Sheet storage device and image forming system having the same

Abstract

This invention provides a sheet-body storage device and an image forming system incorporating the sheet-body storage device. The sheet-body storage device includes a main housing, a sheet-body stacking tray, a rod, a suspension mechanism, a drive unit, and a drive transmission unit. The suspension mechanism has multiple take-up pulleys and multiple wire ropes. The drive transmission unit has multiple drive gears and multiple driven gears. The multiple take-up pulleys can change the engagement position of the multiple driven gears relative to the multiple drive gears in the circumferential direction of the rod. By individually changing the engagement position of each of the multiple driven gears, the drive transmission unit changes the relative position of the rotation direction of the fixing parts of each of the multiple take-up pulleys, thereby allowing for individual adjustment of the release amount of each of the multiple wire ropes.

Description

Technical Field

[0001] The present invention relates to a sheet storage device and an image forming system including the sheet storage device. Background Art

[0002] In image forming devices such as copiers, printers, and fax machines, when multiple users share one image forming device, the consumption of sheets (including recording media such as printing paper and envelopes) of each image forming device increases. Generally, since the number of sheets that can be stored in the main body of the image forming device is about hundreds, it is necessary to frequently replenish the sheets. Here, there is an image forming system in which a large-capacity sheet storage device that can store thousands of sheets is installed on the side of the image forming device, and sheets are supplied from the sheet storage device to the image forming device.

[0003] The sheet storage device includes: a sheet stacking tray for stacking sheets; a suspension mechanism for suspending the sheet stacking tray; and a driving device for applying a rotational driving force to the suspension mechanism to raise and lower the sheet stacking tray. The suspension mechanism includes: a rod supported to be rotatable in both forward and reverse directions; a plurality of pulleys installed at both ends of the rod in the direction of the rotation axis; and four wire ropes, one end of which is fixed to the pulley and the other end is fixed to the sheet stacking tray.

[0004] The drive device is connected to the rod and applies a rotational driving force to the rod to rotate it. The pulley is stopped relative to the rod and rotates integrally with the rotation of the rod. The drive device rotates the rod and the pulley to wind the wire rope around the pulley or release it from the pulley, thereby raising and lowering the sheet stacking tray. That is, the release amount of the wire rope changes according to the rotation speed of the pulley.

[0005] The other end of each wire rope is fixed to the fixing parts at the four corners of the sheet stacking tray. Each fixing part is configured so that the center of gravity of the sheet stacking tray coincides with the center position of each fixing part. The release amount of each wire rope is equal, and the sheet stacking tray is suspended on the wire rope and raised and lowered while maintaining a horizontal state.

[0006] A sheet supply unit for supplying sheets from the sheet storage device to the image forming device is arranged above the sheet stacking tray. When the sheet stacking tray is raised so that the upper surface of the sheet stack on the sheet stacking tray contacts the sheet supply unit, the sheet supply unit supplies the contacted sheets to the image forming device. Summary of the invention

[0007] An object of the present invention is to provide a sheet storage device that can suppress inclination of a sheet stacking tray and thereby suppress feeding failure.

[0008] The sheet storage device of the first structure of the present invention comprises: a main body shell; a sheet stacking tray supported to be able to be lifted and lowered in the main body shell and used to stack sheets; a rod extending in a direction orthogonal to the lifting direction and supported to be able to rotate in both positive and negative directions; a suspension mechanism comprising: a plurality of take-up pulleys installed at both ends of the rod; and a plurality of wire ropes, one end of which is respectively fixed to the plurality of take-up pulleys and the other end is fixed to the sheet stacking tray and suspends the sheet stacking tray; and a driving device to rotate the rod, wherein the sheet storage device also includes a drive transmission part, the drive transmission part comprising: a plurality of drive gears fixed to positions of the rod corresponding to the plurality of take-up pulleys, respectively, and rotating integrally with the rod; and a plurality of driven gears are respectively formed on the plurality of take-up pulleys and can engage with the corresponding plurality of driving gears. The plurality of driving gears engage with the plurality of driven gears, and the drive transmission part transmits the rotation of the rod toward the plurality of take-up pulleys. The plurality of take-up pulleys have a fixing part for fixing the ends of the plurality of wire ropes, and can change the engagement position of the plurality of driven gears relative to the plurality of driving gears in the circumferential direction of the rod. The drive transmission part changes the relative position of the rotation direction of the fixing part of each of the plurality of take-up pulleys by individually changing the engagement position of each of the plurality of driven gears, and can adjust the release amount of each of the plurality of wire ropes.

