JP2009029559A - Sheet feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly and securely attach/detach a shaft member without plastically deforming a ground plate. <P>SOLUTION: A sheet feeder is provided with the shaft member 21 comprising feed rollers 26 and 27, a pair of shaft bearing parts 22 and 23 provided at a specific distance from each other to rotatably support both end parts 21a and 21b of the shaft member 21, the ground plate 24 of metal provided on one end side of the shaft member 21 in such a state as to press an end surface 21c of the shaft member 21 in the axial direction, and a regulation member (retaining ring) 25 provided on the opposite side of the ground plate 24 to the shaft member 21 to regulate deformation quantity of the ground plate 24. The pair of shaft bearing members 22 and 23 make the shaft member 21 slide in such a way that the ground plate 24 increases its pressure, so that the end part 21b on the side of the shaft member 21 opposite to the ground plate 24 is attachable/detachable to the shaft bearing part 23. The regulation member 25 (retaining ring) 25 is positioned in such a way that the ground plate 24 is not plastically deformed as the shaft member 21 slides. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a paper supply device provided in the vicinity of a paper feed unit such as a paper feed cassette in an image forming apparatus such as a facsimile, a copying machine, and a printer.

  As the paper supply apparatus described above, one having the configuration shown in FIGS. 7 and 8 is known (see, for example, FIGS. 4 and 5 of Patent Document 1).

  The paper supply device 102 is provided in the vicinity of the paper feed cassette 101 set at the lower part of the image forming apparatus 100 and is configured to supply the paper P of the paper feed cassette 101 to the transport line 103 one by one. The feed roller 105 has a shaft member 106 attached to the roller shaft 104.

A ground plate 107 is provided in contact with one end of the shaft member 106. The ground plate 107 is statically charged when the rubber feed roller 105 is frictionally engaged with the paper P at the time of paper feeding, and the static electricity adversely affects the electrical and electronic components built in the image forming apparatus 100. Arranged to prevent.
JP-A-8-277045

  By the way, the shaft member 106 is mounted again after being removed and subjected to maintenance / inspection. Then, for removal, the roller shaft 104 is moved toward one side in the axial direction (left side in FIG. 8), and the end opposite to the approached side (right side end in FIG. 8) is extracted from the bearing 108. Thereafter, the end (the left end in FIG. 8) that is approached is extracted from the bearing 109. On the other hand, the shaft member 106 is attached by reversing the above operation.

  Therefore, when the shaft member 106 is attached or detached, if the roller shaft 104 is moved too far, the ground plate 107 may be greatly bent to cause plastic deformation. Further, when attaching and detaching such plastic deformation does not occur, careful work is required, and the work cannot be performed quickly and reliably.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a paper supply device that can quickly and reliably attach and detach the shaft member without plastically deforming the ground plate.

  The paper supply device according to the present invention is a paper supply device provided in an image forming apparatus, and rotatably supports a shaft member having a paper feed roller and both ends of the shaft member, and is provided at a certain distance from each other. A pair of bearings provided, a metal ground plate provided on one end side of the shaft member in a state of pressing the end surface of the shaft member in the axial direction, and a side opposite to the shaft member of the ground plate A regulating member that regulates the deformation amount of the ground plate, and the pair of bearing portions slides the shaft member in a state in which the ground plate increases the pressing force, and the ground plate of the shaft member Is configured such that the end on the opposite side can be attached to and detached from the corresponding bearing portion, and the regulating member is positioned so that the ground plate does not plastically deform as the shaft member slides. Features .

  The paper supply device according to claim 2 of the present invention is the paper supply device according to claim 1, wherein the end of the shaft member on the side of the ground plate is opposite to the ground plate of the shaft member. An extraction preventing member for preventing the end portion from coming out of the corresponding bearing portion is detachably attached.

  According to a third aspect of the present invention, there is provided the paper supply device according to the first or second aspect, wherein the restriction member is a part of a metal frame built in the image forming apparatus, and the metal frame includes The ground plate is screwed.

  In the case of the paper supply device of the present invention, the shaft member is slid so that the pressing force of the ground plate increases, and the end of the shaft member opposite to the ground plate is pulled out from the corresponding bearing portion, and then the shaft is moved. If the end of the member on the ground plate side is pulled out of the corresponding bearing portion, both ends of the shaft member can be removed from both bearing portions. On the other hand, both ends of the shaft member can be attached to both bearing portions by the reverse operation. In such an attaching / detaching operation, the sliding operation of the shaft member that bends and deforms the ground plate is restricted by the restricting member. Since the position of the regulating member is determined so that the ground plate does not plastically deform as the shaft member slides, the ground plate does not undergo plastic deformation. Therefore, according to the present invention, the shaft member can be quickly and reliably attached to and detached from the bearing portion without plastically deforming the ground plate.

