JP2008239266A - Paper feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeder in which a shaft pivotally supporting a pair of rollers is biased with a uniform force, there occurs no abrasive noise and shaft wear even if the shaft is rotated, and the quantity of the other members is reduced. <P>SOLUTION: The shaft 30 pivotally supporting the nip rollers 22 used for this paper feeder is supported by a support member 38. The support member 38 is disposed at the center part of the shaft 30 between the pair of nip rollers 22. The support member 38 pivotally supporting the shaft 38 is pressingly supported on the wall part 48 of a support frame body 32 by a coiled spring 54. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a paper feeding device, and more particularly to, for example, a paper feeding device that stores copying paper in a copying machine and sends it to an image forming apparatus.

  FIG. 1 is an illustrative view showing an example of a sheet feeding device in a copying machine or the like. The paper feeding device 10 includes a paper feeding tray 12. A bottom plate 16 is pressed against the pickup roller 18 by a spring 14 in the paper feed tray 12. The bottom plate 16 functions as a storage unit for storing paper, and a plurality of sheets of paper are stored on the bottom plate 16. Then, the paper placed on the bottom plate 16 is sent upward along the bottom plate 16 by the pickup roller 18. In the paper feeding direction, the paper is fed by the feeding roller 20 and the nip roller 22. The pickup roller 18, the delivery roller 20, the nip roller 22, and the like constitute a delivery mechanism for delivering paper. The paper fed by the feed roller 20 and the nip roller 22 is sent to the image forming apparatus, and the contents described in the original are copied by the image forming apparatus.

  A roller for applying an urging force toward an opposing roller, such as the nip roller 22, is supported by a support shaft 1 as shown in FIGS. 8, 9, and 10, for example. Is inserted into a long hole formed in the bracket 2. Further, two support members 3 having guide grooves 3a formed in opposing portions of the cylindrical wall portion are used, the support shaft 1 is passed through the guide grooves 3a, and the support shaft 3 is supported by a spring 4 housed inside the support member 3. 1 is energized. As a result, the nip roller 22 is urged toward the delivery roller 20 side, and the paper sandwiched between these rollers 20 and 22 is delivered toward the image forming apparatus (see Patent Document 1).

JP-A-5-155460

  However, when the spring is directly applied to the support shaft and biased, the spring hits the support shaft at a point, so the biasing force is not uniformly transmitted to the support shaft. Therefore, as shown in Patent Document 1, it is necessary to urge the support shaft by a plurality of springs using a plurality of support members. Further, when the support shaft rotates while the spring is in contact with the support shaft, a frictional noise is generated and the support shaft is scraped by the spring. Furthermore, not only a plurality of support members and springs are necessary, but also a plurality of brackets that are supported at both ends of the support shaft are necessary, resulting in an increase in cost.

  Therefore, the main object of the present invention is to urge the shaft supporting the pair of rollers with a uniform force, and there is no generation of friction noise or shaft wear even when the shaft rotates. It is an object of the present invention to provide a paper feeding device that can reduce the number of paper feeds.

The present invention is a paper feeding device having a pair of rollers for transporting paper, and supports a shaft that rotatably supports the pair of rollers and a central portion of the shaft between the pair of rollers. A supporting member for supporting the supporting member such that a part of the pair of rollers protrudes from the end, and a pressing member for pressing the supporting member against the wall surface of the end of the supporting frame And a sheet feeding device.
The central portion of the shaft that supports the pair of rollers is supported by the support member, and the support member is pressed against the wall surface of the support frame by the press member, so that the press member does not contact the shaft directly, and the support member is The shaft is indirectly biased by the pressing member. In addition, since the central portion of the shaft is supported by the support member, the pair of rollers is arranged in a balanced manner with the support portion of the shaft as the center.

In such a sheet feeding device, it is preferable that the pressing member is a coil spring, and a holding portion for holding the coil spring is formed on the support member.
A coil spring can be used as the pressing member. By forming the holding portion on the support member, the coil spring is unlikely to come off the holding portion.

Moreover, it is preferable that the support frame is formed with a positioning portion for positioning the shaft at a predetermined position.
By forming the positioning portion on the support frame, the support member is pressed against the wall surface of the support frame by the pressing member after the shaft is positioned at a predetermined position. Thereby, the displacement of the shaft is not increased, and the position of the roller is stabilized.

