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

Abstract

To provide a configuration in which a brake is actuated when a saddle part is forcefully inserted, the configuration being capable of suppressing occurrence of a failure in a centrifugal brake unit 820.SOLUTION: A saddle part is movable between a drawing position of being drawn from a sheet processing device and a storage position of being stored in the sheet processing device, and applies predetermined processing on a sheet. The centrifugal brake unit 820 is actuated when the saddle part is inserted from the drawing position in a direction toward the storage position at a speed equal to or higher than a predetermined speed, and brakes the saddle part. When the centrifugal brake unit 820 is actuated, the gear unit 810 applies a load to the saddle part moving from the drawing position in a direction toward the storage position and absorbs an impact applied to the centrifugal brake unit 820.SELECTED DRAWING: Figure 15

Description

Technical Field

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

Background Art

[0002] Conventionally, a sheet processing apparatus has a processing unit that performs various processes such as binding on a sheet. In addition, in the sheet processing apparatus, there is a configuration in which the processing unit can be pulled out from the housing of the apparatus for replacement work of replacement parts of the processing unit and jam processing of the sheet. Also, regarding a storage apparatus that stores a sheet, there is a configuration in which a storage unit that stores a sheet can be pulled out from the housing of the apparatus when replenishing the sheet in the storage unit that stores the sheet or for jam processing or the like.

[0003] Here, in the case of a configuration including a pull-out unit such as a processing unit of a sheet processing apparatus or a storage unit of a sheet storage apparatus, when the pull-out unit is inserted into the apparatus from the pulled-out state, the pull-out unit may be inserted forcefully. In this case, the pull-out unit inserted forcefully may collide with the frame of the apparatus or components inside the apparatus, resulting in problems such as malfunctions and damages. There is a risk of such problems occurring.

[0004] Therefore, it is conceivable to apply a brake to a pull-out unit that moves using a brake device such as that in Patent Document 1. In a brake device such as that in Patent Document 1, it is conceivable to apply a brake to the pull-out unit that moves when the pull-out unit is inserted forcefully, and suppress the pull-out unit from colliding with the frame of the apparatus or components inside the apparatus.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when the configuration of Patent Document 1 is used as the braking mechanism of the drawer unit, when the drawer unit inserted forcefully is braked, the movement of the drawer unit will suddenly stop. At this time, especially when the weight of the drawer unit is heavy, etc., due to the sudden stop of the movement of the drawer unit, a large load is applied to the braking mechanism, and there is a risk of malfunction in the braking mechanism.

[0007] An object of the present invention is to provide a configuration capable of suppressing the occurrence of malfunctions in a braking mechanism in a configuration where a braking operation is performed when a pull-out unit such as a processing unit or a storage unit is forcefully inserted.

Means for Solving the Problems

[0008] One aspect of the present invention is a sheet processing apparatus, comprising: a processing unit that is movable between a pull-out position pulled out from the sheet processing apparatus and a storage position stored in the sheet processing apparatus, and that performs a predetermined process on a sheet; a braking mechanism that operates when the processing unit is inserted at a speed equal to or higher than a predetermined speed in a direction from the pull-out position toward the storage position, and brakes the processing unit; and a damper mechanism that, when the braking mechanism operates, applies a load to the processing unit moving in a direction from the pull-out position toward the storage position to absorb an impact applied to the braking mechanism.

[0009] One aspect of the present invention is a sheet storage device, which is movable between a pull-out position pulled out from the sheet storage device and a storage position stored in the sheet storage device, and includes a storage unit for storing sheets, and a braking mechanism that operates when the storage unit is inserted at a speed equal to or higher than a predetermined speed in a direction from the pull-out position toward the storage position to brake the storage unit, and a damper mechanism that applies a load to the storage unit moving in the direction from the pull-out position toward the storage position when the braking mechanism operates to absorb an impact applied to the braking mechanism.

Advantages of the Invention

[0010] According to the present invention, in a configuration in which a brake is operated when a pull-out unit such as a processing unit or a storage unit is inserted forcefully, it is possible to suppress the occurrence of a defect in the braking mechanism.

Brief Description of the Drawings

[0011]

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Figure 18

[0012] The embodiment will be described with reference to FIGS. 1 to 17(b). First, the schematic configuration of the image forming system of the present embodiment will be described with reference to FIG. 1.

[0013] [Image Forming System] In this embodiment, a copier is used as the image forming apparatus. A sheet processing apparatus is connected to the sheet discharge port of this copier, and the sheet processing apparatus further includes a saddle part for performing double-stitching and middle folding processes inside. The image forming system 1000 includes an image forming apparatus A and a sheet processing apparatus B. The sheet S formed with an image by the image forming apparatus A is received by the downstream sheet processing apparatus B, and is subjected to double-stitching processing, middle folding processing, corner folding processing, etc. as necessary, and then discharged to the downstream discharge part. The image forming apparatus A includes various structures such as, for example, a copier, a printer, a printing machine, a facsimile machine, and a multi-functional 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, regarding 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 there is an operation panel or operation buttons) is referred to as the front side (F side, the front side of the paper surface in FIGS. 1, 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, 2, etc.).

[0014] [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 a 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.

[0015] The sheet feeding unit 2 includes a plurality of cassettes 2a, 2b, and 2c. Each cassette 2a, 2b, 2c can store a plurality of sheets S of different standard sizes selected in advance in multiple layers. The sheet S is, for example, paper, a plastic sheet, or the like. Each cassette 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 sheet feeding unit 2 with 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 sheet S supplied from one of the plurality of cassettes 2a, 2b, 2c is further conveyed downstream by the conveying roller 7. The sheet conveyed by the conveying roller 7 has its leading edge aligned and its skew corrected by the registration roller pair 8. Then, the sheet S with its leading edge aligned by the registration roller pair 8 is fed to the image forming unit 3 on the downstream side at a predetermined timing.

[0016] 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 and feeding are difficult.

[0017] The image forming unit 3 may be configured to form an image on the sheet S sent from the sheet 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.

[0018] 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 an electrostatic latent image on 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. In FIG. 1, a monochrome printing mechanism is shown 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 the transfer device 12. The sheet S onto which the toner image has been transferred is fixed by the 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 has been fixed by the fixing device 13 is reversed front to back, it is sent again to the registration roller pair 8, and an image is formed on the back surface of the sheet S. A discharge roller 15 is provided downstream of the fixing device 13 and downstream of 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.

[0019] 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.

[0020] 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, the image of the document placed on the first platen glass 17 is irradiated 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.

[0021] The original document feeding unit A3 includes a feeding tray 22 and a discharging 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 discharging 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 stopped in advance below the second platen glass 21, and image data is read from the image passing over the second platen glass 21.

[0022] [Overall Configuration of the Sheet Processing Apparatus] Next, the overall configuration of the sheet processing apparatus B that performs processing such as stapling and folding on the sheets conveyed from the image forming apparatus A will be described with reference to FIG. 2. FIG. 2 shows the detailed configuration of the sheet processing apparatus B. The sheet processing apparatus 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 apparatus A, after processing, on 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 through which the sheet is conveyed by a conveyance guide, conveyance rollers, or the like.

[0023] In the illustrated apparatus, the sheets sent to 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 apparatus has a control unit, a communication unit, etc., like the blocks showing the control configuration in the entire apparatus shown in FIG. 3, and controls the apparatus accordingly.

[0024] The processing unit B1 as the end-binding processing unit is disposed below the path exit (delivery unit 35) of the conveyance path 28, and assembles and stacks a plurality of sheets sequentially delivered from the conveyance path 28 via the delivery unit 35 into a sheet bundle, and is capable of performing 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 sheets or sheet bundles stacked on the first tray 49 abut against the stacking wall 50 on the upstream side in the discharge direction of the sheets on the first tray 49 with their rear ends (upstream ends), and are stacked along the stacking wall 50.

[0025] The first tray 49 is capable of moving up and down with respect to the processing tray 37 described later, and stacks the sheet bundles bound by the binding processing mechanism 47 described later. In the present embodiment, the first tray 49 and the second tray 71 are capable of moving up and down by a lifting mechanism (not shown). That is, in the present embodiment, when feeding 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.

[0026] The saddle unit B2 is disposed below the delivery unit of the saddle path 32 as the second conveyance path that branches vertically downward from the conveyance path 28, and 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 the sheet bundle to the saddle discharge unit 131. Hereinafter, each configuration will be described in detail.

[0027] [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, and the like. The conveyance path 28, the processing unit B1, and the saddle unit B2 are disposed 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 the respective processing units. 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.

[0028] [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 conveyance is also possible in the second straight conveyance direction from the first discharge path 31 toward the receiving portion 26. Entrance rollers 29, a first conveyance roller 201, a second conveyance roller 202, and a third conveyance roller 203 are arranged as conveyance rollers. That is, the entrance rollers 29, the first conveyance roller 201, the second conveyance roller 202, and the third conveyance roller 203 can convey the sheet in the first straight conveyance direction and in the second straight conveyance direction opposite to the 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.

[0029] 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 either 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.

[0030] [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. At each branching section between the conveyance path 28 and the saddle path 32 and the upper conveyance path 30, 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.

[0031] [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.

[0032] [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).

[0033] The processing unit B1 includes a processing tray 37 as a placement unit for placing the sheets conveyed on the first discharge path 31 on the downstream side of the conveyance path 28 and aligning and stacking the plurality of placed sheets, and a binding mechanism 47 for binding 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 for changing 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 guiding the sheet onto the processing tray 37.

[0034] Specifically, the first discharge path 31 is provided with an upper conveyance roller 41 and a lower conveyance roller 48 for sandwiching and conveying 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 the direction toward the first tray 49 and in the 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.

[0035] Further, 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 loading tray (loading section). 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.

[0036] 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.

[0037] 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.

[0038] [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 a saddle path switching member 33 for guiding the sheet to the saddle path 32 is provided at the path branching portion. The sheet guided to the saddle portion B2 by the saddle path 32 is discharged to the saddle discharge unit 131 via the post-fold path guide 114, the second roller post-path guide 116, the pre-clamp guide 119, and the saddle discharge guide 124 in a substantially horizontal direction after being center-folded and folded. In the present embodiment, the saddle discharge guide 124 as the discharge guide portion is used as an auxiliary guide for appropriately loading the sheet onto the saddle discharge unit 131.