[0009] In addition, the image forming system of the second structure of the present invention includes: an image forming device having an image forming unit that forms an image on the sheet; and a sheet storage device of the first structure that is connected to the image forming device and has a sheet feeding mechanism that feeds the sheet to the image forming unit.

[0010] According to the first configuration of the present invention, the inclination of the sheet stacking tray relative to the horizontal direction can be adjusted by adjusting the release amount of each wire rope, so that a sheet storage device can be provided which can suppress the inclination of the sheet stacking tray and suppress sheet feeding failure.

[0011] According to the second configuration of the present invention, it is possible to provide an image forming system capable of suppressing a sheet feeding failure from the sheet storage device to the image forming apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic cross-sectional view showing a schematic structure of an image forming system 100 including a sheet storage device 20 and an image forming apparatus 1 according to an embodiment of the present invention.

[0013] Figure 2 It is a perspective view showing the structure inside the main body housing 26 of the sheet storage device 20 .

[0014] Figure 3 It is expressed from above Figure 2 The sheet stacking tray 27 is shown in a front view.

[0015] Figure 4 It is a plan view showing the periphery of one end portion of the rod 35 .

[0016] Figure 5 This is a plan view of the first pulley 28a as viewed from the inner side in the axial direction.

[0017] Figure 6 It is a perspective view in which the structure of the first pulley 28a is developed.

[0018] Figure 7 It is a side view of the suspension mechanism 60 for suspending the sheet stacking tray 27 in a tilted state.

[0019] Figure 8 It means to make Figure 7 The illustrated side view is of the suspension mechanism 60 in a state where the driven gear 37 is rotated in the forward direction by a predetermined rotation angle to shorten the pay-out amount of the first wire rope 29a. DETAILED DESCRIPTION

[0020] Hereinafter, a sheet storage device 20 according to an embodiment of the present invention and an image forming system 100 including the sheet storage device 20 will be described with reference to the drawings.

[0021] Figure 1 This is a schematic cross-sectional view showing a schematic structure of an image forming system 100 including a sheet storage device 20 and an image forming device 1 according to an embodiment of the present invention. The image forming device 1 includes a paper feed unit 2, a sheet conveying unit 3, an image forming unit 4, a fixing device 5, and an image reading unit 6. The paper feed unit 2 is arranged at the lower part of the image forming device 1. The sheet conveying unit 3 is arranged on the side of the paper feed unit 2. The image forming unit 4 is arranged above the sheet conveying unit 3. The fixing device 5 is arranged on the discharge side of the image forming unit 4. The image reading unit 6 is arranged above the image forming unit 4 and the fixing device 5.

[0022] The paper feed unit 2 includes a plurality of paper feed cassettes 7 for storing plain paper sheets P. The paper feed unit 2 reliably delivers the sheets P one by one from a selected one of the plurality of paper feed cassettes 7 to the sheet conveying unit 3 by rotating a paper feed roller 8 .

[0023] The manual feed tray 25 places plain paper of a size different from the sheets P stored in the paper feed cassette 7 , or sheets P such as OHP sheets and envelopes, and feeds the sheets P such as OHP sheets and envelopes to the sheet conveying unit 3 .

[0024] The sheet P fed to the sheet conveying unit 3 is conveyed toward the image forming unit 4 via the sheet supply path 10. The sheet supply path 10 extends upward from each paper feed cassette 7, and merges with a merging path 52 at an intermediate position, and the merging path 52 is connected to a sheet discharge port 51 of the sheet storage device 20 described later.

[0025] The image forming section 4 forms a toner image on the sheet P by an electrophotographic method. The image forming section 4 includes a Figure 1 A photoconductor 11 rotates in the direction of an arrow, and a charging unit 12, an exposure unit 13, a developer 14, a transfer unit 15, a cleaning unit 16 and a neutralizing unit 17 are arranged around the photoconductor 11 along the rotation direction of the photoconductor 11.

[0026] The charging section 12 includes a charging wire to which a high voltage is applied, and a predetermined potential is given to the surface of the photoreceptor 11 by corona discharge from the charging wire, so that the surface of the photoreceptor 11 is uniformly charged. Furthermore, when the exposure section 13 irradiates the photoreceptor 11 with light based on the image data of the original document read by the image reading section 6, the surface potential of the photoreceptor 11 is selectively attenuated, and an electrostatic latent image is formed on the surface of the photoreceptor 11.

[0027] Next, the developing device 14 develops the electrostatic latent image on the surface of the photoreceptor 11 to form a toner image on the surface of the photoreceptor 11. The toner image is transferred by the transfer unit 15 to the sheet P supplied between the photoreceptor 11 and the transfer unit 15.

