Paper conveying device

Abstract

To provide a paper conveying device which, with a simple operation, can support a driven roller and reduce creaking noise between the rotation shaft of the driven rollers and an energizing member.SOLUTION: A paper conveying device includes a pair of conveying rollers and a supporting part 41 that supports the driven roller 33B of the conveying roller pair, the driven roller 33B has a rotating shaft 51 and a roller body 53 that is rotatably supported on the rotating shaft 51, the supporting part 41 is formed along a transverse direction intersecting the axial direction of the rotating shaft 51 and has a groove 75 into which the rotating shaft 51 is inserted along the transverse direction, a hook 85 which protrudes inwardly from the groove 75, and against which the rotating shaft is pressed, an energizing member 67 which energizes the rotating shaft 51 towards the hook 85, and an elastically deformable lever 65 that is positioned between the energizing member 67 and the rotating shaft 51.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a paper transport device for transporting paper such as an original. [Background technology]

[0002] A paper transport device such as a document transport unit feeds documents placed on a paper feed tray one by one and transports them to an image reading section of an image reading unit. As described in Patent Document 1, the document transport unit is provided with a pair of transport rollers at a predetermined position on the transport path.

[0003] The conveying roller pair includes a drive roller that is driven to rotate by a motor or the like, and a driven roller that rotates following the drive roller. The driven roller includes a rotating shaft and a roller body rotatably supported on the rotating shaft, and the rotating shaft is supported by a support portion. The support portion has a groove formed in a direction intersecting the axial direction of the rotating shaft, and a hook that protrudes inside the groove. The rotating shaft is inserted into the groove, and is pressed against the hook by a biasing member such as a coil spring, whereby the rotating shaft is supported by the support portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-59399 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned driven roller, in order to reduce the creaking noise generated by the contact between the coil spring and the rotating shaft, the coil spring is covered with a cap so that the coil spring comes into contact with the rotating shaft via the cap. In this case, since the dimensions of the cap are small, there is a problem that it is difficult to support the driven roller on the support part.

[0006] Therefore, in consideration of the above circumstances, the present invention aims to provide a paper transport device that can support a driven roller with simple operations and reduce the generation of creaking noise between the rotating shaft of the driven roller and the biasing member. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the paper transport device of the present invention is a paper transport device comprising a pair of transport rollers including a drive roller that is driven to rotate and a driven roller that rotates driven by the drive roller, and a support part that supports the driven roller, wherein the driven roller has a rotating shaft and a roller body rotatably supported on the rotating shaft, and the support part is characterized in that it comprises a groove formed along a transverse direction that intersects with the axial direction of the rotating shaft and into which the rotating shaft is inserted along the transverse direction, a hook that is arranged to protrude inside the groove and against which the rotating shaft is pressed, a biasing member that biases the rotating shaft toward the hook, and an elastically deformable lever that is arranged between the biasing member and the rotating shaft.

[0008] In the present invention, the rotating shaft may have a flat surface with a portion of its outer peripheral surface cut out along a direction parallel to the axial direction of the rotating shaft, and the lever may have a flat tip surface, and the rotating shaft may rotate until the flat surface of the rotating shaft coincides with the tip surface of the lever, thereby restricting rotation of the rotating shaft.

[0009] In the present invention, the support portion may include a protrusion that limits the movement of the lever member. Effect of the Invention

[0010] According to the present invention, the rotating shaft is biased via the lever member to engage with the hook, so that no creaking noise is generated due to contact between the rotating shaft and the coil spring. Furthermore, the rotating shaft can be engaged with the hook with a simple operation. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing a paper transport device according to an embodiment of the present invention. [Diagram 2] 4 is a front view showing a driven roller supported by a support portion in the paper transport device according to the embodiment of the present invention. FIG. [Diagram 3] 4 is a perspective view showing a driven roller supported by a support portion in the paper transport device according to the embodiment of the present invention. FIG. [Figure 4A] FIG. 2 is a cross-sectional view of FIG. [Figure 4B] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 4C] FIG. 3 is a cross-sectional view taken along line III-III of FIG. [Diagram 5] FIG. 2 is a perspective view showing a rotation shaft of a driven roller in the paper transport device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A paper transport device according to an embodiment of the present invention will now be described with reference to the drawings.

[0013] First, the overall configuration of the paper transport device 1 will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing the paper transport device. In each figure, Fr, Rr, L, and R indicate the front side, rear side, left side, and right side of the paper transport device 1, respectively.

[0014] The paper transport device 1 includes a transport unit 3 through which an original (paper) is transported, a paper feed tray 5 on which the original transported by the transport unit 3 is placed, and an output tray 7 on which the original transported by the transport unit 3 is stacked.