[0039] [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 controls by referring to the data stored in the RAM 313 based on the above-described program and the like.

[0040] The operation unit 302 is an operation panel provided, for example, 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.

[0041] 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. Similar to the control unit 310, the stacker control unit 330 includes a CPU 331, a ROM 332, and a RAM 333. The conveyance control unit 322 controls various conveyance rollers for conveying sheets and a switching member for switching conveyance paths, except in 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.

[0042] 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 binding processing control unit 345, and a communication unit 341. Similar to the control unit 310, the saddle control unit 350 includes a CPU 351, a ROM 352, and a RAM 353. The conveyance control unit 342 controls various conveyance rollers for conveying sheets and a switching member for switching 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 binding processing control unit 345 controls the corner binding 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. However, a configuration in which each unit is controlled by a common control unit may also be used. Further, 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. However, a configuration in which each unit is controlled by one control unit may also be used.

[0043] [Saddle Portion] The saddle part B2 will be described with reference to FIGS. 2 and 4. The saddle part B2 has a center-folding processing mechanism C1 and a corner-back processing part C2, and performs center-folding processing, center-stitching 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 center-folding processing mechanism C1 aligns and stacks the sheets sent from the conveyance path 28 into a sheet bundle, and performs a stitching process on the center part in the conveyance direction of the sheet bundle (the intermediate part in the second conveyance direction which is the conveyance direction of the saddle path roller 100 as the second conveyance part described later), and performs a center-folding process of folding the sheet bundle at the stitched 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 center-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 described later), and performs a corner-back processing of making a crease on the back of the center-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 stack one or a plurality of sheets, and only perform a center-folding process of folding the center part in the conveyance direction without performing center-stitching processing and corner-back processing.

[0044] [Center-folding processing mechanism] The middle folding processing mechanism C1 includes a tip regulation stopper 109, a middle stapling processing unit (middle stapling staple unit) 104, and a middle folding processing unit 112, accumulates sheets in a bundle form, 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 a saddle path roller 100 as a second conveyance unit to a saddle stack tray 150 as an accumulation unit and a second accumulation unit. 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 regulation stopper 109. The middle stapling processing unit 104 performs stapling processing on the central portion (the intermediate portion in the second conveyance direction) in the conveyance direction of the sheet bundle positioned by the tip regulation stopper 109. The middle folding processing unit 112 includes a pushing plate 112a and a pair of folding rollers 113, and conveys the sheet bundle with the 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 the stapling processing) stapled by the middle stapling processing unit 104 with the pushing plate 112a, thereby folding the sheet bundle and conveying it so that the back of the sheet bundle faces the downstream side in the conveyance direction. Note that the middle folding processing unit 112 can also perform middle folding processing on a sheet bundle (or a single sheet) not subjected to middle stapling processing. Here, the middle folding processing means a process of making a crease near the center of the sheet bundle and folding the sheet bundle in two. The crease formed by the middle folding processing unit 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 setting.

[0045] The middle stapling processing unit 104 is a mechanism that moves the head unit and the anvil unit along the central portion (line) of the sheet with the sheet bundle sandwiched between the head unit and the anvil unit to perform stapling processing. Also, as shown in FIGS. 2 and 4, the middle folding processing unit 112 employs 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.

[0046] [Book spine processing unit] The book spine processing unit C2 performs book spine processing on the sheet bundle to form a book spine shape along the fold line (crease) of the sheet bundle that has been center-folded. The book spine 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 book spine processing unit 134 having a pressing roller 123.

[0047] The lower clamp unit 120 and the upper clamp unit 121 move relative to each other along the thickness direction of the sheet bundle being 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) to clamp and release the clamping of the sheet bundle. 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 book spine 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 book spine 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 back 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.

[0048] Specifically, with the back of the sheet bundle mid-folded by the mid-fold processing mechanism C1 protruding downstream in the first conveyance direction, the lower clamp unit 120 and the upper clamp unit 121 sandwich 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 back 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 cornering processing unit C2 performs cornering processing on the back of the sheet bundle. The cornering processing is a process of forming two streaks on the back of the sheet bundle as shown in FIGS. 11(c) and 11(d) by crushing the back of the sheet bundle shown in FIGS. 11(a) and 11(b) to be described later with the pressing roller 123, thereby forming two corners on the back of the sheet bundle. The two corners on the back of the sheet bundle are formed at positions that sandwich the staple pins driven in when being stitched by the middle stitching processing unit 104 in the thickness direction of the sheet bundle. Also, the two corners formed on the back of the sheet bundle are formed at positions that sandwich the fold line formed during the mid-fold processing by the mid-fold processing unit 112.

[0049] Note that a mid-fold conveyance mechanism for conveying and stopping the sheet bundle mid-folded by the mid-fold processing mechanism C1 to the downstream cornering processing unit C2 is disposed between the mid-fold processing mechanism C1 and the cornering processing unit C2.

[0050] As described above, the processing unit B1 and the conveyance path 28 are disposed in a substantially horizontal direction, the saddle path 32 for guiding the sheet to the saddle portion B2 is disposed in a substantially vertical direction, and the saddle stack tray 150 for aligning and stacking the sheets is disposed so as to follow the substantially vertical direction. By disposing the conveyance path 28 along the direction crossing the housing 27 in this way and disposing the saddle path 32 and the saddle portion B2 along the substantially vertical direction, it is possible to reduce the horizontal width of the apparatus and achieve slimming.

[0051] 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 relation to the specification of the device.

[0052] [Configuration of the saddle portion] Next, each configuration of the center folding processing mechanism C1, the center folding conveyance mechanism C3, and the corner back processing unit C2 that constitute the saddle portion B2 will be described in more detail.

[0053] [Details of the center folding processing mechanism] As shown in FIG. 2, the saddle path switching member 33 is switched to convey the sheet to the saddle path 32, thereby guiding the sheet to the center folding processing mechanism C1. 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, a middle binding processing unit 104, a pulling and separating roller 105, a center folding processing unit 112, a first alignment roller 107, a second alignment roller 108, a front end regulating stopper 109, and a front end gripper 110 are arranged.

[0054] 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 loaded on the saddle stack tray 150. The middle 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 and separating roller 105 is a roller that assists in conveying the sheet conveyed to the saddle stack tray 150 and pulls this sheet toward the front end regulating stopper 109. The pulling and separating roller 105 is arranged so as to be able to contact and separate from the opposing roller 105a.

[0055] 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 fold line 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 restricting stopper 109 determines the position in the height direction of the leading edge of the sheet by hitting against 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 restricting stopper 109.

[0056] 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 downstream of the sorting ridge 102 and the rear end pressing guide 103 and upstream of the retracting and separating roller 105.

[0057] 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 restricting stopper 109 that has moved to a position corresponding to the size. The retracting and separating roller 105 has an auxiliary conveying function for accurately conveying the conveyed sheet to the leading edge restricting stopper 109 in 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.

[0058] The first alignment roller 107 and the second alignment roller 108 accurately abut the conveyed sheet against the leading edge restricting stopper 109 and perform alignment processing in the height direction of the sheet.

[0059] The sorted stacker 102 moves the sheet conveyed to the tip regulation stopper 109 up 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 to prepare for receiving the next sheet. At this time, the rear end pressing guide 103 moves to a position corresponding to the size and waits.

[0060] The tip (lower end) of the sheet bundle formed by stacking 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 portion in the second conveyance direction of the sheet bundle 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 sheet bundle is held 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 sheet bundle from the binding position.

[0061] 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 portion of the sheet bundle is pushed into the nip portion of the folding roller pair 113 by the pushing plate 112a. Thereby, the sheet bundle is middle-folded.

[0062] The saddle inlet roller 101, the pulling separation roller 105, the sorted stacker 102, and the rear end pressing guide 103 are controlled by the conveyance control unit 342 (FIG. 3). Further, 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). Furthermore, the folding roller pair 113 and the pushing plate 112a are controlled by the middle folding control unit 344 (FIG. 3).

[0063] [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 (here, a substantially horizontal direction) with respect to the folding roller conveyance direction 113c (FIG. 2) that is in a direction along a perpendicular line (a first virtual line α2 described below, FIG. 4) to a straight line passing through the rotation centers of the respective rollers of the folding roller pair 113 as the first conveyance roller pair, and is disposed on the downstream side in the conveyance direction of the folding roller pair 113.

[0064] Here, as shown in FIG. 4, a first virtual line α2 is defined as a straight line that is perpendicular to a first line α1 passing through the rotation centers of the folding roller pair 113 and a line in the width direction (a direction perpendicular to the conveyance direction of the sheet bundle, the front-back direction in FIGS. 2 and 4) and that 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.

[0065] 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 in a direction along a perpendicular line to a straight line passing through the rotation centers of the respective rollers of the saddle second roller pair 115, is arranged along a direction that slopes 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.

[0066] 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 includes 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 above the guide surface of the second roller rear path upper guide 116a in the vertical direction 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.

[0067] 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 a direction along a perpendicular line (a second imaginary line β2, FIG. 4 described below) to a straight line passing through the rotation center of each roller 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.

[0068] The saddle third roller pair 118 as the conveying unit and the conveying roller pair is driven by the middle folding control unit 344, and sandwiches and conveys 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 sheet bundle is conveyed by the saddle third roller pair 118 which is also the first conveying unit is defined as the first conveying direction (saddle third roller conveying direction 118c), the saddle path roller 100 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 sheet bundle is conveyed by the saddle third roller pair 118 may be simply referred to as the "upstream side" and the "downstream side".

[0069] 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 processing unit 112 and conveys it toward the corner back processing unit C2, and is located immediately upstream of the corner back processing unit C2.

[0070] Here, as shown in FIG. 4, a second line β1 passing through the rotation centers of the saddle third roller pair 118 and a straight line orthogonal to the width direction and passing 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.

[0071] 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 is inclined 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.

[0072] 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 is inclined with respect to the direction in which the sheet bundle is guided by the post-folding path guide 114.

[0073] 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 miniaturized. Also, by setting the folding roller conveyance direction 113c, which is the sheet conveyance direction of the saddle third roller pair 118, to be diagonally 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 direction of the sheet or sheet bundle, cases where there are angles with respect to horizontal, vertical, or parallel due to relationships such as tolerances are also included.

