JP2022138854A - Sheet storage device, and image forming device with the sheet storage device - Google Patents

Abstract

To provide a sheet storage device capable of suppressing deflection of a pulley and suppressing defective feeding.SOLUTION: A sheet storage device includes a body housing, a sheet placement tray, a shaft, a plurality of pulleys, a plurality of wires, a driving device, a regulation part and an urging member. The sheet placement tray is supported in the body housing so as to be able to move up and down, and the sheets are placed thereon. The shaft is supported by the body housing so as to be rotatable in both forward and reverse directions. The pulley is externally fitted on both ends of a rotary axis of the shaft and attached with play in a direction of the rotary axis. The wire has one end fixed to the pulley and the other end fixed to the sheet placement tray to suspend the sheet placement tray. A driving device rotates the shaft. The regulation part regulates the movement of the pulley in an axial direction. The urging member urges each pulley toward the regulation part.SELECTED DRAWING: Figure 3

Description

The present invention relates to a sheet storage device and an image forming system provided with the sheet storage device.

For image forming devices such as copiers, printers, and facsimiles, when a single image forming device is shared by many users, the number of sheets per image forming device (recording media including printing paper and envelopes) ) consumption increases. Generally, the number of sheets that can be accommodated inside the main body of the image forming apparatus is about several hundred, so it is necessary to replenish the sheets frequently. Therefore, in Patent Document 1, a large-capacity sheet storage device capable of storing thousands of sheets is attached to the side of the image forming apparatus, and the sheet is fed from the sheet storage device to the image forming apparatus. A forming system is disclosed.

The sheet storage device disclosed in Patent Document 1 includes a sheet stacking tray on which sheets are stacked, a suspension mechanism for suspending the sheet stacking tray, and a rotational driving force applied to the suspension mechanism to raise and lower the sheet stacking tray. and a driving device. The suspension mechanism includes a shaft supported to be rotatable in both forward and reverse directions, a plurality of pulleys attached to both ends of the shaft in the rotation axis direction, one end fixed to the pulley, and the other end fixed to the sheet stacking tray. 4 wires;

The driving device is connected to the shaft and applies a rotational driving force to the shaft to rotate it. The pulley is fixed against the shaft and rotates together with the shaft. The driving device rotates the shaft and the pulley to wind the wire around the pulley and let it out from the pulley, thereby raising and lowering the sheet stacking tray.

A sheet feeding unit that feeds sheets from the sheet storage device to the image forming apparatus is arranged above the sheet stacking tray. The sheet feeding section feeds the contacting sheets to the image forming apparatus in a state in which the sheet stacking tray is lifted and the upper surface of the sheet stack stacked on the sheet stacking tray is in contact with the sheet feeding section. send.

The pulley of such a sheet storage device is fitted around the shaft, and is positioned so as to be restrained from moving in the axial direction with respect to the shaft. For positioning, for example, a positioning member such as a parallel pin that is insertably provided so as to pass through the shaft is used. The positioning member is inserted into the shaft member so as to face the side surface of the pulley in the axial direction. When the shaft moves in the axial direction, it contacts the positioning member and is restricted from moving in the axial direction.

Japanese Patent Application Laid-Open No. 2020-33161

By the way, each pulley is attached to the shaft in a state in which there is leeway (play) in the axial direction (a state in which there is a gap between the pulley and the positioning member) in consideration of ease of assembly. Therefore, during operation of the sheet storage device, each pulley may move in the axial direction due to, for example, vibration caused by the operation of the driving device or the sheet feeding section. When the pulley moves in the axial direction, the wire winding position relative to the pulley deviates in the axial direction. When the pulley rotates in the direction of winding the wire in this state, the wire is wound on the pulley so as to ride on the wire already wound on the pulley, and is wound on the pulley in a multi-layered state. end up As a result, the wire becomes entangled during feeding or winding, preventing the sheet stacking tray from moving up and down, or causing the sheet stacking tray to tilt due to a change in the amount of wire fed from the pulley, causing the sheets to be fed normally. There is a possibility that the paper may not be fed, that is, a so-called feeding failure may occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet storage device capable of suppressing deviation of a wire winding position due to axial movement of a pulley and suppressing feeding failure.

