JP4748569B2 - Tray apparatus, sheet processing apparatus, and image forming apparatus - Google Patents

Description

  The present invention incorporates / connects a sheet processing apparatus that accepts a sheet discharged from an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine, or another office machine, and stacks the sheet on a sheet stacking member. More specifically, the present invention relates to a technique for increasing the possible stacking amount of sheets on a sheet stacking member.

  Accepts sheets transported from image forming apparatuses such as copiers, printers, facsimiles, and processes such as alignment, sorting, stacking, staple binding, folding, envelope packing, packing, binding processing, bookbinding, punching, inspection, processing, etc. A sheet processing apparatus for performing the above has been put into practical use. Also, in some models of image forming apparatuses, such a sheet processing apparatus is built in or connected as a purchase option (so-called option).

  The sheet processing apparatus disclosed in Patent Document 1 includes two stages of tray apparatuses (stack trays) that are self-running with a built-in motor, and the remaining one stage is retracted to a position higher than the discharge roller. Is positioned lower than the discharge roller, stacks sheets and sheet bundles, and gradually lowers the tray device as the stacking progresses, so that the stacking surface height is kept almost constant and a large number of sheets can be stacked. .

  In the sheet processing apparatus disclosed in Patent Document 2, a sheet processing apparatus capable of staple binding is disposed between a lower image forming unit including a photosensitive drum and an upper image reading unit that reads a document image. In addition, a sheet processing apparatus including a fixed or elevating stacking tray is stored in a housing of the image forming apparatus to achieve space saving.

JP 2004-269163 A JP 2001-72311 A

  Since the sheet processing apparatus as shown in Patent Document 2 has only one stacking tray, sheets and sheet bundles on which images are formed cannot be sorted and stacked, and copying machines, printers, facsimiles, etc. If the built-in printer is equipped with a mode (function), the output sheets corresponding to the copier, printer, facsimile, etc. mode are mixedly loaded on the same stacking tray, and the mode in which the extracted sheet is It is difficult to discriminate (determine) whether the sheet is output in (1).

  Therefore, a plurality of stages of self-propelled tray apparatuses as shown in Patent Document 1 are attached to the sheet processing apparatus of the image forming apparatus as shown in Patent Document 2 so that the tray apparatus as a loading destination can be selected. Was proposed. In the image forming apparatus as disclosed in Patent Document 2, since the up / down range of the tray device is limited up and down, a torque limiter mechanism is provided in the drive device of the tray device so that the stacked sheets are within the up / down range. It was proposed to prevent motor overload when it hits the ceiling or the lower surface of the upper tray device.

  However, when the torque limiter mechanism is incorporated in the tray device, naturally the lifting force exceeding the upper limit torque is lost, and even if the stacked sheets do not collide, the torque limiter mechanism can limit the load weight and load enough sheets. become unable. In particular, when a single tray device is attached to the sheet processing device or when the tray device is not retracted to a position higher than the discharge roller, the raising / lowering range of the tray device becomes large and a large number of sheets can be stacked. When the load weight reaches the upper limit value, the torque limiter mechanism works, and it becomes impossible to load any more while keeping the possible lifting range.

  Therefore, it was proposed to prepare multiple types of tray devices with different upper limit torques of the torque limiter mechanism, and select and install tray devices according to the user's specifications, but prepare multiple types of tray devices. Therefore, when the specification is changed in the field work after installation, it is necessary to make the old tray device unusable or to purchase a new tray device.

  It is an object of the present invention to provide a sheet processing apparatus that can stack a large amount of heavy sheets by using a possible lifting range as much as possible, and that can cope with an increase or decrease in the number of tray apparatuses in the field work by using an old tray apparatus as it is. It is aimed.