Furthermore, it is preferable that the support frame body is formed with a shaft suppressing portion for suppressing the movement of the shaft along the wall surface of the end portion of the support frame body.
By suppressing the movement of the shaft along the wall surface of the end portion of the support frame by the shaft suppressing portion, the positions of the two rollers are stabilized, and the paper conveyance can be stabilized.

  According to this invention, since the pressing member does not contact the shaft directly, even if the shaft rotates, no friction noise is generated, and the shaft is not scraped by the pressing member. Further, since the biasing force of the pressing member acts on the shaft indirectly via the support member, the shaft can be biased with a uniform force. Further, since the pair of rollers is arranged in a balanced manner around the shaft support portion, a uniform biasing force can be obtained by the two rollers, and the paper can be transported stably. Here, by positioning the shaft at a predetermined position or suppressing the movement of the shaft along the wall surface of the support frame, the position of the roller can be further stabilized, and the paper conveyance becomes stable. . In addition, since the central portion of the shaft is supported by the support member between the pair of rollers, only one support member may be used as a member for supporting the shaft.

  The above object, other objects, features, and advantages of the present invention will become more apparent from the following description of the best mode for carrying out the invention with reference to the drawings.

  In the paper feeder 10 shown in FIG. 1, for example, a peripheral portion of a nip roller 22 used as a pair of rollers is shown in FIG. The pair of nip rollers 22 are pivotally supported on both sides of the central portion of the shaft 30 so as to be rotatable at substantially equal intervals from the central portion of the shaft 30. The shaft 30 having the nip roller 22 is supported by a support frame body 32. The support frame body 32 is formed in a rectangular shape as a whole, and a shaft support portion 34 in which the center portion of the shaft 30 is disposed at the center portion in the longitudinal direction is formed. In addition, roller support portions 36 for supporting the nip roller 22 are formed on both sides of the shaft support portion 34 in the longitudinal direction of the support frame body 32.

  As shown in FIG. 3, a support member 38 that supports the center portion of the shaft 30 is disposed between the pair of nip rollers 22 in the shaft support portion 34. As shown in FIG. 4, a through hole 40 for inserting the shaft 30 is formed in the support member 38. In parallel with the through hole 40, a flat portion 42 pressed against the wall surface of the support frame 32 is formed. Further, a cylindrical holding portion 44 for holding the coil spring is formed on the opposite side of the flat portion 42. Further, a T-shaped engaging portion 46 is formed in a direction orthogonal to the line connecting the flat portion 42 and the holding portion 44 to engage and hold the support frame 32.

  In the shaft support portion 34, a wall portion 48 is formed at the end in the width direction of the support frame 32, and a support member 38 that supports the shaft 30 is pressed against the wall surface of the wall portion 48. As shown in FIG. 5, a concave portion 50 is formed in the central portion of the wall portion 48, and the flat portion 42 of the support member 38 is pressed against the concave portion 50. A spring retaining wall 52 is formed so as to face the concave surface portion 50 of the wall portion 48. A coil spring 54 as a pressing member is disposed between the spring retaining wall 52 and the support member 38 pressed against the concave surface portion 50. The coil spring 54 is prevented from coming off the support member 38 by covering the holding portion 44 of the support member 38.

  Ribs 56 are formed so as to extend from both sides of the concave surface portion 50 toward the spring retaining wall 52. A positioning portion 58 is formed at an intermediate portion of these ribs 56 so as to protrude, for example, in an arc shape. The positioning portion 58 positions the approximate position of the shaft 30 so that the shaft 30 does not leave the wall portion 48.

  Further, as shown in FIG. 6, a T-shaped engagement hole 60 is formed on the bottom surface of the support frame 32. The engagement hole 60 is formed in the vicinity of the wall portion 48, and the engagement portion 46 of the support member 38 is engaged therewith. The engaging portion 46 is inserted through the wide portion of the engaging hole 60 and is slid to the wall portion 48 side. As a result, the support member 38 cannot be removed from the bottom surface of the support frame 32 in a state where the support member 38 is pressed against the concave surface portion 50.

  Further, in the roller support portion 36, a through portion 62 is formed at the end portion and the bottom portion of the support frame body 32. In this penetration part 62, it arrange | positions so that a part of nip roller 22 may protrude toward the edge part side of the support frame 32. FIG. The protruding portion of the nip roller 22 is brought into contact with the feed roller 20.

