JPH0628511Y2 - Double feed prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is applied to a copying machine, a facsimile machine, or the like, when conveying stacked sheet-shaped members such as copy paper and originals.
The present invention relates to a double-feed preventive device that can reliably transport sheets one by one.

<Prior Art> In the following, the case where the copying papers are conveyed one by one from the stacked copying papers will be described.

FIG. 3 is a schematic view of a paper feeding portion of a conventional copying machine, and FIG. 4 is an exploded perspective view of a separation roller used in a conventional double feed prevention device.

The copy paper P stacked in the paper feed cassette 50 is the copy paper P.
Pick-up roller 40 that abuts the top copy paper P ₁ of
Are transported by being rotationally driven in the transport direction of the copy paper P. At this time, the friction coefficient mu ₁ between copy sheet P, between the friction coefficient mu ₂ between the uppermost copying paper P ₁ and the pick-up roller 40, a relationship of 0 _{<μ 1} <μ ₂ For,
The uppermost sheet P of the copy sheet P is picked up by the pickup roller 40.
_{When 1} is fed, the second copy sheet P ₂ will be double-fed with the feeding of the uppermost sheet P ₁ .

At this time, in order to prevent double feeding of a plurality of copy sheets P to a process unit (not shown), the pickup roller 40
A feed roller 30 that rotates in the conveyance direction of the copy paper P on a conveyance path in the vicinity of, and the copy paper P while being in contact with the feed roller 30.
There is provided a separation roller 10 which is driven and loaded in a direction opposite to the conveyance direction of.

The separation roller 10 includes a roller portion 11, a torque limiter 12 connected to the roller portion 11, and a drive shaft 13 that drives the roller portion 11 via the torque limiter 12.

In the roller portion 11, a rubber 112 is wound around the outer circumference of a tubular body 111 having a bottomed tubular shape, a ridge 111a is formed in the bottom portion of the tubular body 111, and a drive shaft 13 is provided in the central portion. Opening to be inserted
111b has been opened.

The torque limiter 12 has a collar 121, a flange 122, and a coil spring 123.

The collar 121 has a substantially columnar shape and includes an insertion portion 121a to be inserted into the cylindrical body 111 and a first boss 121b to which the winding spring 123 having a diameter slightly smaller than the diameter of the insertion portion 121a is fixed. A flange portion 121c having a diameter larger than the diameter of the first boss 121b is formed between the insertion portion 121a and the first boss 121b. The insertion portion 121a is formed with a fitting portion 121d that fits into the ridge 111a. Further, an opening 121e through which a drive shaft 13 described later penetrates is formed in the axial direction of the collar 121.

The flange 122 has a substantially columnar shape with steps, and has a second boss 122a to which the winding spring 123 is attached and a drive shaft 13a.
And a connecting portion 122b that is connected to. The diameter of the second boss 122a is set smaller than the diameter of the connecting portion 122b and slightly smaller than the diameter of the first boss 121b. Further, in the axial direction of the flange 122, the drive shaft 13
The opening 122c through which the
A groove 122d that passes through the opening 122c is formed therein.

That is, the torque limiter 12 is configured such that one end side of the winding spring 123 is attached to the second boss 122a of the flange 122 and the other end side is fixed to the first boss 121b of the collar 121, and the drive shaft 13 is It is configured by penetrating the openings 121e and 122c. In the torque limiter 12 having such a configuration, when the winding spring 123 is rotationally driven in the tightening direction, the winding spring 123 is tightened and the second boss 122a is closed.
And the coil spring 123 are fixed. Also, the coil spring 123
Is driven to rotate in a slackening direction with a torque equal to or greater than a predetermined value,
Slip occurs between the spiral spring 123 and the second boss 122a, and the flange 122 and the collar 121 rotate in opposite directions.

Next, the operation of the separation roller 10 using the torque limiter 12 having the above configuration will be described.

When there is no copy sheet P between the feed roller 30 and the separation roller 10 or only one copy sheet P is conveyed, the separation roller 10 is driven to rotate with a torque equal to or more than a predetermined value by the drive of the feed roller 30. Therefore, a slip occurs between the winding spring 123 and the second boss 122a, and the roller portion 11 of the separation roller 10
Is driven by the feed roller 30 to rotate in the conveyance direction of the copy paper P.