In order to achieve the above object, the configuration of the present invention includes a main body housing, a sheet stacking tray, a shaft, a plurality of pulleys, a plurality of wires, a driving device, a restricting section, and an urging member. It is a sheet storage device provided. The sheet stacking tray is supported in the main body housing so as to be able to move up and down, and the sheets are stacked thereon. The shaft is supported by the body housing so as to be rotatable in both forward and reverse directions. The pulleys are externally fitted on both ends of the rotation axis of the shaft and attached with play in the direction of the rotation axis. The wire has one end fixed to the pulley and the other end fixed to the sheet stacking tray to suspend the sheet stacking tray. A drive rotates the shaft. The restrictor restricts axial movement of the pulley. The biasing member biases each pulley toward the restricting portion.

According to the configuration of the present invention, the pulley is biased toward the restricting portion by the biasing member and comes into contact with the restricting portion in the axial direction. Axial movement of the pulley is restricted by the biasing force of the biasing member. Therefore, the winding position of the wire with respect to the pulley is less likely to fluctuate in the axial direction, and it is possible to suppress the wire from being wound on the pulley so as to ride on the wire already wound on the pulley. This makes it easier for the wire to be wound smoothly in the axial direction, making it less likely that the wire will get tangled or that the wire feed amount will change. Therefore, it is possible to provide a sheet storage device capable of suppressing sheet feeding failure.

1 is a schematic sectional view showing a schematic configuration 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; FIG. FIG. 2 is a perspective view showing the internal configuration of the body housing 26 of the sheet storage device 20; FIG. 3 is a front view showing the sheet stacking tray 27 shown in FIG. 2 from above; A perspective view showing the periphery of the rear-side pulley 72. A plan view showing the periphery of one end of the shaft 35 (back side of the body housing 26). Cross-sectional view showing the periphery of the restricting portion 64a FIG. 4 is a cross-sectional view showing another example of the restricting portion 64 of the sheet storage device 20 according to the present invention; FIG. 4 is a cross-sectional view showing another example of the restricting portion 64 of the sheet storage device 20 according to the present invention;

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 below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing a schematic configuration of an image forming system 100 including a sheet storage device 20 and an image forming apparatus 1 according to an embodiment of the invention. The image forming apparatus 1 includes a paper feeding section 2 arranged below, a sheet conveying section 3 arranged on the side of the paper feeding section 2, and an image forming section arranged above the sheet conveying section 3. 4 , a fixing device 5 arranged on the discharge side of the image forming section 4 , and an image reading section 6 arranged above the image forming section 4 and the fixing device 5 .

The paper feed unit 2 includes a plurality of paper feed cassettes 7 that accommodate sheets P, which are plain paper. Then, the sheets P are surely sent to the sheet conveying part 3 one by one.

A sheet P such as an OHP sheet or an envelope, or a sheet P such as an OHP sheet or an envelope, is placed on the manual feed tray 25 . send to

The sheet P sent to the sheet conveying portion 3 is conveyed toward the image forming portion 4 via the sheet feeding path 10 . The sheet feeding path 10 extends upward from each sheet feeding cassette 7 and merges with a merging path 52 connected to a sheet discharge port 51 of the sheet storage device 20 (to be described later) at an intermediate position.

The image forming unit 4 forms a toner image on the sheet P by an electrophotographic process. A charging section 12, an exposure section 13, a developing device 14, a transfer section 15, a cleaning section 16, and a static elimination section 17 are provided along the rotation direction.

The charging unit 12 has a charging wire to which a high voltage is applied. When a predetermined potential is applied to the surface of the photoreceptor 11 by corona discharge from the charging wire, the surface of the photoreceptor 11 is uniformly charged. When light based on the image data of the document read by the image reading unit 6 is applied to the photoreceptor 11 by the exposure unit 13, the surface potential of the photoreceptor 11 is selectively attenuated, and the surface potential of the photoreceptor 11 is reduced. An electrostatic latent image is formed.

