JPH0229067Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a friction separation paper feeding device used in copying machines and the like.

Conventional technology A transfer paper feeding device for copying machines, facsimile machines, etc. consists of a feed roller that rotates in the paper feeding direction the sheets that are sequentially fed from the top of a stack of sheets placed on a paper feed tray, and a paper path that is sandwiched between the feed rollers. A torque limiter applies a constant torque in the counter-feeding direction, and a separation roller that can rotate in either direction separates the double feed and feeds the sheets one by one to a pair of registration rollers. A friction separation sheet feeding device is known in which a registration roller is activated at the timing when the leading edge of the paper is to be aligned with the leading edge of the image on the photoreceptor.

By the way, in the conventionally known friction separation paper feeding device,
Generally, a torque limiter that applies torque to the separation roller is driven by a drive shaft of the registration roller through a gear train, and the separation roller is rotated in synchronization with the rotation of the registration roller.

Therefore, it is necessary to drive the registration roller and torque limiter at the same time as the feed roller rotates based on the paper feed signal, and when the leading edge of the paper separated from the double feed by the feed roller and separation roller reaches the registration roller, the registration roller When the paper is rotating, the paper is transported by the registration rollers, and the leading edge position cannot be aligned with the image on the photoconductor. Therefore, the leading edge of the paper is detected by a sensor and registered by the time the leading edge of the paper reaches the pair of registration rollers. I had to stop the rollers. Therefore, from the time when the sensor in front of the registration rollers detects the leading edge of the paper, the leading edge of the paper hits the nip portion of the pair of registration rollers, a buckling is formed, and the timing at which the leading edge position of the paper and the leading edge position of the image on the photoconductor is aligned. The torque limiter of the separation roller is not driven until the registration roller starts rotating again to send out the paper, which has the disadvantage that the possibility of double feeding of paper increases by that time. . When the drive of the registration rollers is restarted, the torque limiter is also driven again, but once the double-fed sheets are once caught between the pair of registration rollers, it is no longer possible to return them using the separation rollers.

In order to improve the above problem, the torque limiter is driven from the rotary shaft of the feed roller through a gear train, so that the paper fed by the feed roller comes into contact with a pair of registration rollers, and a predetermined back ring is formed. A friction separation paper feeding device has been proposed in which the torque limiter operates until the feed roller stops when the feed roller stops, thereby preventing double feeding. There is a possibility that double feeding may occur due to the paper being carried along with the other paper.

Purpose This invention solves the above-mentioned drawbacks of the above-mentioned frictional separation paper feeding devices that have been conventionally adopted or proposed. Another object of the present invention is to provide a friction separation paper feeding device in which a torque limiter is activated and the possibility of double feeding is minimized.

Configuration The present invention will be described in detail below based on embodiments shown in the drawings.

In the friction separation paper feeding device of the embodiment shown in the accompanying drawings, each roller constituting the paper feeding device is driven by a gear train and an electromagnetic clutch from a gear 1 that meshes with a gear (not shown) rotated by a drive source. It can be done.

When the gear 1 meshes with the gear driven by the drive source and rotates counterclockwise in the figure as shown by the arrow, the feed roller 10 is rotated through the gears 2 and 3.
The rear gear 4, which is supported by the shaft 11, rotates clockwise. An electromagnetic clutch MC1 is provided between the gear 4 and the feed roller shaft 11, and an electromagnetic clutch MC2 is provided between the gear 1 and the shaft 15 of the registration roller 13. Therefore gear 4
and 1 are rotating, the electromagnetic clutch MC
1. When the MC2 enters, the feed roller shaft 11 and the registration roller shaft 15 rotate in the directions of the arrows, respectively, and the feed roller 10 and the registration roller pair 1 rotate.
3 and 14 rotate in the paper feeding direction. A front gear 5 is rotatably supported on the feed roller shaft 11 via a one-way clutch 22 which allows free rotation only in the direction of rotation, and meshes with a gear 6 fixed to a torque limiter drive shaft 16. Torque limiter drive shaft 1
Gear 7 is further fixed to 6, and torque limiter 1
It is meshed with a gear 8 which rotates together with the drive side of the gear 7. A separation roller 12 is provided on the driven side of the torque limiter 17 so as to rotate integrally therewith. Further, a front gear 18 is pivotally supported on the shaft 15 of the registration roller 13 via a one-way clutch 21 that allows free rotation only in the rotational direction. They are engaged via 19 and 20.

Therefore, when clutch MC1 is engaged with gear 1 meshing with a drive gear (not shown) and gears 1, 2, 3, and 4 rotating in the directions shown by the arrows, shaft 11 of feed roller 10 is engaged. rotates, the gear 5 rotates clockwise via the one-way clutch 22, the torque limiter 17 is driven via the gear 6, shaft 16, gears 7 and 8, and the separation roller 12 receives a reaction signal indicated by a broken line arrow. A constant torque is applied in the paper feeding direction. As described above, when the gear 5 rotates clockwise via the one-way clutch 22 due to rotation of the shaft 11, the gear 18 is rotated counterclockwise via the gear trains 20 and 19; Since the clutch 21 allows free rotation in the counterclockwise direction, it rotates without any problem.