[0074] [Details of the saddle processing unit] The saddle 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 parts, and a saddle 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.

[0075] 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 the maximum-thickness sheet bundle that can be conveyed in that apparatus is subjected to a folding process). 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 folded by the 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.

[0076] 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 moving relatively 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.

[0077] 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)).

[0078] 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. 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.

[0079] [Corner rounding processing unit] Next, the internal configuration of the corner back processing unit 134 will be described with reference to FIGS. 5 to 10. The corner back 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 the pressing roller (corner back processing roller) 123. As shown in FIGS. 5 and 10, the pressing roller 123 is arranged such that the outer peripheral surface contacts the end surfaces on the downstream side of the lower clamping unit 120 and the upper clamping unit 121, respectively. 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.

[0080] 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.

[0081] 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 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.

[0082] That is, the upper movement restricting portion 139 is provided at the tip of a support shaft 139a that is fixed to the upper plate 147c and extends downward from the upper plate 147c. Further, the lower movement restricting portion 140 is provided at the tip of a support shaft 140a that is fixed to the lower plate 147d and extends upward from the lower plate 147d. Also, 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, two upper movement restricting portions 139 may be used. 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.

[0083] Roller pressing 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 conveying direction. Pressure springs 145a and 145b are arranged between the roller pressing 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 conveying direction, the pressing force with which the pressing roller 123 presses the back of the sheet bundle due to the urging force of the pressure springs 145a and 145b changes in accordance with changes in the amount of protrusion from the lower clamp unit 120 and the upper clamp unit 121 of the back of the sheet bundle, which will be described later.

[0084] Further, since the pressing roller 123 is biased by the pressing 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 between 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.

[0085] As shown in Figs. 9 and 10, the end face 120a on the upstream side of the lower clamp unit 120 is in contact with the lower movement restricting portion 140. Also, the end face 121a on the upstream side 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 each having a rotation axis in the width direction of the sheet bundle and 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.

[0086] When the saddle third roller pair 118 conveys a bundle of sheets, the leading end of the bundle of sheets is detected by the aforementioned saddle conveyance sensor 117, and the conveyance amount is counted by the square-back processing control unit 345 and stopped after conveying by a predetermined conveyance amount. Specifically, as shown in FIG. 11(a) described later, the back of the folded bundle of sheets is stopped in a state where it protrudes downstream in the conveyance direction from the upper clamp unit 121 and the lower clamp unit 120. In the present embodiment, in the square-back processing, by controlling the conveyance amount of the bundle of sheets by the saddle third roller pair 118, the protruding amount of the back of the bundle of sheets from the upper clamp unit 121 and the lower clamp unit 120 is adjusted.

[0087] [Upper clamp unit and lower clamp unit] The upper clamp unit 121 moves from the receiving position (first position) for receiving the bundle of sheets to the clamp holding position (second position) for holding the bundle of sheets, thereby pressing the bundle of sheets between itself and the lower clamp unit 120, and holding the bundle of sheets 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 end of the bundle of sheets protrudes by a predetermined protruding amount P1 from the end faces 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.

[0088] The upper clamp unit 121 operates by driving the clamp drive motor 132 (Figs. 7(a) and (b)) with the skew processing control unit 345. As shown in Figs. 7(a) and (b), the skew 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. With the movement amount of the clamp drive link 122 remaining constant, the compression amount of the clamp spring 144 changes according to the thickness of the sheet bundle, so that the pressing force also changes. The aforementioned clamp holding position also changes according to the thickness of the sheet bundle.

[0089] [Skew processing unit] As shown in Fig. 11(c) to be described later, the skew processing unit C2 performs skew processing on the sheet bundle held in a state of protruding by a predetermined protrusion amount P1 from the end faces 120c and 121b 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.

[0090] During skew processing, the pressing roller 123 is moved by operating the drive motor 135 (Fig. 7(b)) with the skew processing control unit 345. As shown in Fig. 8, the pressing roller 123 is connected to the drive belt 137 arranged in the width direction of the sheet bundle and is movable in the width direction of the sheet bundle along the 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 the 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.

[0091] Note that 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 for corner folding processing, the pressing roller 123 can be moved from the front side to the rear side with respect to the second sheet bundle for corner folding processing. Sensors (not shown) are provided at each home position of the pressing roller 123, enabling the detection of 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 a home position is provided on either one side 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 for corner folding processing, 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 for corner folding processing, and so on.

[0092] 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, whether to move the pressing roller 123 in one direction or reciprocally may be set 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. Furthermore, in one corner folding process, whether to move the pressing roller 123 in one direction or reciprocally may be arbitrarily set by the operator side.

[0093] As shown in FIGS. 9 and 10, the lower clamp unit 120 has guide rails 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.

[0094] 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.

[0095] [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 (the first conveyance direction, the saddle third roller conveyance direction 118c) by the saddle third roller pair 118. And the saddle discharge guide 124 is arrange | positioned so that it may hang vertically downward from the 1st fulcrum 124b.

[0096] Further, the saddle discharge guide 124 has a side surface on the upstream side in the first conveyance direction that is inclined so as to face upstream 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 of the saddle discharge guide 124 on the upstream side in the first conveyance direction is inclined so as to face downstream 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 of the saddle discharge guide 124 on the upstream side in the first conveyance direction is formed to bend 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 of the side surface of the saddle discharge guide 124 on the upstream side in the first conveyance direction.

[0097] The guide surface 124d is located below the line extending the above-described saddle third roller conveyance direction 118c, 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, contact with the guide surface 124d of the saddle discharge guide 124 may not occur, and even when contact occurs, the amount of rotation changes depending on the rigidity, so the saddle discharge guide 124 does not necessarily rotate.

[0098] Also, a second fulcrum 124c is provided at the lower end of the saddle discharge guide 124, and a saddle discharge roller 125, which will be described later, is connected 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.

[0099] When the conveyance of the sheet bundle by the saddle third roller pair 118 continues, it is delivered to a saddle discharge unit 131 disposed downstream in the first conveyance direction from the angular back processing unit 134 and vertically below 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.

[0100] The saddle discharge upstream belt 127 is positioned below the guide surface 124d of the saddle discharge guide 124, and conveys the sheet bundle 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 toward the downstream side in the conveyance direction. The saddle discharge downstream belt 129 as the sheet bundle discharge part receives the sheet bundle 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 toward the downstream side in the conveyance direction. For this reason, the sheet bundle 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.

[0101] Also, a saddle discharge upstream sensor 128 for detecting the sheet bundle upstream 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 sheet bundle downstream is arranged on the upstream side within the conveyance possible region of the saddle discharge downstream belt 129.

[0102] The sheet bundle 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 sheet bundle is stacked. The saddle discharge upstream belt 127 sandwiches the sheet bundle at the nip point with the saddle discharge roller 125 described above on the downstream side in the conveyance direction. The sheet bundle 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 according to the thickness of the sheet bundle.

[0103] When processing a subsequent stack of sheets, the preceding stack of sheets is conveyed upstream in the conveyance direction by the saddle discharge upstream belt 127 and stopped at a predetermined conveyance amount after being detected by the saddle discharge upstream sensor 128 or 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 with the saddle discharge roller 125, and is in 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 shingle-like manner).

[0104] 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, or extrusion do not occur in the preceding stack of sheets, and they are stably stacked in a shingle-like manner. That is, by appropriately changing the above-mentioned 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.

[0105] 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.

[0106] In addition, when there is another device on the downstream side of the saddle discharge unit 131, it is also possible to transfer the stack of sheets to the downstream device by continuing the conveyance without stacking. Further, in the present embodiment, an ejection cover 151 as a cover member is provided outside the saddle discharge portion 126. The ejection cover 151 is disposed so as not to prevent the stack of sheets from being ejected from the saddle discharge portion 126, and is disposed so that an operator such as a user cannot access the inside of the apparatus through the saddle discharge portion 126.

[0107] [Control of Corner Rounding Process] Next, the control of the corner rounding process of this embodiment will be described with reference to FIGS. 11(a) to (d). As described above, the corner rounding processing unit C2 performs a corner rounding 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 rounding process will be described for the corner rounding 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.

[0108] The corner rounding mode will be described. The corner rounding 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.

[0109] In this state, the corner rounding 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 clamps the sheet bundle Sb with the upper clamp unit 121 and the lower clamp unit 120 as shown in FIG. 11(b). At this time, the back Ssp of the sheet bundle Sb protrudes by P1 further downstream 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.

[0110] Next, the corner-back processing control unit 345 moves the pressing roller 123 in the width direction of the sheet bundle Sb by operating the drive motor 135 (Fig. 7(b)). At this time, as shown in Fig. 11(c), as the pressing roller 123 moves in the width direction while pressing the back Ssp of the sheet bundle Sb, a corner-back process is performed on the back Ssp of the sheet bundle Sb. Then, as shown in Fig. 11(d), the corner-back processing control unit 345 drives the clamp drive motor 132 (Figs. 7(a) and 7(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-back process ends here, and the discharge operation of the sheet bundle Sb described above is performed.

[0111] [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.

[0112] 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) in the front-rear direction (F-B direction), which is a 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.

[0113] 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 main support parts support the housing 27 with respect to the installation surface. By providing the casters 502 in this way, it is easier for the user or service technician to move the sheet processing apparatus B when installing it at a desired position.

[0114] When the sheet processing apparatus B is connected to the image forming apparatus A, it is fixed to the image forming apparatus A by a connecting part 510 (FIGS. 12(b) and (c)) provided on the main body frame 500. Also, the connection between the sheet processing apparatus B and the image forming apparatus A is also achieved by the engagement of engagement members such as pins and hooks provided in the vicinity of the sheet discharge port of the image forming apparatus A and in the vicinity of the sheet receiving port of the sheet processing apparatus B. However, the connection configuration between the sheet processing apparatus B and the image forming apparatus A may be either the fixing by the connecting part 510 or the engagement of the engagement parts, or other connection configurations may be used.

[0115] As shown in Fig. 12(a), the front cover 501 is provided with a handle 501a at the end on the R side. Further, 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 hinge 502b has its axis of rotation in the vertical direction, and the end on the L side of the front cover 501 is rotatably supported about the axis of rotation of the hinge 502b. When a user or a service technician performs maintenance on the saddle portion 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 hinge 502b, and the operation lever 550 that is operated when pulling out the saddle portion 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.

