JPH05162876A - Paper feed device - Google Patents

Abstract

PURPOSE:To constitute a separating brake unit composed of cheap components, and to restrain the components from vibrating and changing its posture. CONSTITUTION:A cushion member 69 is press-inserted between a holder 57 for holding a separating brake 54 and a guide 67 for guiding the motion of the holder 57, and accordingly, it is possible to prevent vibration of the holder 57 during slide between the separating brake 54 and the paper feed roller 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device for feeding paper to, for example, an electronic copying machine.

[0002]

2. Description of the Related Art In an electronic copying machine or the like, a paper feed cassette is provided in its main body, and paper is supplied from this paper feed cassette.

Sheets are stacked inside the sheet cassette, and a pickup roller is brought into contact with the upper surface of the sheet to rotate the sheet to take out the sheet. The paper thus taken out is sent out by the paper feed roller and is supplied to the image transfer portion.

When the paper is fed by the paper feed roller, there is a risk that the paper may be fed in an overlapping state. Therefore, a separation break is brought into contact with the paper feed roller, and the separation break is made. This prevents the taking of two sheets of paper. The separation brake is provided as a unit.

That is, the separation brake is held by a holder, which is connected to the piston. The piston is reciprocally inserted into the cylinder and pressed by a spring, and the separating brake is pressed against the sheet feeding roller by the spring force. The holder is guided by a guide to bring the separation brake into contact with a predetermined position of the sheet feeding roller. An appropriate gap is formed between the guide and the holder so that the holder can smoothly operate.

By the way, if the gap between the guide and the holder is too large, the holder vibrates due to friction between the separation brake and the paper feed roller, and an unpleasant sound is generated. There is a possibility that they may come into contact with each other to cause a paper feed error. Therefore, in order to minimize the gap between the guide and the holder, highly accurate parts are required.

[0007]

However, the use of highly accurate parts has a problem in that it is disadvantageous in cost in a machine that requires mass productivity. Therefore,
It is an object of the present invention to provide a sheet feeding device capable of preventing the occurrence of vibration of the holder of the separating member without requiring high precision of parts.

[0008]

In order to solve the above problems, the present invention solves the above-mentioned problems by feeding a paper feed cassette, a take-out roller for taking out the paper stored in the paper feed cassette, and a take-out roller for feeding the paper. A sheet feeding roller for feeding the separated sheet, a separating member that is brought into contact with the sheet feeding roller to separate the sheets one by one, and a holding body that holds the separating brake,
A pressure contact means for reciprocally supporting the holding body to press the separation brake against the sheet feeding roller, a guide body for guiding the reciprocating movement of the holding body, and a space between the guide body and the holding body. And an elastic member press-fitted in.

[0009]

[Operation] By pressing the elastic member between the guide body and the holding body, the gap between the guide body and the holding body is eliminated,
Vibration of the holder due to friction between the separating member and the paper feed roller is prevented.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 2 shows a schematic configuration of the image forming apparatus. In the figure, 1 is a main body of the apparatus. A document mounting table glass 3 is provided on the upper surface of the apparatus main body 1.

An automatic document feeder 45 is provided on the original table glass 3 to automatically convey an original document and set it on the original table glass 3. The automatic document feeder 45 includes a feed roller 46 ... And a feed roller 46 ...
It is constituted by a conveyor belt 47 that is stretched over the. In addition, the exposure means 3 is provided on the upper side of the apparatus main body 1.
0 is provided. The exposing means 30 is a first and a second carriage 3 that runs along the original platen glass 3.
3, 37 are provided.

A light source 31 and a first mirror 32 are arranged on the first carriage 33. Second and third mirrors 35 and 36 are arranged on the second carriage 37.

A lens 34 is provided in the optical path of the reflected light of the third mirror 36, and the light passing through this lens 34 passes through the fourth to sixth mirrors 38, 39 and 40. An image is formed on the photosensitive drum 12. Around the peripheral portion of the photosensitive drum 12, along the rotation direction thereof, a charging charger 13, an exposure unit 14, a developing device 15, a transfer / separation charger-16, 17, a cleaning device 18, and a charge eliminating charger are sequentially installed. 19 is provided, and the image forming means 10 is formed.