Also, if only clutch MC2 is engaged while gear trains 1, 2, 3, and 4 are rotating, shaft 15 of registration roller 13 rotates, and one-way clutch 2
1, the gear 18 rotates counterclockwise. This rotation is transmitted to the gear 5, which is rotatable clockwise, through the gear trains 19 and 20, and even if the shaft 11 of the feed roller 10 is stopped, the gear 5
rotates clockwise, gear 6, shaft 16, gear 7,
8, the torque limiter 17 is activated, and a constant torque is applied to the separation roller 12 in the opposite direction.

The two electromagnetic clutches MC1 and MC2 are controlled at the following timing.

When you turn on the main switch of the machine, gear train 1,
2, 3, and 4 rotate in the direction of the arrow, respectively. When a paper feed signal is input, first the clutch MC1 is engaged and the feed roller 10 and torque limiter 17 are driven, and torque is applied to the separation roller 12. Paper is fed in the direction of arrow A, and feed roller 1
The leading edge of the paper, which has been separated from the double feed by the roller 0 and the separation roller 12, hits the clamping portion of the stopped pair of registration rollers 13 and 14, and after further buckling by a predetermined amount, the clutch MC1 is disengaged. Next, the electromagnetic clutch MC2 is engaged at the timing when the leading edge of the paper is to be aligned with the leading edge of the image on the photoreceptor.
The registration rollers 13 rotate to feed the paper toward the photoreceptor.

As the shaft 15 of the registration roller 13 rotates, the torque limiter 17 is operated again, and torque is applied to the separation roller 12 in the opposite paper feeding direction.

By controlling the paper as described above, the paper is conveyed by the feed roller 10, the leading edge of the sheet contacts the stopped registration roller, and the sheet is further fed until a predetermined buckling is formed and the feed roller stops. The roller starts rotating at the timing when the leading edge of the paper is to be aligned with the leading edge of the image on the photoconductor, and the roller starts rotating at the timing when the leading edge of the paper is to be aligned with the leading edge of the image on the photoconductor, and the roller rotates both during the time when the leading edge of the paper is to be aligned with the leading edge of the image on the photoreceptor, and during the entire period when the paper is being transported through the paper feeder. The torque limiter is activated, applying torque in the opposite direction to the separation roller, and the double feed separation function is activated.

Effects As described above, according to the present invention, the torque limiter acts while the paper is being conveyed through the paper feed section by the feed roller or registration roller, and the double feed separation function is activated, which makes it possible for double feed to occur. can be greatly reduced.

[Brief explanation of the drawing]

The accompanying drawings are perspective views showing embodiments of the invention. 1, 2, 3, 4...gear train, 5, 6, 7, 8...
...Gear train (for driving the torque limiter from the feed roller shaft), 10...Feed roller, 12...
Separation roller, 13, 14... Registration roller pair, 17... Torque limiter, 18, 1
9, 20... Gear train (for driving the torque limiter from the registration roller shaft), 21, 22... One-way clutch, A... Paper feeding direction, MC1, MC2... Electromagnetic clutch.

Claims (1)

[Scope of Claim for Utility Model Registration] A feed roller 10 that rotates in the paper feeding direction, and a torque limiter 17 that pinches the paper path and presses against it.
A constant torque is applied in the counter-feeding direction through
The separation roller 12, which can rotate in any direction, separates multiple sheets of paper fed in by the pick-up roller from the top of the stack of sheets placed on the paper feed tray and pairs them one by one with the registration rollers. 13 and 14, in which the feed roller 10, torque limiter 17, and registration roller 13 are driven by a single drive gear 1 rotated by a drive source via a transmission means, a first clutch MC1 interposed between a gear 4 meshing with the drive gear 1 through gear trains 2 and 3 and the shaft 11 of the feed roller 10; a shaft 1 of the drive gear 1 and the registration roller 13;
a second clutch MC2 interposed between the feed roller shaft 11 and the gear 5 that drives the torque limiter 17, and a first direction that allows free rotation only in the direction of rotation of the feed roller shaft 11; A clutch 22 is interposed between the registration roller shaft 15 and a gear 18 that meshes with the torque limiter drive gear 5 via the gear trains 2 and 3 and another gear train 19 and 20, and It has a second one-way clutch 21 that allows free rotation only in the rotational direction, and the feed roller 10 and registration roller 13 are connected to each other via first and second clutches MC1 and MC2, which are connected and disconnected at predetermined timings. When the feed roller shaft 11 is being driven, the torque limiter 17 is driven via the first one-way clutch 22, and the torque limiter 17 is driven by the first one-way clutch 22,
is being driven, the first and second one-way clutches 21, 22 and the gear trains 18, 1 between them are activated.
8, 20, and 5.