  Further, in the case of the paper supply device according to claim 2, since the anti-extraction member is detachably attached to the end of the shaft member on the ground plate side, the normal use state with the anti-extraction member attached Then, it prevents that the edge part on the opposite side to the earth plate of a shaft member slips out from a corresponding bearing part. On the other hand, at the time of attaching / detaching the shaft member, the shaft member can be attached / detached by removing the extraction preventing member from the shaft member.

  Further, in the case of the paper supply device according to the third aspect, since the restricting member is formed by a part of the metal frame to which the ground plate is attached, there is no need to prepare and attach the restricting member separately. Further, since the ground plate is screwed to the metal frame, the ground plate can be easily attached.

  The present invention will be specifically described below.

  FIG. 1 is a front view showing an example of an image forming apparatus according to the present invention.

  The image forming apparatus 1 is, for example, a printer, and includes a substantially cylindrical photosensitive drum 2 whose surface is made of amorphous silicon as an image carrier, and a charger 3 and a developer around the photosensitive drum 2. The apparatus 4, a transfer roller 5 as an example of a transfer body, a cleaning unit 6, and a static eliminator 7 are arranged along the rotation direction of the photosensitive drum 2 (clockwise direction in FIG. 1). The cleaning unit 6 includes a polishing roller 6a provided on the upstream side in the rotation direction of the photosensitive drum 2, and a cleaning blade 6b provided on the downstream side thereof.

  The image forming process by the image forming apparatus 1 is performed as follows. After the surface of the photosensitive drum 2 is uniformly charged by the charger 3, the surface of the photosensitive drum 2 is exposed by irradiating a laser beam 9 according to the image data by the exposure device 8, whereby the photosensitive member is exposed. An electrostatic latent image is formed on the drum 2. Thereafter, the electrostatic latent image on the photosensitive drum 2 is developed by the developing device 4 into a toner image, and the toner image on the photosensitive drum 2 is transferred to a transfer material, for example, recording paper P by the transfer roller 5. . At the time of this transfer, a transfer bias potential is applied between the photosensitive drum 2 and the transfer roller 5 so that the charged toner moves smoothly to the recording paper P.

  After the transfer, the toner remaining on the photosensitive drum 2 adheres to the polishing roller 6a by polishing the photosensitive drum 2 by the polishing roller 6a, and is then collected by the cleaning blade 6b. Thereafter, the residual potential on the photosensitive drum 2 is erased by the static eliminator 7. Thereafter, it is charged again by the charger 3 and the above image forming process is repeated.

  On the other hand, the recording paper P is unwound from a paper feed cassette 10 by a paper supply device 20 to be described later, is transported along a transport line 12, and is sent between the photosensitive drum 2 and the transfer roller 5, where the transfer roller 5, the toner image on the photosensitive drum 2 is transferred, and then discharged to the discharge tray 14 through the fixing unit 13. A registration sensor (not shown) is provided on the upstream side of the transfer roller 5 in the transport line 12, and both ends of the recording paper P in the transport direction are detected based on the on / off state of the registration sensor. Position alignment of the toner image on the drum 2 and the recording paper P is performed.

  In the lower part of the image forming apparatus 1 configured as described above, a storage unit 15 into which the paper feed cassette 10 is put in and out is provided, and in the vicinity of the storage unit 15 and above the paper feed cassette 10 according to the present invention. The paper supply device 20 which is a main part is provided.

  2 is a perspective view showing the paper supply device 20, FIG. 3 is a plan view showing the paper supply device 20, FIG. 4A is a front view showing the normal paper supply device 20, and FIG. 4B. FIG. 4A is an enlarged front view showing the left end (front end) of the paper supply device 20 in FIG. 4A, and FIG. 4C is the right end (rear side) of the paper supply device 20 in FIG. FIG. 5 is an exploded perspective view showing a mounting state of the left end portion (front end portion) of the shaft member.

  The paper supply device 20 includes a shaft member 21 and a pair of bearing portions 22 and 23 that rotatably support both end portions 21a and 21b of the shaft member 21.

  The bearing portion 22 includes a through hole 22a provided in the resin frame 1a disposed on the front side of the image forming apparatus 1, and a bearing 22b attached to the inside of the through hole 22a. The bearing portion 23 is provided at a certain distance from the bearing portion 22, and includes a through hole 23 a provided in the resin frame 1 b disposed on the rear side, and a bearing 23 b attached to the inside of the through hole 23 a. And a drive transmission member 23d having an insertion portion 23c mounted on the inner side of the bearing 23b on the front side (see FIG. 4).

