheet material storage device, a retard roller 7 that rotates in a direction opposite to the rotation direction of the feed roller 6 to separate the transfer paper 2 into one transfer paper 2; The image forming apparatus includes a pair of conveying rollers 9 disposed in front of the image forming apparatus main body.

The sheet material passage area 1 between the pickup roller 5, the feed roller 6, and the retard roller 7
0, a guide 11 is arranged, and a guide 12 is arranged between the feed roller 6 and the retard roller 7 and the transport roller pair 9, 9 and between the transport roller pair 9, 9 and the image forming apparatus main body. The paper 2 is guided and conveyed.

The feed roller 6 and the retard roller 7 are driven by a drive transmission device 13 shown in FIG.
As shown in FIG. 2, the drive transmission device 13 includes a feed roller shaft 15 that supports the feed roller 6, a retard roller shaft 16 that supports the retard roller 7, and a retard roller that is connected to the retard roller shaft 16. Drive shaft 17
Are provided substantially in parallel.

As shown in FIGS. 1 and 2, the retard roller shaft 1
Numeral 6 is supported by a swingable support member (not shown) so as to be able to contact and separate from the feed roller shaft 15 in parallel.
The torque limiter 20 is disposed between the retard roller 7 and the retard roller shaft 16 so that the retard roller 7 and a part thereof are fitted so as to transmit the idling torque of the torque limiter 20. The torque limiter 20 includes a cylindrical main body 2.
02a, a rotating body 202 composed of a lid 202b whose end is closed, and a rotating body 201 concentrically arranged in the rotating body 202, and each rotating body 20
The rotational load generated by the hysteresis generated in the gap 208 between the magnet 206 and the magnetic body 207 fixed to 1, 202 becomes the torque transmitted by the inner and outer diameters of the torque limiter 20. Of the two rotating bodies 201 and 202 constituting the torque limiter 20, the inner rotating body 201 that is not fitted to the retard roller 7 is fixed by a positioning pin 24 so as not to rotate relative to the retard roller shaft 16.

The rotating body 202 outside the torque limiter 20
Is fitted to the core 7a of the retard roller 7 by means (not shown) so as not to rotate relative to each other, and is prevented from falling out of the rotating body 202 by the C ring 30.

A coupling 19 is arranged between the retard roller shaft 16 and the retard roller drive shaft 17. Further, at an end of the feed roller shaft 15, there is provided an electromagnetic clutch 22 for transmitting the driving force transmitted from the main drive unit of the image forming apparatus main body (not shown) via the drive input belt 21 to the feed roller shaft 15. I have. Between the feed roller shaft 15 and the retard roller drive shaft 17, a retard drive belt 23 that transmits the rotational driving force transmitted to the feed roller shaft 15 to the retard roller drive shaft 17 is wound.

The coupling 19 is for transmitting the drive from the retard roller drive shaft 17 to the retard roller shaft 16 even when the retard roller 7 is displaced.

When the transfer paper 2 is fed one by one in the paper feeding direction (the direction of the arrow b shown in FIGS. 2 and 3) by the pickup roller 5 in FIG. 3, the retard roller 7 makes the feed roller 6 and the transfer paper 2 Is set so as to exceed the idling torque of the torque limiter 20, the feed roller follows the feed roller in the direction opposite to the drive rotation direction of the retard roller drive shaft 17 while idling the torque limiter 20. Rotate.

Further, when a plurality of transfer sheets 2 are supplied, the idling torque of the torque limiter 20 is set to be large with respect to the frictional force between the plurality of transfer sheets 2, so that the retard roller 7 Rotates in the same direction as the rotational drive direction of the retard roller drive shaft 17, and sequentially transports the transfer paper 2 except the uppermost transfer paper 2 from the lowermost layer in a direction opposite to the supply direction. The transfer paper 2 of the uppermost layer is conveyed into the image forming apparatus main body (not shown) by the idle rotation of the torque limiter 20 in the same manner as when the transfer paper 2 is fed one by one.

As described above, according to the sheet feeding apparatus described in the present embodiment, it was possible to reduce the number of bearings, which was conventionally required as a structural requirement. As a result, an inexpensive sheet material feeding device can be provided, and since the retard roller 7 and the torque limiter 20 are separate types, the cost of replacing the roller can be reduced integrally, which is very convenient. is there.

[0028]

As described above, according to the present invention, it is possible to reduce the number of bearings for the driven member, which has been required in the past, and to provide a simple and low-cost sheet feeding apparatus. Further, since the retard roller is detachable from the torque limiter side (separate type), it is not necessary to replace even the torque limiter when replacing the retard roller, and the replacement of the retard roller can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a sheet material feeding device including a retard separation mechanism according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a sheet material feeding device including a retard separation mechanism according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of a sheet material feeding device including a retard separation mechanism according to a conventional technique and an embodiment of the present invention.

FIG. 4 is a diagram illustrating a conventional technique.

FIG. 5 is a view for explaining a conventional technique, in which a retard roller and a feed roller are not pressed against each other.

FIG. 6 is a diagram illustrating a conventional technique, in which a retard roller and a feed roller are pressed against each other.

FIG. 7 is a view for explaining a conventional technique, in which a retard roller and a torque limiter are integrally formed.

FIG. 8 is a view for explaining a conventional technique, in which a retard roller and a torque limiter are arranged so as to be partially fitted.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheet material feeding device 2 sheet material 3 sheet material storage device 5 pickup roller 6 feed roller 7 retard roller 9 transport roller pair 10 sheet material passage area 11 guide 12 guide 13 drive transmission device 15 feed roller shaft 16 retard roller shaft 17 retard Roller drive shaft 19 Coupling 20 Torque limiter 201 Rotating body 202 Rotating body 202a Body 202b Lid 206 Permanent magnet 207 Magnetic body 208 Gap 21 Drive input belt 22 Electromagnetic clutch 23 Retarted drive belt 24 Positioning pin 25 Bearing

Claims (1)

[Claims] 1. A sheet fed to the roller pair, comprising: a feed roller and a retard roller forming a pair of rollers; a feed roller driving unit for driving the feed roller; and a retard roller driving unit for driving the retard roller. In a sheet material feeding device configured to feed a sheet one by one in a predetermined feeding direction, the retard roller driving unit has a power supply device and a power transmission device, and the power transmission device is A driving member that is rotatable about the rotation axis by the power supply device, and a driven member that is disposed on the outer peripheral side of the driving member via a torque limiter mechanism and that is rotatable about the rotation axis. The retard roller is detachably provided on the outer peripheral side of the driven member in a form in which the retard roller is aligned with the torque limiter mechanism in a radial direction from the rotation shaft. A sheet material feeding device, characterized in that: