Sheet processing device, sheet storage device, and image formation system

Abstract

To provide a configuration in which a saddle part includes a caster 601, the configuration being capable of suppressing a decrease in usability without inhibiting movement of a sheet processing device itself.SOLUTION: A caster 502 supports a sheet processing device so as to be movable. A saddle part is provided so as to be drawable from and insertable to the sheet processing device and applies predetermined processing on a sheet. The caster 601 is provided in the saddle part. When the saddle part moves in a drawing direction, the caster 601 contacts with an installation surface of the sheet processing device to support the saddle part. A support leg part 600 supports the caster 601 so as to be movable between a storage position at which the saddle part is located in a state of being inserted to the sheet processing device and a support position for supporting the saddle part drawn from the sheet processing device with respect to an installation surface on which the sheet processing device is installed. The support leg part 600 moves the caster 601 from the support position to the storage position along with operation of inserting the saddle part.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to a sheet processing apparatus that performs a predetermined process on a sheet, a sheet storage apparatus that stores sheets, an image forming system including the sheet processing apparatus, and an image forming system including the sheet storage apparatus.

Background Art

[0002] Conventionally, in a sheet processing apparatus, a sheet storage apparatus, etc., in order to perform jam processing of a sheet generated in a processing unit or to replenish a sheet storage unit, a configuration is known in which a processing unit or a sheet storage unit can be pulled out from the apparatus.

[0003] In this way, when pulling out a pull-out unit such as a processing unit or a storage unit that can be pulled out from the apparatus, in order to assist the pulling-out operation, a configuration including a caster that supports the pull-out unit during the pulling-out operation by rotating in contact with the installation surface has been proposed (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in a sheet processing apparatus or a sheet storage apparatus having a drawer unit, casters for moving the entire apparatus are provided separately from casters provided on the drawer unit to assist the pulling-out operation of the drawer unit. For this reason, when moving the entire apparatus using the casters for moving the entire apparatus such as a sheet processing apparatus or a sheet storage apparatus, for example, when the installation surface such as the floor has irregularities, the casters for assisting the pulling-out operation provided on the drawer unit may come into contact with the irregular portions of the floor surface or the like. As a result, the movement of the apparatus itself using the casters for moving the entire apparatus is hindered, and there is a possibility that usability may deteriorate.

[0006] An object of the present invention is to provide a configuration that can suppress a decrease in usability without hindering the movement of the apparatus itself in a configuration having casters that assist the pulling-out operation when pulling out a unit from the apparatus.

Means for Solving the Problem

[0007] One aspect of the present invention is a sheet processing apparatus, comprising: a first caster that movably supports the sheet processing apparatus; a processing unit that is provided so as to be pullable out and insertable into the sheet processing apparatus and that performs a predetermined process on a sheet; a second caster that is provided on the processing unit and that supports the processing unit in contact with the installation surface of the sheet processing apparatus when the processing unit moves in the pulling-out direction; a storage position where the processing unit is located in a state of being inserted into the sheet processing apparatus; and a support position for supporting the processing unit pulled out from the sheet processing apparatus with respect to the installation surface on which the sheet processing apparatus is installed, and a support portion that movably supports the second caster between the support position and the storage position, the support portion moving the second caster from the support position to the storage position in accordance with an operation of inserting the processing unit.

[0008] One aspect of the present invention is a sheet storage device, including: a first caster that movably supports the sheet storage device; a storage unit that is provided so as to be pullable out and inserted into the sheet storage device and stores sheets; a second caster that is provided on the storage unit and contacts the installation surface of the sheet storage device when the storage unit moves in the pulling-out direction to support the storage unit; a storage position where the storage unit is located when the storage unit is inserted into the sheet storage device; and a support position for supporting the storage unit pulled out from the sheet storage device with respect to the installation surface on which the sheet storage device is installed. The support portion movably supports the second caster between the support position and the storage position, and moves the second caster from the support position to the storage position along with the operation of inserting the storage unit.

Advantages of the Invention

[0009] According to the present invention, in a configuration having a caster that assists the pulling-out operation when pulling out the unit from the device, it is possible to suppress a decrease in usability without hindering the movement of the device itself.

Brief Description of the Drawings

[0010]

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[0011] The embodiments will be described with reference to FIGS. 1 to 20(f). First, the schematic configuration of the image forming system of the present embodiment will be described with reference to FIG. 1.

[0012] [Image Forming System] In the present embodiment, a copying machine is used as the image forming apparatus, a sheet processing apparatus is connected to the sheet discharge port of the copying machine, and a saddle portion for performing saddle stitching and middle folding processing is further provided inside the sheet processing apparatus. The image forming system 1000 includes an image forming apparatus A and a sheet processing apparatus B, receives the sheet S formed with an image by the image forming apparatus A by the downstream sheet processing apparatus B, performs saddle stitching processing, middle folding processing, corner binding processing, etc. as necessary, and discharges it to the downstream discharge unit. The image forming apparatus A includes various structures such as a copying machine, a printer, a printing machine, a facsimile machine, and a multifunction machine having a plurality of these functions. Hereinafter, the image forming apparatus A and the sheet processing apparatus B will be described in detail. In the following description, for the image forming apparatus A and the sheet processing apparatus B, the side where an operator such as a user operates the apparatus (for example, the side where an operation panel or operation buttons are provided) is referred to as the front side (F side, the front side of the paper surface in FIGS. 1 and 2, etc.), and the side opposite to the front side is referred to as the rear side (B side, the back side of the paper surface in FIGS. 1 and 2, etc.).

[0013] [Image Forming Apparatus] As shown in FIG. 1, the image forming apparatus A includes an image forming unit A1, an image reading unit A2, and an original document feeding unit A3. The image forming unit A1 includes a feeding unit 2, an image forming unit 3, a discharging unit 4, and a data processing unit 5 in a housing 1.

[0014] The feeding unit 2 includes a plurality of cassettes 2a, 2b, 2c. Each of the cassettes 2a, 2b, 2c can store a plurality of sheets S of different standard sizes selected in advance in multiple stages. The sheet S is, for example, paper, a plastic sheet, or the like. Each of the cassettes 2a, 2b, 2c is provided with a separating mechanism for separating the internal sheets S one by one and a feeding mechanism for feeding out the sheets S. The sheet S stored in the feeding unit 2 having such a configuration feeds out the sheet S of the size designated by the control unit 310 (FIG. 3) of the image forming apparatus A. The sheets S supplied from the plurality of cassettes 2a, 2b, 2c are further conveyed downstream by the conveying roller 7. The sheet conveyed by the conveying roller 7 has its leading edge aligned by the registration roller pair 8, and skew is corrected. Then, the sheet S with its leading edge aligned by the registration roller pair 8 is fed to the downstream image forming unit 3 at a predetermined timing.

[0015] A sheet storage device 2d and a manual feed tray 2e are connected to the image forming apparatus A. The sheet storage device 2d is composed of an optional unit that stores sheets of a size that is consumed in large quantities. The manual feed tray 2e is configured to be able to supply special sheets such as thick paper sheets, coated sheets, and film sheets for which separation feeding is difficult.

[0016] The image forming unit 3 only needs to be configured to form an image on the sheet S sent from the feeding unit 2, and various image forming mechanisms can be adopted. In the illustrated embodiment, an electrostatic image forming mechanism is shown as the image forming unit 3. However, the image forming unit 3 is not limited to the illustrated electrostatic image forming mechanism, and an inkjet image forming mechanism, an offset image forming mechanism, or the like can also be adopted.

[0017] In the image forming unit 3 shown in Fig. 1, there are provided a photoreceptor 9 formed in a drum shape or a belt shape, an exposure device 10 for exposing the photoreceptor 9, a developing device 11 for developing the photoreceptor 9 using toner, a charging device (not shown) for charging the photoreceptor 9, and a cleaner (not shown) for cleaning the photoreceptor 9. Fig. 1 shows a monochrome printing mechanism as an example. The photoreceptor 9 is exposed by the exposure device 10 to form an electrostatic latent image, and the electrostatic latent image is developed by the developing device 11 to form a toner image on the photoreceptor 9. The toner image formed on the photoreceptor 9 is transferred to a sheet S conveyed from the registration roller pair 8 by a transfer device 12. The sheet S onto which the toner image is transferred is fixed by a fixing device 13. Further, the image forming apparatus A is provided with a reverse conveyance path, and after the sheet S on which the toner image is fixed by the fixing device 13 is reversed front to back, it is sent to the registration roller pair 8 again to form an image on the back surface of the sheet S. A discharge roller 15 is provided downstream of the fixing device 13 and further downstream than the branch to the reverse conveyance path, and the discharge roller 15 conveys the sheet S from the discharge port 16 of the image forming apparatus A to a sheet processing apparatus B described later.

[0018] An image reading unit A2 for optically reading a document image is provided above the image forming unit A1 configured as described above, and a document feeding unit A3 is mounted further above the image reading unit A2.

[0019] The image reading unit A2 includes a first platen glass 17, a second platen glass 21, a reading carriage 18 having a light source, a photoelectric conversion element 19, and a reduction optical system 20 configured by combining mirrors and lenses. Then, the reading carriage 18 is scanned along the first platen glass 17 to irradiate the image of the document placed on the first platen glass 17 with light from the light source, and the reflected light from the image of the document is guided to the photoelectric conversion element 19 by the reduction optical system 20 to read the image. The photoelectric conversion element 19 converts the image data into an electrical signal and transfers it to the image forming unit 3, so that the image read by the image reading unit A2 can be used by the image forming unit A1 to form an image on the sheet.

[0020] The original document feeding unit A3 includes a feeding tray 22 and a discharge tray 24, conveys the original documents placed on the feeding tray 22 one by one, passes them over the second platen glass 21, and discharges them to the discharge tray 24. When reading the original documents fed from the original document feeding unit A3 and passing over the second platen glass 21, the reading carriage 18 is pre-stopped below the second platen glass 21, and image data is read from the image passing over the second platen glass 21.

[0021] [Overall Configuration of the Sheet Processing Device] Next, the overall configuration of the sheet processing device B that performs processing such as stapling and folding on the sheets conveyed from the image forming device A will be described with reference to FIG. 2. FIG. 2 shows the detailed configuration of the sheet processing device B. The sheet processing device B can stack the sheets received from the receiving portion 26, which is the entrance of the conveyance path 28 connected to the discharge port 16 of the image forming device A, after processing, onto the first tray (first stacking tray) 49, the saddle discharge unit 131, and the second tray (second stacking tray) 71, which will be described later. In the present embodiment, the path refers to the entire path along which the sheet is conveyed by conveyance guides, conveyance rollers, etc.

[0022] In the illustrated device, the sheets sent to the conveyance path and the conveyance path 28 as the first conveyance path are discharged to the first tray 49 after being processed by the processing unit B1, which will be described later, or the sheets conveyed through the conveyance path 28 are discharged to the second tray 71, or are discharged to the saddle discharge unit 131 after being processed by the saddle portion B2, which will be described later. Each device has a control unit, a communication unit, etc., like the blocks showing the control configuration in the entire device shown in FIG. 3, and controls the device accordingly.

[0023] The processing unit B1 as the end binding processing unit is arranged below the path exit (delivery unit 35) of the conveyance path 28, assembles and stacks a plurality of sheets sequentially delivered from the conveyance path 28 via the delivery unit 35 into a sheet bundle, and can perform a binding process on the end of this sheet bundle. The bound sheet bundle is stacked on the first tray 49 as a stacking unit. The sheet or sheet bundle stacked on the first tray 49 abuts against the stacking wall 50 at the rear end (upstream end) on the upstream side of the discharge direction of the sheets on the first tray 49, and is stacked along the stacking wall 50.

[0024] The first tray 49 is capable of moving up and down with respect to the processing tray 37 described later, and stacks the sheet bundle bound by the binding mechanism 47 described later. In the present embodiment, the first tray 49 and the second tray 71 can be moved up and down by a lifting mechanism (not shown). That is, in the present embodiment, when sending out the sheets to the first tray 49 or the second tray 71 as stacking trays, the first tray 49 and the second tray 71 are moved up and down so as to keep the position of the uppermost sheet on the stacking surface of the tray constant with respect to the discharge roller pair 42 and the second discharge roller 207 so that the alignment of the stacked sheets does not deteriorate.

[0025] The saddle unit B2 is arranged below the delivery unit of the saddle path 32 as the second conveyance path that branches vertically downward from the conveyance path 28, assembles and stacks a plurality of sheets sequentially delivered from the conveyance path 28 via the saddle path 32 and the delivery unit into a sheet bundle, performs an intermediate binding process, or performs a folding process without performing the intermediate binding process, and discharges it to the saddle discharge unit 131. Hereinafter, each configuration will be described in detail.

[0026] [Housing] As shown in FIG. 2, the sheet processing apparatus B includes a housing 27, a conveyance path 28, a processing unit B1, a saddle unit B2, a first tray 49, a saddle discharge unit 131, a second tray 71, etc. The conveyance path 28, the processing unit B1, and the saddle unit B2 are arranged inside the housing 27. Further, the conveyance path 28 has a sheet receiving portion 26 and a sheet delivery portion 35. The processing unit B1 and the saddle unit B2 process the sheet delivered from the delivery portion 35 of the conveyance path 28. The first tray 49, the saddle discharge unit 131, and the second tray 71 stack the sheets sent from each processing unit. The illustrated housing 27 is connected to the housing 1 of the image forming apparatus A located on the upstream side in the sheet conveyance direction in the conveyance path 28. Then, the housing 27 and the housing 1 are arranged such that the height from the discharge port 16 of the image forming apparatus A and the installation surface of the receiving portion 26 of the sheet processing apparatus B is substantially the same, and the discharge port 16 and the receiving portion 26 are connected.

[0027] [Sheet Loading Path] The conveyance path 28, which is the sheet loading path, is configured as a substantially straight path that crosses the housing 27 in a substantially horizontal direction, and includes a receiving portion 26 that is continuous with the discharge port (main body discharge port) 16 of the image forming apparatus A, and a delivery portion 35 that is located on the opposite side across the apparatus from this receiving portion 26. In this conveyance path 28, sheet conveyance is possible in the first straight conveyance direction from the receiving portion 26 toward the first discharge path 31, and there are arranged entrance rollers 29, first conveyance rollers 201, second conveyance rollers 202, and third conveyance rollers 203 as conveyance rollers that can convey in the second straight conveyance direction from the first discharge path 31 toward the receiving portion 26. That is, the entrance rollers 29, the first conveyance rollers 201, the second conveyance rollers 202, and the third conveyance rollers 203 can convey the sheet in the first straight conveyance direction and the second straight conveyance direction opposite to this first straight conveyance direction in the conveyance path, and are arranged in order from the receiving portion 26 side with respect to the first straight conveyance direction.

[0028] The first discharge path 31 is connected to the delivery section 35 of the conveyance path 28, and a first conveyance roller 36 is disposed at this connection section. The sheet delivered from the conveyance path 28 to the first discharge path 31 and discharged from the first discharge path 31 is stacked on the first tray 49 or guided to the processing unit B1. Note that each of the above-described conveyance rollers may be another member capable of conveying a sheet, such as a conveyance belt.

[0029] [Layout of Sheet Loading Path] As shown in FIG. 2, a saddle path 32, which is a branch path, and an upper conveyance path 30 are connected to the conveyance path 28. The saddle path 32 and the upper conveyance path 30 are arranged in order from the receiving section 26 toward the first discharge path 31 with respect to the first straight conveyance direction. Further, the saddle path 32 branches downward in the vertical direction from the conveyance path 28, and the upper conveyance path 30 branches upward in the vertical direction from the conveyance path 28. A saddle path switching member 33 and an upper conveyance path switching member 34, which are switching members for switching the conveyance direction of the conveyed sheet, are disposed at each branching section between the conveyance path 28 and the saddle path 32 and the upper conveyance path 30.

[0030] [Branch Section of Path] The upper conveyance path switching member 34 is configured as a switching guide that is movable to change the conveyance path so as to convey the sheet carried in from the receiving section 26 to either the first discharge path 31 or the upper conveyance path 30, and is moved by a driving section (not shown) such as an electromagnetic solenoid or a mini motor.

[0031] [Upper Conveyance Path] The upper conveyance path 30 (printout discharge path) that conveys sheets other than those discharged to the first discharge path 31 branches from the conveyance path 28, and a switching member 34 for guiding the sheet to the upper conveyance path 30 is provided at the path branching portion. Further, the upper conveyance path 30 is provided with a fourth conveyance roller 204, a fifth conveyance roller 205, a sixth conveyance roller 206, and a second discharge roller 207 as conveyance rollers for guiding the sheet to the second tray 71. By these, the sheet guided to the upper conveyance path 30 is discharged from the upper conveyance path discharge port 40 to the second tray 71 (overflow tray).

[0032] The processing unit B1 includes a processing tray 37 as a placement unit that places the sheet conveyed on the first discharge path 31 on the downstream side of the conveyance path 28 and aligns and stacks the placed plurality of sheets, and a binding mechanism 47 that performs a binding process on the stacked sheet bundle. Then, the processing unit B1 performs a binding process on the sheet bundle placed on the processing tray 37. The binding mechanism 47 is disposed vertically downward with respect to the conveyance path 28. As shown in FIG. 2, a step is formed in the first discharge path 31, and the processing tray 37 is disposed below the step. Between the first discharge path 31 and the processing tray 37, a first switchback path is provided that changes the conveyance direction in the reverse direction in a state where a part of the sheet is discharged from the discharge port 31a of the first discharge path 31 to the first tray 49 and guides the sheet onto the processing tray 37.

[0033] Specifically, the first discharge path 31 is provided with an upper conveyance roller 41 and a lower conveyance roller 48 that sandwich and convey the sheet. The upper conveyance roller 41 and the lower conveyance roller 48 constitute a pair of discharge rollers 42 as a discharge unit. The upper conveyance roller 41 can come into contact with and separate from the lower conveyance roller 48, and can convey the sheet in a direction toward the first tray 49 and in a direction opposite to this direction in a state where the upper conveyance roller 41 and the lower conveyance roller 48 sandwich the sheet. And it can be conveyed by the upper conveyance roller 41 and the lower conveyance roller 48 toward the processing tray 37 via the first switchback path.

[0034] Also, the upper conveyance roller 41 and the lower conveyance roller 48 (i.e., the discharge roller pair 42) discharge the sheet or the bundle of sheets on the processing tray 37 from the discharge port 31a to the first tray 49 as a stacking tray (stacking portion). The discharge port 31a is a portion opened above the lower conveyance roller 48 of the housing 27. Further, the discharge roller pair 42 discharges the sheet conveyed to the first discharge path 31 without passing through the processing tray 37 from the discharge port 31a to the first tray 49.

[0035] The binding processing mechanism 47 has a rear end regulating portion 47a that abuts against the end portion (rear end) of the sheet to position the sheet. On the processing tray 37, a scraping portion 38 is disposed that conveys the sheet conveyed to the processing tray 37 by the upper conveyance roller 41 and the lower conveyance roller 48 toward the rear end regulating portion 47a. Then, the binding processing mechanism 47 performs a binding process on the end portion of a bundle of sheets placed on the processing tray 37 and composed of a plurality of sheets whose end positions are regulated by the rear end regulating portion 47a. Further, the binding processing mechanism 47 has a sheet bundle unloading mechanism that unloads the sheet bundle to the first tray 49 after performing the binding process on the end portion of the sheet bundle.

[0036] Note that the binding processing mechanism 47 shown in FIG. 2 supports the sheet sent from the first discharge path 31 so as to straddle between the processing tray 37 and the first tray 49 on the downstream side thereof. That is, the sheet sent from the first discharge path 31 has its front end portion on the uppermost sheet of the first tray 49 on the downstream side and its rear end portion supported on the processing tray 37.

[0037] [Saddle Path] A saddle path 32 for conveying the sheet to the saddle portion B2 described above is connected to the conveyance path 28, and the path branching portion is provided with a saddle path switching member 33 for guiding the sheet to the saddle path 32. The sheet guided to the saddle portion B2 by the saddle path 32 is discharged to a saddle discharge unit 131 via a post-fold path guide 114 in a substantially horizontal direction, a second roller post-path guide 116, a pre-clamp guide 119, and a saddle discharge guide 124 after being center-folded and folded. In the present embodiment, the saddle discharge guide 124 as a discharge guide portion is used as an auxiliary guide for appropriately loading the sheet onto the saddle discharge unit 131.

[0038] [Control Configuration] The schematic of the control configuration of the image forming system 1000 will be described with reference to FIG. 3. First, the image forming apparatus A includes a control unit 310, an operation unit 302, a conveyance control unit 303, an image processing unit 304, a drive unit 305, and a communication unit 306. The control unit 310 includes a CPU (Central Processing Unit) 311, a ROM (Read Only Memory) 312, and a RAM (Random Access Memory) 313. The CPU 311 controls each unit while reading a program corresponding to the control procedure stored in the ROM 312. Further, work data and input data are stored in the RAM 313, and the CPU 311 performs control by referring to the data stored in the RAM 313 based on the above-described program and the like.

[0039] The operation unit 302 is, for example, an operation panel provided on the image forming apparatus A, which is connected to the control unit 310, and an operator performs operations and various settings of the apparatus. The conveyance control unit 303 controls various conveyance rollers and switching members for switching conveyance paths that convey the sheet in the image forming apparatus A. The image processing unit 304 controls the image forming unit 3. The drive unit 305 controls various motors and power supplies. The communication unit 306 communicably connects the control unit 310 to an external device 301 such as a personal computer and the communication unit 321 of the sheet processing apparatus B.

[0040] The sheet processing apparatus B includes a stacker control unit 330, a conveyance control unit 322, an edge binding control unit 323, a discharge processing control unit 324, and a communication unit 321. The stacker control unit 330 has a CPU 331, a ROM 332, and a RAM 333, similar to the control unit 310. The conveyance control unit 322 controls various conveyance rollers that convey sheets and switching members that switch conveyance paths, except for the saddle portion B2 of the sheet processing apparatus B. The edge binding control unit 323 controls the processing unit B1. The discharge processing control unit 324 controls the discharge of sheets and various stacking trays on which the discharged sheets are stacked. The communication unit 321 communicably connects the communication unit 306 of the image forming apparatus A and the communication unit 341 of the saddle portion B2 to the stacker control unit 330. Note that the communication between the communication unit 306 and the communication unit 321 may be performed by wired communication or wireless communication.

[0041] The saddle portion B2 includes a saddle control unit 350, a conveyance control unit 342, a middle binding control unit 343, a middle folding control unit 344, a corner back processing control unit 345, and a communication unit 341. The saddle control unit 350 has a CPU 351, a ROM 352, and a RAM 353, similar to the control unit 310. The conveyance control unit 342 controls various conveyance rollers that convey sheets and switching members that switch conveyance paths in the saddle portion B2. The middle binding control unit 343 controls the middle binding processing unit 104. The middle folding control unit 344 controls the middle folding mechanism C1. The corner back processing control unit 345 controls the corner back processing unit C2. The communication unit 341 communicably connects the communication unit 321 of the sheet processing apparatus B to the saddle control unit 350. In this embodiment, the saddle control unit 350 is configured to communicate with the stacker control unit 330 via the communication unit 341 and the communication unit 321, but a configuration in which each unit is controlled by a common control unit may also be used. Also, in this embodiment, the sheet processing apparatus B is configured to include a conveyance control unit 322, an edge binding control unit 323, a discharge processing control unit 324, a stacker control unit 330, and a saddle control unit 350 to control the sheet processing apparatus B, but a configuration in which each unit is controlled by one control unit may also be used.

[0042] [Saddle portion] The saddle part B2 will be described with reference to FIGS. 2 and 4. The saddle part B2 has a middle folding processing mechanism C1 and a corner back processing part C2, and performs middle folding processing, middle binding processing, and corner back processing as predetermined processing. The predetermined processing may be any one of these processes, or may be a plurality of processes. The middle folding processing mechanism C1 aligns and accumulates the sheets sent from the conveyance path 28 into a sheet bundle, and performs binding processing on the central part in the conveyance direction of the sheet bundle (the middle part in the second conveyance direction which is the conveyance direction of the saddle path roller 100 as the second conveyance part to be described later), and performs middle folding processing of bending the sheet bundle at the bound position (hereinafter also referred to as "magazine finishing"). The corner back processing part C2 is arranged on the downstream side in the conveyance direction of the sheet bundle of the middle folding processing mechanism C1 (the downstream side in the first conveyance direction which is the conveyance direction of the saddle third roller pair 118 as the first conveyance part to be described later), and performs corner back processing of making a fold on the back of the middle folded sheet bundle. And a saddle discharge unit 131 is arranged on the downstream side in the first conveyance direction of the corner back processing part C2 to stack the bound sheet bundles. It should be noted that it is also possible to align and accumulate one or a plurality of sheets and only perform middle folding processing of bending the central part in the conveyance direction without performing middle binding processing and corner back processing.

[0043] [Middle folding processing mechanism] The middle folding processing mechanism C1 includes a tip restricting stopper 109, a middle stapling processing section (middle stapling unit) 104, and a middle folding processing section 112. It accumulates sheets in a bundle shape and performs middle folding processing and middle stapling processing. That is, the sheets conveyed from the conveyance path 28 to the saddle path 32 are conveyed by the saddle path roller 100 as the second conveyance section to the saddle stack tray 150 as the accumulation section and the second accumulation section. The saddle stack tray 150 accumulates a plurality of sheets conveyed in the second conveyance direction by the saddle path roller 100 via the saddle path 32 to form a sheet bundle. The sheet bundle accumulated on the saddle stack tray 150 is positioned at a predetermined position on the saddle stack tray 150 by the tip restricting stopper 109. The middle stapling processing section 104 performs stapling processing on the central portion (the middle portion in the second conveyance direction) in the conveyance direction of the sheet bundle positioned by the tip restricting stopper 109. The middle folding processing section 112 has a pushing plate 112a and a pair of folding rollers 113. While pushing the vicinity of the position (the central portion in the conveyance direction of the sheet bundle subjected to stapling processing) where the stapling processing is performed by the middle stapling processing section 104 with the pushing plate 112a, the sheet bundle is conveyed by the pair of folding rollers 113 to fold the sheet bundle so that the back of the sheet bundle faces the downstream side in the conveyance direction. Note that the middle folding processing section 112 can also perform middle folding processing on a sheet bundle (or a single sheet) that does not undergo middle stapling processing. Here, the middle folding processing is a process of making a crease near the center of the sheet bundle and folding the sheet bundle in half. The crease formed by the middle folding processing section 112 does not necessarily have to be at the center of the sheet bundle and may be shifted from the center within the range of component tolerances. Also, the folding position may be changed according to the user's settings.

[0044] The middle stapling processing section 104 is a mechanism that performs stapling processing by moving along the central portion (line) of the sheet while sandwiching the sheet bundle between the head unit and the anvil unit. Also, as shown in FIGS. 2 and 4, the middle folding processing section 112 adopts a configuration in which the sheet bundle is inserted into the nip of the pair of folding rollers 113 that are in pressure contact with each other by the pushing plate 112a and the sheet bundle is conveyed while being folded by the rotation of the pair of folding rollers 113.

[0045] [Corner back processing section] The corner-back processing unit C2 performs corner-back processing to form a corner-back shape along the fold (line) of the sheet bundle that has been center-folded. The corner-back processing unit C2 includes a lower clamp unit 120 and an upper clamp unit 121 as a pair of clamp units (clamping units), and a corner-back processing unit 134 having a pressing roller 123.

[0046] The lower clamp unit 120 and the upper clamp unit 121 perform clamping and release of the sheet bundle by relatively moving along the thickness direction of the sheet bundle conveyed by the saddle third roller pair 118 described later (the direction in which a virtual line connecting the respective rotation axes of the saddle third roller pair 118 extends, or the direction orthogonal to the conveyance direction 118c of the saddle third roller pair 118). The pressing roller 123 presses the back of the sheet bundle by moving along the width direction of the sheet bundle (the direction orthogonal to the conveyance direction of the sheet bundle, the front-back direction in FIGS. 2 and 4). Then, in the first conveyance direction, the corner-back processing unit C2 presses the back of the sheet bundle clamped by the lower clamp unit 120 and the upper clamp unit 121 with the back of the sheet bundle protruding downstream with respect to the lower clamp unit 120 and the upper clamp unit 121 by the pressing roller 123 to perform corner-back processing to form a corner on the back of the sheet bundle. Note that the above-mentioned "corner" includes a curved surface and refers to the boundary between the front cover and the back cover of the sheet bundle, and the boundary between the back cover and the inner cover. Also, the "width direction of the sheet bundle" is the direction along the front-back direction (F-B direction) of the image forming apparatus A and the sheet processing apparatus B, and may be simply referred to as the "width direction" hereinafter.

[0047] Specifically, with the spine of the sheet bundle mid-folded by the mid-folding mechanism C1 protruding downstream in the first conveyance direction, the lower clamp unit 120 and the upper clamp unit 121 clamp a part of the sheet bundle from both sides in the vertical direction (the thickness direction of the sheet bundle). The pressing roller 123 presses the spine of the sheet bundle clamped by the lower clamp unit 120 and the upper clamp unit 121 while moving it along the width direction of the sheet bundle, which is orthogonal to both the conveyance direction of the sheet bundle and the thickness direction of the sheet bundle. In this way, the corner-back processing unit C2 performs corner-back processing to put a corner on the spine of the sheet bundle. The corner-back processing is a process of forming two streaks on the spine of the sheet bundle as shown in FIGS. 11(c) and (d) by crushing the spine of the sheet bundle shown in FIGS. 11(a) and (b) described later with the pressing roller 123, thereby forming two corners on the spine of the sheet bundle. The two corners on the spine of the sheet bundle are formed at positions that sandwich the staple pins driven in when stapling is performed by the mid-stapling processing unit 104 in the thickness direction of the sheet bundle. Also, the two corners formed on the spine of the sheet bundle are formed at positions that sandwich the fold line formed during the mid-folding process by the mid-folding processing unit 112.

[0048] Note that between the mid-folding mechanism C1 and the corner-back processing unit C2, a mid-folding conveyance mechanism is arranged to convey and stop the sheet bundle mid-folded by the mid-folding mechanism C1 to the downstream corner-back processing unit C2.

[0049] As described above, the processing unit B1 and the conveyance path 28 are arranged in a substantially horizontal direction, the saddle path 32 for guiding the sheet to the saddle portion B2 is arranged in a substantially vertical direction, and the saddle stack tray 150 for aligning and stacking the sheets is arranged to follow a substantially vertical direction. By arranging the conveyance path 28 along the direction crossing the housing 27 in this way and arranging the saddle path 32 and the saddle portion B2 along a substantially vertical direction, it is possible to reduce the horizontal width of the apparatus and make it slimmer.

[0050] On the downstream side in the conveyance direction of the sheet bundle in the saddle portion B2, a saddle discharge unit 131 is arranged to store the sheet bundle folded in a magazine shape. The illustrated saddle discharge unit 131 is arranged vertically below the first tray 49. This is because, assuming that the usage frequency of the first tray 49 is higher than that of the saddle discharge unit 131, the height position at which it is easy to take out the sheet on the tray is set for the first tray 49 in the device specifications.

[0051] [Configuration of the saddle portion] Next, the configurations of the center folding processing mechanism C1, the center folding conveyance mechanism C3, and the corner folding processing unit C2 that constitute the saddle portion B2 will be described in more detail.

[0052] [Details of the center folding processing mechanism] As shown in FIG. 2, the saddle path switching member 33 guides the sheet to the center folding processing mechanism C1 by being switched to convey the sheet to the saddle path 32. In the height direction of the center folding processing mechanism C1, in order from the upper side (upstream side) in the vertical direction which is the inlet side, a saddle inlet roller 101, a sorting flapper 102, a rear end pressing guide 103, an intermediate binding processing unit 104, a pulling-in and separating roller 105, a center folding processing unit 112, a first alignment roller 107, a second alignment roller 108, a front end restricting stopper 109, and a front end gripper 110 are arranged.

[0053] The saddle inlet roller 101 further conveys the sheet received from the saddle path 32 by the saddle path roller 100 downward. The sorting flapper 102 moves the sheet conveyed downward from the saddle inlet roller 101 toward the right side in FIG. 2 and accumulates the sheets on the saddle stack tray 150. The rear end pressing guide 103 presses the rear end of the sheet stacked on the saddle stack tray 150. The intermediate binding processing unit 104 performs a binding process on the central portion in the conveyance direction of the sheet bundle accumulated on the saddle stack tray 150. The pulling-in and separating roller 105 assists in conveying the sheet conveyed to the saddle stack tray 150, and is a roller that pulls this sheet toward the front end restricting stopper 109. The pulling-in and separating roller 105 is arranged so as to be able to contact and separate from the opposing roller 105a.

[0054] The middle folding processing unit 112 includes a pair of folding rollers 113, a pushing plate 112a as a pressing part, and a roller guide 111. The pair of folding rollers 113 forms a crease in the middle folding process. The pushing plate 112a pushes the sheet into the nip part of the pair of folding rollers 113. The roller guide 111 covers the pair of folding rollers 113. The first alignment roller 107 and the second alignment roller 108 both convey the sheet conveyed to the saddle stack tray 150 and perform alignment processing in the height direction of the sheet. The leading edge regulating stopper 109 determines the position in the height direction of the leading edge of the sheet by hitting the leading edge (lower end) of the conveyed sheet. The leading edge gripper 110 holds down the leading edge (lower end) of the sheet loaded on the leading edge regulating stopper 109.

[0055] The saddle inlet roller 101 and the retracting and separating roller 105 are driven by the same motor. The rear end pressing guide 103 is provided at a position facing the sorting ridge 102 with respect to the saddle stack tray 150. The intermediate binding processing unit 104 is arranged on the downstream side of the sorting ridge 102 and the rear end pressing guide 103 and on the upstream side of the retracting and separating roller 105.

[0056] The sheet conveyed from the saddle path 32 to the saddle part B2 is conveyed by the saddle inlet roller 101 to the leading edge regulating stopper 109 that has moved to a position according to the size. The retracting and separating roller 105 has an auxiliary conveying function for accurately conveying the conveyed sheet to the leading edge regulating stopper 109 within the saddle stack tray 150. At this time, in order to prevent the leading edge of the sheet from being caught by the pair of folding rollers 113 and convey it efficiently, the roller guide 111 partially covers the pair of folding rollers 113.

[0057] The first alignment roller 107 and the second alignment roller 108 accurately abut the conveyed sheet against the leading edge regulating stopper 109 and perform alignment processing in the height direction of the sheet.

[0058] The sorted stacker 102 moves the sheet conveyed up to the tip regulation stopper 109 closer to the rear end pressing guide 103, and holds the rear end (upper end) of the sheet pushed by the rear end pressing guide 103, thereby preparing to receive the next sheet. At this time, the rear end pressing guide 103 moves to a position corresponding to the size and waits.

[0059] The tip (lower end) of the stack of sheets formed by loading a predetermined number of sheets on the saddle stack tray 150 is fixed by being grasped by the tip gripper 110. In this state, the binding process is performed on the central part in the second conveyance direction of the stack of sheets by the intermediate binding processing unit 104. After the binding process, the tip regulation stopper 109 is lowered while the tip (lower end) of the stack of sheets is still grasped by the tip gripper 110. At this time, the tip regulation stopper 109 is lowered so that the position pushed into the folding roller pair 113 by the pushing plate 112a becomes the position of 1 / 2 of the sheet size, thereby lowering the stack of sheets from the binding position.

[0060] When performing the middle folding process, the roller guide 111 is retracted, the fixing of the tip gripper 110 is released, and then the central part of the stack of sheets is pushed into the nip part of the folding roller pair 113 by the pushing plate 112a. Thereby, the stack of sheets is middle-folded.

[0061] The saddle inlet roller 101, the pulling-in and separating roller 105, the sorted stacker 102, and the rear end pressing guide 103 are controlled by the conveyance control unit 342 (FIG. 3). Also, the tip regulation stopper 109, the tip gripper 110, the intermediate binding processing unit 104, the first alignment roller 107, and the second alignment roller 108 are controlled by the intermediate binding control unit 343 (FIG. 3). Further, the folding roller pair 113 and the pushing plate 112a are controlled by the middle folding control unit 344 (FIG. 3).

[0062] [Middle Folding Conveying Mechanism] The configuration of the middle folding conveyance mechanism C3 will be described with reference to FIGS. 2 and 4. The middle folding conveyance mechanism C3 is a mechanism that delivers the sheet bundle that has been middle-folded by the middle folding processing mechanism C1 to the corner-back processing unit C2. Specifically, the middle folding conveyance mechanism C3 first conveys the middle-folded sheet bundle as it is with the folding roller pair 113 so that the spine of the sheet bundle is located on the downstream side in the conveyance direction from the fore edge, and delivers the sheet bundle to the post-folding path guide 114. The post-folding path guide 114 is in a direction that bends downward in the vertical direction with respect to the folding roller conveyance direction 113c (FIG. 2) that is along the direction perpendicular to the straight line passing through the rotation centers of the rollers of the folding roller pair 113 as the first conveyance roller pair (the first virtual line α2 described below, FIG. 4) (here, a substantially horizontal direction), and is arranged on the downstream side in the conveyance direction of the folding roller pair 113.

[0063] Here, as shown in FIG. 4, a first virtual line α2 is defined as a straight line that is perpendicular to the first line α1 passing through the rotation centers of the folding roller pair 113 and the width direction (the direction perpendicular to the conveyance direction of the sheet bundle, the front-back direction in FIGS. 2 and 4) and passes through the nip of the folding roller pair 113 in a state where the sheet bundle is not pinched. In this case, the folding roller pair 113 is arranged such that the first virtual line α2 is parallel to the horizontal direction or inclined upward in the vertical direction to such an extent that it is directed downstream in the conveyance direction with respect to the horizontal direction. In the present embodiment, the first virtual line α2 is inclined upward in the vertical direction to such an extent that it is directed downstream in the conveyance direction with respect to the horizontal direction. On the other hand, the post-folding path guide 114 extends in a direction inclined with respect to the first virtual line α2, and in the present embodiment, it extends in a substantially horizontal direction.

[0064] The post-folding path guide 114 guides the conveyance of the sheet bundle and guides the sheet bundle to the saddle second roller pair 115 located downstream in the conveyance direction. The saddle second roller conveyance direction 115c, which is along the direction perpendicular to the straight line passing through the rotation centers of the rollers of the saddle second roller pair 115, is arranged along a direction that goes downward in the vertical direction as it goes downstream in the conveyance direction. The saddle second roller pair 115 is driven by the middle folding control unit 344 to convey the sheet bundle.

[0065] The sheet bundle conveyed by the saddle second roller pair 115 is delivered to a second roller rear path guide 116 that is arranged downstream in the conveyance direction and parallel to the saddle second roller conveyance direction 115c (Fig. 2), and is guided by the second roller rear path guide 116. Further, the second roller rear path guide 116 has a second roller rear path upper guide 116a that guides the upper surface of the sheet bundle and a second roller rear path lower guide 116b that guides the lower surface of the sheet bundle. A saddle conveyance sensor 117 is arranged vertically above the guide surface of the second roller rear path upper guide 116a and between the sheet bundle inlet and the sheet bundle outlet. The position of the leading end of the sheet bundle is detected by this saddle conveyance sensor 117.

[0066] The second roller rear path guide 116 guides the conveyance of the sheet and guides it to the saddle third roller pair 118 located downstream in the conveyance direction. The saddle third roller conveyance direction 118c (Fig. 2), which is in the direction along the perpendicular line (the second virtual line β2, Fig. 4 described below) to the straight line passing through the rotation centers of the respective rollers of the saddle third roller pair 118, is arranged along a direction that slopes downward in the vertical direction as it goes downstream in the conveyance direction.

[0067] The saddle third roller pair 118, serving as the conveying unit and the conveying roller pair, is driven by the middle folding control unit 344, and conveys while sandwiching a sheet bundle subjected to the middle binding process and the middle folding process so as to be located on the downstream side in the conveying direction from the end on the short side of the back of the sheet bundle. That is, the saddle third roller pair 118 conveys the sheet bundle so that the tip of the back of the sheet bundle becomes the leading end. When the direction in which the saddle third roller pair 118, which is also the first conveying unit, conveys the sheet bundle is defined as the first conveying direction (saddle third roller conveying direction 118c), the saddle path roller 100, serving as the second conveying unit that conveys the sheet to the middle folding mechanism C1, is located on the upstream side in the first conveying direction from the saddle third roller pair 118. And the saddle path roller 100 conveys the sheet in a second conveying direction different from the first conveying direction on the upstream side in the first conveying direction from the saddle third roller pair 118. Hereinafter, the upstream side and the downstream side in the first conveying direction (saddle third roller conveying direction 118c), which is the direction in which the saddle third roller pair 118 conveys the sheet bundle, may be simply referred to as the "upstream side" and the "downstream side".

[0068] Note that the folding roller pair 113, the saddle second roller pair 115, and the saddle third roller pair 118 are driven by the same motor, and the middle folding control unit 344 controls the driving of these roller pairs by controlling this motor. The saddle third roller pair 118 sandwiches the sheet bundle folded by the middle folding unit 112 and conveys it toward the corner back processing unit C2, and is located immediately upstream of the corner back processing unit C2.

[0069] Here, as shown in FIG. 4, a second line β1 passing through the centers of rotation of the saddle third roller pair 118 and a straight line that is orthogonal to the width direction and passes through the nip of the saddle third roller pair 118 in a state where the sheet bundle is not sandwiched are defined as a second virtual line β2. In this case, the saddle third roller pair 118 is provided such that the second virtual line β2 intersects the first virtual line α2 and is inclined downward in the vertical direction so that the second virtual line β2 is directed downstream in the conveying direction of the folding roller pair 113.

[0070] In other words, the saddle third roller pair 118 is arranged such that the second virtual line β2 inclines downward in the vertical direction as it goes downstream in the conveyance direction with respect to the horizontal direction. That is, in the present embodiment, the second virtual line β2 inclines with respect to the first virtual line α2. And in the folding roller pair 113, the sheet bundle is conveyed in a direction (folding roller conveyance direction 113c) that inclines upward in the vertical direction as it goes downstream in the conveyance direction with respect to the horizontal direction or the horizontal direction. In contrast, in the saddle third roller pair 118, the sheet bundle is conveyed in a direction (saddle third roller conveyance direction 118c) that inclines downward in the vertical direction as it goes downstream in the conveyance direction with respect to the horizontal direction.

[0071] Therefore, in the case of the present embodiment, the middle folding conveyance path C4 as the third conveyance path for conveying the sheet bundle between the folding roller pair 113 and the saddle third roller pair 118 is bent such that the sheet bundle conveyed by the folding roller pair 113 is delivered to the saddle third roller pair 118. That is, the middle folding conveyance path C4 has a post-folding path guide 114 and a second roller post-path guide 116, and the conveyance path is bent between the post-folding path guide 114 and the second roller post-path guide 116. In other words, the direction in which the sheet bundle is guided by the second roller post-path guide 116 inclines with respect to the direction in which the sheet bundle is guided by the post-folding path guide 114.

[0072] In this way, by making the conveyance direction of the sheet bundle of the folding roller pair 113 different from the conveyance direction of the sheet bundle of the saddle third roller pair 118 and bending the conveyance path between the post-folding path guide 114 and the post-second-roller path guide 116, the width of the sheet processing apparatus B (the length in the second conveyance direction, the length in the left-right direction in FIG. 2) can be reduced, and the apparatus can be made smaller. Further, by setting the folding roller conveyance direction 113c, which is the sheet conveyance direction of the saddle third roller pair 118, to be obliquely downward and discharging the sheet bundle downward by the saddle third roller pair 118, the sheet bundle processed in the saddle portion B2 can be discharged to a lower position in the apparatus. As a result, the saddle discharge unit 131, from which the sheet bundle processed in the saddle portion B2 is discharged, can be arranged below the apparatus, and the amount by which the first tray 49 located above the saddle discharge unit 131 can descend can be increased. As a result, the sheet loading capacity of the first tray 49 can be increased. Note that in the arrangement of the conveyance path guides for the above-described sheet or sheet bundle and the conveyance directions of the sheet and sheet bundle, cases where there are angles with respect to horizontal, vertical, or parallel due to relationships such as tolerances are also included.

[0073] [Details of the corner folding processing unit] The corner folding processing unit C2 will be described with reference to FIGS. 2 and 4 and using FIGS. 5 to 10. As described above, it includes a lower clamp unit 120 and an upper clamp unit 121 as a pair of clamp units, and a corner folding processing unit 134 having a pressing roller 123. As shown in FIG. 5, a clamp mechanism C5 having the lower clamp unit 120 and the upper clamp unit 121 has a pre-clamp guide 119. The pre-clamp guide 119 is arranged on the downstream side in the conveyance direction from the saddle third roller pair 118 and along a direction that bends downward in the vertical direction with respect to the saddle third roller conveyance direction 118c, and guides the conveyance of the sheet bundle.

[0074] The pre-clamp guide 119 has a pre-clamp upper guide portion 119a as a first guide portion for guiding the upper surface of the sheet bundle and a pre-clamp lower guide portion 119b as a second guide portion for guiding the lower surface of the sheet bundle. The pre-clamp upper guide portion 119a and the pre-clamp lower guide portion 119b are arranged at positions separated in the thickness direction by more than half of the thickness of the sheet bundle that can pass into the apparatus from a line centered on the saddle third roller conveyance direction 118c (the thickness of the sheet bundle when a center folding process is performed on the sheet bundle having the maximum thickness that can be conveyed in the apparatus). That is, the interval between the pre-clamp upper guide portion 119a and the pre-clamp lower guide portion 119b is larger than the maximum thickness of the sheet bundle that can be processed by the sheet processing apparatus B (the maximum thickness of the sheet bundle that can be center-folded by the center folding mechanism C1). Note that at least one of the pre-clamp upper guide portion 119a and the pre-clamp lower guide portion 119b may be omitted.

[0075] The lower clamp unit 120 and the upper clamp unit 121 as a pair of clamp units perform clamping and release of clamping of the sheet bundle by relatively moving along the thickness direction of the sheet bundle conveyed by the saddle third roller pair 118. That is, the lower clamp unit 120 and the upper clamp unit 121 are relatively movable between a first position where they can receive the sheet bundle conveyed from the saddle third roller pair 118 and a second position where they clamp the sheet bundle. Then, by moving from the first position to the second position, the lower clamp unit 120 and the upper clamp unit 121 clamp a part of the sheet bundle from both sides in the thickness direction of the sheet bundle.

[0076] In the case of this embodiment, the upper clamp unit 121 as the first clamp part is movable, and the lower clamp unit 120 as the second clamp part is fixed. That is, the upper clamp unit 121 moves in a direction approaching the lower clamp unit 120 to clamp the sheet bundle. However, the upper clamp unit 121 may be fixed, the lower clamp unit 120 may be movable, or both may be movable. In any case, the upper clamp surface (upper clamp pressing part) 142, which is the surface of the upper clamp unit 121 facing the lower clamp unit 120, and the lower clamp surface (lower clamp pressing part) 143, which is the surface of the lower clamp unit 120 facing the upper clamp unit 121, clamp the sheet bundle (see FIGS. 5 and 11(a) to (d)).

[0077] The lower clamp surface 143 of the lower clamp unit 120 and the upper clamp surface 142 of the upper clamp unit 121 are parallel to the pre-clamp upper guide part 119a and the pre-clamp lower guide part 119b, respectively, and are arranged on the downstream side in the conveyance direction of the sheet bundle of the pre-clamp guide 119. Then, the sheet bundle conveyed while being guided by the pre-clamp guide 119 is further guided by the upper clamp surface 142 and the lower clamp surface 143 and conveyed by a predetermined amount. Note that the pre-clamp lower guide part 119b is fixed to the lower clamp unit 120, and the pre-clamp upper guide part 119a is fixed to the upper clamp unit 121. In this embodiment, the pre-clamp upper guide part 119a moves in a substantially vertical direction (the thickness direction of the sheet bundle) together with the upper clamp unit 121.

[0078] [Corner rounding processing unit] Next, with reference to FIGS. 5 to 10, the internal configuration of the chamfering processing unit 134 will be described. The chamfering processing unit 134 includes a unit frame 147, roller pressing portions 138a and 138b, pressing springs 145a and 145b, an upper movement restricting portion 139, and a lower movement restricting portion 140 as a configuration for supporting and moving a pressing roller (chamfering processing roller) 123. As shown in FIGS. 5 and 10, the pressing roller 123 is arranged such that the outer peripheral surface thereof contacts the end surfaces on the downstream side of each of the lower clamping unit 120 and the upper clamping unit 121. Further, as shown in FIG. 6(b), a roller shaft 141 is arranged on the inner diameter side of the pressing roller 123, and the pressing roller 123 is rotatable with respect to the roller shaft 141.

[0079] As shown in FIGS. 6(a) and 6(b), the unit frame 147 includes a pair of side plates 147a arranged on both sides of the pressing roller 123, a rear side plate 147b arranged on the left side of the downstream side in the first conveyance direction (FIG. 6(b)) of the pressing roller 123, and upper side plates 147c and lower side plates 147d arranged on both sides in the rotational axis direction of the pressing roller 123 and provided so as to bend from both end portions of the rear side plate 147b. With such a configuration, the unit frame 147 accommodates the pressing roller 123 inside each side plate and exposes the pressing roller 123 on the upstream side in the first conveyance direction.

[0080] In the present embodiment, the rear side plate 147b, the upper side plates 147c, and the lower side plates 147d are integrally formed and have a substantially U-shaped cross section as shown in FIG. 6(b). Note that these may be separate bodies or may be integrally formed with the pair of side plates 147a. Both end portions of the roller shaft 141 of the pressing roller 123 are rotatably supported by the upper side plates 147c and the lower side plates 147d, respectively. Further, the upper side plates 147c and the lower side plates 147d extend upstream in the first conveyance direction from the pressing roller 123, and the upper movement restricting portion 139 and the lower movement restricting portion 140 are supported at the tip portions thereof, respectively.

[0081] That is, the upper movement restricting portion 139 is provided at the tip of a support shaft 139a fixed to the upper plate 147c and extending downward from the upper plate 147c. Further, the lower movement restricting portion 140 is provided at the tip of a support shaft 140a fixed to the upper plate 147c and extending downward from the lower plate 147d. Further, the upper movement restricting portion 139 is a roller rotatably supported at the tip of the support shaft 139a, and the lower movement restricting portion 140 is a roller rotatably supported at the tip of the support shaft 140a. In this embodiment, two lower movement restricting portions 140 are arranged side by side, but one may also be used. Also, the upper movement restricting portion 139 may also be two. The upper movement restricting portion 139 and the lower movement restricting portion 140 are located on both sides of the pressing roller 123 in the rotational axis direction of the roller shaft 141.

[0082] Roller pressure applying portions 138a and 138b are respectively connected to the roller shaft 141 on the outer side in the roller thickness direction of the pressing roller 123 and on the downstream side in the conveyance direction. Pressure springs 145a and 145b are arranged between the roller pressure applying portions 138a and 138b and the back plate 147b of the unit frame 147, and the roller shaft 141 is urged by the pressure springs 145a and 145b. Since the roller shaft 141 is configured to be movable in the conveyance direction, the pressing force with which the pressing roller 123 presses the back of the sheet bundle by the urging force of the pressure springs 145a and 145b changes in accordance with the change in the protruding amount from the lower clamp unit 120 and the upper clamp unit 121 at the back of the sheet bundle, which will be described later.

[0083] Further, since the pressing roller 123 is biased by the biasing springs 145a and 145b via the roller shaft 141, it is pressed against the lower clamp unit 120 and the upper clamp unit 121. On the other hand, on the opposite side sandwiching the pressing roller 123 with the lower clamp unit 120 and the upper clamp unit 121, an upper movement restricting portion 139 and a lower movement restricting portion 140 are arranged so as to face the lower clamp unit 120 and the upper clamp unit 121 respectively (FIG. 5). That is, with respect to the conveyance direction (first conveyance direction) of the sheet bundle, on the upstream side of the lower clamp unit 120 and the upper clamp unit 121, the upper movement restricting portion 139 is arranged with respect to the upper clamp unit 121, and the lower movement restricting portion 140 is arranged with respect to the lower clamp unit 120 respectively.