[0116] When the operation lever 550 is operated by the user or the service technician, a lock (not shown) between the saddle portion B2 and the main body frame 500 is released, and as shown in Fig. 13, the saddle portion B2 can be pulled out from the inside of the housing 27 toward the F side (front side). Note that by pushing the pulled-out saddle portion B2 toward the B side (rear side), the saddle portion 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 portion (not shown).

[0117] 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 a similar rail part 503 is 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.

[0118] 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 (accommodation 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 pull-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.

[0119] 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 in which a part such as the operation lever 550 and the 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.

[0120] Also, the pull-out position shown in FIG. 13 only needs to be a position where the user or service technician can access the saddle part B2, and not all elements constituting the saddle part B2 must be outside the main body frame 500. For example, parts arranged on the B side of the saddle part B2, such as wire bundling and various drive mechanisms, may be located inside the main body frame 500.

[0121] Further, 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 part B2 may be pulled out further to the F side than the maintenance position by the user. By doing so, during maintenance by the user, unnecessary pulling-out and insertion operations of the saddle part 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 part B2 is pulled out further than the state of the position in FIG. 13 (maintenance position by the user).

[0122] Also, 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 saddle portion B2 which is a heavy object, 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 on 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 that occurs in the saddle portion B2.

[0123] 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 support leg portion 600 as a support portion that supports the saddle portion B2 is provided. In this embodiment, the support leg portion 600 functions as a support portion that supports the saddle portion B2 only when the saddle portion B2 is pulled out by a mechanism (not shown).

[0124] In this way, after maintenance by the user or service technician with the saddle portion B2 pulled out, the user or service technician inserts the saddle portion B2 to the mounting position inside the housing 27. When the saddle portion B2 is inserted (returned), if the saddle portion B2 is forcefully returned, it may collide with the main body frame 500 of the housing 27, resulting in deformation of the main body frame 500 or malfunction of components within the device. Also, when the saddle portion B2 collides with the main body frame 500, the connecting portion 510 between the above-described sheet processing device B and the image forming device A may be deformed, or the engagement between the engaging members provided near the sheet discharge port of the image forming device A and near the sheet receiving port of the sheet processing device B may be displaced. In this case, the position of the image forming device A and the sheet processing device B may shift, causing the sheet to be conveyed diagonally from the image forming device A to the sheet processing device B. Furthermore, deformation of the connecting portion 510 between the image forming device A and the sheet processing device B may cause the positions of the devices to shift.

[0125] In particular, the saddle portion B2 in the present embodiment has a center folding mechanism C1 and a corner back processing portion C2, and is the heaviest unit in the sheet processing device B. Therefore, when returning the saddle portion B2 from the pulled-out state into the main body frame 500, it is likely to gain momentum, and when it collides with the main body frame 500, the impact is likely to be large.

[0126] Therefore, in the present embodiment, a braking device 800 is provided as a regulating unit for regulating the movement of the saddle portion B2 when the saddle portion B2 is forcefully inserted into the main body frame 500. The braking device 800 is provided on the main body frame 500 side, and by coming into contact with a contact portion 580 (FIG. 13) fixed to the saddle portion B2, it reduces the moving speed of the saddle portion B2 when the saddle portion B2 is forcefully returned to the mounting position.

[0127] [Braking Device] Details of such a braking device 800 will be described with reference to FIGS. 14 and 15. FIG. 14 is a perspective view of the braking device 800 fixed to the lower right stay 500b of the main body frame 500 which is a fixed part. FIG. 15 is a perspective view of the braking device 800 viewed from the B side with the lower right stay 500b omitted.

[0128] Here, as shown in FIG. 13, the main body frame 500 includes a bottom frame including a front lower stay 500a and a lower right stay 500b, a right front support column 500c, a rear side plate 500d, and the like. A processing unit B1, a control board (not shown), and the like are fixed to each sheet metal constituting the main body frame 500. The four casters 502 are fixed to the bottom frame including the front lower stay 500a and the lower right stay 500b.

[0129] When the saddle part B2 is inserted into the housing 27 at a speed equal to or higher than a predetermined speed, the braking device 800 restricts the movement of the saddle part B2 in the insertion direction, and when the saddle part B2 is inserted into the housing 27 at a speed lower than the predetermined speed, the braking device 800 allows the movement of the saddle part B2 in the insertion direction. Such a braking device 800 is fixed to the lower right stay 500b of the main body frame 500. Further, the braking device 800 includes a contact surface 801a that contacts a contact part 580 (FIG. 13) fixed to the saddle part B2, a rack 801 having a rack gear part 801b, a gear unit 810 including a gear 802 that meshes with the rack 801, and a centrifugal brake unit 820.

[0130] [Gear Unit] The gear unit 810 as a damper mechanism will be described in detail. When the centrifugal brake unit 820 brakes the saddle portion B2 as described later, the gear unit 810 applies a load to the saddle portion B2 that moves in the direction from the pulled-out position to the mounted position (accommodated position), and absorbs the impact applied to the centrifugal brake unit 820. As described above, the gear unit 810 has a rack 801 and a gear 802, and further has a plurality of gears 804, 806, 808, and a transmission member 805. The rack 801 is arranged to be slidable in the F-B direction with respect to the lower right stay 500b of the main body frame 500, and the end face on the F side of the rack 801 is the above-described contact surface 801a. Further, a rack gear portion 801b is formed on the side surface of the rack 801.

[0131] The gear 802 as the first gear is arranged at a position adjacent to the rack 801, meshes with the rack gear portion 801b, and rotates as the rack 801 slides. That is, the gear 802 rotates when power is input by the movement of the saddle portion B2 in the direction from the pulled-out position to the mounted position. The gear 804 as the second gear is supported on the same rotation shaft 803 as the gear 802 and rotates integrally with the gear 802 as the gear 802 rotates. The gear 806 meshes with the gear 804, and the rotation of the gear 804 is transmitted. The gear 808 is provided on the same rotation shaft 807 as the gear 806 and rotates integrally with the gear 806. The gear 808 has a larger diameter and more teeth than the gear 806. Further, the gear 808 meshes with a gear 821 fixed to the rotation shaft 822 of the centrifugal brake unit 820 described later, and transmits the rotation to the gear 821. In the present embodiment, the gear unit 810 is configured to increase the speed of the rotation input from the rack 801 to the gear 802 and transmit it to the rotation shaft 822.

[0132] As shown in FIG. 14, the rotating shaft 803 and the rotating shaft 807 are rotatably supported by the first fixed sheet metal 811 and the second fixed sheet metal 812. The first fixed sheet metal 811 and the second fixed sheet metal 812 are each formed into a substantially U-shaped cross section by bending the sheet metal, and are arranged so as to sandwich the above-described gears 802, 804, 806, and 808 from above and below. Both ends of the rotating shafts 803 and 807 of each gear are rotatably supported by the fixed plate portion 811a of the first fixed sheet metal 811 and the fixed plate portion 812a of the second fixed sheet metal 812, respectively. Bent plate portions 811b bent downward are provided at both ends in the F-B direction of the fixed plate portion 811a of the first fixed sheet metal 811 that covers the upper side of each gear. Then, the bent plate portion 811b is fixed to the lower right stay 500b with screws or the like.

[0133] On the other hand, bent plate portions 812b bent upward are provided at both ends in the F-B direction of the fixed plate portion 812a of the second fixed sheet metal 812. Then, the bent plate portion 812b is fixed to the first fixed sheet metal 811 with screws or the like. Further, the fixed plate portion 812a has an extended portion 812c extending toward the rack 801 side. The extended portion 812c has a support plate portion 812c1 that supports the rack 801 from below, and a first regulating plate portion 812c2 formed so as to project upward at positions on both sides in a direction orthogonal to the sliding direction of the rack 801, that is, the L-R direction. Further, a second regulating plate portion 812d arranged so as to sandwich the rack 801 between it and the support plate portion 812c1 is fixed to the upper end portion of the first regulating plate portion 812c2.

[0134] Therefore, the movement of the rack 801 in the L-R direction is restricted by a pair of first restricting plate portions 812c2, and the movement in the vertical direction (U-D direction) is restricted between the second restricting plate portion 812d and the support plate portion 812c1. For this reason, the rack 801 is slidable in the F-B direction while the movement in the L-R direction and the U-D direction is restricted with respect to the second fixed sheet metal 812. In particular, a force acts on the rack 801 in a direction away from the gear 802 due to the reaction force caused by the meshing with the gear 802. Therefore, the first restricting plate portion 812c2 disposed on the side opposite to the gear 802 can restrict the movement of the rack 801 in this direction. Also, although not shown in the figure, the first restricting plate portion 812c2 on the gear 802 side faces the rack 801 on both sides in the F-B direction at the position where the rack gear portion 801b of the rack 801 meshes with the gear 802, and is formed so that these gears can mesh with each other.

[0135] Furthermore, other configurations may be added to restrict the movement of the rack 801 in the L-R direction. For example, a groove extending in the B-F direction may be formed on the lower surface of the rack 801, and a plurality of shafts that fit into the groove with play may be provided. At this time, the plurality of shafts may be fixed to the second fixed sheet metal 812. By reducing the play between the groove of the rack 801 and the plurality of shafts fixed to the second fixed sheet metal 812, the movement of the rack 801 in the L-R direction can be more restricted.

[0136] In this way, each gear and the rack 801 are fixed or supported by the first fixed sheet metal 811 and the second fixed sheet metal 812, and are fixed to the lower right stay 500b via the first fixed sheet metal 811 and the second fixed sheet metal 812. Incidentally, the centrifugal brake unit 820 described later is also fixed to the first fixed sheet metal 811 as shown in FIG. 14. For this reason, the braking device 800 including the gear unit 810 and the centrifugal brake unit 820 can be fixed to the lower right stay 500b in a state where these units are assembled. For this reason, it is easy to assemble the braking device 800 to the main body frame 500.

[0137] Also, as shown in FIG. 14, the rack 801 is biased toward the F side by a spring 830. The spring 830 is hooked to a hook 801c (FIG. 15) provided on the rack 801 and a hook 500bb of a fixed sheet metal 500ba fixed to the lower right stay 500b. The fixed sheet metal 500ba is arranged on the F side with respect to the movement range of the rack 801. By stretching the spring 830 between the hook 500bb provided on the fixed sheet metal 500ba and the hook 801c of the rack 801, the rack 801 is biased toward the F side, that is, in the direction from the back side to the front side of the sheet processing apparatus B.