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 . This toner image is transferred by the transfer section 15 onto the sheet P supplied between the photosensitive member 11 and the transfer section 15 .

The sheet P onto which the toner image has been transferred is conveyed toward the fixing device 5 arranged downstream 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 fused and fixed on the sheet P. As shown in FIG. Next, the sheet P on which the toner image is fixed is discharged onto the discharge tray 21 by the discharge roller pair 22 .

After transfer by transfer unit 15 , toner remaining on the surface of photoreceptor 11 is removed by cleaning unit 16 , and residual charges on the surface of photoreceptor 11 are removed by charge removal unit 17 . Then, the photosensitive member 11 is charged again by the charging section 12, and image formation is performed in the same manner.

Adjacent to the side of the image forming apparatus 1 is a large-capacity sheet storage device 20 capable of storing several thousand sheets P. As shown in FIG. The sheet storage device 20 includes a sheet stacking tray 27, a suspension mechanism 60, wires 29a to 29d, a driving device 30, and a sheet feeding mechanism 32 inside a body housing 26 forming a housing of the sheet storage device 20. and are stored. The body housing 26 is formed in a substantially rectangular parallelepiped shape, and a plurality of casters 24 are attached to the bottom surface of the body housing 26 so that the sheet storage device 20 can be easily moved.

FIG. 2 is a perspective view showing the configuration inside the body housing 26 of the sheet storage device 20. As shown in FIG. FIG. 3 is a front view showing the sheet stacking tray 27 shown in FIG. 2 from above. 2 is the front side (the front side of the image forming apparatus 1) in the paper surface direction shown in FIG. The left front side of the body housing 26 shown in FIG. 2 is the rear side (the front side of the image forming apparatus 1) in the direction of the paper in FIG. The width direction of the sheets P stored in the sheet storage device 20 is the same direction as the direction from the front to the back of the body housing 26 (horizontal direction shown in FIG. 3).

As shown in FIGS. 2 and 3, the sheet stacking tray 27 includes a tray portion 33, which is a rectangular plate-like body extending parallel to the horizontal plane, and four corners of the tray portion 33 extending in the width direction (the width direction of the sheets P). and a fixing portion 34 that protrudes outward, and is supported in the body housing 26 so as to be able to move up and down along the vertical direction (direction of arrow Y shown in FIG. 2). The sheets P are stacked in the center of the tray portion 33 (the position indicated by the dashed line in FIG. 3).

The suspension mechanism 60 suspends the sheet stacking tray 27 from the main body via a plurality of (here, four) wires 29a to 29d (a first wire 29a, a second wire 29b, a third wire 29c, and a fourth wire 29d). It is suspended inside the housing 26 so as to be able to move up and down. The suspension mechanism 60 includes a shaft 35, a plurality of pulleys 72 and 73 (back side pulley 72 and front side pulley 73), an urging member 63, and pulleys 41a to 41f.

The shaft 35 extends in a horizontal direction (the width direction of the sheets P) perpendicular to the vertical direction of the sheet stacking tray 27 . The shaft 35 is supported inside the body housing 26 so as to be rotatable in forward and reverse directions (both clockwise and counterclockwise directions about the central axis of the shaft 35). A rear-side pulley 72 is externally fitted to the end of the shaft 35 on one side (the rear side of the main body housing 26) with respect to the direction along the rotation axis of the shaft 35 (hereinafter referred to as the “axial direction”). is installed. A front side pulley 73 is externally inserted and attached to the end portion of the shaft 35 on the other side in the axial direction (the side opposite to the one side (the front side of the main body housing 26)). The rear-side pulley 72 and the front-side pulley 73 are axially slidable relative to the shaft. The rear-side pulley 72 and the front-side pulley 73 are connected to the shaft 35 by a connecting mechanism 71, which will be described later, with an axially movable gap (play) interposed therebetween.