[0084] As shown in FIGS. 9 and 10, the upstream end face 120a of the lower clamp unit 120 is in contact with the lower movement restricting portion 140. Further, the upstream end face 121a of the upper clamp unit 121 is in contact with the upper movement restricting portion 139. In the present embodiment, the lower movement restricting portion 140 and the upper movement restricting portion 139 are rollers having rotation axes in the width direction of the sheet bundle and in the direction orthogonal to the conveyance direction of the sheet bundle (the vertical direction in FIG. 10, substantially the vertical direction in the present embodiment), and rotate while being in contact with the end faces 120a and 121a. Thereby, the pressing force applied from the pressing roller 123 to the lower clamp unit 120 and the upper clamp unit 121 restricts the lower clamp unit 120 and the upper clamp unit 121 from moving upstream.

[0085] When the saddle conveyance sensor 117 detects the leading edge of the sheet bundle conveyed by the saddle third roller pair 118, the corner-back processing control unit 345 counts the conveyance amount and stops after conveying by a predetermined conveyance amount. Specifically, as shown in FIG. 11(a) described later, the back of the folded sheet bundle is stopped in a state where it protrudes downstream of the upper clamp unit 121 and the lower clamp unit 120 in the conveyance direction. In the present embodiment, in the corner-back process, by controlling the conveyance amount of the sheet bundle by the saddle third roller pair 118, the protruding amount of the back of the sheet bundle from the upper clamp unit 121 and the lower clamp unit 120 is adjusted.

[0086] [Upper clamp unit and lower clamp unit] The upper clamp unit 121 moves from the receiving position (first position) for receiving the sheet bundle to the clamp holding position (second position) for holding the sheet bundle, thereby pressing the sheet bundle between itself and the lower clamp unit 120, and holding the sheet bundle by the upper clamp surface 142 and the lower clamp surface 143. At this time, as shown in FIG. 11(b) described later, the leading edge of the sheet bundle protrudes by a predetermined protruding amount P1 from the end surfaces 120c and 121b on the downstream side in the conveyance direction of the lower clamp unit 120 and the upper clamp unit 121 after clamp holding.

[0087] The upper clamp unit 121 operates by driving the clamp drive motor 132 (Figs. 7(a) and (b)) by the angular back processing control unit 345. As shown in Figs. 7(a) and (b), the angular back processing unit C2 further transmits the drive transmitted by the clamp drive train 133 composed of a pulley, a belt, and further a gear train to the clamp drive link 122, thereby moving the upper clamp unit 121 connected to the clamp drive link 122 in the sheet bundle thickness direction. A plurality of clamp springs 144 for pressing the sheet bundle are built in between the clamp drive link 122 and the upper clamp unit 121. The amount of movement of the clamp drive link 122 remains constant, and the pressing force changes as the amount of compression of the clamp spring 144 changes according to the thickness of the sheet bundle. The aforementioned clamp holding position also changes according to the thickness of the sheet bundle.

[0088] [Angular back processing unit] As shown in Fig. 11(c) to be described later, the angular back processing unit C2 performs angular back processing on the sheet bundle held in a state of protruding from the end faces 120c and 121b by a predetermined protruding amount P1 between the lower clamp unit 120 and the upper clamp unit 121 by pressing the back of the sheet bundle while scanning in the width direction of the sheet bundle by the pressing roller 123 arranged on the downstream side in the conveyance direction.

[0089] During angular back processing, the pressing roller 123 is moved by operating the drive motor 135 (Fig. 7(b)) by the angular back processing control unit 345. As shown in Fig. 8, the pressing roller 123 is connected to a drive belt 137 arranged in the width direction of the sheet bundle and is movable in the width direction of the sheet bundle along a guide rail 120b shown in Fig. 9 to be described later. The drive belt 137 rotates by receiving power transmitted from the drive motor 135 via a drive train 136 (Fig. 7(b)) composed of a gear train. Thereby, the pressing roller 123 can scan in the width direction of the sheet bundle.

[0090] Incidentally, the home positions of the pressing roller 123 are provided on the front side and the rear side of the sheet processing apparatus B. That is, after moving the pressing roller 123 from the rear side to the front side with respect to the first sheet bundle and performing the corner folding process, the pressing roller 123 can be moved from the front side to the rear side with respect to the second sheet bundle to perform the corner folding process. Sensors (not shown) are provided at each home position of the pressing roller 123, and it is possible to detect the position of the pressing roller 123. However, a home position may be provided on either the front side or the rear side, and the scanning of the pressing roller 123 in the width direction may be performed from the front side to the rear side or from the rear side to the front side. When the home position is provided on either one in this way, for example, after moving the pressing roller 123 from the rear side to the front side with respect to the first sheet bundle and performing the corner folding process, the pressing roller 123 is returned from the front side to the rear side, and the pressing roller 123 is also moved from the rear side to the front side with respect to the second sheet bundle to perform the corner folding process, and so on.

[0091] Also, in one corner folding process, the pressing roller 123 is moved in one direction from the front side to the rear side or from the rear side to the front side, but the pressing roller 123 may be reciprocally moved in one corner folding process. For example, in one corner folding process, it may be set whether to move the pressing roller 123 in one direction or reciprocally according to the number of sheets included in the sheet bundle and the type of sheet. At the time of this setting, it may be automatically performed on the control unit side, or an operator such as a user or a service technician may set it. Further, in one corner folding process, it may be made possible for the operator to arbitrarily set whether to move the pressing roller 123 in one direction or reciprocally.

[0092] As shown in FIGS. 9 and 10, the lower clamp unit 120 has a guide rail 120b formed along the width direction of the sheet bundle. When the pressing roller 123 moves in the width direction of the sheet bundle, the lower movement restricting portion 140 moves along the guide rail 120b while engaging with the guide rail 120b. The guide rail 120b is formed in a substantially U-shaped cross section by combining a plurality of members as shown in FIG. 10, and is formed so that a part of the roller-shaped lower movement restricting portion 140 can enter. The lower surface on the outer diameter side of the lower movement restricting portion 140 is engaged with the lower surface of the guide rail 120b, and the outer peripheral surface of the lower movement restricting portion 140 is in contact with the end surface 120a. Thereby, the movement in the sheet bundle thickness direction when the pressing roller 123 moves is restricted. Note that the guide rail 120b may be a groove formed in a member on the upstream side in the conveyance direction of the lower clamp unit 120.

[0093] After the corner folding process is completed, the pressing roller 123 is moved in the width direction by operating the drive motor 135 (FIG. 7(b)) to retract it from the conveyance path of the sheet bundle, and further, the upper clamp unit 121 is moved in a direction away from the sheet bundle by operating the clamp drive motor 132 (FIGS. 7(a) and (b)) (FIG. 11(d) described later). Thereby, it becomes possible to convey the sheet bundle further downstream. Note that it is also possible to discharge the sheet bundle without performing the above-described corner folding process.

[0094] [Discharge unit] As shown in FIG. 2, the sheet bundle that has passed through the saddle portion B2 is conveyed toward the saddle discharge guide 124 disposed further downstream in the first conveyance direction than the pressing roller 123 by the saddle third roller pair 118. The saddle discharge guide 124 is swingably supported about a first fulcrum 124b having a rotation axis parallel to the rotation axis of each roller of the saddle third roller pair 118. The first fulcrum 124b is located above a line extending the conveyance direction of the sheet bundle (first conveyance direction, saddle third roller conveyance direction 118c) by the saddle third roller pair 118 downstream. Then, the saddle discharge guide 124 is disposed so as to hang vertically downward from the first fulcrum 124b.

[0095] Further, in the saddle discharge guide 124, the side surface on the upstream side in the first conveyance direction is inclined so as to face the upstream side in the first conveyance direction from the first fulcrum 124b toward the intermediate portion 124a with respect to the vertical direction. Also, the side surface on the upstream side in the first conveyance direction of the saddle discharge guide 124 is inclined so as to face the downstream side in the first conveyance direction from the intermediate portion 124a toward the lower end with respect to the vertical direction. That is, the side surface on the upstream side in the first conveyance direction of the saddle discharge guide 124 is formed to be bent such that the intermediate portion 124a in the vertical direction protrudes more upstream in the first conveyance direction than the other portions. And, a guide surface 124d is provided between the intermediate portion 124a and the lower end among the side surfaces on the upstream side in the first conveyance direction of the saddle discharge guide 124.

[0096] The guide surface 124d is located below the line obtained by extending the above-described saddle third roller conveyance direction 118c downstream, contacts the sheet bundle conveyed by the saddle third roller pair 118, and guides this sheet bundle downward. The saddle discharge guide 124 is rotatable about the first fulcrum 124b when the sheet bundle contacts the guide surface 124d. Note that depending on the rigidity of the sheet bundle, the sheet bundle may not contact the guide surface 124d of the saddle discharge guide 124, and even when contact occurs, the amount of rotation changes depending on the rigidity, so the saddle discharge guide 124 does not necessarily rotate.

[0097] Also, a second fulcrum 124c is provided at the lower end portion of the saddle discharge guide 124, and a saddle discharge roller 125 described later is connected so as to be rotatable about the second fulcrum 124c. The second fulcrum 124c is located below the guide surface 124d and has a rotation axis parallel to the rotation axis of the first fulcrum 124b.

[0098] If the saddle third roller pair 118 continues to convey the stack of sheets, it is delivered to the saddle discharge unit 131, which is arranged on the downstream side in the first conveyance direction from the corner-back processing unit 134 and on the lower side in the vertical direction from the saddle discharge guide 124. The saddle discharge unit 131 includes a saddle discharge upstream belt 127, a saddle discharge upstream sensor 128, a saddle discharge downstream belt 129, and a saddle discharge downstream sensor 130.

[0099] The saddle discharge upstream belt 127 is located below the guide surface 124d of the saddle discharge guide 124 and conveys the stack of sheets guided downward by the guide surface 124d while guiding it further downstream. The saddle discharge upstream belt 127 is inclined so as to go downward in the vertical direction as it goes downstream in the conveyance direction. The saddle discharge downstream belt 129 as the sheet stack discharge part receives the stack of sheets conveyed from the saddle discharge upstream belt 127 and conveys it while guiding it further downstream. The saddle discharge downstream belt 129 is inclined so as to go upward in the vertical direction as it goes downstream in the conveyance direction. For this reason, the stack of sheets guided to the saddle discharge upstream belt 127 by the guide surface 124d is conveyed in a direction inclined downward in the vertical direction by the saddle discharge upstream belt 127 and then conveyed in a direction inclined upward in the vertical direction by the saddle discharge downstream belt 129.

[0100] Also, a saddle discharge upstream sensor 128 for detecting the stack of sheets on the upstream side is arranged on the upstream side within the conveyance possible region of the saddle discharge upstream belt 127, and a saddle discharge downstream sensor 130 for detecting the stack of sheets on the downstream side is arranged on the upstream side within the conveyance possible region of the saddle discharge downstream belt 129.

[0101] The stack of sheets delivered to the saddle discharge unit 131 is guided and conveyed by the saddle discharge upstream belt 127 and the saddle discharge downstream belt 129, and then the stack of sheets is loaded. The saddle discharge upstream belt 127 sandwiches the stack of sheets at the nip point between the saddle discharge roller 125 described above on the downstream side in the conveyance direction. The stack of sheets existing on the saddle discharge upstream belt 127 is configured to suppress the opening on the opening side (the small opening side) at this nip point. The position of this nip point can be changed with the second fulcrum 124c as a fulcrum depending on the thickness of the stack of sheets.

[0102] When processing the subsequent stack of sheets, the preceding stack of sheets is conveyed upstream in the conveyance direction by the saddle discharge upstream belt 127 and stops at a predetermined conveyance amount after being detected by the saddle discharge upstream sensor 128 and the saddle discharge downstream sensor 130. This conveyance amount is a position where the opening on the opening side of the preceding stack of sheets can be suppressed at the nip point between the saddle discharge roller 125, and has a positional relationship such that it contacts the upper surface of the preceding stack of sheets when discharging the subsequent stack of sheets. That is, in the present embodiment, in the saddle discharge unit 131, the subsequent stack of sheets is stacked on the preceding stack of sheets (so-called, in a lap-like manner).

[0103] In this way, the saddle discharge unit 131 discharges the subsequent stack of sheets onto the upper surface of the preceding stack of sheets without entering the opening of the preceding stack of sheets, so that problems such as snagging, curling, and extrusion do not occur in the preceding stack of sheets, and it is stably stacked in a lap-like manner. That is, by appropriately changing the above-described conveyance amount according to the size of the stack of sheets, the subsequent stack of sheets can be stably stacked on the preceding stack of sheets.

[0104] The saddle discharge portion 126 is disposed on the downstream side in the first conveyance direction from the saddle discharge guide 124 and between the saddle discharge upstream belt 127 and the saddle discharge downstream belt 129. The stack of sheets conveyed to the saddle discharge unit 131 is discharged to the outside of the sheet processing apparatus B by passing through the saddle discharge portion 126, making it easier for the user to access the discharged stack of sheets.

[0105] In addition, when there is another device on the downstream side of the saddle discharge unit 131, it is also possible to transfer the sheet bundle to the downstream device by continuing the conveyance without loading. Further, in the present embodiment, an ejection cover 151 as a cover member is provided outside the saddle ejection portion 126. The ejection cover 151 is arranged so as not to prevent the sheet bundle from being ejected from the saddle ejection portion 126, and is arranged so that an operator such as a user cannot access the inside of the device through the saddle ejection portion 126.

[0106] [Control of the corner folding process] Next, the control of the corner folding process of the present embodiment will be described with reference to FIGS. 11(a) to (d). As described above, the corner folding unit C2 performs a corner folding process of forming a corner on the back of the sheet bundle subjected to the middle binding process and the middle folding process. Hereinafter, the control for performing the corner folding process will be described as the corner folding mode. Further, the middle folding control unit 344 shown in FIG. 3 controls each conveyance roller pair of the folding roller pair 113, the saddle second roller pair 115, and the saddle third roller pair 118 with the same drive.

[0107] The corner folding mode will be described. The corner folding mode is a mode in which the pressing roller 123 is pressed against the back of the sheet bundle Sb to form a corner on the back of the sheet bundle Sb. The middle folding control unit 344 uses the detection of the leading end of the sheet bundle Sb by the saddle conveyance sensor 117 as a trigger to convey the middle-folded sheet bundle Sb between the upper clamp unit 121 and the lower clamp unit 120 in a separated state. Then, as shown in FIG. 11(a), the middle folding control unit 344 stops the conveyance of the sheet bundle Sb in a state where the back Ssp of the sheet bundle Sb protrudes further downstream in the first conveyance direction than the end faces 121b and 120c on the downstream side in the first conveyance direction of the upper clamp unit 121 and the lower clamp unit 120.

[0108] In this state, the corner creasing processing control unit 345 drives the clamp drive motor 132 (Figs. 7(a) and (b)) to move the upper clamp unit 121 toward the lower clamp unit 120, and as shown in Fig. 11(b), the sheet bundle Sb is clamped by the upper clamp unit 121 and the lower clamp unit 120. At this time, the back Ssp of the sheet bundle Sb protrudes by P1 downstream of the end faces 121b and 120c on the downstream side in the first conveyance direction of the upper clamp unit 121 and the lower clamp unit 120.

[0109] Next, the corner creasing processing control unit 345 operates the drive motor 135 (Fig. 7(b)) to move the pressing roller 123 in the width direction of the sheet bundle Sb. At this time, as shown in Fig. 11(c), the pressing roller 123 moves in the width direction while pressing the back Ssp of the sheet bundle Sb, so that corner creasing processing is performed on the back Ssp of the sheet bundle Sb. Then, as shown in Fig. 11(d), the corner creasing processing control unit 345 drives the clamp drive motor 132 (Figs. 7(a) and (b)) to separate the upper clamp unit 121 from the lower clamp unit 120 and release the clamping of the sheet bundle Sb. In the first mode, the corner creasing processing is completed up to this point, and the discharging operation of the sheet bundle Sb described above is performed.

[0110] [Pull-out of the saddle unit B2] Next, the operation when performing maintenance on the saddle unit B2 as a processing unit will be described with reference to Figs. 12(a) to 13. The maintenance here includes jam processing in which the user removes the sheets in the unit when a sheet conveyance abnormality occurs, and replacement of parts by the user or service technician. Figs. 12(a) to 13 are perspective views seen from the side (upstream side in the sheet conveyance direction) where the sheet processing apparatus B is connected to the image forming apparatus A. Fig. 12(a) shows the state where the front cover 501 of the sheet processing apparatus B is closed, Fig. 12(b) shows the state where the front cover 501 of the sheet processing apparatus B is open, and Fig. 13 shows the state where the saddle unit B2 of the sheet processing apparatus B is pulled out.

[0111] The saddle part B2 is arranged so that it can be pulled out from the housing 27 serving as the casing and inserted into the mounting position of the housing 27. In the present embodiment, the saddle part B2 is pulled out from the front side (F side) with respect to the front-rear direction (F-B direction) which is the direction orthogonal to the sheet conveyance direction in the sheet processing apparatus B. Hereinafter, when referring to the sheet conveyance direction (sometimes simply referred to as the "conveyance direction"), it is the sheet conveyance direction in the conveyance path 28 (the left-right direction in FIG. 2). Also, as shown in the coordinates of FIG. 12(a), the U side is the upper side in the vertical direction, and the D side is the lower side in the vertical direction. Further, the F side is the front side of the sheet processing apparatus B, and the B side is the back side (also referred to as the rear side) of the sheet processing apparatus B. Furthermore, the L side is the left side when viewing the sheet processing apparatus B from the front side and is the downstream side in the sheet conveyance direction. The R side is the right side when viewing the sheet processing apparatus B from the front side and is the upstream side in the sheet conveyance direction.

[0112] The sheet processing apparatus B is provided with a front cover (opening / closing door) 501 that forms a part of the exterior of the apparatus. The housing 27 serving as the casing includes a main body frame 500, a front cover 501, and other exterior covers. The main body frame 500 is provided with casters 502 at four locations on the lower surface. The four casters 502 as the first casters (main support parts) support the housing 27 with respect to the installation surface. By providing the casters 502 in this way, it is made easier for the user or service technician to move the sheet processing apparatus B when installing or moving it to a desired position.

[0113] As shown in Fig. 12(a), the front cover 501 is provided with a handle 501a at the end on the R side. Also, as shown in Fig. 12(b), the front cover 501 is rotatably supported with respect to the main body frame 500 via hinges 502b at three locations in the illustrated example. The hinges 502b have a vertical rotation axis direction, and the end on the L side of the front cover 501 is rotatably supported about the rotation axis of the hinges 502b. When a user or a service technician performs maintenance on the saddle part B2, first, by grasping the handle 501a of the front cover 501 in the state of Fig. 12(a) and pulling it toward the F side, the front cover 501 is opened from the R side to the L side. At this time, the front cover 501 rotates about the hinges 502b, and the operation lever 550 that is operated when pulling out the saddle part B2 is exposed as shown in Fig. 12(b). Note that the direction of opening the front cover 501 may be the reverse of the above. Also, the front cover 501 may be opened like double doors.

[0114] When the operation lever 550 is operated by a user or a service technician, a lock (not shown) between the saddle part B2 and the main body frame 500 is released, and as shown in Fig. 13, the saddle part B2 can be pulled out from the inside of the housing 27 to the F side (front side). Note that by pushing the pulled-out saddle part B2 toward the B side (rear side), the saddle part B2 is inserted into the housing 27, and when it is inserted to the mounting position, it is locked to the main body frame 500 by a lock part (not shown).

[0115] The saddle part B2 is supported with respect to the main body frame 500 via the rail part 503. The rail part 503 guides the saddle part B2 so that it can be pulled out from the inside and inserted into the main body frame 500 of the housing 27. Such a rail part 503 has a fixed rail 503a fixed to the main body frame 500 and a slide rail 503b that can slide in the F-B direction (front-rear direction) with respect to the fixed rail 503a. In FIG. 13, the rail part 503 that supports the R side of the saddle part B2 is illustrated, but similar rail parts 503 (see FIGS. 14(a) and (b) described later) are also arranged on the L side. Such a rail part 503 guides the saddle part B2 so that it can be pulled out from the inside and inserted into the housing 27. That is, the saddle part B2 is supported and fixed to the slide rail 503b, and when the slide rail 503b slides in the F-B direction with respect to the fixed rail 503a, the saddle part B2 can be pulled out and inserted with respect to the main body frame 500 of the housing 27.

[0116] As shown in FIG. 12(b), the state in which the saddle part B2 is located inside the main body frame 500 is the mounting position of the saddle part B2. On the other hand, as shown in FIG. 13, the position where the saddle part B2 protrudes outside the housing 27 is the pulled-out position of the saddle part B2, and it is the maintenance position when removing the seat or performing component replacement when a jam of the seat occurs inside the saddle part B2.

[0117] Note that the mounting position in FIG. 12(b) only needs to be a position where the front cover 501 is in a closed state, and not all elements constituting the saddle part b2 must be inside the main body frame 500 including columns and the like. For example, it also includes a state where a part such as an operation lever 550 and a cover member protrudes to the front side of the main body frame 500. In this case, for example, the part protruding to the front side of the main body frame 500 is positioned in a recess formed inside the front cover 501.

[0118] Further, the pull-out position shown in FIG. 13 only needs to be a position where the user or the service technician can access the saddle portion B2, and it is not necessary that all the elements constituting the saddle portion B2 must be outside the main body frame 500. For example, parts such as wire harnesses and various drive mechanisms arranged on the B side of the saddle portion B2 may be located inside the main body frame 500.

[0119] Also, the pull-out position may be a two-stage position including a maintenance position where the user performs jam processing and a maintenance position where the service technician performs maintenance on each unit. For example, in order to enable access to electrical components and the like arranged on the B side (rear side) of the device by the service technician, the saddle portion B2 may be further pulled out to the F side from the maintenance position by the user. By doing so, during maintenance by the user, unnecessary pulling-out and insertion operations of the saddle portion B2 do not occur, and during maintenance by the service technician, it becomes easier for the service technician to perform the work, and the usability of the device can be improved. For example, the slide rail 503b can be pulled out in two stages with respect to the fixed rail 503a. And during maintenance by the service technician, the saddle portion B2 is further pulled out compared to the state of the position in FIG. 13 (maintenance position by the user).

[0120] In addition, in this embodiment, the rail portion 503 is provided below the saddle portion B2. However, the position of the rail portion 503 that supports the saddle portion B2 may be any other position as long as it does not interfere with maintenance. For example, the rail portion 503 that guides the saddle portion B2 may be provided above. However, since the rail portion 503 supports the heavy saddle portion B2, it is easier to ensure the support rigidity of the rail portion 503 when it is provided below than when it is provided above. Further, in this embodiment, a part of the saddle stack tray 150 from which the sheet is conveyed from the saddle path 32 protrudes above the saddle portion B2 (see FIG. 2). For this reason, the width in the L-R direction (left-right direction) of the upper portion of the saddle portion B2 is narrower than that of the lower portion, and it is difficult to arrange the rail portion 503 above the saddle portion B2. Even if the rail portion 503 is arranged above, it becomes difficult to perform jam processing at the upper portion of the saddle portion B2. On the other hand, by arranging the rail portion 503 below the saddle portion B2 as in this embodiment, access from above the saddle portion B2 becomes easy, so that it becomes easy to perform jam processing occurring in the saddle portion B2.

[0121] [Supporting leg portion] Here, as described above, when the saddle portion B2 is pulled out to the F side with respect to the main body frame 500, the center of gravity position of the sheet processing apparatus B shifts to the F side compared to the state where the saddle portion B2 is mounted in the main body frame 500. For this reason, when the saddle portion B2 is pulled out, the apparatus may tilt forward. When the saddle portion B2 is heavy, a load is further applied to the rail portion 503, which may cause factors such as deformation of the main body frame 500. Therefore, in this embodiment, in order to suppress the apparatus from tilting when the saddle portion B2 is pulled out, a supporting leg portion 600 as a supporting portion that supports the saddle portion B2 is provided.

[0122] In addition, if the casters 502 for moving the entire sheet processing apparatus B are provided separately from the casters 601 provided on the saddle portion B2 to assist the pulling-out operation of the saddle portion B2 as described later, when moving the entire apparatus using the casters 502, especially when there are irregularities on the installation surface such as the floor, the casters 601 may come into contact with the irregular portions of the floor surface or the like, thereby hindering the movement of the apparatus itself and potentially reducing usability. For this reason, in the present embodiment, the support legs 600 are moved from the support position to the storage position in accordance with the operation of inserting the saddle portion B2 into the sheet processing apparatus B. The support position is the position where the support legs 600 are located to support the saddle portion B2 pulled out from the sheet processing apparatus B with respect to the installation surface on which the sheet processing apparatus B is installed. The storage position is the position where the support legs 600 are located when the saddle portion B2 is inserted into the sheet processing apparatus B. Hereinafter, the support legs 600 will be described with reference to FIGS. 14(a) to 20(f).

[0123] FIG. 14(a) is a perspective view of the vicinity of the support legs 600 in a state where the saddle portion B2 is housed inside the main body frame 500. FIG. 14(b) is a perspective view of the vicinity of the support legs 600 in a state where the saddle portion B2 is pulled out from the main body frame 500. In FIGS. 14(a) and 14(b), the saddle portion B2 is omitted for clarity in showing the relationship between the support legs 600 and the rail portion 503.

[0124] The main body frame 500 is configured by combining a plurality of stays. FIGS. 14(a) and 14(b) show that the lower part of the front right side of the main body frame 500 is composed of a front lower stay 500a arranged in the L-R direction at the lower part on the F side and a lower right stay 500b arranged in the F-B direction at the lower part on the R side. The rail portion 503 for supporting the saddle portion B2 is arranged to span between the front lower stay 500a and a rear lower stay (not shown) arranged similarly at the lower part on the B side, and moves in the F-B direction between the lower right stay 500b and a lower left stay (not shown) arranged similarly at the lower part on the L side. Hereinafter, the configuration of the lower part of the front right side will be described, but the configurations of the four corners at the lower part of the main body frame 500 are basically the same.

[0125] The F-side end of the lower right stay 500b is disposed on the upper surface of the R-side end of the front lower stay 500a, and these ends are fixed to each other. With the caster 502 fixed to the R-side end of the front lower stay 500a, an adjustment handle 502bb is provided at a position on the side opposite to the caster 502 (upper side) through a hole formed in the F-side end of the lower right stay 500b. By rotating the adjustment handle 502bb, it is possible to adjust the height of the caster 502 with respect to the front lower stay 500a. Thus, even if there are variations in the installation surface such as the floor on which the sheet processing apparatus B is installed, by adjusting the height of each of the four casters 502 provided on the lower surface of the main body frame 500, it is possible to easily align the heights of the sheet processing apparatus B and the image forming apparatus A.

[0126] As shown in FIG. 12(b) described above, in a state where the saddle portion B2 is in the mounting position, as shown in FIG. 14(a), the support leg portion 600 is located between the front lower stay 500a and a rail stay 504 provided between a pair of rail portions 503. The rail stay 504 is provided on the F side, and both ends of the F-side rail stay 504 in the L-R direction are fixed to the slide rails 503b so as to span the F-side ends of the pair of slide rails 503b. The saddle portion B2 is supported by the rail stay 504 in a state where its position in the F-B direction is determined by a plurality of positioning members 503bb provided on the slide rails 503b of the rail portion 503. For this reason, the saddle portion B2 can move in the F-B direction along the fixed rail 503a together with the pair of slide rails 503b and the rail stay 504.

[0127] The support leg 600 is movable between a storage position (Fig. 14(a)) where the saddle portion B2 is located with the saddle portion B2 inserted inside the housing 27 and a support position (Fig. 14(b)) where the saddle portion B2 is supported against the installation surface on which the sheet processing apparatus B is installed with the saddle portion B2 pulled out from inside the housing 27. In the present embodiment, the support leg 600 is rotatable about the rotation axis 602a between the storage position and the support position. Specifically, the support leg 600 is rotatably supported about the rotation axis 602a with respect to the rail stay 504 as a rail-side support portion provided on the rail portion 503.

[0128] Further, as shown in Fig. 14(a), the support leg 600 is located between the front lower stay 500a and the rail stay 504 in a state where the saddle portion B2 is located at the mounting position. This position is the storage position of the support leg 600. In the present embodiment, in response to the saddle portion b2 moving from the mounting position to the pulling-out position, the support leg 600 rotates from the storage position shown in Fig. 14(a) to the support position shown in Fig. 14(b) by the biasing of a spring 603 described later. Also, in response to the saddle portion B2 moving from the pulling-out position to the mounting position, a part of the support leg 600 abuts against a part of the sheet processing apparatus B, thereby releasing a lock state described later, and the support leg 600 rotates from the storage position shown in Fig. 14(a) to the support position shown in Fig. 14(b). That is, the support leg 600 moves from the storage position to the support position in conjunction with the operation of pulling out the saddle portion B2 and moves from the support position to the storage position in conjunction with the insertion operation of the saddle portion B2.

[0129] As shown in Fig. 14(a), in the storage position, the casters 601 and the support legs 600 are located above the bottom surface of the sheet processing apparatus B that supports the caster 502. That is, in the storage position, the casters 601 and the support legs 600 are located inside the main body frame 500 (above the front lower stay 500a). In this way, since the support legs 600 are located inside the main body frame 500 (above the bottom surface of the main body frame 500 (the bottom surface of the sheet processing apparatus B)) in the storage position, when moving the sheet processing apparatus B by the caster 502, the support legs 600 can be prevented from hindering the movement of the sheet processing apparatus B.

[0130] Note that the movement of the support legs 600 is not limited to the above-described rotation, and may be a movement combining a plurality of slide movements such as a slide movement to the F side and a slide movement to the D side. For example, when moving the support legs 600 from the storage position to the support position, the support legs 600 may be lifted and moved to the storage position.

[0131] Further, the support legs 600 support the caster 601 as a second caster (rotating member). The caster 601 is provided on the saddle portion B2 and contacts the installation surface of the sheet processing apparatus B when the saddle portion B2 moves in the pulling-out direction to support the saddle portion B2. Such a caster 601 is rotatably provided about a rotation axis 601a parallel to the rotation axis 602a at the lower end portion in the vertical direction of the support legs 600. Specifically, the caster 601 is rotatably supported by a support sheet metal 602 constituting the support legs 600 via the rotation axis 601a. The rotation axis 601a extends in the L-R direction (the sheet conveyance direction, a direction intersecting the vertical direction and the front-rear direction).

[0132] The four casters 502 provided on the main body frame 500 have a plurality of rotation axes (not shown), enabling the casters themselves to rotate and the main body frame 500 to pivot within a range of 360°. This is to facilitate handling when moving the apparatus, such as when installing the sheet processing apparatus B. On the other hand, the caster 601 provided on the support leg 600 can rotate only in one direction (the direction in which the saddle part B2 is pulled out, the front-rear direction).

[0133] Accordingly, when the saddle part B2 is pulled out, the caster 601 moves only in the same direction as the pulling direction of the saddle part B2, so it does not become a burden when the user operates to pull out the saddle part B2, and the operability is good. In other words, it suppresses a decrease in operability caused by the caster 601 facing a direction different from the pulling direction when the saddle part B2 is pulled out.

[0134] On the other hand, when moving the sheet processing apparatus B, if the caster 601 of the support leg 600 is in contact with the installation surface when the caster 502 tries to rotate and move in a direction different from the direction in which the caster 601 advances, since the caster 601 can rotate only in one direction, it is difficult to move the sheet processing apparatus B. In contrast, in this embodiment, since the support leg 600 is located at the storage position, when moving the sheet processing apparatus B by the caster 502, the caster 601 that rotates only in one direction of the support leg 600 does not hinder the movement of the sheet processing apparatus B, and the movement of the sheet processing apparatus B can be performed smoothly, and the operability is good.

[0135] Also, even if the caster 601 is configured to be pivotable in the same manner as the caster 502, when moving the sheet processing apparatus B, if there are irregularities on the installation surface such as the floor, the caster 601 may come into contact with the irregularities and hinder the movement of the apparatus. However, in this embodiment, since the support leg 600 can be moved from the support position to the storage position, it is possible to suppress a decrease in usability without hindering the movement of the apparatus itself.

[0136] Thus, even when providing the caster 601 that supports the movement of the saddle portion B2 in the pulling-out direction as in the present embodiment, it is possible to prevent the movement of the sheet processing apparatus B itself from being hindered and suppress a decrease in usability. Note that the movement of the sheet processing apparatus B itself is, for example, the movement when installing the sheet processing apparatus B or when separating the sheet processing apparatus B from the image forming apparatus A due to a sheet conveyance failure or the like.

[0137] Next, the configuration of the support leg portion 600 will be described in detail with reference to FIGS. 15(a) to 17(b). FIG. 15(a) is a side view of the periphery of the support leg portion 600 as viewed from the upstream side (R side) in the conveyance direction, and FIG. 15(b) is a cross-sectional view of the periphery of the support leg portion 600 as viewed from the downstream side (L side) in the conveyance direction. FIG. 16(a) is a side view of the periphery of the support leg portion 600 with the saddle portion B2 pulled out as viewed from the R side, and FIG. 16(b) is a cross-sectional view thereof. FIG. 17(a) is a perspective view of the support leg portion 600 with the saddle portion B2 pulled out as viewed from the upstream side (B side) in the pulling-out direction of the saddle portion B2, and FIG. 17(b) is a perspective view of the support leg portion 600 with the saddle portion B2 pulled out as viewed from the downstream side (F side) in the pulling-out direction of the saddle portion B2.

[0138] The support leg 600 is biased in a first direction to rotate from the storage position to the support position about the rotation axis 602a as the urging portion and the spring 603 as the first urging portion, along with the operation of pulling out the saddle portion B2 from the housing 27. Further, when the saddle portion B2 moves from the pulled-out state to the mounting position of the housing 27, the support leg 600 is restricted by the restricting portion 610 from rotating in a second direction toward the storage position about the rotation axis 602a until the saddle portion B2 reaches a predetermined position with respect to the housing 27. Also, the restricting portion 610 releases the rotation restriction of the support leg 600 in the second direction in response to the operation of inserting the saddle portion B2 into the housing 27 beyond the predetermined position with respect to the housing 27, and allows the support leg 600 to move to the storage position. Further, the spring 603 and the restricting portion 610 constitute a locking mechanism 620 that locks the support leg 600 in the support position when the saddle portion B2 is pulled out from the sheet processing apparatus B. This will be described in detail below.

[0139] The support leg 600 has a support sheet metal 602 that is rotatably supported about a rotation axis 602a as a first rotation axis with respect to a protruding plate portion 504d provided so as to protrude below or downward of the lower part of the rail stay 504. Specifically, one end portion (the upper end portion in the support position) of the support sheet metal 602 is supported by the rotation axis 602a. On the other hand, a caster 601 is rotatably supported about a rotation axis 601a at the other end portion (the lower end portion in the support position) of the support sheet metal 602. The support sheet metal 602 has a first sheet metal 605 as a first member and a second sheet metal 606 as a second member. The first sheet metal 605 is a sheet metal member formed in a U-shaped cross section and is rotatably supported by the rotation axis 602a. The second sheet metal 606 is a sheet metal member formed in a U-shaped cross section and is rotatably supported about a rotation axis 602c as a second rotation axis with respect to the first sheet metal 605. A spring 607 as a second urging portion that urges the second sheet metal 606 in a direction away from the first sheet metal 605 is disposed between the first sheet metal 605 and the second sheet metal 606.