[0138] Therefore, as will be described later, when the saddle portion B2 is inserted toward the mounting position on the B side and the contact portion 580 (FIG. 13) of the saddle portion B2 comes into contact with the contact surface 801a, the rack 801 moves to the B side together with the saddle portion B2 against the biasing force of the spring 830. On the other hand, when the saddle portion B2 is pulled out to the F side, the rack 801 moves to the F side by the biasing force of the spring 830. When the contact portion 580 moves away from the contact surface 801a due to the movement of the saddle portion B2 in the pulling-out direction, the movement of the rack 801 to the F side is restricted by a restricting portion (not shown). This restricted position is a position where the contact portion 580 comes into contact with the contact surface 801a before the saddle portion B2 reaches the mounting position when the saddle portion B2 is inserted toward the mounting position, and is set as a position where the contact portion 580 comes into contact with the contact surface 801a at an appropriate timing.

[0139] As shown in FIG. 15, the above-described gear unit 810 has a transmission member 805 as a one-way rotation transmission unit. The transmission member 805 includes a load applying unit 805a that applies a load of a predetermined torque to the rotation shaft 803 when rotating in one direction, and a fixing member 805b that is fixed to the gear 804 via the load applying unit 805a. When the saddle portion B2 moves in the insertion direction (B direction), the transmission member 805 transmits rotation to the rotation shaft 822 of the centrifugal brake unit 820, and when the saddle portion B2 moves in the pulling-out direction (F direction), it does not transmit the rotation of the rotation shaft 822 (i.e., idles). In particular, when the rack 801 moves in the B direction, the load applying unit 805a applies a load of a predetermined torque to the rotation shaft 803, so that the rotation shaft 803 and the fixing member 805b rotate integrally, and the rotational drive of the rotation shaft 803 is transmitted to the gear 804.

[0140] In the present embodiment, the transmission member 805 is provided on the rotation shaft 803 of the gears 802 and 804, but the transmission member 805 may be provided on any rotation transmission member from the rack 801 to the rotation shaft 822. However, it is preferable to provide the transmission member 805 on the rotation shaft 803 that is closest to the rack 801 in the rotation transmission direction. By providing it at this position, when the transmission member 805 idles, rotation is not transmitted to the subsequent gear train, and the rotational load can be reduced. In the present embodiment, a one-way hinge manufactured by Origin Co., Ltd. is used as the transmission member 805, but any configuration may be used as long as it idles when the rotation shaft 803 is rotated in one direction and applies a predetermined rotational load to the rotation shaft 803 to rotate integrally with the gear 804 when rotated in the other direction.

[0141] By providing the transmission member 805 on the rotation shaft 803 in this way, when the saddle part B2 is inserted in the direction from the pulled-out position to the mounted position and the rack 801 moves to the F side, as shown by the arrow in Fig. 15, the gears 802 and 804 rotate integrally with the rotation shaft 803, and the rotation is transmitted to the rotation shaft 822 via the gears 806, 808, and 821. At this time, the gears 806, 808, and 821 rotate in the direction shown by the arrow in Fig. 15. On the other hand, when the saddle part B2 is pulled out from the mounted position toward the pulled-out position and the rack 801 moves to the B side, the gear 802 rotates in the direction opposite to the arrow in Fig. 15. At this time, since the transmission member 805 idles and the rotation to the gear 804 is blocked, the gears 806, 808, and 821 do not rotate.

[0142] [Centrifugal brake unit] Next, the centrifugal brake unit 820 as a braking mechanism will be described with reference to Figs. 16(a) to 17(b) in addition to Figs. 14 and 15 described above. Figs. 16(a) and 17(a) are a plan view and a perspective view of the centrifugal brake unit 820 in a state where no brake is applied. Figs. 16(b) and 17(b) are a plan view and a perspective view of the centrifugal brake unit 820 in a state where the brake is applied.

[0143] The centrifugal brake unit 820 operates when the saddle part B2 is inserted at a speed equal to or higher than a predetermined speed in the direction from the pulled-out position to the mounted position, and brakes the saddle part B2. The centrifugal brake unit 820 includes a gear 821, a rotation shaft 822, an engagement member 823, a rotating sheet metal 824, a pair of engagement sheet metals (first engagement sheet metal, second engagement sheet metal) 825a, 825b, rotation shafts 826a, 826b, and a spring 827. The gear 821 meshes with the gear 808 of the gear unit 810, and the rotation is transmitted from the gear 808. The rotation shaft 822 rotates integrally with the gear 821.

[0144] The engaging member 823 is a cylindrical member fixed to the first fixed sheet metal 811 of the gear unit 810 as shown in FIG. 14. In the present embodiment, the engaging member 823 is fixed to the upper surface of the fixed plate portion 811a of the first fixed sheet metal 811, that is, the surface opposite to the side where the gear row of the gear unit 810 including the gear 821 is arranged. That is, the engaging member 823 has a bottom surface 823a and a wall portion 823b, and as shown in FIGS. 16(a) and (b), the bottom surface 823a is fixed to the first fixed sheet metal 811 by screws 815a and 815b. The wall portion 823b is provided integrally with the bottom surface 823a and is a substantially cylindrical member provided so as to rise upward from the peripheral edge portion of the bottom surface. In the present embodiment, the engaging member 823 is made of resin. The rotation shaft 822 of the gear 821 penetrates the fixed plate portion 811a and the bottom surface 823a and enters the inside of the wall portion 823b. Therefore, the wall portion 823b is fixed around the rotation shaft 822.

[0145] Further, as shown in FIGS. 16(a) and 17(a), the engaging member 823 is formed with second engaging portions 823ba and 823bb that can engage with first engaging portions 825ab and 825bb described later. The second engaging portions 823ba and 823bb are formed by recessing a part of the inner peripheral surface of the wall portion 823b of the engaging member 823 radially outward and being point-symmetrical about the rotation shaft 822. Specifically, the second engaging portion 823ba has an inclined surface portion 823ba1 in which a part of the inner peripheral surface of the wall portion 823b is gradually inclined radially outward with respect to the rotation direction of the rotating sheet metal 824 (clockwise in FIGS. 16(a) and (b)) described later, and an engaging surface 823ba2 that is continuous with the downstream end of the inclined surface portion 823ba1 and extends radially inward from this downstream end. Similarly, the second engaging portion 823bb has an inclined surface portion 823bb1 and an engaging surface 823bb2.

[0146] The rotating sheet metal 824 rotates as the rotating shaft 822 rotates. In this embodiment, the rotating sheet metal 824 is disposed inside the wall portion 823b that constitutes the engaging member 823, and is fixed to the rotating shaft 822 and rotates integrally with the rotating shaft 822. The pair of engaging sheet metals 825a and 825b are provided inside the wall portion 823b so as to be rotatable with respect to the rotating sheet metal 824. Specifically, the pair of engaging sheet metals 825a and 825b are respectively rotatably supported with respect to the rotating sheet metal 824 by the rotating shafts 826a and 826b. The pair of engaging sheet metals 825a and 825b are formed to be point-symmetrical about the rotating shaft 822. Further, since the pair of engaging sheet metals 825a and 825b are supported by the rotating sheet metal 824 via the rotating shafts 826a and 826b, they rotate about the axis line of the rotating shaft 822 together with the rotating sheet metal 824 and the rotating shaft 822.

[0147] In addition, spring-hooking portions 825aa and 815ba and first engaging portions 825ab and 825bb are respectively formed on the pair of engaging sheet metals 825a and 825b. The spring-hooking portions 825aa and 815ba are portions for hooking both ends of a spring 827 described later. The first engaging portions 825ab and 825bb are formed below the spring-hooking portions 825aa and 815ba and at the downstream ends with respect to the rotation direction of the rotating sheet metal 824 (clockwise in FIGS. 16(a) and (b)). And, as will be described later, they can engage with the second engaging portions 823ba and 823bb of the engaging member 823.

[0148] The rotating shafts 826a and 826b are fixed to the rotating sheet metal 824 so as to be substantially parallel to the rotating shaft 822, and rotatably support the pair of engaging sheet metals 825a and 825b respectively. Therefore, the pair of engaging sheet metals 825a and 825b rotate about the rotating shafts 826a and 826b respectively in the directions in which the first engaging portions 825ab and 825bb approach and depart from the inner peripheral surface of the wall portion 823b of the engaging member 823.

[0149] The spring 827 as the biasing portion has both ends respectively hooked to the spring hooking portion 825aa of the engaging sheet metal 825a and the spring hooking portion 825ba of the engaging sheet metal 825b. That is, the spring 827 is stretched across two engaging sheet metals 825a and 825b each having first engaging portions 825ab and 825bb. And the spring 827 biases the two first engaging portions 825ab and 825bb (the first engaging portions with each other) in a direction approaching each other. That is, the spring 827 biases the first engaging portions 825ab and 825bb in a direction away from the inner peripheral surface of the wall portion 823b. FIGS. 16(a) and 17(a) show a state where the first engaging portions 825ab and 825bb are separated from the inner peripheral surface of the wall portion 823b due to the biasing force of the spring 827.

[0150] Here, when the moving speed of the saddle portion B2 in the insertion direction reaches a predetermined speed, the rotation speed of the rotating shaft 822 that rotates through a gear train including the rack 801 and the gear 802 is set to a predetermined rotation speed. In this case, when the rotation speed of the rotating shaft 822 becomes equal to or higher than the predetermined rotation speed, the first engaging portions 825ab and 825bb spread radially outward due to centrifugal force. The second engaging portions 823ba and 823bb engage with the first engaging portions 825ab and 825bb when the first engaging portions 825ab and 825bb spread radially outward due to centrifugal force, and stop the rotation of the rotating shaft 822.

[0151] Specifically, when the saddle portion B2 is vigorously returned to the mounting position, the contact portion 580 fixed to the saddle portion B2 contacts the contact surface 801a of the rack 801, so that the rack 801 slides from the front side toward the back side at the same speed as the saddle portion B2. Then, the rotation of the gear 802 is transmitted to the gear 821 of the centrifugal brake unit 820 via the gears 802, 806, and 808, so that the rotation speed of the gear 821 is increased compared to the rotation speed of the gear 802 corresponding to the sliding speed of the rack 801, and the gear 821 rotates.