However, when a plurality of copy sheets P are conveyed between the feed roller 30 and the separation roller 10, the friction coefficient is 0 <μ ₁ <μ ₂ as described above,
The uppermost copy paper P ₁ is conveyed in the conveyance direction by the feed roller 30, and the _{second and} subsequent copy papers P _{2 to} P _n are pushed back in the opposite direction to the conveyance direction. Therefore, the second and subsequent copy sheets P _{2 to} P _n are pushed back in the direction opposite to the transport direction,
Double feeding is prevented.

<Problems to be Solved by the Invention> However, the torque transmission force between the second boss of the flange and the winding spring is proportional to the area of the winding spring in contact with the second boss, Since the machining accuracy such as the inner diameter and the outer diameter of the second boss varies, it is very difficult to make the torque transmission force between the second boss and the winding spring constant.

The present invention has been made in view of the above circumstances, and provides a double-feeding prevention device that can reliably convey copy paper one by one without requiring the machining accuracy of the winding spring and the flange to be so high. The purpose is to do.

<Means for Solving Problems> A multi-feed preventing device according to the present invention includes a feed roller that is rotationally driven in a sheet-member conveying direction, and a feed roller that is in contact with the feed roller and is in a direction opposite to the conveying direction. A multi-feed prevention device comprising a drive-loaded separation roller, wherein the separation roller has a roller portion, a torque limiter, and a drive shaft, and the torque limiter has the roller portion. A first boss portion that rotates integrally and is rotatable with respect to the drive shaft, and a second boss portion that is disposed opposite to the first boss portion and that rotates integrally with the drive shaft. The boss has a winding spring wound around both bosses, and a movable spacer screwed onto a male screw formed on the peripheral surface of the first boss. The diameter is larger than the diameter of the second boss The diameter of the second boss portion is smaller than the diameter of the spiral spring, and one end of the spiral spring is always in contact with the movable spacer.

<Operation> The separation roller is driven in the direction opposite to the copy paper conveyance direction.

By moving the movable spacer, the area where the spiral spring and the boss contact each other can be adjusted. If this area is large, the torque transmission force increases, and if it is small, the torque transmission force decreases. Therefore, the torque transmission force of the torque limiter can be adjusted by appropriately adjusting the movable spacer.

<Embodiment> An embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of a separation roller used in a double feed prevention device according to the present invention, and FIG. 2 is a sectional view thereof.

Since the pickup roller, the feed roller and the like are the same as conventional ones, detailed description thereof will be omitted. Further, the same parts as those of the related art will be described by giving the same numbers.

The separation roller 10 has a roller portion 11, a torque limiter 12 and a drive shaft 13.

The roller portion 11 includes a bottomed cylindrical tubular body 111 and a rubber 112 wound around the outer periphery of the tubular body 111. An opening 111b into which the drive shaft 13 is inserted is formed at the center of the bottom of the cylindrical body 111, and a ridge 111a passing through the opening 111b is formed.

The torque limiter 12 has a collar 121, a flange 122, a coil spring 123, and a cover 124 as a movable spacer.

The collar 121 has a substantially columnar shape as a whole, and has an insertion portion 121a to be inserted into the cylindrical body 111, a first boss 121b extending from the insertion portion 121a, an insertion portion 121a and a first boss.
It has a collar part 121c between it and 121b. A male screw 121f is formed on the collar portion 121c. On the open end side of the insertion portion 121a,
A fitting portion 121d corresponding to the ridge 111a is formed.
Further, an opening 121e through which the drive shaft 13 penetrates is opened at the center of the collar 121 in the longitudinal direction.

The flange 122 has a substantially columnar shape with steps, one end of which is formed as a second boss 122a, and a fixing portion 122b having a diameter larger than the diameter of the second boss 122a is formed. Further, an opening 122c through which the drive shaft 13 penetrates is opened in the axial center direction of the flange 122, and a groove 122d passing through the center of the fixed portion 122b is formed.

The spiral spring 123 is made of an elastic filament having a substantially rectangular cross section, one end side of which is fixed to the first boss 121b of the collar 121 and the other end side of which is the second boss 122a of the flange 122.
Is configured to be attached to.

That is, the diameter of the second boss 122a of the flange 122 is 1
It is set to be slightly smaller than the diameter of the first boss 121b of 21.

The cover 124 has a substantially donut shape in which an opening 124b having a size substantially equal to the outer diameter of the first boss 121b of the collar 121 is formed in the center of the substantially circular dish shape, and the inner peripheral surface of the cover 124 is formed. A male screw 124a corresponding to the male screw 121f is formed.
Further, a set screw 125, which will be described later, is provided around the opening 124b.
The screw hole 124c for is opened.