[0028] The sheet P to which the toner image has been transferred is conveyed toward the fixing device 5 disposed on the downstream side of the image forming section 4 in the sheet conveying direction. In the fixing device 5, the sheet P is heated and pressed by the heating roller 18 and the pressure roller 19, and the toner image is melted and fixed on the sheet P. Then, the sheet P to which the toner image has been fixed is discharged by the discharge roller pair 22 onto the discharge tray 21.

[0029] After transfer by transfer section 15, the toner remaining on the surface of photoreceptor 11 is removed by cleaning section 16, and the residual charge on the surface of photoreceptor 11 is removed by charge removing section 17. Then, photoreceptor 11 is charged again by charging section 12, and image formation is performed in the same manner.

[0030] A large-capacity sheet storage device 20 capable of storing several thousand sheets P is disposed adjacent to the side of the image forming apparatus 1. The sheet storage device 20 stores a sheet stacking tray 27, a hanging mechanism 60, a first wire 29a, a second wire 29b, a third wire 29c, a fourth wire 29d, a driving device 30, and a sheet feeding mechanism 32 inside a main body housing 26 constituting the frame of the sheet storage device 20. The main body housing 26 is formed in a substantially rectangular parallelepiped shape, and a plurality of casters 24 are mounted on the bottom surface of the main body housing 26 to facilitate movement of the sheet storage device 20.

[0031] Figure 2 It is a perspective view showing the structure inside the main body housing 26 of the sheet storage device 20 . Figure 3 It is expressed from above Figure 2 The sheet stacking tray 27 is shown in a front view. Figure 2 The side surface of the main body housing 26 shown in the drawing on the right inner side is Figure 1 The side surface is the front side in the paper direction shown. Figure 2 The side surface of the left front side of the main body shell 26 shown in the paper is Figure 1 The width direction of the sheets P stored in the sheet storage device 20 is the same as the direction from the front to the back of the main body housing 26 .

[0032] like Figure 2 , Figure 3 As shown in FIG. 1 , the sheet stacking tray 27 is configured to include: a tray portion 33, which is a rectangular plate-like body extending parallel to a horizontal plane; and fixing portions 34a1, 34a2, 34b1, 34b2 (an upstream fixing portion and a downstream fixing portion) protruding from four corners of the tray portion 33 toward the outside in the width direction (the width direction of the sheet P). The sheet stacking tray 27 is configured to be able to be moved in the up-down direction ( Figure 2 The sheet P is supported in the main housing 26 in a manner of being lifted and lowered in the direction of the arrow Y shown in the figure. The sheet P is stacked on the center ( Figure 3 The position indicated by the dotted line).

[0033] The fixing portions 34a1, 34a2, 34b1, 34b2 have a pair of fixing portions 34a1, 34a2 (upstream fixing portions) located at the side end portions on the upstream side of the tray portion 33 in the sheet conveying direction, and a pair of fixing portions 34b1, 34b2 (downstream fixing portions) located at the side end portions on the downstream side of the tray portion 33 in the sheet conveying direction. The fixing portions 34a1, 34a2 are arranged on one side (front side (back side of the image forming device 1)) and the other side (rear side (front side of the image forming device 1)) along the axial direction. The fixing portions 34b1, 34b2 are arranged on one side (front side (back side of the image forming device 1)) and the other side (rear side (front side of the image forming device 1)) along the axial direction.

[0034] The suspension mechanism 60 suspends the sheet stacking tray 27 by means of a plurality of (four in this case) wire ropes 29a to 29d (a first wire rope 29a, a second wire rope 29b, a third wire rope 29c, and a fourth wire rope 29d) so as to be able to be raised and lowered in the main body housing 26. The suspension mechanism 60 is configured to include a rod 35, a plurality of pulleys 28a to 28d (winding pulleys), and pulleys 41a to 41f. The plurality of pulleys 28a to 28d are a first pulley 28a (front pulley), a second pulley 28b (front pulley), a third pulley 28c (rear pulley), and a fourth pulley 28d (rear pulley).

[0035] The rod 35 extends in a horizontal direction (width direction of the sheet P) orthogonal to the lifting direction of the sheet stacking tray 27. The rod 35 is supported inside the main body housing 26 so as to be rotatable in both positive and negative directions (clockwise and counterclockwise directions with the central axis of the rod 35 as the rotation axis). In the direction along the rotation axis of the rod 35 (hereinafter referred to as the "axial direction"), a plurality of pulleys 28a to 28d (herein, four pulleys: the first pulley 28a, the second pulley 28b, the third pulley 28c, and the fourth pulley 28d) are mounted on both ends of the rod 35.