[0140] The spring 603 is a torsion coil spring. As shown in FIGS. 15(a), 16(a), 17(a), and (b), the coil portion is supported by the rotation shaft 602a, one end portion 603a is hooked on a notch 504a (FIG. 17(a)) formed in the rail stay 504, and the other end portion 603b is hooked on a notch 602b (FIG. 17(b)) formed in the support sheet metal 602. The rail stay 504 has a first plate portion 5041 disposed above the support sheet metal 602, a second plate portion 5042 formed to be bent downward from the end portion on the B side of the first plate portion 5041, and third plate portions 5043 respectively formed to be bent downward from both end portions in the L-R direction of the first plate portion 5041.

[0141] The notch 504a is formed by cutting out a part in the L-R direction of the second plate portion 5042 from the upper end portion downward. Further, the notch 504a is formed vertically above the rotation shaft 602a, and one end portion 603a of the spring 603 is hooked on the notch 504a vertically above the rotation shaft 602a. Note that the above-described protruding plate portion 504d is provided on the lower surface of the first plate portion 5041. Also, the pair of third plate portions 5043 are respectively fixed to the slide rails 503b.

[0142] The support sheet metal 602 is composed of a first sheet metal 605 and a second sheet metal 606, each of which is formed in a U-shaped cross-section as described above. In this embodiment, with the support leg 600 in the support position, the first sheet metal 605 is located on the F side of the second sheet metal 606, and the second sheet metal 606 is disposed inside the first sheet metal 605. The notch 602b is formed by cutting out a part of the corner on the F side of the first sheet metal 605 at the support position. As shown in FIG. 15(a), the position where the other end side portion 603b of the spring 603 is hung on the notch 602b is above the rotation axis 602a in the vertical direction in the storage position, and as shown in FIG. 16(a), it is below the rotation axis 602a in the vertical direction in the support position. Then, with the other end side portion 603b of the spring 603 hung on the notch 602b at such a position and the one end side portion 603a hung on the notch 504a at the above-mentioned position, the support sheet metal 602 is biased in the direction from the storage position to the support position (counterclockwise in FIGS. 15(a) and 16(a)) by the spring 603.

[0143] The spring 607 is a compression spring and is disposed inside the first sheet metal 605 and the second sheet metal 606, each of which is formed in a U-shaped cross-section in this embodiment. Then, the spring 607 generates a biasing force in the direction in which the first sheet metal 605 and the second sheet metal 606 separate by elastically compressing and pushing the bottom surfaces of the respective sheet metals. Note that the position and shape of the spring 607 are not limited to this. As long as a biasing force in the direction in which the first sheet metal 605 and the second sheet metal 606 separate can be generated, it does not have to be a compression spring. For example, it may be a torsion coil spring. Also, the spring 607 may be disposed outside the first sheet metal 605 and the second sheet metal 606.

[0144] In addition, a contact member 604 is provided on the support sheet metal 602. The contact member 604 is fixed to the side surface of the second sheet metal 606 opposite to the first sheet metal 605. As shown in FIGS. 15(a) and (b), when the support leg 600 is in the storage position, the contact member 604 contacts the front lower stay 500a due to the biasing force of the spring 603. Also, when the support leg 600 is in the storage position, the surface of the support leg 600 on the side opposite to the contact member 604 (the side surface of the first sheet metal 605) contacts the first plate portion 5041 of the rail stay 504 due to the biasing force of the spring 607 between the first sheet metal 605 and the second sheet metal 606. That is, in the state where the support leg 600 is in the storage position, the support sheet metal 602 and the contact member 604 are arranged to be stretched between the rail stay 504 and the front lower stay 500a by the biasing forces of the spring 603 and the spring 607. Therefore, it is possible to suppress the inadvertent wobbling in the state where the support leg 600 is in the storage position. For example, it is possible to suppress the generation of abnormal noise due to the support leg 600 swinging in the vertical direction when moving the sheet processing apparatus B.

[0145] And, as will be described in detail later, in the process of the support leg 600 moving from the storage position to the support position, when the restriction by the contact between the contact member 604 and the front lower stay 500a is eliminated, the support leg 600 moves to the support position by the biasing force of the spring 603. At this time, due to the biasing force of the spring 607 provided between the first sheet metal 605 and the second sheet metal 606 constituting the support sheet metal 602, the second sheet metal 606 rotates in a direction away from the first sheet metal 605.

[0146] [Restriction of Support Leg] Next, a configuration for restricting the rotation of the support leg portion 600 will be described with reference to FIGS. 16(b), 17(a), and 18. The second sheet metal 606 that constitutes the support sheet metal 602 has a bent portion 606a as a first engaging portion and a contact portion 606b, as shown in FIG. 16(b). The bent portion 606a is formed so as to bend the upper end portion of the second sheet metal 606 at the support position toward the B side. The contact portion 606b is a portion located below the bent portion 606a on the B-side side surface of the second sheet metal 606 at the support position. On the other hand, a hole portion 504b as a second engaging portion is formed in the second plate portion 5042 of the rail stay 504. The hole portion 504b is a hole penetrating in the F-B direction.

[0147] As described above, when the support leg portion 600 moves from the storage position to the support position and the second sheet metal 606 rotates in a direction away from the first sheet metal 605 by the biasing force of the spring 607, as shown in FIG. 16(b), the bent portion 606a of the second sheet metal 606 is inserted into the hole portion 504b of the rail stay 504. At this time, the contact portion 606b of the second sheet metal 606 contacts the portion to be contacted 504c, which is the F-side side surface below the hole portion 504b of the second plate portion 5042 at the support position. Thereby, the rotation of the support leg portion 600 biased toward the support position by the spring 603 is restricted, and the support leg portion 600 is positioned at the support position. That is, the contact portion 606b of the second sheet metal 606 and the portion to be contacted 504c of the second plate portion 5042 function as a restricting portion for restricting the rotation of the support leg portion 600 in the first direction, and the state in which the contact portion 606b and the portion to be contacted 504c are in contact is the state in which the support leg portion 600 is positioned at the support position.

[0148] At this time, as shown by a circle D1 indicated by a broken line in Fig. 16(b), the biasing force of the spring 603 acts counterclockwise about the rotation axis 602a on the support sheet metal 602. On the other hand, the biasing force of the spring 607 acts between the first sheet metal 605 and the second sheet metal 606 that constitute the support sheet metal 602. For this reason, as shown by a circle D2 indicated by a broken line in Fig. 16(b), the biasing force of the spring 607 acts clockwise about the rotation axis 602c on the second sheet metal 606. Note that in this state, the bent portion 606a of the second sheet metal 606 is only inserted into the hole portion 504b of the second plate portion 5042, and the bent portion 606a and the hole portion 504b are not engaged with each other.

[0149] The support leg 600 rotates from the storage position due to the biasing of the spring 603, and when the rotation of the support leg 600 is restricted by the contact between the contact portion 606b and the portion to be contacted 504c, as shown in Fig. 16(a), the caster 601 is not in contact with the installation surface α such as the floor on which the sheet processing apparatus B is installed. That is, immediately after the saddle portion B2 is pulled out from the housing 27 and the support leg 600 rotates from the storage position to the support position, the lowermost surface β of the caster 601 is in a state of being separated from the installation surface α. In other words, in a state where the support leg 600 is in the support position, when the distance between the rotation axis 602a and the lowermost surface β of the caster 601, which is the lower end of the support leg 600, in the vertical direction is L1, and the distance between the rotation axis 602a and the lower end (lowermost surface) of the caster 502 as the main support portion in the vertical direction is L2, L1 < L2 is satisfied. In the present embodiment, in this state, the caster 601 is positioned with a 10 - mm interval from the installation surface α on which the caster 502 is installed at the lowermost surface β.

[0150] This is because if the caster 601 contacts the installation surface α before the support leg 600 moves from the storage position to the support position, the restriction due to the contact between the contact portion 606b of the second sheet metal 606 and the contacted portion 504c of the second plate portion 5042 will not work, and there is a possibility that the support leg 600 cannot be surely positioned at the support position. In this case, there is a possibility that the bent portion 606a of the second sheet metal 606 does not enter the hole portion 504b of the second plate portion 5042. If the bent portion 606a does not enter the hole portion 504b, as will be described later, when a force acts on the support leg 600 in the second direction opposite to the first direction, the support leg 600 rotates in the direction of returning to the storage position, and there is a risk that the saddle portion B2 will not be supported by the support leg 600.

[0151] Therefore, in the present embodiment, when the support leg 600 rotates from the storage position to the support position along with the pulling-out operation of the saddle portion B2, the caster 601 of the support leg 600 is prevented from contacting the installation surface α until the contact portion 606b and the contacted portion 504c come into contact. The caster 601 of the support leg 600 is installed on the installation surface α when the rail portion 503 is deflected by the weight of the saddle portion B2 in a state where the saddle portion B2 is pulled out from the main body frame 500 by more than a predetermined amount. The predetermined amount is the amount until the rotation of the support leg 600 is restricted (the rotation amount from the storage position until the contact portion 606b and the contacted portion 504c come into contact). That is, when the saddle portion B2 is pulled out by a predetermined amount, the rotation of the support leg 600 is restricted. When the saddle portion B2 is further pulled out from this position, the rail portion 503 is deflected by the weight of the saddle portion B2, the caster 601 contacts the installation surface α, and the saddle portion B2 is supported on the installation surface α via the support leg 600.

[0152] Here, for example, when the saddle part B2 is returned from the pulled-out position to the mounted position with the caster 601 of the support leg 600 installed on the installation surface, a force acts on the support leg 600 due to the contact between the caster 601 and the installation surface, causing it to rotate in the clockwise direction in FIG. 16(b), i.e., the second direction, about the rotation axis 602a. At this time, if the support leg 600 is not restricted from rotating in the second direction, there is a risk that the support leg 600 will rotate in the direction of returning to the storage position, and the saddle part B2 will no longer be supported by the support leg 600. Therefore, in this embodiment, when the saddle part B2 moves in the direction of being inserted into the sheet processing apparatus B from the pulled-out state, there is a restricting portion 610 that restricts the caster 601 from moving in the direction from the support position to the storage position. In this embodiment, the restricting portion 610 restricts the support leg 600 that supports the caster 601 from rotating in the second direction toward the storage position about the rotation axis 602a.

[0153] When the saddle part B2 is inserted into the inside of the housing 27 from the pulled-out state, the restricting portion 610 restricts the support leg 600 from rotating in the second direction toward the storage position about the rotation axis 602a until the saddle part B2 reaches a predetermined position with respect to the housing 27. As will be described later, the predetermined position is the position where the contact member 604 abuts against the front lower stay 500a of the main body frame 500 when the saddle part B2 moves from the pulled-out position to the mounted position.

[0154] Such a restricting portion 610 has the bent portion 606a as the above-described first engaging portion and the hole portion 504b as the second engaging portion. As described above, the hole portion 504b is provided in the rail stay 504 which is a member that moves together with the saddle portion B2 during the insertion and withdrawal operations of the saddle portion B2. The hole portion 504b with which the bent portion 606a engages may be other than the rail stay 504 as long as it is a member that moves together with the saddle portion B2 during the insertion and withdrawal operations of the saddle portion B2. And the hole portion 504b restricts the rotation of the support leg portion 600 by engaging with the bent portion 606a when the saddle portion B2 is located upstream in the insertion direction of the saddle portion B2 from a predetermined position, that is, before the contact member 604 comes into contact with the front lower stay 500a, and the support leg portion 600 rotates in the second direction about the rotation axis 602a.

[0155] That is, when a force acts in the direction in which the support leg portion 600 rotates in the second direction about the rotation axis 602a, the support leg portion 600 rotates slightly in the second direction about the rotation axis 602a as shown in FIG. 18 from the support position as shown in FIG. 16(b). At this time, the bent portion 606a inserted into the hole portion 504b is caught by the lower edge portion of the hole portion 504b, so that the support leg portion 600 is restricted from rotating further in the second direction. In this state, the support leg portion 600 is in a state of having rotated slightly in the second direction from the support position, and the saddle portion B2 can be supported with respect to the installation surface. Also, in this state, since the support leg portion 600 is biased in the first direction by the spring 603, the support leg portion 600 is in a state of being locked at the support position. Therefore, in the present embodiment, the restricting portion 610 and the spring 603 function as a locking mechanism 620 that locks the support leg portion 600 at the support position.

[0156] Thus, in this embodiment, when the saddle portion B2 is moved from the mounting position to the pulling-out position with respect to the main body frame 500, the support leg portion 600 can be surely positioned at the support position. Further, when the saddle portion B2 is moved from the pulling-out position to the mounting position, it is possible to suppress the support leg portion 600 from rotating in the second direction to a predetermined position and disabling the support of the saddle portion B2 by the support leg portion 600. As a result, in the pulling-out and insertion operations of the saddle portion B2, it is possible to more surely maintain the support state of the saddle portion B2 by the support leg portion 600. Therefore, it is possible to suppress the sheet processing apparatus B from falling forward when the saddle portion b2 is pulled out.

[0157] Note that the caster 601 is configured not to contact the installation surface until the contact portion 606b contacts the contacted portion 504c even when the distance between the bottom surface of the main body frame 500, on which four casters 502 are fixed so as to be adjustable, and the installation surface is minimized for height adjustment between the image forming apparatus A and the sheet processing apparatus B.

[0158] [Release of Regulation] Next, the configuration for releasing the regulation of the regulation unit 610 will be described. In this embodiment, as described above, by engaging the bent portion 606a with the hole portion 504b, it is possible to suppress the support leg portion 600 from inadvertently rotating from the support position to the storage position. However, when the saddle portion B2 is inserted into the housing 27, it is necessary to rotate the support leg portion 600 to the storage position. For this reason, in this embodiment, the regulation unit 610 releases the rotation regulation of the support leg portion 600 in the second direction in response to the operation of inserting the saddle portion B2 into the housing 27 beyond a predetermined position with respect to the housing 27, and allows the support leg portion 600 to move to the storage position.

[0159] For this purpose, in the present embodiment, the biasing force of the spring 607 disposed between the first sheet metal 605 and the second sheet metal 606 constituting the support sheet metal 602 is made smaller than the biasing force of the spring 603 that biases the support leg portion 600 toward the support position. Further, the bent portion 606a is formed so as not to engage with the hole portion 504b when the second sheet metal 606 rotates in a direction approaching the first sheet metal 605 about the rotation axis 602c. That is, as shown in FIG. 16(b), the bent portion 606a rotates in a direction along the locus of the circle D2 about the rotation axis 602a. The locus of this circle D2 is the direction in which the second sheet metal 606 rotates in a direction approaching the first sheet metal 605 about the rotation axis 602c. When the bent portion 606a rotates about the rotation axis 602a, the positional relationship with the hole portion 504b and the bending angle of the bent portion 606a are defined so that the bent portion 606a does not contact the hole portion 504b whether it rotates in the clockwise direction or the counterclockwise direction in the figure.

[0160] As described above, when the caster 601 contacts the installation surface when returning the saddle portion B2 from the pulled-out position to the mounted position, the support leg portion 600 rotates about the rotation axis 602a in the clockwise direction in FIG. 16(b), that is, in the second direction. Then, the caster 601 rotates along the locus of the circle D1. Then, the tip of the bent portion 606a rotates clockwise from the position shown in FIG. 16(b) and engages with the hole portion 504b as shown in FIG. 18. That is, in the present embodiment, when the support leg portion 600 rotates in the second direction about the rotation axis 602a, the bent portion 606a engages with the hole portion 504b to restrict the support leg portion 600 from further converging toward the storage position. When the second sheet metal 606 rotates in a direction approaching the first sheet metal 605 about the rotation axis 602c, the bent portion 606a disengages from the hole portion 504b without engaging with the hole portion 504b, allowing the support leg portion 600 to rotate in the second direction about the rotation axis 602c.

[0161] As described above, the contact member 604 is provided on the support leg portion 600. The contact member 604 is provided on the second sheet metal 606, is inserted into the housing 27 from the state where the saddle portion B2 is pulled out, and contacts a part of the housing 27 when the saddle portion B2 reaches a predetermined position. Specifically, in the process of shifting from the state of FIG. 20(f) described later to the state of FIG. 20(e), the contact member 604 contacts the F-side surface of the front lower stay 500a of the main body frame 500. Then, as shown in FIG. 20(e), the contact member 604 rotates the second sheet metal 606 in the direction approaching the first sheet metal 605 around the rotation shaft 602c in response to the operation of inserting the saddle portion B2 into the housing 27 from a predetermined position.

[0162] That is, as the saddle portion B2 is inserted into the housing 27, the contact member 604 contacts the front lower stay 500a, so that a force acting toward the first sheet metal 605 with respect to the second sheet metal 606 is applied. As described above, the spring 607 disposed between the first sheet metal 605 and the second sheet metal 606 has a smaller biasing force than the spring 603 that biases the support leg portion 600 toward the support position. For this reason, when the force acting toward the first sheet metal 605 with respect to the second sheet metal 606 is applied as described above, first, the spring 607 elastically contracts, and the second sheet metal 606 approaches the first sheet metal 605. At this time, since the biasing force of the spring 603 is larger than that of the spring 607, the second sheet metal 606 approaches the first sheet metal 605 without the support leg portion 600 rotating around the rotation shaft 602c.