The rear side pulley 72 is positioned on the rear side of the image forming apparatus 1, and the front side pulley 73 is positioned on the front side of the image forming apparatus 1 (see FIG. 2). As shown in FIG. 3, the rear side pulley 72 is composed of a first pulley 28a and a second pulley 28b that are axially adjacent to each other. The front side pulley 73 is composed of a third pulley 28c and a fourth pulley 28d that are axially adjacent to each other. The first pulley 28a is located axially outside the second pulley 28b. The third pulley 28c is located axially outside the fourth pulley 28d. The first pulley 28a is axially bonded to the second pulley 28b so that they rotate integrally with each other. Similarly, the third pulley 28c and the fourth pulley 28d are axially bonded together and rotate integrally with each other.

One end of a first wire 29a is fixed to the first pulley 28a. One end of a second wire 29b is fixed to the second pulley 28b. One end of a third wire 29c is fixed to the third pulley 28c. One end of a fourth wire 29d is fixed to the fourth pulley 28d. By rotating each pulley 28a-28d in the forward direction, each wire 29a-29d fixed to each pulley is wound. Conversely, by rotating the pulleys 28a-28d in the opposite direction, the wires 29a-29d fixed to the pulleys 28a-28d are let out.

FIG. 4 is a perspective view showing the periphery of the rear-side pulley 72. As shown in FIG. FIG. 5 is a plan view showing the periphery of one end of the shaft 35 (back side of the main body housing 26). FIG. 6 is a sectional view showing the periphery of the key 64. As shown in FIG. Since the rear pulley 72 and the front pulley 73 have the same shape and the same configuration, only the rear pulley 72 will be described in detail here, and the front pulley 73 will be given the same reference numerals and will not be described. do.

As shown in FIGS. 4, 5, and 6, the rear pulley 72 includes an outer flange 39a formed on the axially outer end surface of the first pulley 28a and an axially inner end surface of the second pulley 28b. and an intermediate flange 39c formed in the center of the rear side pulley 72 in the axial direction. The outer flange 39a, the inner flange 39b, and the intermediate flange 39c are flanges extending along the radial direction.

A first winding portion 38a and a second winding portion 38b, which are axially adjacent to each other, are formed on the outer peripheral surface of the rear side pulley 72. As shown in FIG. The first winding portion 38a is axially positioned between the outer flange 39a and the intermediate flange 39c. The second winding portion 38b is axially positioned between the intermediate flange 39c and the inner flange 39b. The outer diameters of the first winding portion 38a and the second winding portion 38b form a tapered shape that increases toward one side in the axial direction (outward in the axial direction) (see FIG. 5).

As shown in FIG. 4, the intermediate flange 39c of the rear side pulley 72 is formed with a locking groove 47 for locking the end of the first wire 29a. The locking groove 47 has a rectangular locking hole 48 recessed axially outward from the axially inner end surface of the intermediate flange 39c, and a cut extending radially from the locking hole 48 to reach the outer peripheral surface of the inner flange 39b. The cutout portion 49 is included. Here, a spherical hook portion 50 is formed at one end of the first wire 29a. The width, length, and depth of locking hole 48 are greater than the diameter of hook 50 . A hook portion 50 can be accommodated inside the locking hole 48 . Moreover, the width of the notch portion 49 is narrower than the diameter of the hook portion 50 and wider than the thickness of the first wire 29a. The hook portion 50 is accommodated in the locking hole 48 and the first wire 29a is accommodated in the notch portion 49 .

Since the width of the notch portion 49 is narrower than the diameter of the hook portion 50, even if the first wire 29a is pulled toward the end opposite to the hook portion 50, the hook portion 50 is locked. It catches on the inner wall of the hole 48 and cannot pass through the notch 49. - 特許庁Therefore, it is possible to prevent the one end of the first wire 29 a from slipping out of the locking groove 47 . Similarly, an engaging groove 47 is also formed in the inner flange 39b, and this engaging groove 47 engages the end of the second wire 29b.