  The shaft member 21 is provided such that the axial direction coincides with the front-rear direction, and the front end portion 21 a is attached to the inside of the bearing 22 b of the bearing portion 22. On the other hand, the rear end portion 21 b is attached to the inside of a bottomed recess 23 e provided inside the insertion portion 23 c of the bearing portion 23. The drive transmission member 23d has a gear 23f formed on the outer side on the rear side, and rotation from a drive motor (not shown) is transmitted through a gear train (not shown) meshed with the gear 23f. When the rotation of the drive motor is transmitted to the gear 23f, the drive transmission member 23d is rotated.

  The paper supply device 20 includes a conductive metal ground plate 24 provided in a state of pressing the front end face 21c of the shaft member 21, and the ground plate 24 opposite to the shaft member 21. And a regulating member 25 that regulates the deformation amount of the ground plate 24 (see FIG. 4).

  The restricting member 25 is a conductive metal frame 1c to which the resin frame 1a is attached to the rear side, and a portion corresponding to the through hole 22a is formed in an L-shaped cross section, and the metal frame 1c is moved to the front side. It has an extended horizontal portion 25a and a vertical portion 25b protruding upward from the front end of the horizontal portion 25a. Further, a ground plate insertion hole 25c is formed in the horizontal portion 25a. The metal frame 1c is grounded.

  The ground plate 24 has a stepped portion 24a in the middle of the vertical direction, and the lower portion 24b of the stepped portion 24a has a cross-sectional shape protruding rearward from the upper portion 24c of the stepped portion 24a. Yes. The ground plate 24 is attached by fixing the lower portion 24b to the metal frame 1c with a screw 29 while passing through the ground plate insertion hole 25c of the horizontal portion 25a. The upper portion 24c of the ground plate 24 is The front end surface 21c of the shaft member 21 is pressed toward the rear side.

  A bending allowance A is provided between the upper portion 24 c of the ground plate 24 and the vertical portion 25 b of the regulating member 25. The bending allowance A is such that when the shaft member 21 is slid forward in the axial direction in order to extract the rear end portion 21b from the bearing portion 23 as will be described later, the upper portion 24c of the ground plate 24 can be bent forward. It is for doing so.

  The shaft member 21 is provided with a pair of rubber paper feed rollers 26 and 27 at the center thereof. The paper feed roller 26 is directly attached to the shaft member 21, and the paper feed roller 27 is attached to the rotating shaft 8 provided in parallel with the shaft member 21. The paper feed roller 26 rotates in the same direction as the shaft member 21 due to the rotation of the shaft member 21, and the paper feed roller 27 transmits the rotation of the shaft member 21 to the rotating shaft 8 by an endless belt (not shown). Thus, the sheet feeding roller 26 is configured to rotate in the same direction. The static electricity on the rubber paper feed rollers 26 and 27 is grounded through the shaft member 21, the ground plate 24, and the metal frame 1c.

  Moreover, both the bearing parts 22 and 23 are comprised so that the shaft member 21 can be slid to the front side, and the rear side edge part 21b of the shaft member 21 can be pulled out from the corresponding bearing part 23. FIG. That is, the bending margin A is made larger than the insertion length B of the rear end 21b into the bottomed recess 23e of the bearing 23. Further, the vertical portion 25b of the restricting member 25 is determined at a position where the ground plate 24 is not plastically deformed even if the ground plate 24 is deformed as shown in FIG. 6B as the shaft member 21 slides forward. It has been. In short, the vertical portion 25b functions as a substantial regulating member that prevents plastic deformation of the ground plate 24.

  Further, the front end portion 21a of the shaft member 21 is formed with a concave groove 21d over the entire circumference, and the rear end portion 21b of the shaft member 21 is prevented from slipping out of the corresponding bearing portion 23 in the concave groove 21d. An anti-extraction member to be prevented, such as a retaining ring 28, is detachably attached.

  Therefore, in the case of the paper supply device 20 of the present embodiment configured as described above, the retaining ring 28 is removed and the bearing 22b is slid rearward so that the state shown in FIG. 4 is changed to the state shown in FIG. To remove from the through hole 22a. Thereafter, the shaft member 21 is slid forward so that the force by which the ground plate 24 presses the front end surface 21c of the shaft member 21 is increased, and the rear end portion 21b of the shaft member 21 is removed from the corresponding bearing portion 23 ( If the front end 21a of the shaft member 21 is then pulled out of the corresponding bearing portion 22, the both end portions 21a and 21b of the shaft member 21 can be removed from the both bearing portions 22 and 23. On the other hand, the opposite end portions 21 a and 21 b of the shaft member 21 can be attached to both the bearing portions 22 and 23 by the reverse operation.

  In such an attaching / detaching operation, even if the shaft member 21 is excessively slid forward as shown in FIG. 6B, the sliding operation of the shaft member 21 is restricted by the restriction member 25. . Since the position of the vertical portion 25b in the regulating member 25 is determined so that the ground plate 24 does not plastically deform as the shaft member 21 slides, the ground plate 24 does not undergo plastic deformation. Therefore, according to the present embodiment, the shaft member 21 can be quickly and reliably attached and detached without plastic deformation of the ground plate 24.