[0163] Incidentally, if the biasing force of the spring 603 is smaller than that of the spring 607, when a force acting from the first sheet metal 605 toward the second sheet metal 606 as described above is applied, first, the spring 603 may be elastically deformed and the support leg portion 600 may rotate in the second direction about the rotation shaft 602a. In this case, the bent portion 606a may engage with the hole portion 504b, and the regulation by the regulating portion 610 may not be released. Therefore, in the present embodiment, the biasing force of the spring 603 is made larger than the biasing force of the spring 607. As a result, when a force acting from the second sheet metal 606 toward the first sheet metal 605 is applied, the spring 607 is elastically deformed before the spring 603 is elastically deformed, and before the support leg portion 600 rotates in the second direction about the rotation shaft 602a, the second sheet metal 606 is rotated about the rotation shaft 602c in a direction approaching the first sheet metal 605. Thereby, the regulation release by the regulating portion 610 can be surely performed, and the support leg portion 600 can be rotated from the support position to the storage position along with the operation of inserting the saddle portion B2 into the housing 27.

[0164] In the present embodiment, in order to smoothly rotate the support leg portion 600 between the support position and the storage position along with the insertion and withdrawal operations of the saddle portion B2 in this manner, the shape of the contact member 604 is such that the lower portion has a greater thickness in the F-B direction than the upper portion in a state where the support leg portion 600 is in the support position. Further, the contact surface 604a that contacts the front lower stay 500a, which is a part of the housing 27 of the contact member 604, is formed such that when the saddle portion B2 is inserted into the housing 27 from a predetermined position and contacts the front lower stay 500a, the support leg portion 600 rotates about the rotation shaft 602a and is stored in the storage position.

[0165] Specifically, the shape of the contact surface 604a that contacts the front lower stay 500a of the contact member 604 is formed by a plurality of curved surfaces. FIG. 19 is a perspective view of the contact member 604 as viewed from the contact surface 604a side. The contact surface 604a includes a first region 604a1 that contacts the upper corner of the front lower stay 500a during the insertion and withdrawal operations of the saddle portion B2, and contacts the upper surface of the front lower stay 500a in a state where the support leg 600 is in the storage position, and contacts or is closely opposed to the F-side surface of the front lower stay 500a when the support leg 600 rotates from the storage position to reach the support position.

[0166] The shape of the first region 604a1 is such that when the support leg 600 moves in the F-B direction together with the saddle portion B2, the contact surface 604a smoothly contacts the upper corner of the front lower stay 500a and does not get caught on the corner. Specifically, the first region 604a1 has a curved shape that is recessed toward the second sheet metal 606 and downward as it goes toward the F side in a state where the support leg 600 is in the storage position. In this way, by making the support leg 600 contact the corner of the front lower stay 500a when moving in the F-B direction, the rotation between the storage position and the support position of the support leg 600 can be smoothly performed. The second region 604a2 is smoothly continuous with the first region 604a1 and is formed so as to be farther from the second sheet metal 606 than the first region 604a1, and is a flat surface or a convex surface with a small curvature that stably contacts the upper surface of the front lower stay 500a in a state where the support leg 600 is in the storage position.

[0167] The rotational movement of the support leg 600 having such a contact member 604 accompanying the pulling-out movement of the saddle portion B2 will be described with reference to FIGS. 20(a) to 20(f). FIG. 20(a) shows a state where the saddle portion B2 is in the mounted position and the support leg 600 is in the stored position. In this state, the second region 604a2 of the contact member 604 abuts against the upper surface of the front lower stay 500a by the biasing force of the spring 603. When the saddle portion B2 is pulled out from the housing 27 from this state, as shown in FIG. 20(b), the support leg 600 also moves to the F side. In this state, the second region 604a2 of the contact member 604 still abuts against the upper surface of the front lower stay 500a.

[0168] Next, when the saddle portion B2 is further pulled out from the housing 27, as shown in FIG. 20(c), the first region 604a1 of the contact member 604 begins to contact the upper corner portion of the front lower stay 500a, and the support leg 600 begins to rotate in the first direction by the biasing force of the spring 603. When the saddle portion B2 is further pulled out from the housing 27, as shown in FIG. 20(d), the first region 604a1 of the contact member 604 moves while rubbing against the upper corner portion of the front lower stay 500a, and the support leg 600 further rotates in the first direction by the biasing force of the spring 603.

[0169] When the saddle portion B2 is further pulled out from the state of FIG. 20(d), as shown in FIG. 20(e), the support leg 600 comes out from above the front lower stay 500a, and the support leg 600 further rotates. At this time, the second region 604a2 of the contact member 604 abuts against the F-side side surface of the front lower stay 500a, and the second sheet metal 606 approaches the first sheet metal 605 against the biasing force of the spring 607. For this reason, the contact portion 606b of the second sheet metal 606 does not abut against the contact portion 504c of the rail stay 504.

[0170] When the saddle part B2 is further pulled out from the state of Fig. 20(e), the contact member 604 separates from the side surface of the front lower stay 500a, and the second sheet metal 606 rotates about the rotation shaft 602c in a direction away from the first sheet metal 605 by the biasing force of the spring 607. Then, as shown in Fig. 16(b) described above, the contact part 606b contacts the contacted part 504c, the rotation of the support leg part 600 in the first direction is restricted, and the support leg part 600 is in a state of being located at the support position. Also, in this state, the bent part 606a is inserted into the hole part 504b. This state is a state in which the stopper of the support leg part 600 is functioning.

[0171] On the other hand, when the saddle part B2 is inserted from the pulled-out position to the mounted position, the above-described stopper of the support leg part 600 functions until the state of Fig. 20(f) is reached. That is, until the contact member 604 provided on the support leg part 600 contacts the front lower stay 500a (until the saddle part B2 reaches a predetermined position with respect to the housing 27), even if a force for rotating the support leg part 600 in the second direction around the rotation shaft 602a acts, the bent part 606a engages with the hole part 504b to suppress the support leg part 600 from rotating in the second direction. In the present embodiment, the position where the contact member 604 contacts the F-side side surface of the front lower stay 500a is defined as a predetermined position.

[0172] When the saddle part B2 is further inserted from the state of Fig. 20(f), the second sheet metal 606 is pushed by the contact of the contact member 604 with the F-side side surface of the front lower stay 500a. Then, the second sheet metal 606 rotates about the rotation shaft 602c in a direction approaching the first sheet metal 605 against the biasing force of the spring 607, and as described above, the bent part 606a comes out of the hole part 504b. That is, the stopper function of the support leg part 600 is released. Thereby, the support leg part 600 can rotate in the second direction about the rotation shaft 602a. In this state, when the saddle part B2 is further inserted into the housing 27, due to the contact between the contact member 604 and the upper corner part of the front lower stay 500a, in the order of Fig. 20(d), Fig. 20(c), and Fig. 20(b), the support leg part 600 rotates in the second direction about the rotation shaft 602a against the biasing force of the spring 603 and rotates to the storage position as shown in Fig. 20(a).

[0173] In this embodiment, even when a force that rotates the support leg 600 in the first direction (counterclockwise) about the rotation axis 602a acts on the support leg 600, the contact between the contact portion 606b and the portion to be contacted 504c suppresses the support leg 600 from rotating further in the first direction. That is, even when a load is applied to the support leg 600 when the saddle part B2 is pulled out from inside the housing 27, it is possible to suppress the support leg 600 from being unable to support the saddle part B2.

[0174] Also, even when a force that rotates the support leg 600 in the second direction (clockwise) about the rotation axis 602a acts on the support leg 600, the bent portion 606a engages with the hole portion 504b, thereby suppressing the support leg 600 from rotating further in the second direction. That is, even when a load is applied to the support leg 600 when the saddle part B2 is inserted into the housing 27, it is possible to suppress the support leg 600 from being unable to support the saddle part B2. In this embodiment, when the saddle part B2 is inserted and pulled out, for example, even when forces in the first direction and the second direction act on the support leg 600 about the rotation axis 602a due to friction between the caster 601 and the installation surface, etc., the support leg 600 can be maintained in the support position, and it can be suppressed that the saddle part B2 is not supported by the support leg 600. Note that, as long as the saddle part B2 can be supported by the support leg 600 when the saddle part B2 is pulled out and inserted as described above, a configuration may be adopted in which the manual stopper function is enabled to restrict the support leg 600 from returning to the storage position.

[0175] Also, as shown in FIG. 20(e), when the abutting member 604 abuts against the F-side side surface of the front lower stay 500a during the insertion operation of the saddle portion B2, the second sheet metal 606 rotates and the stopper function of the support leg portion 600 is released. That is, by the operation of the user inserting the saddle portion B2 into the housing 27, the stopper function of the support leg portion 600 is automatically released, allowing the support leg portion 600 to rotate to the storage position. Therefore, there is no need for a special operation to allow the support leg portion 600 to rotate to the storage position, such as manually releasing the stopper function, and the usability can be improved.

[0176] In this embodiment, as shown in FIG. 14(a) described above, the front lower stay 500a is drawn to ensure strength and has unevenness on the upper surface. For this reason, when inserting and pulling out the saddle portion B2, the abutting member 604 of the support leg portion 600 may be caught by this unevenness. Therefore, in the region of the front lower stay 500a that the abutting member 604 contacts, a guide member 500a1 is provided to guide the abutting member 604 so that it is not caught. If there is no portion where the abutting member 604 of the support leg portion 600 is caught during the insertion and pulling out operations of the saddle portion B2, such as when the surface of the front lower stay 500a has no unevenness, the guide member 500a1 may be omitted. Although the guide member 500a1 was not mentioned in the above description, the upper surface, F-side side surface, and upper corner portion of the front lower stay 500a that the abutting member 604 abuts are the upper surface, F-side side surface, and upper corner portion of the guide member 500a1.

[0177] [Another example] In the above description, the configuration in which the support leg portion 600 is provided on the saddle portion B2 of the sheet processing apparatus B has been described. However, the configuration of providing the support leg portion 600 as described above is not limited to the sheet processing apparatus B. For example, as shown in FIG. 21, the support leg portion 600 may be provided on the lowermost cassette 210 of the sheet storage apparatus 2d. The sheet storage apparatus 2d has, for example, the configuration described with reference to FIG. 1.

[0178] The lowermost cassette 210 as the storage unit is arranged so that it can be pulled out from the housing 211 as the casing of the sheet storage device 2d and inserted into the mounting position of the housing 211, and stores the sheets. And, similar to the case of the saddle portion B2 described above, when the cassette 210 is inserted and pulled out, the cassette 210 is supported by the support legs 600. The configuration including the stopper function of the support legs 600 is the same as that described in the above-described sheet processing device B. Also, the relationship between the plurality of casters (first casters) 200 that support the sheet storage device 2d with respect to the installation surface and the support legs 600 is the same as the relationship between the casters 502 and the support legs 600 described above.

[0179] By supporting the cassette 210 with the support legs 600 when the lowermost cassette 210 is inserted and pulled out in this way, for example, even when the weight of the cassette 210 increases due to storing a large amount of sheets inside the cassette 210, it is possible to suppress the sheet storage device 2d from tilting when the cassette 210 is pulled out. Also, by configuring the support legs 600 as described above, even when forces in the first direction and the second direction act on the support legs 600 around the rotation axis 602a during the insertion and pulling-out operations of the cassette 210, the support legs 600 can be maintained in the support position, and it can be suppressed that the cassette 210 is not supported by the support legs 600.

[0180] Also, in the case of this embodiment as well, similar to the first embodiment, the plurality of casters 200 provided on the sheet storage device 2d have a plurality of rotation axes (not shown), so that the casters themselves can rotate and the casters can pivot 360° with respect to the sheet storage device 2d. This is to facilitate the handling when moving the device when installing the sheet storage device 2d or the like. On the other hand, the caster 601 provided on the support legs 600 can rotate only in one direction (the pulling-out direction of the lowermost cassette 210).

[0181] Thus, when pulling out the lowermost cassette 210, the caster 601 moves only in the same direction as the pulling direction of the cassette 210, so it does not become a burden when the user performs the operation of pulling out the cassette 210, and the operability is good. In other words, it suppresses the deterioration of operability caused by the caster 601 facing a direction different from the pulling direction when pulling out the cassette 210.

[0182] On the other hand, when moving the sheet storage device 2d, if the caster 200 tries to rotate and move in a direction different from the direction in which the caster 601 advances due to the rotation of the caster 601 and the caster 601 of the support leg 600 is in contact with the installation surface, since the caster 601 rotates only in one direction, it is difficult to move the sheet storage device 2d. In contrast, in this embodiment, since the support leg 600 is located at the storage position, when moving the sheet storage device 2d by the caster 200, the caster 601 that rotates only in one direction of the support leg 600 does not hinder the movement of the sheet storage device 2d, and the sheet storage device 2d can be moved smoothly, and the operability is good.

[0183] Also, even if the caster 601 is configured to be rotatable in the same way as the caster 200, when there are irregularities on the installation surface such as the floor when moving the sheet storage device 2d, the caster 601 may come into contact with the irregularities and hinder the movement of the device. However, in this embodiment, since the support leg 600 can be moved from the support position to the storage position, it is possible to suppress the deterioration of usability without hindering the movement of the device itself.

[0184] <Other Embodiments>

[0185] In the above-described embodiment, the support leg 600 is configured to move between the support position and the storage position in conjunction with the movement of the saddle portion B2 and the lowermost cassette 210 in the insertion direction and the pulling direction. However, as long as the support leg 600 is configured to return from the support position to the storage position in conjunction with the movement of the saddle portion B2 and the lowermost cassette 210 in the insertion direction, the movement of the support leg 600 from the storage position to the support position may be configured to be manual.

[0186] Also, in the above-described embodiment, the regulation unit 610 regulates the movement (rotation) of the support leg 600 in the direction of returning from the support position to the storage position, and releases this regulation in conjunction with the movement of the saddle part B2 and the lowermost cassette 210 in the insertion direction. However, for example, the support leg 600 may be locked in the support position, and this lock may be manually released so that the support leg 600 returns to the storage position in conjunction with the insertion of the saddle part B2 and the lowermost cassette 210.

[0187] Also, in the above-described embodiment, the case where the processing unit is the saddle part B2 that performs the folding-in process, the middle binding process, and the corner-back process as predetermined processes has been described. However, the processing unit is not limited to this, and it may be a unit that performs any one of these processes, or may be a unit that performs a plurality of processes. Also, the predetermined process is not limited to these processes, and may be an end binding process performed on the end of the sheet bundle, or may be a perforation process for punching holes in the sheet bundle. That is, the predetermined process may include any one or a plurality of processes among various processes conventionally known to be performed on a sheet or a sheet bundle, such as a folding-in process, a middle binding process, a corner-back process, an end binding process, and a perforation process.

[0188] Also, in the above-described embodiment, the sheet processing apparatus B has a control unit and controls each component inside the sheet processing apparatus B. However, each component inside the sheet processing apparatus B may be controlled by the control unit provided in the image forming apparatus.

[0189] Furthermore, as the conveyance unit that conveys the sheet inside the sheet processing apparatus B, in the above-described embodiment, a pair of rollers has been described as an example, but a configuration in which the sheet is conveyed by a belt may also be used. Specifically, it may be any of a configuration in which a belt is sandwiched and conveyed by a pair of rollers, a configuration in which the sheet is sandwiched and conveyed by a pair of belts, or a configuration in which the sheet is sandwiched by a belt and a roller, and the conveyance configuration may be changed depending on the position and path where the sheet is conveyed. For example, at a certain position, the sheet may be conveyed by a pair of rollers, and at another position, the sheet may be conveyed by a pair of belts.

[0190] In the above-described embodiment, the image forming system 1000 in which the sheet processing apparatus B is directly connected to the image forming apparatus A has been described. However, other system configurations may also be used. For example, a configuration in which other processing apparatuses, conveyance apparatuses, etc. are connected between the image forming apparatus A and the sheet processing apparatus B may be used. Further, in the above-described embodiment, the image forming apparatus A that forms a monochrome image using toner has been described as an example. However, an image forming apparatus that forms a color image using toner or an image forming apparatus that forms an image on a sheet using ink may also be used.