The back-side pulley 72 winds the wires 29a and 29b by winding the first wire 29a around the outer peripheral surface of the first winding portion 38a and the second wire 29b around the outer peripheral surface of the second winding portion 38b. take. The first wire 29a and the second wire 29b are wound around the rear pulley 72 when the rear pulley 72 rotates in the forward direction, and are let out from the rear pulley 72 when the rear pulley 72 rotates in the reverse direction.

The hook portion 50 can employ a configuration in which it is press-fitted into the locking hole 48 and fixed. Also, it is possible to employ a configuration in which the locking hole 48 is adhered with an adhesive or the like. In addition, the rear side pulley 72 is provided with a plurality of lid bodies that close the end face of the inner flange 39b and the end face of the intermediate flange 39c. can also

As shown in FIGS. 4, 5 and 6, a key 64 is provided on the shaft 35 outside the rear pulley 72 in the axial direction. A shaft-side keyway 65 is formed that is recessed radially inward from the outer peripheral surface of the shaft 35 . The key 64 is a key body inserted into the shaft-side key groove 65 with an interference. The key 64 has a restricting portion 64a formed on the inner side surface in the axial direction. A portion of the outer peripheral surface of the shaft 35 that overlaps the shaft-side keyway 65 may be formed with a so-called D-cut surface that is parallel to the axial direction.

A shaft hole 66 axially penetrating the rear side pulley 72 and a pulley side key groove 67 radially recessed from the shaft hole 66 are formed in the radial center of the rear side pulley 72 . The pulley-side key groove 67 is a groove formed so as to accommodate the key 64 . The pulley-side key groove 67 opens in the axially outer end surface of the first pulley 28a (the side surface of the rear-side pulley 72) and extends axially inward. The width of the pulley-side keyway 67 (the distance between inner wall surfaces opposed in the circumferential direction) is slightly larger than the width of the key 64 (the length along the circumferential direction). The depth (the length in the radial direction) of the pulley-side key groove 67 is slightly larger than the projection amount of the key 64 (the distance from the outer peripheral surface of the shaft 35 to the end of the key 64 in the projection direction).

A support wall portion 69 (opposing portion) is provided in a portion of the shaft 35 that is located inside the rear side pulley 72 in the axial direction. The support wall portion 69 has a flange shape extending radially from the outer peripheral surface of the shaft 35 and rotates integrally with the shaft 35 . The support wall portion 69 can employ a configuration comprising a groove (not shown) formed in the outer peripheral surface of the shaft 35 and a retaining ring such as a C-ring or E-ring fitted in the groove. A biasing member 63 is arranged between the rear side pulley 72 and the support wall portion 69 in the axial direction. The biasing member 63 is a coil spring externally fitted on the shaft 35, and has both ends in contact with the back side pulley 72 (second pulley 28b) and the support wall portion 69, and the back side pulley 72 (second pulley 28b). , and the first pulley 28a) axially outwardly.

Here, the connecting mechanism 71 is composed of a shaft-side key groove 65 , a pulley-side key groove 67 and a key 64 . As described above, the rear-side pulley 72 is attached to the shaft 35 by the connecting mechanism 71 with play in the axial direction (a gap allowing axial movement). Specifically, the pulley-side key groove 67 and the key 64 inserted into the shaft-side key groove 65 overlap with each other in the circumferential direction of the shaft 35 , and the key 64 is inserted into the shaft-side key groove 65 . It is fitted in the pulley side key groove 67 with a gap therebetween.

The biasing member 63 biases the first pulley 28a together with the second pulley 28b axially outward (biases the rear side pulley 72 axially outward, that is, toward the key 64). As a result, the restricting portion 64a of the key 64 comes into axial contact with the inner wall surface 67a of the pulley-side key groove 67, and the axial movement of the rear-side pulley 72 is restricted. Further, when the shaft 35 rotates around the rotation axis, the circumferential side surface of the key 64 comes into contact with the inner wall surface of the pulley-side key groove 67 in the circumferential direction. As a result, the circumferential movement of the shaft 35 and the back side pulley 72 is restricted (rotated). Therefore, the rear side pulley 72 rotates integrally with the shaft 35 .