[0152] Since the gear 821 is fixed to the rotating shaft 822, the rotating sheet metal 824 fixed to the rotating shaft 822 rotates as the gear 821 rotates. The rotation speed of the rotating sheet metal 824 is a speed corresponding to the speed at which the saddle portion B2 is returned to the mounting position. That is, when the saddle portion B2 is forcefully returned, the rotating sheet metal 824 rotates quickly, and when the saddle portion B2 is slowly returned, the rotating sheet metal 824 rotates slowly. And when the moving speed of the rack 801 in the B direction is slow, the pair of engaging sheet metals 825a and 825b are in a closed state by the biasing force of the spring 827 and continue to rotate inside the engaging member 823.

[0153] Also, when the rotation speed when the rotating shaft 822 rotates becomes faster than a predetermined rotation speed (that is, when the moving speed of the rack 801 in the B direction is fast), the first engaging portions 825ab and 825bb of the engaging sheet metals 825a and 825b open in a direction away from each other by centrifugal force against the biasing force of the spring 827. When opened, the first engaging portions 825ab and 825bb engage with the second engaging portions 823ba and 823bb of the engaging member 823. And when the first engaging portions 825ab and 825bb engage with the second engaging portions 823ba and 823bb, a locked state is formed, and the rotation of the rotating sheet metal 824 with respect to the engaging member 823 temporarily stops. That is, the centrifugal brake unit 820 operates. And as the rotation of the rotating sheet metal 824 stops, the rotations of the rotating shaft 822, gears 821, 808, 806, and 804 also stop.

[0154] In this state, since the saddle portion B2 continues to move in the direction of being returned to the mounting position, as the rack 801 moves, the gear 802 continues to rotate, and the gear unit 810 is in a state where the input of the rotational force in the direction of the arrow shown in FIG. 15 continues. At this time, a load is applied to the gear 802 of the gear unit 810 due to the rotational load of the transmission member 805 that rotates in the other direction, so a load is applied to the sliding movement of the rack 801. That is, when the centrifugal brake unit 820 operates and the rotating sheet metal 824 is in a locked state while the rack 801 continues to move in the B direction, as described above, the rotation of the rotary shafts 822, 821, 808, 806, 804 stops. Since there is a transmission member 805 between the gear 804 and the rotary shaft 803, the rotary shaft 803 rotates while receiving the load from the load applying portion 805a (FIG. 15) of the transmission member 805. Then, the predetermined torque of the load applying portion 805a is transmitted to the saddle portion B2 via the rotary shaft 803, the gear 802, and the rack 801. As a result, when the saddle portion B2 is accommodated at a predetermined speed or higher, the moving speed of the saddle portion B2 is reduced. That is, the moving speed of the saddle portion B2 toward the mounting position decreases. Further, thereby, by allowing the movement of the saddle portion B2 toward the mounting position in a state where the centrifugal brake unit 820 is operating, the impact applied to the centrifugal brake unit 820 when the centrifugal brake unit 820 operates can be absorbed. For this reason, it is possible to suppress the occurrence of defects in the centrifugal brake unit 820.

[0155] Also, in the case of the present embodiment, when the saddle portion B2 is inserted at a speed equal to or higher than a predetermined speed in the direction from the pulled-out position to the mounted position, the centrifugal brake unit 820 continues to be in an operating state until the saddle portion B2 reaches the mounted position. As described above, even when the centrifugal brake unit 820 is operating, the rotating shaft 803 rotates while receiving a predetermined torque from the load applying portion 805a. Therefore, the rotation of the rotating shaft 803 is transmitted to the gear 804 via the load applying portion 805a of the transmission member 805, and further, this rotation is transmitted to the rotating shaft 822 via the gears 806, 808, and 821. At this time, as shown in FIG. 16(b), in a locked state where the first engaging portions 825ab and 825bb of the engaging sheet metals 825a and 825b are engaged with the engaging surfaces 823ba2 and 823bb2 of the second engaging portions 823ba and 823bb, the rotation plate metal 824 continues to be transmitted with a clockwise rotation in the figure. As a result, in a state where the movement of the saddle portion B2 in the direction from the pulled-out position to the mounted position continues, a locked state where the first engaging portions 825ab and 825bb of the engaging sheet metals 825a and 825b are engaged with the second engaging portions 823ba and 823bb is maintained.

[0156] Then, when the saddle part B2 reaches the mounting position and the movement of the rack 801 in the direction of arrow B stops and the rotation of the rotating shaft 803 stops, the rotational load transmitted to the rotating shaft 822 disappears. As a result, the rotational loads on the first engaging parts 825ab and 825bb applied in the direction of engaging with the engaging surfaces 823ba2 and 823bb2 disappear, and the engaging sheet metals 825a and 825b are pulled in the direction of approaching each other by the biasing force of the spring 827. Thereby, the engagement between the first engaging parts 825ab and 825bb and the second engaging parts 823ba and 823bb is disengaged and the lock is released, and the centrifugal brake unit 820 stops operating. That is, when the saddle part B2 is positioned at the mounting position and the movement of the saddle part B2 in the insertion direction stops, the slide movement of the rack 801 and the rotation of the gear 802 stop, and the rotation of the rotating sheet metal 824 stops. As a result, when the rotational load on the rotating sheet metal 824 no longer acts, the first engaging parts 825ab and 825bb move in the closing direction, that is, the direction of approaching each other, by the biasing force of the spring 827, and the engagement between the first engaging parts 825ab and 825bb and the second engaging parts 823ba and 823bb is disengaged. As a result, the brake of the centrifugal brake unit 820 is in a state where it does not act.

[0157] That is, in the present embodiment, when the rotational speed of the rotary shaft 822 becomes equal to or higher than a predetermined rotational speed, the first engaging portions 825ab and 825bb expand radially outward by centrifugal force against the biasing force of the spring 827 and engage with the second engaging portions 823ba and 823bb to enter a locked state. On the other hand, when the insertion operation of the saddle portion B2 is completed and the movement stops, the first engaging portions 825ab and 825bb move radially inward by the biasing force of the spring 827, and the engagement with the second engaging portions 823ba and 823bb is disengaged. Then, when the engagement between the first engaging portions 825ab and 825bb and the second engaging portions 823ba and 823bb is disengaged, the lock of the centrifugal brake unit 820 is released, and the brake is in a non-operating state. In the above-described configuration, the state in which the first engaging portions 825ab and 825bb engage with the second engaging portions 823ba and 823bb and the rotation is locked is the locked state, and the brake of the centrifugal brake unit 820 is in an operating state. And the state in which the engagement between the first engaging portions 825ab and 825bb and the second engaging portions 823ba and 823bb is disengaged and the rotation becomes possible is the unlocked state, and the brake of the centrifugal brake unit 820 is in a non-operating state.

[0158] In the case of the present embodiment, for example, when the moving speed of the saddle portion B2 to the mounting position is 1200 mm / s or more, the rotational speed of the rotary shaft 822 becomes 1080 rpm, and the first engaging portions 825ab and 825bb open in a direction away from each other against the biasing force of the spring 827. That is, when the saddle portion B2 moves toward the mounting position at 1200 mm / s or more, the centrifugal brake unit 820 is configured to operate. In the present embodiment, in order to operate the centrifugal brake unit 820 under this condition, the gear ratio of the gear 802 and the gear 821 is set to 1:9.

[0159] In addition, when the saddle portion B2 is inserted even faster than the above-described moving speed, the centrifugal brake unit 820 may be configured to operate. For example, the condition may be such that the centrifugal brake unit 820 operates when the moving speed of the saddle portion B2 exceeds 1500 mm / s. In order to operate the centrifugal brake when the moving speed of the saddle portion B2 is high using the same configuration as described above, the biasing force of the spring 827 may be increased, the weights of the first engaging portions 825ab and 825bb may be increased, or the reduction ratio of the gear unit may be changed, etc.

[0160] As described above, when the moving speed of the saddle portion B2 in the insertion direction becomes equal to or higher than a predetermined speed, the braking device 800 of the present embodiment reduces the moving speed of the saddle portion B2 in the insertion direction, and then allows the saddle portion B2 to move at a speed lower than the predetermined speed in the insertion direction. That is, when the saddle portion B2 is forcefully returned to the mounting position, the moving speed of the saddle portion B2 is reduced by the braking device 800.

[0161] As described above, in the present embodiment, even if the saddle portion B2 is forcefully inserted into the housing 27, the braking device 800 restricts the movement of the saddle portion B2 in the insertion direction, so that no impact is applied to the main body frame 500 of the housing 27. Therefore, it is possible to suppress the occurrence of device failures such as deformation of the main body frame 500 and failure of other units. Also, it is possible to suppress the relative position of the image forming apparatus A and the sheet processing apparatus B from shifting due to the saddle portion B2 forcefully colliding with the main body frame 500, resulting in skewing of the sheet. Further, in a configuration where the centrifugal brake unit 820 operates when the saddle portion B2 is forcefully inserted, it is possible to suppress an impact from being applied to the centrifugal brake unit 820 itself.

[0162] Note that a configuration in which a spring or the like is disposed on the back side of the main body frame 500 to mitigate an impact even if the saddle portion B2 is vigorously returned to the mounting position is also conceivable. However, there is a risk that when the saddle portion B2 hits the spring, it will vigorously pop out to the front side. On the other hand, in the present embodiment, since the braking device 800 is provided to restrict the movement of the saddle portion B2 when the saddle portion B2 is vigorously inserted, the saddle portion B2 will not vigorously come out to the front side of the device.

[0163] [Alternative Example] In the above description, the configuration in which the above-described braking device 800 is provided in the sheet processing device B has been described. However, the configuration in which the braking device 800 as described above is provided is not limited to the sheet processing device B. For example, as shown in FIG. 18, the braking device 800 may be provided for the cassettes 210a, 210b, and 210c of the sheet storage device 2d. The sheet storage device 2d has, for example, the configuration described with reference to FIG. 1.