[0036] The driving device 30 is connected to the end of one side of the axial direction of the rod 35 (the end on the back side of the image forming apparatus 1). The driving device 30 includes: a driving unit M such as a motor that can provide a rotational driving force; and a driving input gear 31 connected to the driving unit M and the rod 35. The driving input gear 31 is composed of a plurality of gears, and transmits the rotational driving force of the driving unit M to the rod 35. The driving device 30 generates a forward or reverse rotational driving force using the driving unit M, and rotates the rod 35 in the forward or reverse direction with the help of the driving input gear 31.

[0037] like Figure 2 , Figure 3As shown, the first pulley 28a and the second pulley 28b are installed at the end of one side of the axial direction of the rod 35 (the end on the back side of the image forming device 1) and are axially inward of the driving device 30. The third pulley 28c and the fourth pulley 28d are installed at the end of the other side (the opposite side to the above-mentioned one side) of the axial direction of the rod 35 (the end on the front side of the image forming device 1).

[0038] Each pulley 28a to 28d is located on the same axis relative to the rod 35. The first pulley 28a and the second pulley 28b are adjacent and connected in the axial direction. The first pulley 28a is located on the outer side of the axial direction relative to the second pulley 28b. In addition, the third pulley 28c and the fourth pulley 28d are also adjacent and connected in the axial direction. The third pulley 28c is located on the inner side of the axial direction relative to the fourth pulley 28d. In addition, each pulley 28a to 28d is a component composed of separate components independent of each other and can be separated from each other.

[0039] One end of the first wire rope 29a is fixed to the first pulley 28a. One end of the second wire rope 29b is fixed to the second pulley 28b. One end of the third wire rope 29c is fixed to the third pulley 28c. One end of the fourth wire rope 29d is fixed to the fourth pulley 28d. By rotating each pulley 28a to 28d in the forward direction, each wire rope 29a to 29d fixed to each pulley is wound up. Conversely, by rotating each pulley 28a to 28d in the reverse direction, each wire rope 29a to 29d fixed to each pulley 28a to 28d is released.

[0040] Figure 4 It is a plan view showing the periphery of one end portion of the rod 35 . Figure 5 This is a plan view of the first pulley 28a as viewed from the inner side in the axial direction. Figure 6 Since the pulleys 28a to 28d have the same shape and structure, only the first pulley 28a is described in detail, and the other pulleys (second pulley 28b, third pulley 28c, fourth pulley 28d) are marked with the same reference numerals and their description is omitted.

[0041] like Figure 4 , Figure 5 , Figure 6 As shown, the first pulley 28 a includes: a drive gear 36 and a driven gear 37 coaxially disposed with the rod 35 ; and a locking mechanism 40 disposed between the drive gear 36 and the driven gear 37 .

[0042] The driving gear 36 is a spur gear having a plurality of projections 42 formed on an outer peripheral surface 70. The rod 35 passes through the radial center of the driving gear 36. The driving gear 36 is rotationally stopped relative to the rod 35. The projections 42 are arranged at equal intervals in the circumferential direction.

[0043] Here, a stop pin 44 (see FIG. 4 ) is provided at a position overlapping with the drive gear 36 in the axial direction and penetrating the rod 35 in the radial direction. Figure 6 ). The stop pin 44 is supported to be insertable and removable relative to the rod 35. The end surface of the driving gear 36 on one side in the axial direction is formed with a positioning groove 45 that can accommodate the stop pin 44. The width of the positioning groove 45 is slightly larger than the diameter of the stop pin 44. In addition, the length and depth of the positioning groove 45 are respectively larger than the length and diameter of the stop pin 44.

[0044] When the rod 35 rotates while the stop pin 44 is received in the positioning groove 45, the outer peripheral surface of the stop pin 44 contacts the inner wall of the positioning groove 45. Therefore, the relative rotation between the rod 35 and the drive gear 36 is restricted (stopped), and the rod 35 and the drive gear 36 rotate as one. The drive gear 36 and the rod 35 may be bonded by an adhesive or the like, or the stop pin 44 may be pressed into the positioning groove 45 so as to be detachably engaged by the engagement of the positioning groove 45 and the stop pin 44. In addition, the stop pin 44 is provided at each position overlapping with the driven gear 37 of each pulley 28a to 28d.

[0045] like Figure 4 , Figure 5 , Figure 6 As shown, the driven gear 37 has: a take-up portion 38 located at the axial center of the first pulley 28a; an outer flange 39a formed at the end of one axial side (axially outer side) of the take-up portion 38; and an inner flange 39b formed at the end of the other axial side (axially inner side) of the take-up portion 38. The driven gear 37 has an axial hole 46 extending through the axial direction at the radial center.