[0015] First, the transport unit 3 will be described. The transport unit 3 is composed of an inner guide section 11 and an outer cover 13. The outer cover 13 is disposed so as to cover the upper surface and left side surface of the inner guide section 11, and is supported at the front and rear lower left corners of the inner guide section 11 so as to be rotatable.

[0016] A paper feed opening 15 and a paper discharge opening 17 are formed on the right side surface of the transport unit 3. The paper feed opening 15 is formed between the inner guide part 11 and the outer cover 13. The paper discharge opening 17 is formed on the right side surface of the inner guide part 11 below the paper feed opening 15.

[0017] The transport unit 3 is formed with a first transport path 19 and a second transport path 21 along which the document is transported. The first transport path 19 is formed between the inner surface of the outer cover 13 and the outer surface of the inner guide section 11, and extends from the paper feed opening 15 to the image reading position 23. The first transport path 19 extends substantially horizontally to the left from the paper feed opening 15, and then curves downward toward the image reading position 23. The second transport path 21 is provided inside the inner guide section 11, and extends obliquely upward from the image reading position 23 to the discharge opening 17.

[0018] The first conveying path 19 is provided with, in order from the upstream side in the conveying direction, a pickup roller 27, a separation roller pair 29, a first conveying roller pair 31, and a second conveying roller pair 33. The separation roller pair 29 is composed of a paper feed roller 29A and a retard roller 29B. The first conveying roller pair 31 is arranged in a horizontal portion of the first conveying path 19 and is composed of a drive roller 31A driven by a motor, and a driven roller 31B that rotates following the drive roller 31A. The second conveying roller pair 33 is arranged in a curved portion of the first conveying path 19 and is composed of a drive roller 33A driven by a motor, and a driven roller 33B that rotates following the drive roller 33A. The pickup roller 27, the paper feed roller 29A, and the driven rollers 31B and 33B of the first and second conveying roller pairs 31 and 33 are supported on the inner surface of the outer cover 13. The retard roller 29B and the drive rollers 31A and 33A of the first and second conveying roller pairs 31 and 33 are supported on the outer surface of the inner guide portion 11.

[0019] When the outer cover 13 is closed, the first transport path 19 is formed, the feed roller 29A contacts the retard roller 29B, and a separation nip is formed between the rollers 29A and 29B. Furthermore, the driven rollers 31B and 33B of the first and second transport roller pairs 31 and 33 contact the drive rollers 31A and 33A. On the other hand, when the outer cover 13 is opened, the first transport path 19 is opened so that a paper jam or the like can be dealt with.

[0020] The second transport path 21 is provided with, in order from the upstream side in the transport direction, a third transport roller pair 35 and a discharge roller pair 37. The third transport roller pair 35 and the discharge roller pair 37 each have drive rollers 35A and 37A that are driven to rotate by a motor, and driven rollers 35B and 37B that rotate following the drive rollers 35A and 37A, respectively.

[0021] Next, the paper feed tray 5 will be described. The paper feed tray 5 is a plate-shaped member having dimensions that allow a document of the maximum size that can be transported to be placed thereon. The upper surface of the paper feed tray 5 is a document placement surface on which the document is placed. A side cursor (not shown) that aligns the document placed on the document placement surface to the center in the width direction is supported on the paper feed tray 5 so as to be slidable in the width direction of the document (direction intersecting the transport direction). The paper feed tray 5 is supported below the paper feed opening 15 of the inner guide section 11 of the transport unit 3 in a position inclined downward toward the paper feed opening 15.

[0022] Next, a description will be given of the discharge tray 7. The discharge tray 7 is formed below the paper feed tray 5, inclined upward from below the discharge opening 17 toward the downstream side in the transport direction.

[0023] Next, the driven roller 33B of the second conveyor roller pair 33 will be described with reference to Figs. 2, 3, 4A to 4C, and 5. Figs. 2 and 3 are a front view and a perspective view showing the driven roller 33B supported by the support portion 41 of the outer cover 13. Figs. 4A to 4C are a II cross-sectional view, a II-II cross-sectional view, and a III-III cross-sectional view of Fig. 2. Fig. 5 is a perspective view showing the rotation shaft 51.

[0024] As described above, the second transport roller pair 33 is composed of the drive roller 33A and the driven roller 33B. The driven roller 33B is supported by a support portion 41 provided on the inner surface of the outer cover 13.

[0025] First, the driven roller 33B will be described. As shown in Fig. 2 and Fig. 3, the driven roller 33B has a rotating shaft 51 and two roller bodies 53 rotatably supported by the rotating shaft 51. As shown in Fig. 5, the rotating shaft 51 is formed with two flat surfaces 51a parallel to the axial direction at a predetermined interval in the axial direction. The two flat surfaces 51a are formed at the same position in the circumferential direction of the rotating shaft 51.