Further, a paper feed cassette 7 is detachably mounted on one side of the apparatus main body 1, and the paper feed cassette 7 is attached.
The paper inside is taken out by the pickup roller 11. The taken-out paper sheet is separated from the paper feed roller 41 by a separating roller.
The sheets 42 are delivered one by one by the la 42, and the delivered sheets are conveyed along the conveyance path 21.

An aligning roller 24, the transfer / separation chargers 16, 17, a conveyor belt 23, a fixing device 25, and a discharge roller 26 are provided in the conveying path 21 along the sheet conveying direction. It is arranged.

A paper feed cassette 51 is also provided on the inner bottom of the apparatus main body 1, and the paper in the paper feed cassette 51 is taken out by a take-out roller 52. This take-out roller 52
The sheet taken out by the above is sent to the aligning roller 24 through the conveying path 49. A feed roller 53, a separation break unit 50, a sheet detection sensor 43, a positioning roller 55, and a driven roller 56 driven by the positioning roller 55 are provided in the transport path 49. It is arranged.

However, at the time of image formation, the original is set on the original placing table glass 3, and the exposure lamp 31 is applied to the original.
Light is emitted from. The reflected light from the document is sent to the lens 34 via the first to third mirrors 32, 35 and 36,
After passing through this lens 34, the fourth to sixth Mira-3
An electrostatic latent image is formed by forming an image on the peripheral surface of the photoconductor 12 via 8, 39 and 40. This electrostatic latent image is sent to the developing device 15 by the rotation of the photoconductor 12 and is visualized by supplying the developer there. The visualized image is transferred by the transfer charger 16 onto the paper supplied from the paper feed cassette 7 or the paper feed cassette 51. The sheet on which the image is transferred is peeled from the photosensitive drum 12 by the action of the peeling charger 17, and is conveyed by the traveling of the conveying belt 23. This sheet is sent to the fixing device 25,
Here, the transferred image is fixed. The sheet on which the image is fixed is discharged onto the sheet discharge tray 22 via the sheet discharge roller 26. By the way, the separating break unit 50 is constructed as shown in FIGS.

That is, reference numeral 54 in the drawing denotes a separation brake as a separation member, and the separation brake 54 is held by a holder 57 as a holder. This holder 57 is connected to a piston 59 as a pressure contact means via a pin 58. The piston 59 is inserted into the cylinder 60 and pressed by the compression spring 61, so that the separation brake 54 is brought into pressure contact with the sheet feeding roller 53. The cylinder 60
Is fixed to step 63.

Further, a bolt 6 is attached to the cylinder-60.
A guide 67 made of synthetic resin is attached by means of 4, 64, and an attachment portion 68 having an L-shaped cross section is formed at the center of the upper end of the guide 67.

A cushion material 69 as an elastic member is attached to the mounting portion 68 of the guide 67, and a low friction member 70 is attached to the surface of the cushion material 69.

The low friction member 70 of the cushion material 69 is pressed against the side surface of the holder 57, and the cushion material 69 and the low friction member 70 close the gap between the guide body 67 and the holder 57. There is.

A shaft 75 is attached to the outer wall of the cylinder 60, and a release lever 76 is rotatably attached to the shaft 75. The tip of the release lever 76 is connected to the piston 59 via the shaft 77.
The shaft 77 is biased by a tension spring 78.

When the paper feed cassette 51 is attached or detached, the pulling force of the tension spring 78 lowers the piston 59 to separate the separation brake 54 from the paper feed roller 53. Then, the paper stored in the paper feed cassette 51 is taken out by the take-out roller 52 and sent to the paper feed roller 53.