[0046] The first pulley 28a winds up the first wire rope 29a so as to be wound around the outer peripheral surface of the winding portion 38. The winding portion 38 has a tapered shape in which the outer diameter increases toward one side in the axial direction (outer side in the axial direction).

[0047] A plurality of recesses 43 are formed on the inner circumferential surface of the shaft hole 46 at equal intervals in the circumferential direction. The width of the recess 43 (the distance between the inner wall surfaces of the recess 43 opposite to the circumferential direction) is slightly larger than the width of the protrusion 42 of the drive gear 36. In addition, the depth of the recess 43 (the length in the radial direction) is slightly larger than the height (the length in the radial direction) of the protrusion 42 of the drive gear 36. The protrusions 42 of the drive gear 36 and the recesses 43 of the driven gear 37 constitute the locking mechanism 40 (drive transmission part).

[0048] The locking mechanism 40 restricts the relative rotation of the drive gear 36 and the driven gear 37. Specifically, the protrusions 42 of the drive gear 36 are inserted into the recesses 43 of the driven gear 37, and the drive gear 36 is engaged with the shaft hole 46 of the driven gear 37. When the rod 35 and the drive gear 36 rotate, the protrusions 42 and the recesses 43 are in contact in the circumferential direction, and the relative rotation of the drive gear 36 and the driven gear 37 is restricted (stopped). As a result, the drive gear 36 and the driven gear 37 are engaged and rotated together.

[0049] The relative rotation limit position (engagement position) of the driven gear 37 is determined by the circumferential engagement position of the driven gear 37 and the driving gear 36. That is, the recesses 43 are arranged in parallel in the circumferential direction, and the protrusions 42 are also arranged in parallel in the circumferential direction. By inserting any one of the protrusions 42 into any one of the recesses 43, the limit position of the driven gear 37 relative to the driving gear is changed.

[0050] When changing the limiting position of the driven gear 37, the driven gear 37 is rotated relative to the driving gear 36 while the driving gear 36 is pulled out of the shaft hole 46 (the state where the rotation stop is released). That is, the rotation angle (phase) of the driven gear 37 relative to the driving gear 36 is changed. The rotation angle is an angle with the same interval as the parallel interval of the recessed portion 43. With the rotation angle of the driven gear 37 changed, the driving gear is inserted into the shaft hole 46. In this way, by changing the limiting position (engaging position) of the driven gear 37, the release amount of the first wire rope 29a is changed.

[0051] like Figure 5 , Figure 6 As shown, a locking groove 47 for locking the end of the first wire rope 29a is formed on the inner flange 39b of the first pulley 28a. The locking groove 47 is composed of: a locking hole 48 that is recessed into a square shape from the end surface of the inner flange 39b in the axial direction to the outer side in the axial direction; and a cutout portion 49 that extends radially from the locking hole 48 and reaches the outer peripheral surface of the inner flange 39b. Here, a spherical hook portion 50 is formed at one end of the first wire rope 29a. The width, length and depth of the locking hole 48 are larger than the diameter of the hook portion 50. The hook portion 50 can be accommodated inside the locking hole 48. In addition, the width of the cutout portion 49 is narrower than the diameter of the hook portion 50 and wider than the thickness of the first wire rope 29a. The hook portion 50 is accommodated in the locking hole 48, and the first wire rope 29a is accommodated in the cutout portion 49.

[0052] Since the width of the cutout 49 is narrower than the diameter of the hook 50, even if the first wire rope 29a is pulled in the direction of the end portion opposite to the hook 50, the hook 50 will be hooked on the inner wall of the locking hole 48 and cannot pass through the cutout 49. Therefore, it is possible to prevent one end of the first wire rope 29a from being pulled out of the locking groove 47. The hook 50 can be fixed by being pressed into the locking hole 48. In addition, a structure that is bonded to the locking hole 48 by an adhesive or the like can also be adopted. In addition, the driven gear 37 can also adopt a structure that has a cover body having an end surface that blocks the inner flange 39b, and the cover body retains the hook 50 in the locking hole 48. At this time, the above-mentioned cover body does not overlap with the shaft hole 46.

[0053] return Figure 1 , Figure 2 , Figure 3 As described above, one end of each wire rope 29a to 29d (first wire rope 29a, second wire rope 29b, third wire rope 29c, fourth wire rope 29d) is fixed to each pulley 28a to 28d (first pulley 28a, second pulley 28b, third pulley 28c, fourth pulley 28d). The other end of each wire rope 29a to 29d is fixed to each fixed portion 34a1, 34a2, 34b1, 34b2 of the sheet stacking tray 27. Pulleys 41a to 41f are arranged between one end and the other end of each wire rope 29a to 29d. Each wire rope 29a to 29d is suspended from the sheet stacking tray 27 by means of the pulleys 41a to 41f.