[0026] As shown in Figs. 2 and 3, the two roller bodies 53 are disposed axially outside the two flat surfaces 51a, and are prevented from slipping off the rotating shaft 51 by a stop ring or the like.

[0027] Next, the support part 41 will be described. As shown in Fig. 2 and Fig. 3, the support part 41 includes two outer supports 61 and an inner support 63, a bifurcated lever member 65 disposed between the two inner supports 63, and two coil springs 67 that bias the lever member 65.

[0028] First, the outer support 61 will be described. The outer support 61 is disposed at both ends in the width direction of the inner surface of the outer cover 13, and supports the portion of the rotating shaft 51 of the driven roller 33B that is outside the two roller bodies 53. The outer support 61 has a support piece 71 and a regulating piece 73 disposed at a predetermined interval in the width direction. The support piece 71 and the regulating piece 73 are formed perpendicular to the inner surface of the outer cover 13 along the conveying direction. The support piece 71 is disposed on the inside in the width direction, and the regulating piece 73 is disposed on the outside in the axial direction. As shown in FIG. 4A, the support piece 71 has a groove 75 formed from the tip edge along a direction perpendicular to the inner surface of the outer cover 13 (direction intersecting the width direction). The width of the groove 75 is slightly larger than the diameter of the rotating shaft 51 of the driven roller 33B. The groove 75 has a predetermined depth.

[0029] Next, the inner support 63 will be described. The inner support 63 is disposed on the inner side of the outer support 61 in the width direction, and supports a portion of the rotation shaft 51 of the driven roller 33B on the inner side of the two roller bodies 53. The inner support 63 includes an outer guide piece 81 and an inner guide piece 83 disposed at an interval in the width direction and the conveying direction. The outer guide piece 81 and the inner guide piece 83 are formed perpendicular to the inner surface of the outer cover 13 along the conveying direction. The outer guide piece 81 is disposed on the outer side in the width direction, and the inner guide piece 83 is disposed on the inner side in the width direction.

[0030] 4B, the outer guide piece 81 and the inner guide piece 83 are disposed with a gap in the conveying direction equal to the width of the groove 75 formed in the support piece 71 of the outer support 61. In detail, when viewed from the width direction, one side edge of the outer guide piece 81 and one side edge of the inner guide piece 83 overlap both side edges of the groove 75. The height of the gap between both side edges is greater than the depth of the groove 75.

[0031] A hook 85 is formed at the tip of the outer guide piece 81. When viewed in the width direction, the hook 85 protrudes into the gap. Also, as shown in Figures 2 and 3, a rectangular protrusion 87 that protrudes inward in the width direction is formed on the inner surface of the inner guide piece 83 in the width direction. The protrusion 87 is formed below the hook 85. The inner support body 63 is made of resin.

[0032] Next, the lever member 65 will be described with reference to Figs. 2 and 3. The lever member 65 is disposed between the two inner supports 63. The lever member 65 has a base portion 91 fixed to the inner surface of the outer cover 13, and two band-shaped branch portions 93 branching in opposite directions from the base portion 91 toward the two inner supports 63. The tip portions 95 of the two branch portions 93 are formed in a plate shape. As shown in Fig. 4C, the tip portions 95 of the two branch portions 93 overlap with the gaps between the outer and inner guide pieces 81, 83 of the inner support 63 when viewed in the width direction, and are disposed below the protruding piece 87 of the inner guide piece 83. The upper surface of the tip portion 95 is formed flat, and a boss 97 is provided on the lower surface of the tip portion 95. The lever member 65 is made of resin.

[0033] Next, the coil spring 67 will be described. As shown in Figures 2 and 3, the coil spring 67 is disposed between bosses 97 formed on the tip ends 95 of both branched parts 93 of the lever member 65 and a boss (not shown) formed on the inner surface of the outer cover 13. The coil spring 67 biases the tip ends 95 of the branched parts 93 of the lever member 65 in a direction perpendicular to the inner surface of the outer cover 13.

[0034] The procedure for supporting the driven roller 33B on the support part 41 having the above configuration will be described. First, both ends of the rotating shaft 51 (parts outside both roller bodies 53) are inserted into the grooves 75 of the support pieces 71 of the outer support 61. At this time, the direction of the flat surface 51a (see FIG. 5) of the rotating shaft 51 may be arbitrary. Then, the part of the rotating shaft 51 inside both roller bodies 53 is inserted into the gap between the outer and inner guide pieces 81, 83 of the inner support 63. When the rotating shaft 51 hits the hook 85 of the outer guide piece 81, the rotating shaft 51 pushes down the hook 85. As a result, the outer guide piece 81 is elastically deformed in a direction away from the inner guide piece 83, and passes between the hook 85 and the inner guide piece 83.