  Further, according to the present embodiment, the retaining ring 28 is detachably attached to the front end portion 21a of the shaft member 21. Therefore, in the normal use state where the retaining ring 28 is attached, the rear end of the shaft member 21 is provided. The side end portion 21 b is prevented from coming out of the corresponding bearing portion 23. On the other hand, at the time of attaching / detaching the shaft member 21, the shaft member 21 can be attached / detached by removing the retaining ring 28 from the shaft member. At this time, as shown in FIG. 6B, the bearing 22b is slid rearward in the axial direction, so that the gap between the shaft member 21 and the bearing 22a can be increased to facilitate the sliding of the shaft member 21, and The shaft member 21 can be tilted in the radial direction in a state where the shaft member 21 is put in the bearing 22a, and the shaft member 21 can be easily attached to and detached from the bearing portion 22.

  Furthermore, according to the present embodiment, the restricting member 25 is a part of the metal frame 1c, and the ground plate 24 is fixed to the metal frame 1c with a screw 29, and the metal frame to which the ground plate 24 is attached. Since the regulating member 25 is formed in a part of 1c, there is no need to prepare and attach a regulating member separately, and the ground plate 24 is fixed to the metal frame 1c with screws 29. Can be easily installed.

  In the above-described embodiment, the shaft member 21 is slid and attached to the front side of the image forming apparatus (printer) 1. However, in the present invention, the image forming apparatus (printer) 1 is reversed. You may comprise so that the shaft member 21 may be slid and attached to the back side.

  In the above-described embodiment, the retaining ring 28 is used to prevent the rear end portion of the shaft member from slipping out of the corresponding bearing portion. However, the present invention is not limited to this, and the retaining ring 28 is omitted. Further, it may be configured to prevent the rear end portion of the shaft member from coming off from the corresponding bearing portion by the pressing force of the ground plate.

  Further, in the above-described embodiment, an example in which two paper feed rollers are supported by one shaft member is described as an example, but the present invention is not limited to this, and one paper feed roller is supported by one shaft member. The present invention can also be applied in the same manner to those that have been made, or those in which three or more paper feed rollers are supported on one shaft member.

  Furthermore, in the above-described embodiment, the present invention is applied to a printer. However, the present invention is not limited to this, and can be similarly applied to a paper supply device provided in an image forming apparatus such as a facsimile or a copying machine.

1 is a front view illustrating an example of an image forming apparatus according to the present invention. It is a perspective view showing a paper supply device. FIG. 3 is a plan view showing a paper supply device. (A) is a front view showing a normal paper supply device, (b) is an enlarged front view showing a left end (front end) of the paper supply device of (a), and (c) is (a). It is a front view which expands and shows the right side edge part (rear side edge part) in this paper supply apparatus. FIG. 5 is an exploded perspective view showing an attached state of the left end portion (front end portion) of the shaft member. (A) is a front view showing a paper supply device at the time of detachment, (b) is a front view showing an enlarged left end portion (front end portion) of the paper supply device of (a), and (c) is (a). It is a front view which expands and shows the right side edge part (rear side edge part) in this paper supply apparatus. It is a schematic diagram showing a conventional image forming apparatus. It is a schematic diagram showing a conventional paper supply device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 20 Paper supply apparatus 21 Shaft member 21a, 21b End part 21c End surface 22, 23 Bearing part 24 Ground plate 25 Restriction member 26, 27 Paper feed roller 28 Retaining ring (Extraction prevention member)

Claims (3)

In the paper supply device provided in the image forming apparatus,
A shaft member having a feed roller;
A pair of bearing portions that rotatably support both end portions of the shaft member and provided at a fixed distance from each other;
A metal ground plate provided on one end side of the shaft member in a state of pressing the end surface of the shaft member in the axial direction;
Provided on the opposite side of the shaft member of the ground plate, and a regulating member for regulating the deformation amount of the ground plate,
The pair of bearing portions can slide the shaft member in a state in which the ground plate increases the pressing force so that the end portion of the shaft member opposite to the ground plate can be attached to and detached from the corresponding bearing portion. The sheet supply device is characterized in that the regulating member is positioned so that the ground plate is not plastically deformed as the shaft member slides. The paper supply apparatus according to claim 1,
An extraction preventing member that prevents the end of the shaft member on the side opposite to the ground plate from coming out of the corresponding bearing portion is detachably attached to the end of the shaft member on the ground plate side. A paper supply apparatus characterized by the above. In the paper supply apparatus according to claim 1 or 2,
The paper supply device, wherein the regulating member is a part of a metal frame built in the image forming apparatus, and the ground plate is screwed to the metal frame.

Images