  In the roller support portion 36, as shown in FIG. 7, shaft suppression portions 64 are formed on both sides of each nip roller 22. The shaft suppressing portion 64 is formed in a direction orthogonal to the wall portion 48 and suppresses movement along the wall portion 48 of the shaft 30. Further, a cover member 66 is formed between the shaft restraining portions 64 so as to cover the nip roller 22.

  In the sheet feeding apparatus 10 having the nip roller 22 configured as shown in FIG. 2, the central portion of the shaft 30 is supported by the support member 38 between the two nip rollers 22, and the support member 38 is supported by the coil spring 54. It is pressed against the 32 concave surface portions 50. Therefore, the shaft 30 is supported by the inner surface of the through hole 40 of the support member 38 and is not supported by a point. Further, since the two nip rollers 22 are supported at the central portion of the shaft 30, the urging force of the coil spring 54 is uniformly applied to the shaft 30. Accordingly, the two nip rollers 22 are urged toward the feeding roller 20 with a uniform force, so that the paper sandwiched between the feeding roller 20 and the nip roller 22 can be sandwiched with a uniform force, and the paper is fed out in a normal posture. Can do.

  Further, the center portion of the shaft 30 is supported by the support member 38 between the two nip rollers 22, and the shaft 30 is supported by pressing the support member 38 against the concave surface portion 50 of the support frame body 32. Therefore, as a separate member for supporting the shaft 30, there is only one support member 28, and it is not necessary to use a plurality of members. Therefore, the cost can be reduced as compared with a paper feeding device using a plurality of separate members for supporting the shaft 30.

  Further, since the shaft 30 is supported by the support member 32, the coil spring 54 does not directly contact the shaft 30, and even if the shaft 30 rotates, the shaft 30 is not scraped by the coil spring 54. Further, even when the shaft 30 rotates, frictional noise due to contact with the coil spring 54 does not occur.

  Further, since the positioning portion 58 and the shaft restraining portion 64 formed on the rib 56 are formed, the positional deviation of the shaft 30 is suppressed. Further, since the cylindrical holding portion 44 is formed on the support member 32 and the coil spring 54 is held by the holding portion 44, it is possible to prevent the coil spring 54 from coming off the support member 32.

It is an illustration figure which shows an example of a paper feeder. It is an illustration figure which shows the peripheral part of the nip roller used for the paper feeder of this invention. It is an enlarged view which shows the peripheral part of the nip roller shown in FIG. It is a perspective view which shows the supporting member for supporting the shaft of the nip roller shown in FIG. 2 and FIG. It is an illustration figure which shows the shaft support part which supports a shaft with the support member shown in FIG. FIG. 3 is a back view showing the periphery of the nip roller shown in FIG. 2. It is the illustration figure which looked at the peripheral part of the nip roller shown in FIG. 3 from another angle. It is a top view which shows an example of the roller unit used for the conventional paper feeder. It is a side view of the conventional roller unit shown in FIG. FIG. 10 is a front view of a support member used in the roller unit shown in FIGS. 8 and 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Paper feeder 12 Paper feed tray 18 Pickup roller 20 Delivery roller 22 Nip roller 30 Shaft 32 Support frame 38 Support member 40 Through-hole 42 Planar part 44 Holding part 46 Engagement part 48 Wall part 50 Concave part 52 Spring stop wall 54 Coil spring 56 Rib 58 Positioning part 64 Shaft restraint part

Claims (4)

A paper feeding device having a pair of rollers for transporting paper,
A shaft that rotatably supports the pair of rollers;
A support member for supporting a central portion of the shaft between the pair of rollers;
A support frame for supporting the support member such that a part of the pair of rollers protrudes from the end, and a pressing member for pressing the support member against the wall surface of the end of the support frame Including paper feeder.   The sheet feeding device according to claim 1, wherein the pressing member is a coil spring, and a holding portion for holding the coil spring is formed on the support member.   The sheet feeding device according to claim 1 or 2, wherein a positioning portion for positioning the shaft at a predetermined position is formed on the support frame.   The shaft support part for suppressing the movement of the said shaft along the said wall surface of the edge part of the said support frame body was formed in the said support frame body in any one of Claim 1 thru | or 3. Paper feeder.

Images