[0191] Further, the disclosure of the present embodiment includes the following configurations. (Configuration 1) A sheet processing apparatus, a first caster that movably supports the sheet processing apparatus, a processing unit that is provided so as to be pullable out and insertable into the sheet processing apparatus and that performs a predetermined process on a sheet, a second caster that is provided on the processing unit and that contacts the installation surface of the sheet processing apparatus when the processing unit moves in the pull-out direction to support the processing unit, a support portion that movably supports the second caster between a storage position where the processing unit is located in a state of being inserted into the sheet processing apparatus and a support position for supporting the processing unit pulled out from the sheet processing apparatus with respect to the installation surface on which the sheet processing apparatus is installed, and that moves the second caster from the support position to the storage position along with an operation of inserting the processing unit, the sheet processing apparatus comprising the support portion. (Configuration 2) The sheet processing apparatus according to Configuration 1, wherein the support portion moves the second caster from the storage position to the support position along with an operation of pulling out the processing unit. (Configuration 3) The sheet processing apparatus according to Configuration 1 or 2, further comprising a locking mechanism that locks the support portion at the support position in a state where the processing unit is pulled out from the sheet processing apparatus. (Configuration 4) The first caster is provided on the bottom surface of the sheet processing apparatus, The second caster and the support portion are located above the bottom surface at the storage position, and the sheet processing apparatus according to any one of Configurations 1 to 3. (Configuration 5) When the processing unit moves in the direction of being inserted into the sheet processing apparatus from the pulled-out state, the sheet processing apparatus according to any one of Configurations 1 to 4, further comprising a restricting portion that restricts the second caster from moving in the direction from the support position to the storage position. (Configuration 6) The restricting portion releases the restriction on the support portion in the direction toward the storage position according to the operation of inserting the processing unit into the sheet processing apparatus, and the sheet processing apparatus according to Configuration 5 that allows the support portion to move to the storage position. (Configuration 7) A first biasing portion that biases the support portion in the direction from the storage position to the support position, A first rotation shaft that rotatably supports the support portion, and further comprising: The support portion includes a first member rotatably supported by the first rotation shaft, a second member rotatably supported about a second rotation shaft with respect to the first member, and a second biasing portion that biases the second member in a direction away from the first member. The restricting portion includes a first engaging portion provided on the second member, and a second engaging portion provided on a member that moves together with the processing unit during the insertion and withdrawal operations of the processing unit, and that engages with the first engaging portion to restrict the rotation of the support portion when the support portion rotates about the first rotation shaft in the direction toward the storage position. The sheet processing apparatus according to Configuration 5 or 6. (Configuration 8) A rail portion that guides the processing unit to be pulled out from and inserted into the sheet processing apparatus, A rail-side support portion provided on the rail portion that rotatably supports the support portion about the first rotation shaft, and further comprising: The second engaging portion is formed on the rail-side support portion. The sheet processing apparatus according to Configuration 7. (Configuration 9) The second biasing portion has a biasing force smaller than that of the first biasing portion, and the sheet processing apparatus according to Configuration 7 or 8. (Configuration 10) The first engaging portion does not engage with the second engaging portion when the second member rotates in a direction approaching the first member about the second rotation axis, and the sheet processing apparatus according to Configuration 9. (Configuration 11) Provided on the second member, when the processing unit is inserted into the sheet processing apparatus from the pulled-out state, it abuts against a part of the sheet processing apparatus, and according to the operation of inserting the processing unit into the sheet processing apparatus, the second member is rotated about the second rotation axis in a direction approaching the first member, and the sheet processing apparatus according to Configuration 10 further includes a contact member. (Configuration 12) The contact surface of the contact member that abuts against a part of the sheet processing apparatus is formed such that when the processing unit is inserted into the sheet processing apparatus, it abuts against a part of the sheet processing apparatus, and the support portion rotates about the first rotation axis and is stored in the storage position, and the sheet processing apparatus according to Configuration 11. (Configuration 13) A rotation axis that rotatably supports the support portion, A main support portion that supports the sheet processing apparatus with respect to the installation surface, and further includes, In a state where the support portion is in the support position, when the distance between the rotation axis and the lower end portion of the support portion in the vertical direction is L1, and the distance between the rotation axis and the lower end portion of the main support portion in the vertical direction is L2, the sheet processing apparatus according to any one of Configurations 1 to 12 that satisfies L1 < L2. (Configuration 14) The processing unit is, A conveying unit that conveys a sheet bundle that has been subjected to a middle folding process so that the height of the sheet bundle is located on the downstream side in the conveying direction from the back opening, or a sheet bundle that has been subjected to a middle binding process and a middle folding process, A pair of clamping units that move relative to the sheet bundle conveyed by the conveying unit to clamp and release the clamping of the sheet bundle, and a pressing roller that presses the back of the sheet bundle clamped by the pair of clamping units toward the pair of clamping units. In the conveying direction of the sheet bundle by the conveying unit, a corner-back processing unit that performs corner-back processing of pressing the back of the sheet bundle clamped by the pair of clamping units against the pressing roller so that the back of the sheet bundle protrudes downstream with respect to the pair of clamping units. The predetermined processing is the sheet processing apparatus according to any one of Configurations 1 to 13 including the corner-back processing. (Configuration 15) An image forming unit having an image forming section for forming an image on a sheet. A sheet processing apparatus according to any one of Configurations 1 to 14. The sheet processing apparatus is an image forming system that performs the predetermined processing on a sheet on which an image has been formed by the image forming section. (Configuration 16) A sheet storage device. A first caster that movably supports the sheet storage device. A storage unit that is provided so as to be pullable out and insertable into the sheet storage device and stores sheets. A second caster that is provided in the storage unit and contacts the installation surface of the sheet storage device when the storage unit moves in the pull-out direction to support the storage unit. A support portion that movably supports the second caster between a storage position where the storage unit is located in a state of being inserted into the sheet storage device and a support position for supporting the storage unit pulled out from the sheet storage device with respect to the installation surface on which the sheet storage device is installed. The support portion moves the second caster from the support position to the storage position along with the operation of inserting the storage unit. A sheet storage device provided with the support portion. (Configuration 17) The support portion is the sheet storage device according to Configuration 16 that moves the second caster from the storage position to the support position along with the operation of pulling out the storage unit. (Configuration 18) The seat storage device according to Configuration 16 or 17, further comprising a locking mechanism that locks the support portion at the support position in a state where the storage unit is pulled out from the seat storage device. (Configuration 19) The first caster is provided on the bottom surface of the seat storage device, The seat storage device according to any one of Configurations 16 to 18, wherein the second caster and the support portion are located above the bottom surface in the storage position. (Configuration 20) The seat storage device according to any one of Configurations 16 to 19, further comprising a restricting portion that restricts the second caster from moving from the support position toward the storage position when the storage unit moves in a direction of being inserted into the seat storage device from a pulled-out state. (Configuration 21) The seat storage device according to Configuration 20, wherein the restricting portion releases the restriction on the support portion in a direction toward the storage position in response to an operation of inserting the storage unit into the seat storage device, and allows the support portion to move to the storage position. (Configuration 22) A first biasing portion that biases the support portion in a direction from the storage position toward the support position, A first rotation shaft that rotatably supports the support portion, and The support portion includes a first member rotatably supported by the first rotation shaft, a second member rotatably supported about a second rotation shaft with respect to the first member, and a second biasing portion that biases the second member in a direction away from the first member. The seat storage device according to Configuration 20 or 21, wherein the restricting portion includes a first engaging portion provided on the second member and a second engaging portion provided on a member that moves together with the storage unit during insertion and withdrawal operations of the storage unit, and the second engaging portion engages with the first engaging portion to restrict rotation of the support portion when the support portion rotates about the first rotation shaft in a direction toward the storage position. (Configuration 23) A rail section that guides the insertion and extraction of the storage unit from and into the sheet storage device; A rail-side support portion provided on the rail section and rotatably supporting the support portion about the first rotation axis; The second engaging portion is formed on the rail-side support portion, and the sheet storage device according to Configuration 22. (Configuration 24) The second biasing portion, and the sheet storage device according to Configuration 22 or 23 having a biasing force smaller than that of the first biasing portion. (Configuration 25) The first engaging portion, and the sheet storage device according to Configuration 24 that does not engage with the second engaging portion when the second member rotates in a direction approaching the first member about the second rotation axis. (Configuration 26) A contact member provided on the second member, which contacts a part of the sheet storage device when the storage unit is inserted into the sheet storage device from a pulled-out state, and rotates the second member about the second rotation axis in a direction approaching the first member in response to the operation of inserting the storage unit into the sheet storage device, and the sheet storage device according to Configuration 25 further including the contact member. (Configuration 27) The contact surface of the contact member that contacts a part of the sheet storage device is formed such that when the storage unit is inserted into the sheet storage device, the support portion rotates about the first rotation axis and is stored in the storage position by contacting a part of the sheet storage device, and the sheet storage device according to Configuration 26. (Configuration 28) A rotation axis that rotatably supports the support portion; A main support portion that supports the sheet storage device with respect to the installation surface; When the support portion is in the support position, with the distance between the rotation axis and the lower end portion of the support portion in the vertical direction being L1 and the distance between the rotation axis and the lower end portion of the main support portion in the vertical direction being L2, the sheet storage device according to any one of Configurations 16 to 27 that satisfies L1 < L2. (Configuration 29) An image forming unit having an image forming section for forming an image on a sheet, and a sheet storage device according to any one of Configurations 16 to 28, wherein the image forming unit is an image forming system capable of forming an image on a sheet fed from the sheet storage device by the image forming section.

Explanation of Signs

[0192] 2d ··· Sheet storage device 3 ··· Image forming section 27 ··· Housing (frame) 118 ··· Saddle third roller pair (transport section) 120 ··· Lower clamp unit (clamping unit) 121 ··· Upper clamp unit (clamping unit) 123 ··· Pressing roller 134 ··· Corner back processing unit 200 ··· Caster (first caster) 210 ··· Cassette (storage unit) 211 ··· Housing (frame) 502 ··· Caster (first caster) 503 ··· Rail section 504 ··· Rail stay (rail side support section) 504b ··· Hole section (second engagement section) 600 ··· Support leg section (support section) 601 ··· Caster (second caster) 602a ··· Rotation shaft (first rotation shaft) 602c ··· Rotation shaft (second rotation shaft) 603 ··· Spring (biasing section, first biasing section) 604 ··· Contact member 604a ··· Contact surface 605 ··· First sheet metal (first member) 606 ··· Second sheet metal (second member) 606a ··· Bending section (first engagement section) 607 ··· Spring (second biasing section) 610 ··· Regulation section 1000 ··· Image forming system A ··· Image forming apparatus B ··· Sheet processing apparatus B2 ··· Saddle part (processing unit)

Claims

1. A sheet processing apparatus, a first caster that movably supports the sheet processing apparatus; a processing unit that is provided so as to be pullable out and insertable into the sheet processing apparatus and that performs a predetermined process on a sheet; a second caster that is provided on the processing unit and that contacts an installation surface of the sheet processing apparatus when the processing unit moves in a pull-out direction to support the processing unit; a support portion that movably supports the second caster between a storage position where the processing unit is located in a state of being inserted into the sheet processing apparatus and a support position for supporting the processing unit pulled out from the sheet processing apparatus with respect to the installation surface on which the sheet processing apparatus is installed, the support portion moving the second caster from the support position to the storage position along with an operation of inserting the processing unit. A sheet processing apparatus comprising:

2. The sheet processing apparatus according to claim 1, wherein the support portion moves the second caster from the storage position to the support position along with an operation of pulling out the processing unit.

3. The sheet processing apparatus according to claim 1, further comprising a locking mechanism that locks the support portion at the support position when the processing unit is pulled out from the sheet processing apparatus.

4. The first caster is provided on a bottom surface of the sheet processing apparatus, and the second caster and the support portion are located above the bottom surface at the storage position. The sheet processing apparatus according to claim 1.

5. The sheet processing apparatus according to claim 1, further comprising a restricting portion that restricts the second caster from moving from the support position toward the storage position when the processing unit moves in a direction of being inserted into the sheet processing apparatus from a state where the processing unit is pulled out.

6. The sheet processing apparatus according to claim 5, wherein the restricting portion releases the restriction on the support portion in a direction toward the storage position in response to an operation of inserting the processing unit into the sheet processing apparatus and allows the support portion to move to the storage position.

7. a first biasing portion that biases the support portion in a direction from the storage position toward the support position; a first rotation shaft that rotatably supports the support portion, The support portion includes a first member rotatably supported by the first rotation axis, a second member rotatably supported by the first member about a second rotation axis, and a second biasing portion that biases the second member in a direction away from the first member. The restricting portion includes a first engaging portion provided on the second member, and a second engaging portion provided on a member that moves together with the processing unit during the insertion and withdrawal operations of the processing unit, and that engages with the first engaging portion to restrict the rotation of the support portion when the support portion rotates about the first rotation axis in a direction toward the storage position. The sheet processing apparatus according to claim 5.

8. A rail portion that guides the processing unit to be pulled out from and inserted into the sheet processing apparatus. Further provided is a rail-side support portion provided on the rail portion that rotatably supports the support portion about the first rotation axis. The second engaging portion is formed on the rail-side support portion. The sheet processing apparatus according to claim 7.

9. The second biasing portion has a biasing force smaller than that of the first biasing portion. The sheet processing apparatus according to claim 7.

10. The first engaging portion does not engage with the second engaging portion when the second member rotates about the second rotation axis in a direction approaching the first member. The sheet processing apparatus according to claim 9.

11. Further provided is a contact member provided on the second member that contacts a part of the sheet processing apparatus when the processing unit is inserted into the sheet processing apparatus from a pulled-out state, and rotates the second member about the second rotation axis in a direction approaching the first member in response to the operation of inserting the processing unit into the sheet processing apparatus. The sheet processing apparatus according to claim 10.

12. The contact surface of the contact member that contacts a part of the sheet processing apparatus is formed such that when the processing unit is inserted into the sheet processing apparatus, the support portion rotates about the first rotation axis and is stored in the storage position by contacting a part of the sheet processing apparatus. The sheet processing apparatus according to claim 11.

13. A rotation axis that rotatably supports the support portion. Further provided is a main support portion that supports the sheet processing apparatus with respect to the installation surface. When the support portion is in the support position, with the distance between the rotation axis and the lower end of the support portion being L1 and the distance between the rotation axis and the lower end of the main support portion being L2 in the vertical direction, the sheet processing apparatus according to claim 1, wherein L1 < L2.

14. The processing unit includes: a conveying unit that conveys a sheet bundle that has been subjected to a middle folding process so that the back of the sheet bundle is located on the downstream side in the conveying direction from the head end, or a sheet bundle that has been subjected to a middle binding process and a middle folding process; a pair of clamping units that clamp and release the clamping of the sheet bundle by moving relative to the sheet bundle conveyed by the conveying unit; and a pressing roller that presses the back of the sheet bundle clamped by the pair of clamping units toward the pair of clamping units, and a corner back processing unit that performs a corner back process of pressing the back of the sheet bundle clamped by the pair of clamping units by the pressing roller so that the back of the sheet bundle protrudes downstream with respect to the pair of clamping units in the conveying direction of the sheet bundle by the conveying unit. The sheet processing apparatus according to claim 1, wherein the predetermined process includes the corner back process.

15. an image forming unit having an image forming portion that forms an image on a sheet; a sheet processing apparatus according to any one of claims 1 to 14, wherein the sheet processing apparatus is an image forming system that performs the predetermined process on the sheet on which an image has been formed by the image forming portion.

16. A sheet storage device, comprising: a first caster that movably supports the sheet storage device; a storage unit that is provided so as to be able to be pulled out and inserted with respect to the sheet storage device and stores sheets; a second caster that is provided on the storage unit and contacts the installation surface of the sheet storage device when the storage unit moves in the pulling-out direction to support the storage unit; a support portion that movably supports the second caster between a storage position where the storage unit is located in a state of being inserted into the sheet storage device and a support position for supporting the storage unit pulled out from the sheet storage device with respect to the installation surface on which the sheet storage device is installed, and the support portion that moves the second caster from the support position to the storage position along with the operation of inserting the storage unit.

17. The sheet storage device according to claim 16, wherein the support portion moves the second caster from the storage position to the support position as the operation of pulling out the storage unit is performed.

18. The sheet storage device according to claim 16, further comprising a locking mechanism that locks the support portion at the support position when the storage unit is pulled out from the sheet storage device.

19. The first caster is provided on the bottom surface of the sheet storage device, The sheet storage device according to claim 16, wherein the second caster and the support portion are located above the bottom surface at the storage position.

20. The sheet storage device according to claim 16, further comprising a restricting portion that restricts the second caster from moving in a direction from the support position toward the storage position when the storage unit moves in a direction of being inserted into the sheet storage device from a pulled-out state.

21. The sheet storage device according to claim 20, wherein the restricting portion releases the restriction on the support portion in a direction toward the storage position in response to an operation of inserting the storage unit into the sheet storage device, and allows the support portion to move to the storage position.

22. A first biasing portion that biases the support portion in a direction from the storage position toward the support position; A first rotation shaft that rotatably supports the support portion; and further comprising, The support portion includes a first member rotatably supported by the first rotation shaft, a second member rotatably supported about a second rotation shaft with respect to the first member, and a second biasing portion that biases the second member in a direction away from the first member. The restricting portion includes a first engaging portion provided on the second member, and a second engaging portion provided on a member that moves together with the storage unit during the insertion and pulling-out operations of the storage unit, and that engages with the first engaging portion to restrict the rotation of the support portion when the support portion rotates about the first rotation shaft in a direction toward the storage position. The sheet storage device according to claim 20.

23. A rail portion that guides the storage unit to be able to be pulled out from and inserted into the sheet storage device; A rail-side support portion provided on the rail portion and rotatably supporting the support portion about the first rotation shaft; and further comprising, The sheet storage device according to claim 22, wherein the second engaging portion is formed on the rail-side support portion.

24. The sheet storage device according to claim 22, wherein the second biasing portion has a biasing force smaller than that of the first biasing portion.

25. The sheet storage device according to claim 24, wherein the first engaging portion does not engage with the second engaging portion when the second member rotates in a direction approaching the first member about the second rotation axis.

26. The sheet storage device according to claim 25, further comprising a contact member provided on the second member, which contacts a part of the sheet storage device when the storage unit is inserted into the sheet storage device from a pulled-out state, and rotates the second member in a direction approaching the first member about the second rotation axis in response to the operation of inserting the storage unit into the sheet storage device.

27. The sheet storage device according to claim 26, wherein the contact surface of the contact member that contacts a part of the sheet storage device is formed such that when the storage unit is inserted into the sheet storage device, the support portion rotates about the first rotation axis and is stored in the storage position by contacting a part of the sheet storage device.

28. A rotation axis that rotatably supports the support portion, and a main support portion that supports the sheet storage device with respect to the installation surface, and when the support portion is in the support position, with the distance between the rotation axis and the lower end portion of the support portion in the vertical direction being L1 and the distance between the rotation axis and the lower end portion of the main support portion in the vertical direction being L2, the sheet storage device according to claim 16, satisfying L1 < L2.

29. An image forming unit having an image forming portion that forms an image on a sheet, and the sheet storage device according to any one of claims 16 to 28, and the image forming unit is an image forming system capable of forming an image on the sheet fed from the sheet storage device by the image forming portion.

Images