Returning to FIGS. 1, 2, and 3, the driving device 30 is connected to one end of the shaft 35 in the axial direction. The driving device 30 is positioned axially outside the rear pulley 72 of the shaft 35 . The drive device 30 includes a drive unit M such as a motor capable of imparting rotational driving force, and a drive input gear 31 connected to the drive unit M and the shaft 35 . The drive input gear 31 is composed of a plurality of gears and is connected to the shaft 35 via a coupling member (not shown). The driving input gear 31 transmits the rotational driving force of the driving portion M to the shaft 35 . The driving device 30 generates forward or reverse rotational driving force by the driving portion M, and rotates the shaft 35 forward or reverse through the drive input gear 31 .

As described above, one ends of the first wire 29a and the second wire 29b are fixed to the rear side pulley 72 . One ends of the third wire 29 c and the fourth wire 29 d are fixed to the front pulley 73 .

The other ends of the wires 29 a to 29 d are fixed to the fixed portions 34 of the sheet stacking tray 27 . Specifically, the other end of the first wire 29a (the end opposite to the end fixed to the rear pulley 72) and the other end of the second wire 29b (the end fixed to the rear pulley 72) ) is fixed to a fixing portion 34 located on the rear side of the body housing 26 . The other end of the first wire 29a is fixed to the fixing portion 34 closer to the rear pulley 72 (farther from the image forming apparatus 1) than the other end of the second wire 29b.

The other end of the third wire 29c (the end opposite to the end fixed to the front pulley 73) and the other end of the fourth wire 29d (the end opposite to the end fixed to the front pulley 73) end) is fixed to a fixing portion 34 located on the front side of the main body housing 26 . The other end of the third wire 29c is fixed to the fixing portion 34 closer to the front pulley 73 (farther from the image forming apparatus 1) than the other end of the fourth wire 29d.

Pulleys 41a-41f are arranged between one end and the other end of each wire 29a-29d. Each wire 29a-29d suspends the sheet stacking tray 27 via pulleys 41a-41f.

The pulleys 41a to 41f are rotatably positioned above the rear-side pulley 72 and the front-side pulley 73 (see FIG. 2). The pulleys 41a to 41c are arranged on one side (back side of the main body housing 26) of the tray portion 33 of the sheet stacking tray 27 in the axial direction. is arranged on the other side (the front side of the main body housing 26) from the tray portion 33 of the main body.

The first wire 29a extends upward from the rear-side pulley 72, is hooked on the pulley 41a, and extends vertically downward from the pulley 41a to suspend the sheet stacking tray 27. As shown in FIG. The second wire 29b extends upward from the back side pulley 72, is hooked on the pulley 41b, extends horizontally from the pulley 41b toward the upstream side in the sheet conveying direction, and extends farther from the back side pulley 72 than the pulley 41b. It is hooked by the pulley 41c on the far side, extends vertically downward from the pulley 41c, and suspends the sheet stacking tray 27. - 特許庁

The third wire 29c extends upward from the front pulley 73, is hooked on the pulley 41d, and extends vertically downward from the pulley 41d to suspend the sheet stacking tray 27. As shown in FIG. The fourth wire 29d extends upward from the front pulley 73, is hooked on the pulley 41e, extends horizontally from the pulley 41e toward the upstream side in the sheet conveying direction, and extends farther from the front pulley 73 than the pulley 41e. It is hooked by the pulley 41f on the far side, extends vertically downward from the pulley 41f, and suspends the sheet stacking tray 27. - 特許庁

The driving device 30 rotates the shaft 35 in the forward direction, so that the rear-side pulley 72 and the front-side pulley 73 rotate in the forward direction. Then, the wires 29a to 29d are wound around the rear side pulley 72 and the front side pulley 73, and the sheet stacking tray 27 is lifted. Conversely, the driving device 30 rotates the shaft 35 in the opposite direction, so that the rear pulley 72 and the front pulley 73 rotate in the opposite direction. Then, the wires 29a to 29d are let out from the rear side pulley 72 and the front side pulley 73, and the sheet stacking tray 27 is lowered.