The sheet processing apparatus of the present invention comprises: a sheet stacking unit that transmits rotation of a built-in power source to a driving unit and moves up and down by the driving unit; and a discharging unit that discharges the sheet to the sheet stacking unit, and the sheet In the sheet processing apparatus for stacking the sheets discharged by the discharge unit on the sheet stacking unit as the stacking unit is moved up and down, the sheet stacking unit increases when a load torque of the sheet stacking unit increases and a transmission torque reaches an upper limit value. a limiter mechanism for limiting the rise in unit provided in said driving means, before Symbol sheet stacking means I 1-stage or more setup with possible der, the limiter mechanism, said sheet stacking means one stage cases, the A setting unit that can be switched so as to increase the upper limit value as compared with the case where the sheet stacking means has a plurality of stages is provided.

According to another aspect of the invention, there is provided a sheet processing apparatus including: a sheet stacking unit configured to transmit rotation of a built-in power source to a driving unit and to be moved up and down by the driving unit; and a discharge unit configured to discharge the sheet to the sheet stacking unit, In the sheet processing apparatus for stacking the sheets discharged by the discharge unit on the sheet stacking unit as the stacking unit is moved up and down, the sheet stacking unit increases when a load torque of the sheet stacking unit increases and a transmission torque reaches an upper limit value. a limiter mechanism for limiting the rise in unit provided in the drive unit, I can der attaching said sheet stacking means to retract to a position higher than the previous SL discharge means, said limiter mechanism, a position higher than the discharge means in the case of not providing the sheet stacking means for saving to the case of providing the sheet stacking means to retract to a higher position than the discharge means And it has a setting unit capable of switching to increase the remote upper limit.

In the sheet processing apparatus of the present invention, by switching the upper limit value of the limiter mechanism built in the sheet stacking means in at least two ways according to the stackable weight of the sheet obtained from the lifting range of the sheet stacking means, limiter mechanism before reaching allow loading weight of the sheet can be made to not interfere with the increase in the sheet stacking means. That is, when the self-propelled sheet stacking means is only one stage or when the specification is such that the sheet stacking means is not retracted to a position higher than the discharge means, the sheet stacking means has a large ascending / descending range and the stackable height (number of sheets) ) Increases, and the possible stacking weight of sheets assuming a full load of heavy sheets increases, but an upper limit value that can be increased without difficulty even with the increased possible stacking weight can be set in the setting unit of the limiter mechanism.

  Therefore, it is possible to stack a large amount of heavy sheets by making full use of the ascending / descending range, and the old sheet stacking means (tray device) can be used as it is by simply switching the setting of the upper limit value in the limiter mechanism. It is possible to cope with specification changes such as equipment expansion and reduction.

  This eliminates the need to prepare a plurality of types of tray devices having different upper limit torques of the limiter mechanism, and reduces the cost of preparing and managing a plurality of types of tray devices. Also, when changing specifications, the old tray device cannot be used, and the user does not have to purchase a new tray device.

  Hereinafter, a sheet processing apparatus according to an embodiment of the present invention and a copier as an embodiment of an image forming apparatus including the sheet processing apparatus will be described with reference to the drawings. However, the sheet processing apparatus of the present invention is not limited to the stapling process of the present embodiment, and may be configured to simply stack sheets on the sheet stacking member, and may be configured to perform other processes such as punching processes. Alternatively, it may be implemented with a configuration that performs only other processing or another configuration that performs the same processing. The image forming apparatus of the present invention is not limited to the copying machine of the present embodiment, and may be implemented by a facsimile, a printer, a complex machine of these, or the like.

  Further, the sheet processing apparatus 400 according to the present embodiment may be connected to a printing apparatus or the like other than the apparatus main body 500A of the copying machine 500 in which the raising / lowering range of the stack tray 421 is limited, and the sheet processing apparatus 400 according to the present embodiment. May be configured as a separate casing separable from the apparatus main body 500A, or may be incorporated in the casing of the apparatus main body 500A in an inseparable manner.