Set screw 125, after assembling the torque limiter 12,
The cover 124 is fixed so as not to shift, and is set so as to correspond to the screw hole 124c.

The insertion portion 121a of the collar 121 is inserted into the cylindrical body 111 of the roller portion 11, and the fitting portion 121d of the insertion portion 121a is engaged with the protrusion 111a of the cylindrical body 111. Further, the flange 122 in which the coil spring 123 is attached to the second boss 122a has the opening of the cover 124 in the first boss 121b of the collar 121 in which the cover 124 is engaged with the flange portion 121c.
It is attached to the collar 121 by fixing one end side of the coil spring 123 via 124b. That is, one end of the spiral spring 123 is attached to the second boss 122a, the other end of the spiral spring 123 always contacts the cover 124, and the first boss 121b.
It is fixed to. Then, the set screw 125 is attached to the screw hole 124c, and the set screw 125 is brought into contact with the flange 121c to fix the cover 124. At this time, the winding spring 123 is set so as to be loosened when rotating in the transport direction of the copy paper P. That is, if the winding spring 123 is wound in the counterclockwise direction as shown in FIG. 1, the direction of arrow A (clockwise direction) is the conveying direction of the copy paper P.

However, the set screw 125 may be provided perpendicular to the drive shaft 13, that is, in contact with the male screw 121f, instead of being provided in parallel with the drive shaft 13.

Separation roller 10 assembled in this way
The drive shaft 13 is penetrated through the openings 111b, 121e, 124b, and 122c, and is driven and loaded in the direction opposite to the direction in which the copy paper P is conveyed.

By changing the screwing state of the male screw 121f of the collar 121 and the female screw 124a of the cover 124, that is, by screwing the cover 124 into the collar 121, the area of contact between the second boss 122a and the coil spring 123 is increased. Can be adjusted. If this area is large, the torque transmission force increases, and if it is small, the torque transmission force decreases. Therefore, the torque transmission force of the torque limiter 12 can be adjusted by adjusting the screwed state with the both members (121) and (124).

Further, as another embodiment, a small hole is formed around the opening 124b of the cover 124, and the tip of the coil spring 123 is inserted and hooked so that the length of the coil spring 123 related to the second boss 122a of the flange 122 is increased. It is also possible to change the height.

It should be noted that in the above-described embodiment, the double feed prevention device according to the present invention has been described as being adapted to the prevention of double feed of copy paper, but the present invention is not limited to the above embodiment, and it is not limited to the above embodiment. It can also be applied to prevention of sending.

Further, the set screw 125 is set on the cover 124 along the axial direction of the separation roller 10, but the present invention is not limited to the above embodiment, and an appropriate fixing screw is provided on the outer circumference of the cover 124 to fix the fixing screw. You may make it prevent the rotation of the cover 124 by pressing the screw part 121f of the roller part 11 with a screw.

<Effect of the device> According to the double feed prevention device of the present invention, the contact area between the second boss of the flange of the torque limiter and the coil spring can be adjusted by the movable spacer, so that the finishing accuracy of each component can be improved. It doesn't have to be that high.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a separation roller used in a multi-feed preventing device according to the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is a schematic view of a paper feeding section of a conventional copying machine, and FIG. FIG. 6 is an exploded perspective view of a separation roller used in a conventional double feed prevention device. 10 …… Separation roller, 11 …… Roller section, 121…
… Color, 121f …… Male thread, 122 …… Flange, 123 ……
Winding spring, 124 …… Cover (movable spacer), 124a ……
Female screw.

Claims (1)

[Scope of utility model registration request] 1. A double-feeding prevention comprising a feed roller which is rotationally driven in a sheet-conveying direction, and a separation roller which is in contact with the feed roller and is driven and driven in a direction opposite to the conveying direction. In the apparatus, the separation roller has a roller portion, a torque limiter, and a drive shaft. The torque limiter rotates integrally with the roller portion and is rotatable with respect to the drive shaft. Boss portion, a second boss portion that is disposed so as to face the first boss portion and that rotates integrally with the drive shaft, and a winding spring that is wound around both boss portions. And a movable spacer screwed onto a male screw formed on the peripheral surface of the first boss portion, the diameter of the first boss portion being larger than the diameter of the second boss portion, The diameter of the part is smaller than the diameter of the coil spring, Multi-feed preventing device, characterized in that one end are always in contact with the movable spacer Kibane.