[0164] The sheet storage device 2d has a plurality of pull-out cassettes 210a to 210c. The plurality of cassettes 210a to 210c as storage units are arranged so as to be pullable out of the housing 211 as a housing and insertable into the mounting position of the housing 211, and store sheets. In such cassettes 210a to 210c, 1500 to 2000 sheets of sheets may be stored respectively. As the number of stored sheets increases, the cassette becomes heavier, so that it becomes easier to move in a state of gaining momentum when returning from the position pulled out from the device to the mounting position. Therefore, by providing the above-described braking device 800, it is possible to suppress the cassettes 210a to 210c from being vigorously returned to the sheet storage device 2d in the same manner as when provided in the sheet processing device B.

[0165] This can suppress deformation of the support frame of the housing 211 of the sheet storage device 2d and failure of each unit. Further, deformation of the connection portion between the image forming apparatus A and the sheet storage device 2d can be suppressed. As a result, skewing of the sheet conveyed from the sheet storage device 2d to the image forming apparatus A due to a shift in the relative position between the image forming apparatus A and the sheet storage device 2d can be suppressed. Further, in a configuration in which the centrifugal brake unit 820 operates when the cassettes 210a to 210c are inserted forcefully, it is possible to suppress an impact from being applied to the centrifugal brake unit 820 itself.

[0166] <Other Embodiments> In the above-described embodiment, the braking device 800 is provided on the lower right stay 500b near the lower right rail with respect to the main body frame 500, but it may be provided near the lower left rail. Further, in the above-described embodiment, only one braking device 800 is provided, but a plurality of braking devices may be provided. For example, they may be provided at symmetric positions. Further, the first engaging portions 825ab and 825bb and the second engaging portions 823ba and 823bb may be one or a plurality as long as they can reduce the speed when the unit moves forcefully. It is preferable to provide a plurality (two or more) of the first engaging portions 825ab and 825bb and the second engaging portions 823ba and 823bb because the stopping operation of the unit can be made faster. When two or more are provided, it is preferable to provide them at point-symmetric positions centered on the rotating shaft 822 as described above.

[0167] Further, in the above-described embodiment, the wall portion 823b of the engaging member 823, which is the member in which the second engaging portions 823ba and 823bb are formed, is formed in a substantially cylindrical shape. However, as long as the rotation of the engaging sheet metals 825a and 825b is not hindered during normal rotation and the first engaging portions 825ab and 825bb of the engaging sheet metals 825a and 825b can engage with the second engaging portions 823ba and 823bb of the wall portion 823b when rotating quickly, the member in which the second engaging portions 823ba and 823bb are formed does not have to be a cylindrical shape. For example, a plurality of plate-like members may be arranged in a circular shape with a predetermined interval therebetween.

[0168] In the above-described embodiment, the rack 801 is provided on the main body frame 500 side, but it may be provided on the saddle portion B2 side. However, when the rack 801 is provided on the saddle portion B2 side, springs 830 and the like are not necessary as in the case of providing it on the main body frame 500, but it is necessary to have a configuration in which the rack 801 always meshes with the gear 802 of the gear unit 810 provided on the main body frame 500. Therefore, in this case, the length of the rack 801 in the front-rear direction is longer than that in the above-described embodiment. In the above-described embodiment, since the rack 801 is provided on the main body frame 500 side, the size in the F-B direction can be made smaller than in the case of providing it on the saddle portion B2 side. Also, the workability when assembling the apparatus can be improved.

[0169] In the above-described embodiment, the case where the processing unit is the saddle portion B2 that performs the middle folding process, the middle binding process, and the corner binding 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 punching process for making 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 middle folding process, a middle binding process, a corner binding process, an end binding process, and a punching process.

[0170] Furthermore, as the conveying 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, 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, and a configuration in which the sheet is sandwiched by a belt and a roller may be used, and the conveying 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.

[0171] 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 be used. For example, a configuration in which other processing apparatuses or conveying apparatuses 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 be used.

[0172] Further, the disclosure of the present embodiment includes the following configurations. (Configuration 1) A sheet processing apparatus, a processing unit that is movable between a pull-out position pulled out from the sheet processing apparatus and a storage position stored in the sheet processing apparatus, and that performs a predetermined process on the sheet; a braking mechanism that operates when the processing unit is inserted at a speed equal to or higher than a predetermined speed in a direction from the pull-out position toward the storage position, and that brakes the processing unit; a damper mechanism that, when the braking mechanism operates, applies a load to the processing unit moving in a direction from the pull-out position toward the storage position and absorbs an impact applied to the braking mechanism. A sheet processing apparatus comprising the same. (Configuration 2) The braking mechanism according to Configuration 1, wherein when the processing unit is inserted at a speed equal to or higher than the predetermined speed in a direction from the pull-out position toward the storage position, the braking mechanism continues to be in an operating state until the processing unit reaches the storage position. (Configuration 3) The damper mechanism, a first gear that rotates by receiving power when the processing unit moves in a direction from the pull-out position toward the storage position; a second gear that rotates as the first gear rotates. The braking mechanism, When the processing unit is inserted at a speed less than the predetermined speed in the direction from the extraction position to the accommodation position, rotation of the second gear is allowed, and when the processing unit is inserted at a speed equal to or higher than the predetermined speed in the direction from the extraction position to the accommodation position, rotation of the second gear is stopped. The damper mechanism applies a load to the first gear when the rotation of the second gear stops, and decelerates the moving speed of the processing unit. The sheet processing apparatus according to Configuration 1 or 2. (Configuration 4) The sheet processing apparatus further includes a rack that abuts on the processing unit moving in the direction from the extraction position to the accommodation position and moves along with the movement of the processing unit in the direction from the extraction position to the accommodation position. The rack engages with the first gear and inputs power to the first gear. The sheet processing apparatus according to Configuration 3. (Configuration 5) The braking mechanism a rotating shaft that rotates when the rotation of the second gear is transmitted; a first engaging portion that rotates together with the rotating shaft, and when the moving speed of the processing unit in the direction from the extraction position to the accommodation position becomes the predetermined speed, and when the rotation speed of the rotating shaft that rotates via the first gear and the second gear is set to a predetermined rotation speed, a first engaging portion that expands radially outward by centrifugal force when the rotation speed of the rotating shaft becomes equal to or higher than the predetermined rotation speed; a second engaging portion that engages with the first engaging portion and stops the rotation of the rotating shaft when the first engaging portion expands radially outward by centrifugal force. The sheet processing apparatus according to Configuration 3 or 4. (Configuration 6) The braking mechanism has a biasing portion that biases the first engaging portion radially inward. The first engaging portion expands radially outward by centrifugal force against the biasing force of the biasing portion when the rotation speed of the rotating shaft becomes equal to or higher than the predetermined rotation speed, and engages with the second engaging portion. The sheet processing apparatus according to Configuration 5. (Configuration 7) The first engaging portion has a first engaging sheet metal and a second engaging sheet metal. The biasing portion is stretched between the first engaging metal plate and the second engaging metal plate, and biases the first engaging metal plate and the second engaging metal plate in a direction approaching each other. The sheet processing apparatus according to Configuration 6. (Configuration 8) The braking mechanism has a cylindrical member fixed around the rotating shaft. The first engaging portion is disposed inside the cylindrical member. The second engaging portion is formed on the inner peripheral surface of the cylindrical member. The sheet processing apparatus according to Configuration 6 or 7. (Configuration 9) When the processing unit moves in a direction from the pulled-out position toward the housed position, the damper mechanism transmits rotation to the rotating shaft, and when the processing unit moves in the pulling-out direction, the damper mechanism has a one-way rotation transmission portion that does not transmit the rotation of the rotating shaft. The sheet processing apparatus according to any one of Configurations 5 to 8. (Configuration 10) The processing unit 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 notch, 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. The pair of clamping units have a corner-back processing unit that performs corner-back processing to press the back of the sheet bundle clamped by the pair of clamping units with 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 predetermined process includes the corner-back process. The sheet processing apparatus according to any one of Configurations 1 to 9. (Configuration 11) An image forming unit having an image forming portion that forms an image on a sheet, The sheet processing apparatus according to any one of Configurations 1 to 10. The sheet processing apparatus is an image forming system that performs the predetermined processing on a sheet on which an image is formed by the image forming unit. (Configuration 12) A sheet storage device, A storage unit that is movable between a pull-out position pulled out from the sheet storage device and a storage position stored in the sheet storage device, and that stores sheets; A braking mechanism that operates when the storage unit is inserted at a speed equal to or higher than a predetermined speed in a direction from the pull-out position toward the storage position, and brakes the storage unit; A damper mechanism that, when the braking mechanism operates, applies a load to the storage unit moving in a direction from the pull-out position toward the storage position to absorb an impact applied to the braking mechanism. A sheet storage device provided with the damper mechanism. (Configuration 13) The braking mechanism continues to be in an operating state until the storage unit reaches the storage position when the storage unit is inserted at a speed equal to or higher than the predetermined speed in a direction from the pull-out position toward the storage position. The sheet storage device according to Configuration 12. (Configuration 14) The damper mechanism, A first gear that is rotated by power input by the movement of the storage unit in a direction from the pull-out position toward the storage position; A second gear that rotates as the first gear rotates. The damper mechanism has the second gear, The braking mechanism, allows rotation of the second gear when the storage unit is inserted at a speed less than the predetermined speed in a direction from the pull-out position toward the storage position, and stops rotation of the second gear when the storage unit is inserted at a speed equal to or higher than the predetermined speed in a direction from the pull-out position toward the storage position, The damper mechanism applies a load to the first gear when rotation of the second gear stops to decelerate the moving speed of the storage unit. The sheet storage device according to Configuration 12 or 13. (Configuration 15) The sheet storage device further includes a rack that abuts against the storage unit moving in a direction from the extraction position to the storage position, and moves along with the movement of the storage unit in the direction from the extraction position to the storage position. The rack engages with the first gear and inputs power to the first gear, and is the sheet storage device according to Configuration 14. (Configuration 16) The braking mechanism a rotating shaft that rotates when the rotation of the second gear is transmitted; a first engaging portion that rotates together with the rotating shaft, and when the moving speed of the storage unit in the direction from the extraction position to the storage position becomes the predetermined speed, and when the rotation speed of the rotating shaft that rotates through the first gear and the second gear is set to a predetermined rotation speed, a first engaging portion that expands radially outward by centrifugal force when the rotation speed of the rotating shaft becomes equal to or higher than the predetermined rotation speed; a second engaging portion that engages with the first engaging portion and stops the rotation of the rotating shaft when the first engaging portion expands radially outward by centrifugal force, and is the sheet storage device according to Configuration 14 or 15. (Configuration 17) The braking mechanism has a biasing portion that biases the first engaging portion radially inward. The first engaging portion expands radially outward by centrifugal force against the biasing force of the biasing portion when the rotation speed of the rotating shaft becomes equal to or higher than the predetermined rotation speed, and engages with the second engaging portion, and is the sheet storage device according to Configuration 16. (Configuration 18) The first engaging portion has a first engaging sheet metal and a second engaging sheet metal. The biasing portion is stretched between the first engaging sheet metal and the second engaging sheet metal, and biases the first engaging sheet metal and the second engaging sheet metal in a direction approaching each other, and is the sheet storage device according to Configuration 17. (Configuration 19) The braking mechanism has a cylindrical member fixed around the rotating shaft. The first engaging portion is disposed inside the cylindrical member. The second engaging portion is the sheet storage device according to Configuration 17 or 18 formed on the inner peripheral surface of the cylindrical member. (Configuration 20) The damper mechanism has a one-way rotation transmission portion that transmits rotation to the rotary shaft when the storage unit moves in a direction from the pulled-out position to the storage position, and does not transmit the rotation of the rotary shaft when the storage unit moves in the pulling-out direction. The sheet storage device according to any one of Configurations 16 to 19. (Configuration 21) An image forming unit having an image forming portion for forming an image on a sheet, The sheet storage device according to any one of Configurations 12 to 20, and is provided with 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 portion.