[0054] The pulleys 41a to 41f are rotatably supported above the pulleys 28a to 28d (see Figure 2 The pulleys 41a to 41c are axially arranged on one side (the back side of the main housing 26) of the tray portion 33 of the sheet stacking tray 27, and the pulleys 41d to 41f are axially arranged on the other side (the front side of the main housing 26) of the tray portion 33 of the sheet stacking tray 27.

[0055] The other end of the first wire rope 29a (the end on the opposite side to the end fixed to the first pulley 28a) is fixed to the fixing portion 34a1 (the front upstream fixing portion) located on the back side of the main body housing 26. The other end of the second wire rope 29b (the end on the opposite side to the end fixed to the second pulley 28b) is fixed to the fixing portion 34b1 (the front downstream fixing portion) located on the back side of the main body housing 26. The other end of the first wire rope 29a is fixed to the fixing portion 34a1 closer to the first pulley 28a and the second pulley 28b side (farther from the image forming apparatus 1 side) than the other end of the second wire rope 29b.

[0056] The other end of the third wire rope 29c is fixed to the fixing portion 34a2 (the fixing portion on the upstream side of the rear side) located on the front side of the main body housing 26. The other end of the fourth wire rope 29d is fixed to the fixing portion 34b2 (the fixing portion on the downstream side of the rear side) located on the front side of the main body housing 26. The other end of the third wire rope 29c is fixed to the fixing portion 34a2 closer to the third pulley 28c and the fourth pulley 28d side (farther from the image forming apparatus 1 side) than the other end of the fourth wire rope 29d.

[0057] The first wire rope 29a extends upward from the first pulley 28a and is hung on the pulley 41a, and extends vertically downward from the pulley 41a to hang the sheet stacking tray 27. The second wire rope 29b extends upward from the second pulley 28b and is hung on the pulley 41b, and extends horizontally from the pulley 41b toward the downstream side in the sheet conveying direction and is hung on the pulley 41c located farther from the second pulley 28b than the pulley 41b, and then extends vertically downward from the pulley 41c to hang the sheet stacking tray 27.

[0058] The third wire rope 29c extends upward from the third pulley 28c and is hung on the pulley 41d, and extends vertically downward from the pulley 41d to hang the sheet stacking tray 27. The fourth wire rope 29d extends upward from the fourth pulley 28d and is hung on the pulley 41e, and extends horizontally from the pulley 41e toward the downstream side in the sheet conveying direction and is hung on the pulley 41f located farther from the fourth pulley 28d than the pulley 41e, and then extends vertically downward from the pulley 41f to hang the sheet stacking tray 27.

[0059] Each wire rope 29a to 29d applies a vertical downward load, i.e., a suspension load, to the suspension mechanism 60 by utilizing the weight of the sheet stacking tray 27 and the sheet P. The suspension load becomes a rotational force that causes each pulley 28a to 28d to rotate in the opposite direction via the pulleys 41a to 41f. In addition, when the user presses down the sheet stacking tray 27, the suspension load also includes a downward force.

[0060] return Figure 1 A sheet feeding mechanism 32 for feeding the sheet P to the downstream side in the sheet conveying direction is arranged on the upper part of the main housing 26. The sheet feeding mechanism 32 includes a pickup roller 53, a feed roller pair 54, a conveying roller pair 62, and a sheet discharge port 51. The pickup roller 53 is located above the sheet stacking tray 27. If the sheet stacking tray 27 rises, the pickup roller 53 is in contact with the upper surface of the stacked sheet P. If the pickup roller 53 is in contact with the upper surface of the sheet P and is moved in the supply direction ( Figure 1 If the sheet feeding device rotates in the clockwise direction, the top sheet P of the stack of sheets P is fed.

[0061] The paper feed roller pair 54 is disposed opposite to the downstream side of the pickup roller 53 in the sheet conveying direction. The conveying roller pair 62 is disposed opposite to the downstream side of the paper feed roller pair 54 in the sheet conveying direction. The sheet discharge port 51 is located at the downstream end of the sheet feeding mechanism 32 in the sheet conveying direction, and is opened in the side surface of the main body housing 26. The sheet P supplied to the downstream side by the pickup roller 53 is further conveyed to the downstream side by the paper feed roller pair 54 and the conveying roller pair 62, and is discharged to the outside of the sheet storage device 20 through the sheet discharge port 51. As described above, the merging path 52 of the image forming apparatus 1 is connected to the sheet discharge port 51. Therefore, the sheet P discharged from the sheet discharge port 51 is fed into the sheet feeding path 10 through the merging path 52, and is conveyed toward the image forming unit 4 in the image forming apparatus 1, and image formation is performed as described above.