Returning to FIG. 1, a sheet feeding mechanism 32 that feeds the sheet P to the downstream side in the sheet conveying direction is arranged above the main body housing 26 . The sheet feeding mechanism 32 includes a pickup roller 53 , a sheet feeding roller pair 54 , a conveying roller pair 62 and a sheet discharge port 51 . The pickup roller 53 is positioned above the sheet stacking tray 27, and is in a position to contact the upper surface of the stacked sheets P when the sheet stacking tray 27 is raised. When the pickup roller 53 rotates in the feeding direction (clockwise direction in FIG. 1) while being in contact with the upper surface of the sheet P, one sheet P positioned on the uppermost surface of the bundle of sheets P is fed.

The paper feed roller pair 54 is arranged downstream of the pickup roller 53 in the sheet conveying direction. The transport roller pair 62 is arranged downstream of the paper feed roller pair 54 in the sheet transport direction. The sheet discharge port 51 is located at the downstream end of the sheet feeding mechanism 32 with respect to the sheet conveying direction, and opens on the side surface of the main body housing 26 . The sheet P fed downstream by the pickup roller 53 is further transported downstream by the paper feed roller pair 54 and the transport roller pair 62, and is discharged outside the sheet storage device 20 through the sheet discharge port 51. be done. As described above, the confluence 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 conveyed into the sheet feeding path 10 through the confluence path 52, is conveyed to the image forming section 4 in the image forming apparatus 1, and is imaged as described above. formation takes place.

According to the configuration of the sheet storage device 20 according to the embodiment, the rear side pulley 72 and the front side pulley 73 abut against the restricting portion 64 a of the key 64 in the axial direction, and are pushed toward the key 64 by the biasing member 63 . energized. The back side pulley 72 and the front side pulley 73 are restrained from moving in the axial direction by the biasing force of the biasing member 63 . Therefore, the winding positions of the wires 29a to 29d with respect to the back side pulley 72 and the front side pulley 73 are less likely to fluctuate in the axial direction, and the wires 29a to 29d are already wound on the back side pulley 72 and the front side pulley 73. It is possible to prevent the wires 29a to 29d from being wound up by the rear-side pulley 72 and the front-side pulley 73. As a result, the wires 29a to 29d are easily wound smoothly in the axial direction, and the wires 29a to 29d are less likely to get tangled and the amount of the wires 29a to 29d fed out is less likely to change. Therefore, it is possible to provide the sheet storage device 20 capable of suppressing sheet feeding failure.

Further, as described above, the outer diameters of the first winding portion 38a and the second winding portion 38b form a tapered shape that increases toward one side in the axial direction (outward in the axial direction). Therefore, when the wires 29a to 29d are wound around the first winding portion 38a and the second winding portion 38b of the rear side pulley 72 and the front side pulley 73, the wires 29a to 29d are axially wound. It is sequentially wound from the inner end of the winding portion 38 . Therefore, the wires 29a to 29d are wound more smoothly from the inner end to the outer end of the winding portion 38 in the axial direction, and are less likely to get entangled.

In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. For example, the pulley-side key grooves 67 are formed in the rear-side pulley 72 and the front-side pulley 73, and the key 64 is fitted into the pulley-side key grooves 67, but the configuration is not limited to this. For example, as shown in FIG. 7, it is possible to employ a configuration in which the pulley-side keyway 67 is not formed and an annular restricting member 74 is fixed to the shaft 35 instead of the key 64 . The restricting member 74 is an annular retaining ring similar to the C-ring and the E-ring, and is fixed to the shaft 35 by being fitted into a groove (not shown) formed on the outer peripheral surface of the shaft 35 . In this case, the inner end surface of the restricting member 74 in the axial direction serves as the restricting portion 64a. The restricting portion 64 a faces the axially outer end face of the rear-side pulley 72 . When the back side pulley 72 is biased by the biasing member 63, the restricting portion 64a and the axially outer end face of the back side pulley 72 come into contact with each other, and the axial movement of the back side pulley 72 is restricted.