As shown in FIG. 2, the take-out roller 52 and the paper feed roller 53 are interlocked and rotate in the direction of arrow A, and the take-out roller 52 has a paper feed roller 53 and a separation brake 54.
It is lifted when a certain amount of time has passed from the time when the sheet should be nipped (the time when the slip of the sheet and the take-out roller 52 is expected). The paper nipped by the paper feed roller 52 and the separation brake 54 is sent to the aligning roller 55 and the driven roller 56 by the frictional force between the paper feed roller 52 and the paper.

When a certain amount of time elapses after the sheet before the aligning roller 55 is detected by the sheet before the aligning roller switch 43 (paper and the sheet feeding roller 52)
The time for which the paper is allowed to bend to some extent after the paper hits the contact portion of the aligning roller 52 and the driven roller 56 during the time when the slip of
Align the leading edge of the paper by stopping the rotation of 2. The aligning roller 55 and the driven roller 56 align the leading edge of the paper and then rotate again in the direction of arrow C to feed the paper in the direction of arrow P.

The paper feed roller 52 has a built-in one-way clutch that locks in the direction of arrow B, and when the aligning roller 55 and the driven roller 56 are rotating to feed the paper in the direction of arrow P, the paper is fed. The paper roller 53 is adapted to rotate along with the frictional force with the paper.

At the time of this paper feeding and conveying operation, the take-out roller 5
By the time the sheet taken out by 2 reaches the sheet feeding roller 53, the sheet feeding roller 53 frictionally rotates on the surface of the separation brake 54.

At this time, as shown in FIG. 1, the separation brake 54 is formed by the gap between the holder 57 and the guide 19.
Vibrates in the direction of arrow D together with the holder 57 to release the frictional force, which causes an unpleasant noise, or the tip of the holder 57 is lifted in the direction of arrow E and the sheet hits there, causing a paper feed error. May occur.

However, as described above, the cushion material 69 and the low friction material 70 are press-fitted into the gap between the holder 57 and the guide 19 to press the holder 57 in the direction of arrow G, so that the vibration of the holder 57 is caused. Will be prevented.

Therefore, even if the parts precision of the guide 19 is low, it is possible to prevent the unpleasant sound from being generated by the vibration of the holder 57 and the contact of the sheet due to the lifting of the tip of the holder 57. The surface of the cushion material 69 has a low friction material 7
In order to provide 0, the cushion material 69 has the separation brake 54
It does not interfere with the movement of.

In the above embodiment, the guide 6
Although the cushion material 69 is attached to the 7 side, the present invention is not limited to this, and the same effect can be obtained even if the cushion material 69 is attached to the holder 57 side.

[0032]

As described above, according to the present invention, since the elastic member is press-fitted between the holding body for holding the separating member and the guide body for guiding the reciprocating movement of the holding body, the precision of the guide body parts is improved. Even if the value is low, the holder can be prevented from vibrating, and unpleasant noise and paper feed error can be prevented from occurring, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a paper feeding device that is an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an electronic copying machine including the paper feeding device of FIG.

FIG. 3 is an explanatory view showing a paper feeding operation of the paper feeding device of FIG.

FIG. 4 is an exploded perspective view showing the sheet feeding device of FIG.

[Explanation of symbols]

52 ... take-out roller, 53 ... paper feed roller, 54 ... separation brake (separation member), 59 ... piston (press contact means), 61
... compression springs (pressure contact means), 67 ... guides, 65 ... cushion materials (elastic members), 66 ... low friction materials.

Claims (2)

[Claims] 1. A paper feed cassette for storing paper, a take-out roller for taking out the paper stored in the paper feed cassette, a paper feed roller for feeding the paper sent out by the take-out roller, and the paper feed roller. A separating member that is brought into contact with the sheet and separates the sheets one by one; a holding member that holds the separating member; and a pressure contacting unit that reciprocally supports the holding member and presses the separating member against the paper feed roller. A sheet feeding device comprising: a guide body for guiding the reciprocating movement of the holding body; and an elastic member press-fitted between the guide body and the holding body. 2. The paper feeding device according to claim 1, wherein a low friction material is provided on the surface of said elastic member so as to be in sliding contact with a holding body.