[0062] Next, adjustment of the pay-out amount of each of the wire ropes 29a to 29d will be described. Figure 7 It is a side view of the suspension mechanism 60 for suspending the sheet stacking tray 27 in a tilted state. Figure 8 It means to make Figure 7 The illustrated side view is of the suspension mechanism 60 in a state where the driven gear 37 is rotated in the forward direction by a predetermined rotation angle to shorten the pay-out amount of the first wire rope 29a.

[0063] like Figure 7 As shown, when the amount of the first wire rope 29a released from the first pulley 28a is greater than the amount of the other wire ropes 29b to 29d (the second wire rope 29b, the third wire rope 29c, and the fourth wire rope 29d) released from the other pulleys 28b to 29d (the second pulley 28b, the third pulley 28c, and the fourth pulley 28d) due to deformation of the sheet stacking tray 27, the sheet stacking tray 27 tilts. In this case, the drive gear 36 is pulled out from the shaft hole 46 of the driven gear 37 to release the restriction on the relative rotation of the drive gear 36 and the driven gear 37, and the driven gear 37 is rotated in the forward direction (the winding direction of the wire rope) by a predetermined angle. Then, each protrusion 42 is inserted into each recess 43, so that the drive gear 36 is engaged with the shaft hole 46 of the driven gear 37, and the relative rotation of the drive gear 36 and the driven gear 37 is restricted by the locking mechanism 40. As a result, Figure 8 As shown, the amount of the first wire 29a released is reduced, and the inclination of the sheet stacking tray 27 is eliminated.

[0064] On the contrary, when the amount of the first wire rope 29a released from the first pulley 28a is less than the amount of the other wire ropes 29b to 29d released from the other pulleys 28b to 28d, the restriction on the relative rotation of the drive gear 36 and the driven gear 37 is temporarily released in the same manner as described above, and the driven gear 37 is rotated in the reverse direction (wire release direction) by a predetermined angle, and the relative rotation of the drive gear 36 and the driven gear 37 is restricted by the locking mechanism 40. As a result, the amount of the first wire rope 29a released increases, and the inclination of the sheet stacking tray 27 can be eliminated.

[0065] As described above, the relative rotation of the driven gear 37 with respect to the driving gear 36 in the embodiment is restricted to a predetermined restriction position selected from a plurality of restriction positions. That is, by setting the restriction position of the driven gear 37 of each pulley 28a to 28d to a different position, the release amount of each wire rope 29a to 29d can be adjusted.

[0066] As described above, one end of the wire ropes 29a to 29d is fixed to the driven gear 37, and the release amount of the wire ropes 29a to 29d changes according to the rotation angle of the pulleys 28a to 28d, that is, the driven gear 37. Since a plurality of limiting positions are arranged in the circumferential direction, if the limiting position of the driven gear 37 is changed, the rotation angle of the driven gear 37 also changes. Therefore, by changing the limiting position of the driven gear 37 of each pulley 28a to 28d, the rotation angle of the driven gear 37 of each pulley 28a to 28d can be set to different states. Thus, the release amount of each wire rope 29a to 29d can be adjusted. Even if the sheet stacking tray 27 is tilted as described above, the sheet stacking tray 27 can be made horizontal by adjusting the release amount of each wire rope 29a to 29d. Therefore, a sheet storage device 20 that can suppress poor sheet supply can be provided.

[0067] Furthermore, as described above, the winding portion 38 has a tapered shape in which the outer diameter increases toward one side in the axial direction (outer side in the axial direction). Therefore, when each wire rope 29a to 29d is wound by the winding portion 38 of each pulley 28a to 28d, each wire rope 29a to 29d is wound sequentially from the outer end of the winding portion 38 in the axial direction. Therefore, the wire rope 29a to 29d is smoothly wound from the outer end to the inner end of the winding portion 38 in the axial direction, and is not easily entangled.

[0068] In addition, the present invention is not limited to the above-mentioned embodiment, and various changes can be made within the scope of the present invention. For example, although a plurality of protrusions 42 are formed on the outer peripheral surface 70 of the driving gear 36, it is not limited to this, and a structure in which at least one protrusion 42 is formed on the outer peripheral surface 70 of the driving gear 36 and the number thereof is less than the number of recesses 43 can be adopted.