[0035] When the rotating shaft 51 passes between the hook 85 and the inner guide piece 83, the rotating shaft 51 comes into contact with the tip 95 of the branched portion 93 of the lever member 65, and the hook 85 elastically returns. Since the tip 95 of the branched portion 93 is biased by the coil spring 67, the rotating shaft 51 is biased via the tip 95 and locked to the hook 85. As shown in FIG. 4A, the rotating shaft 51 does not reach the bottom of the groove 75 of the support piece 71 of the outer support 61. In addition, the end face of the rotating shaft 51 faces the regulating piece 73 of the outer support 61. This restricts the movement of the rotating shaft 51 in the width direction (the axial direction of the rotating shaft 51).

[0036] After the rotary shaft 51 is supported by the support portion 41 in this manner, the outer cover 13 is closed and the document transport operation is started. At this time, the driving roller 33A is driven by the motor to rotate, and the driven roller 33B is driven to rotate. At this time, the rotary shaft 51 also rotates, but when the flat surface 51a of the rotary shaft 51 matches the flat surface of the tip portion 95 of the branch portion 93 of the lever member 65, the rotation of the rotary shaft 51 is restricted. Thereafter, the roller body 53 rotates relative to the rotary shaft 51 in response to the transport of the document.

[0037] As described above, according to the present invention, the rotating shaft 51 is biased via the resin lever member 65 to engage with the hook 85, so no creaking noise is generated due to contact between the rotating shaft 51 and the coil spring 67. Furthermore, by simply inserting the rotating shaft 51 into the groove 75, the rotating shaft 51 can be biased towards the hook 85 via the lever member 65 by the coil spring 67, so that the rotating shaft 51 can be engaged with the hook 85 with a simple operation.

[0038] In addition, since the second transport roller pair 33 is disposed at the curved portion of the first transport path 19, the load applied to the rollers from the document is large. This causes the rotation shaft 51 to swing more strongly, which is likely to cause creaking noise. According to the present invention, it is possible to reduce creaking noise generated by the transport roller pair disposed at the curved portion of the transport path, in particular, with a simple configuration.

[0039] Furthermore, since the rotation shaft 51 is automatically prevented from rotating, the oscillation of the rotation shaft 51 is suppressed, and the roller body 53 can be rotated smoothly.

[0040] Furthermore, since the movement of the branched portion 93 of the lever member 65 is restricted by the protrusion 87 provided on the inner guide piece 83 of the inner support 63, damage to the lever member 65 when supporting the driven roller 33B can be suppressed.

[0041] In the above embodiment, the second transport roller pair 33 provided in the curved portion of the transport path of the transport unit 3 has been described, but the driven roller 31B of the first transport roller pair 31 provided in the horizontal portion of the transport path and the driven roller of the transport roller pair provided in the transport path of the image forming unit (not shown) may also be supported by the above support portion 41.

[0042] Furthermore, the above description of the embodiments of the present invention describes preferred embodiments of the paper feeding device and image forming device according to the present invention, and therefore may include various technically preferable limitations, but the technical scope of the present invention is not limited to these aspects unless there is a specific description that limits the present invention. [Explanation of symbols]

[0043] 1 Paper transport device 33 Transport roller 33A Drive roller 33B Driven roller 41 Support part 51 Rotation axis 53 Roller body 75 Groove 65 Lever 67 Coil spring (biasing member) 85 Hook 87 Projection piece

Claims

1. A paper transport device including a transport roller pair including a drive roller that is driven to rotate and a driven roller that rotates following the drive roller, and a support portion that supports the driven roller, The driven roller is A rotation axis; a roller body rotatably supported on the rotation shaft, The support portion is a groove formed along a cross direction intersecting an axial direction of the rotating shaft, into which the rotating shaft is inserted along the cross direction; a hook provided to protrude into the groove and against which the rotating shaft is pressed; A biasing member that biases the rotation shaft toward the hook; a resiliently deformable lever disposed between the biasing member and the rotating shaft.

2. the rotating shaft has a flat surface formed by cutting out a part of an outer circumferential surface along a direction parallel to an axial direction of the rotating shaft, The lever has a flat tip surface, 2. The paper transport device according to claim 1, wherein the rotation of the rotating shaft is restricted by rotating the rotating shaft until the flat surface of the rotating shaft coincides with the tip surface of the lever.

3. 2. The paper transport device according to claim 1, wherein the support portion includes a protrusion that limits the movement of the lever member.

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