Further, in place of the restricting member 74, an inner wall formed at a predetermined portion of the body housing 26 may be used to restrict the axial movement of the rear-side pulley 72 and the front-side pulley 73 (shown in the figure). omit). The inner wall is formed in a rib-like shape extending from a predetermined position inside the body housing 26 toward the shaft 35 . The inner walls are provided on the axially outer side of the rear side pulley 72 and the axially outer side of the front side pulley 73, and face the axially outer end faces of the rear side pulley 72 and the front side pulley 73, respectively.

Further, although the support wall portion 69 is provided on the shaft 35, for example, instead of the support wall portion 69, as shown in FIG. A configuration with rib-shaped sidewalls 70 may be employed. The side wall 70 is a rib-shaped wall formed so as to bridge between the inner wall surfaces (not shown) of the main body housing 26 . The side walls 70 are provided axially inside the rear side pulley 72 (see FIG. 8) and axially inside the front side pulley 73 (not shown). Each side wall 70 axially faces the inner end faces of the rear pulley 72 and the front pulley 73 . In this case, the side wall 70 is separated from the shaft 35, and even if the shaft 35 is displaced in the axial direction due to vibration or the like, the side wall 70 is fixed to the main body housing 26. Therefore, the biasing member 63 contacting the side wall 70 is fixed to the body housing 26. Also, the rear-side pulley 72 and the front-side pulley 73 become more difficult to move in the axial direction. Also, the shaft 35 may be rotatably supported by the side wall 70 via a bearing or the like.

In addition, the first pulley 28a and the second pulley 28b, and the third pulley 28c and the fourth pulley 28d are not adhered to each other, and are individually prevented from rotating with respect to the shaft 35 so as to be integrally rotatable with the shaft 35. configuration may be employed.

INDUSTRIAL APPLICABILITY The present invention can be used for a large-capacity sheet storage device capable of storing sheets to be supplied to an image forming apparatus. By using the present invention, it is possible to suppress sheet feeding failure from the sheet storage device to the image forming apparatus.

1 image forming apparatus 4 image forming section 20 sheet storage device 26 main body housing 27 sheet stacking tray 72, 73 pulleys 29a to 29d wire 30 drive device 32 sheet feeding mechanism 35 shaft 38 winding section 38a first winding section 38b second Winding part 63 Biasing member 64 Key 64a Regulating part 69 Supporting wall part (facing part)
70 side wall 100 image forming system P sheet

Claims (5)

a body housing;
a sheet stacking tray supported in the body housing so as to be vertically movable and on which sheets are stacked;
a shaft rotatably supported in both forward and reverse directions by the body housing;
a plurality of pulleys externally inserted on both ends of the shaft in the rotation axis direction and attached with play in the rotation axis direction;
a plurality of wires each having one end fixed to the pulley and the other end fixed to the sheet stacking tray to suspend the sheet stacking tray;
a driving device for rotating the shaft;
a regulating portion that regulates the movement of the pulley in the rotation axis direction;
a biasing member that biases each of the pulleys toward the restricting portion;
A sheet storage device comprising: A facing portion provided inside each pulley with respect to the rotation axis direction of the shaft,
2. The urging member according to claim 1, wherein the biasing member is positioned between the pulley and the facing portion with respect to the rotation axis direction of the shaft, and is in contact with the facing portion and the pulley. sheet storage device. the body housing has a pair of side walls on which the shaft is rotatably supported;
The pulley is arranged outside the pair of side walls,
3. The sheet storage device according to claim 2, wherein the facing portion is formed by outer side surfaces of the pair of side walls. 4. The sheet storage device according to claim 1, wherein each pulley has a tapered shape in which an outer diameter of a winding portion for winding the wire increases outward in the axial direction. . an image forming apparatus having an image forming unit that forms an image on the sheet;
5. The sheet storage device according to any one of claims 1 to 4, comprising a sheet feeding mechanism connected to the image forming apparatus and feeding the sheet to the image forming section;
An image forming system comprising:

Images