[0069] The present invention can be applied to a large-capacity sheet storage device capable of storing sheets to be supplied to an image forming apparatus. By utilizing the present invention, it is possible to suppress sheet supply failure from the sheet storage device to the image forming apparatus.

Claims

1. A sheet storage device, comprising: Main body shell; A sheet stacking tray is supported to be able to rise and fall in the main housing and is used to stack sheets; A rod extending in a direction perpendicular to the lifting direction and supported to be rotatable in both forward and reverse directions; The suspension mechanism comprises: a plurality of take-up pulleys mounted on both ends of the rod; and a plurality of wire ropes, one end of which is fixed to the plurality of winding pulleys respectively, and the other end of which is fixed to the sheet stacking tray and suspends the sheet stacking tray; and A drive device causes the rod to rotate, The sheet storage device is characterized in that: The sheet storage device further includes a drive transmission unit, the drive transmission unit comprising: a plurality of drive gears fixed to the rod at positions corresponding to the plurality of winding pulleys and rotating integrally with the rod; and a plurality of driven gears respectively formed on the plurality of winding pulleys and capable of engaging with the corresponding plurality of drive gears. The drive transmission unit transmits the rotation of the rod toward the plurality of take-up pulleys by engaging the plurality of drive gears with the plurality of driven gears. The plurality of take-up pulleys have fixing portions for fixing the ends of the plurality of wire ropes, and can change the engagement positions of the plurality of driven gears relative to the plurality of driving gears in the circumferential direction of the rod. The drive transmission part can adjust the release amount of each of the plurality of wire ropes by changing the relative position of the rotation direction of the fixing part of each of the plurality of winding pulleys by individually changing the engagement position of each of the plurality of driven gears. The plurality of driving gears are respectively arranged one at each end of the rod, The plurality of take-up pulleys are arranged two adjacent to each end of the rod, The plurality of driving gears are spur gears, and teeth are formed on the outer peripheral surface of a cylindrical portion extending along the axial direction of the rod. The plurality of driven gears are internal gears, and teeth are formed on the inner peripheral surface of a shaft hole, and the shaft hole is recessed along the axial direction from the ends of the plurality of take-up pulleys in the axial direction. At each end of the rod, teeth formed on the outer peripheral surface of the cylindrical portion are engaged with teeth formed on the inner peripheral surface of the shaft hole, so that the internal gear of each of the take-up pulleys is engaged with the spur gear.

2. The sheet storage device according to claim 1, wherein: The plurality of wire ropes include four wire ropes, The plurality of take-up pulleys include four take-up pulleys for fixing the four wire ropes respectively. The four take-up pulleys are composed of two front pulleys arranged adjacent to the front end of the rod in the axial direction and two rear pulleys arranged adjacent to the rear end of the rod in the axial direction. The sheet stacking tray has: a pair of upstream fixing portions located at the front end and the rear end in the axial direction of the side end portions on the upstream side of the sheet stacking tray in the sheet conveying direction; and a pair of downstream fixing portions, at the front end and the rear end in the axial direction of the side end portions located on the downstream side of the sheet stacking tray in the sheet conveying direction, The four wire ropes include: A first wire rope, one end of which is fixed to one of the two front pulleys, and the other end of which is fixed to the upstream fixing portion of the front side; A second wire rope, one end of which is fixed to the other of the two front pulleys, and the other end of which is fixed to the downstream fixing portion of the front side; a third wire rope, one end of which is fixed to one of the two rear pulleys, and the other end of which is fixed to the upstream fixing portion on the rear side; and A fourth wire rope has one end fixed to the other of the two rear pulleys, and the other end fixed to the downstream fixing portion on the rear side.

3. The sheet storage device according to claim 1, wherein: Each of the plurality of winding pulleys includes a cylindrical winding portion on an outer circumferential surface for winding up the plurality of wire ropes. The outer peripheral surface of the winding portion has a tapered shape in which the outer diameter of the winding portion increases toward the outer side in the axial direction of the rod.

4. The sheet storage device according to claim 3, wherein: The plurality of take-up pulleys each have a flange formed on the take-up portion, The fixing portion is formed by cutting away a portion of the flange.

5. The sheet storage device according to claim 4, wherein: Each of the plurality of wire ropes has a spherical hook portion at the end. The fixing portion comprises: a locking groove through which the plurality of wire ropes can pass respectively; and a locking hole formed at an end of the locking groove for the hook portion to be locked.

6. An image forming system, characterized in that: include: An image forming device including an image forming unit that forms an image on a sheet; as well as The sheet storage device according to any one of claims 1 to 5 is connected to the image forming device and includes a sheet feeding mechanism for feeding the sheets to the image forming section.

Images