Explanation of Signs

[0173] 2d ··· Sheet storage device 3 ··· Image forming portion 27 ··· Housing (frame) 118 ··· Saddle third roller pair (transport portion) 120 ··· Lower clamp unit (clamp unit) 121 ··· Upper clamp unit (clamp unit) 123 ··· Pressing roller 134 ··· Corner rounding processing unit 210a, 210b, 210c ··· Cassette (storage unit) 211 ··· Housing (frame) 800 ··· Braking device 801 ··· Rack 802 ··· Gear (first gear) 804 ··· Gear (second gear) 805 ··· Transmission member (one-way rotation transmission portion) 810 ··· Gear unit (damper mechanism) 820 ··· Centrifugal brake unit (braking mechanism) 822 ··· Rotary shaft 823 ··· engaging member (cylindrical member) 823ba, 823bb ··· second engaging portion 825ab, 825bb ··· first engaging portion 827 ··· spring (biasing portion) 1000 ··· image forming system A ··· image forming apparatus B ··· sheet processing apparatus B2 ··· saddle portion (processing unit)

Claims

1. A sheet processing apparatus, comprising: a processing unit that is movable between a drawn-out position drawn out from the sheet processing apparatus and a housed position housed in the sheet processing apparatus, and that performs a predetermined process on a sheet; a braking mechanism that operates when the processing unit is inserted at a speed equal to or higher than a predetermined speed in a direction from the drawn-out position toward the housed position, and brakes the processing unit; a damper mechanism that, when the braking mechanism operates, applies a load to the processing unit moving in a direction from the drawn-out position toward the housed position and absorbs an impact applied to the braking mechanism.

2. The sheet processing apparatus according to claim 1, wherein the braking mechanism continues to be in an operating state until the processing unit reaches the housed position when the processing unit is inserted at a speed equal to or higher than the predetermined speed in a direction from the drawn-out position toward the housed position.

3. The damper mechanism includes: a first gear that is rotated by power input by movement of the processing unit in a direction from the drawn-out position toward the housed position; a second gear that rotates as the first gear rotates. The braking mechanism: allows rotation of the second gear when the processing unit is inserted at a speed lower than the predetermined speed in a direction from the drawn-out position toward the housed position, and stops rotation of the second gear when the processing unit is inserted at a speed equal to or higher than the predetermined speed in a direction from the drawn-out position toward the housed position. The sheet processing apparatus according to claim 1, wherein the damper mechanism applies a load to the first gear when rotation of the second gear stops, and decelerates the moving speed of the processing unit.

4. The sheet processing apparatus further includes a rack that abuts against the processing unit moving in a direction from the drawn-out position toward the housed position and moves as the processing unit moves in a direction from the drawn-out position toward the housed position. The sheet processing apparatus according to claim 3, wherein the rack engages with the first gear and inputs power to the first gear.

5. The braking mechanism includes: a rotating shaft that rotates when rotation of the second gear is transmitted. A first engaging portion that rotates together with the rotating shaft, when the moving speed in the direction from the pulling-out position to the housing position of the processing unit becomes the predetermined speed and the rotating speed of the rotating shaft that rotates via the first gear and the second gear is set to a predetermined rotating speed, a first engaging portion that expands radially outward by centrifugal force when the rotating speed of the rotating shaft becomes equal to or higher than the predetermined rotating speed; The sheet processing apparatus according to claim 3, further comprising: a second engaging portion that engages with the first engaging portion to stop the rotation of the rotating shaft when the first engaging portion expands radially outward by centrifugal force.

6. The braking mechanism includes a biasing portion that biases the first engaging portion radially inward. The first engaging portion expands radially outward by centrifugal force against the biasing force of the biasing portion and engages with the second engaging portion when the rotating speed of the rotating shaft becomes equal to or higher than the predetermined rotating speed, according to the sheet processing apparatus of claim 5.

7. The first engaging portion includes a first engaging sheet metal and a second engaging sheet metal. The biasing portion is stretched between the first engaging sheet metal and the second engaging sheet metal, and biases the first engaging sheet metal and the second engaging sheet metal in a direction approaching each other, according to the sheet processing apparatus of claim 6.

8. The braking mechanism includes a cylindrical member fixed around the rotating shaft. The first engaging portion is disposed inside the cylindrical member. The second engaging portion is formed on the inner peripheral surface of the cylindrical member, according to the sheet processing apparatus of claim 6.

9. The damper mechanism includes a one-way rotation transmission portion that transmits rotation to the rotating shaft when the processing unit moves in the direction from the pulling-out position to the housing position, and does not transmit the rotation of the rotating shaft when the processing unit moves in the pulling-out direction, according to the sheet processing apparatus of claim 5.

10. The processing unit A conveying unit that conveys a sheet bundle subjected to middle folding processing or a sheet bundle subjected to middle binding processing and middle folding processing so that the back of the sheet bundle is located on the downstream side in the conveying direction from the notch. 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 skew-back processing unit that performs skew-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 sheet processing apparatus according to claim 1, wherein the predetermined processing includes the skew-back processing.

11. An image forming unit having an image forming section for forming an image on a sheet. The sheet processing apparatus according to any one of claims 1 to 10. The sheet processing apparatus is an image forming system that performs the predetermined processing on a sheet on which an image is formed by the image forming section.

12. A sheet storage device. A storage unit that is movable between a pulled-out position pulled out from the sheet storage device and a storage position stored in the sheet storage device, and that stores sheets. A braking mechanism that operates when the storage unit is inserted at a speed equal to or higher than a predetermined speed in a direction from the pulled-out position toward the storage position, and brakes the storage unit. A damper mechanism that, when the braking mechanism operates, applies a load to the storage unit moving in a direction from the pulled-out position toward the storage position to absorb an impact applied to the braking mechanism.

13. The sheet storage device according to claim 12, wherein the braking mechanism continues to be in an operating state until the storage unit reaches the storage position when the storage unit is inserted at a speed equal to or higher than the predetermined speed in a direction from the pulled-out position toward the storage position.

14. The damper mechanism. A first gear that is rotated by inputting power by the movement of the storage unit in a direction from the pulled-out position toward the storage position. A second gear that rotates along with the rotation of the first gear. The braking mechanism. When the storage unit is inserted at a speed less than the predetermined speed in a direction from the pulled-out position toward the storage position, the rotation of the second gear is allowed, and when the storage unit is inserted at a speed equal to or higher than the predetermined speed in a direction from the pulled-out position toward the storage position, the rotation of the second gear is stopped. The seat storage device according to claim 12, wherein the damper mechanism applies a load to the first gear when the rotation of the second gear stops, and decelerates the moving speed of the storage unit.

15. The seat storage device further comprises a rack that contacts the storage unit moving in a direction from the pull-out position to the storage position, and moves along with the movement of the storage unit in the direction from the pull-out position to the storage position. The rack engages with the first gear and inputs power to the first gear, according to the seat storage device of claim 14.

16. The braking mechanism includes a rotating shaft that rotates when the rotation of the second gear is transmitted, and a first engaging portion that rotates together with the rotating shaft, and when the moving speed of the storage unit in the direction from the pull-out position to the storage position reaches the predetermined speed, and when the rotation speed of the rotating shaft that rotates via the first gear and the second gear is set to a predetermined rotation speed, a first engaging portion that expands radially outward by centrifugal force when the rotation speed of the rotating shaft becomes equal to or higher than the predetermined rotation speed, and a second engaging portion that engages with the first engaging portion to stop the rotation of the rotating shaft when the first engaging portion expands radially outward by centrifugal force, according to the seat storage device of claim 14.

17. The braking mechanism has a biasing portion that biases the first engaging portion radially inward. The first engaging portion expands radially outward by centrifugal force against the biasing force of the biasing portion when the rotation speed of the rotating shaft becomes equal to or higher than the predetermined rotation speed, and engages with the second engaging portion, according to the seat storage device of claim 16.

18. The first engaging portion has a first engaging sheet metal and a second engaging sheet metal. The biasing portion is stretched between the first engaging sheet metal and the second engaging sheet metal, and biases the first engaging sheet metal and the second engaging sheet metal in a direction approaching each other, according to the seat storage device of claim 17.

19. The braking mechanism has a cylindrical member fixed around the rotating shaft. The first engaging portion is disposed inside the cylindrical member. The second engaging portion is formed on the inner peripheral surface of the cylindrical member, according to the seat storage device of claim 17.

20. The sheet storage device according to claim 16, wherein the damper mechanism has a one-way rotation transmission unit that transmits rotation to the rotation shaft when the storage unit moves in a direction from the pulled-out position toward the storage position, and does not transmit the rotation of the rotation shaft when the storage unit moves in the pulling-out direction.

21. An image forming unit having an image forming unit that forms an image on a sheet, A sheet storage device according to any one of claims 12 to 20, and 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 unit.

Images