  In the following description, the upstream side portion of the conveyed sheet is the rear end, the downstream side portion is the front end, both side portions of the sheet connecting the rear end and the front end are side ends, and the distance between the side ends is the sheet width. Aligning the trailing edge of the sheet is trailing edge alignment, aligning the side edges is side edge alignment, and aligning the sheet width is width alignment.

<Image forming apparatus>
FIG. 1 is a front view of a copying machine provided with a sheet processing apparatus according to an embodiment of the present invention. The copier 500, which is an image forming apparatus of the present invention, includes, for example, a printer unit 200, which is an image forming unit, and a sheet processing apparatus 400, which is a sheet processing apparatus.

  The copier 500 combines a reader unit 120 that reads an image of a document and a printer unit 200 that forms an image in the apparatus main body 500A, and a sheet processing apparatus 400 that aligns and staples the image-formed sheets. It is arranged in the space SP provided. An automatic document feeder 300 (hereinafter referred to as “ADF”) that feeds documents one by one onto the platen glass 102 is attached to the upper portion of the apparatus main body 500A so as to be openable and closable rearward.

  The copying machine 500 functions as a copying machine that copies a document image read by the reader unit 120 to a sheet by the printer unit 200, and also receives image data sent from an external personal computer or the like by the printer unit 200 and forms a sheet. It also functions as a printer that prints images. Further, the copier 500 also functions as a facsimile that transmits a facsimile signal of an original image read by the reader unit 120 to another facsimile, or receives a facsimile signal from another facsimile and prints it by the printer unit 200. To do.

  When copying images of a plurality of originals, the originals are stacked on the ADF 300, conveyed one by one onto the platen glass 102 of the reader unit 120, and passed over the stopped scanner unit 104. When copying an image of a document that cannot be handled by the ADF 300, the ADF 300 is opened rearward, the document is placed on the platen glass 102, and the scanner unit 104 is moved in the horizontal direction in the drawing. In any case, the image of the band-like area illuminated by the lamp of the scanner unit 104 is imaged on the CCD image sensor unit 109 through the mirrors 105, 106, 107 and the lens 108, and the line image is read by the CCD image sensor unit 109. Then, it is photoelectrically converted into an image signal and subjected to digital processing such as image data conversion and image processing.

  The digitally processed image signal is transmitted to the exposure control unit 201 of the printer 200 and converted into an optical signal of a modulated laser beam. The exposure control unit 201 scans the optical signal and irradiates the photosensitive drum 202, and an electrostatic latent image is formed on the surface of the photosensitive drum 202 by the irradiation light. The electrostatic latent image is developed with toner attached by the developing unit 203, and a toner image is formed on the photosensitive drum 202.

  The sheet S is conveyed from the sheet cassettes 204 and 205 in synchronization with the leading edge of the toner image, and the toner image is transferred to the sheet S by the transfer unit 206. The toner image transferred to the sheet S is fixed to the sheet by being subjected to high temperature and pressure by the fixing unit 207. The sheet S that has been fixed is transferred to the sheet processing apparatus 400 through the sheet discharge unit 208.

  The sheet processing apparatus 400 is accommodated in a space SP formed on the side of the apparatus main body 500A of the copier 500 without protruding from the apparatus main body 500A of the copier. In addition to the sorting function for sorting sheets, the stapler unit A stapling function 420 (FIG. 3) is provided.

  The copier 500 accommodates a sheet processing apparatus 400 provided with stack trays 421 and 422 that can be moved up and down independently in a space SP formed in a side portion of the apparatus main body 500A below the reader unit 120, and the stack tray 421. Since sheets can be selectively stacked at 422, space saving can be achieved even when the sheet processing apparatus 400 is incorporated in a composite printer having modes such as a copying machine, a printer, and a facsimile. In addition, it is possible to stack separately according to the mode such as copy, printer, facsimile, etc., and it is easy to distinguish which mode the sheet is output, so it is an output device that is optimal for office needs. Yes.

  Further, by moving the stack tray 422 above the sheet discharge port 400A, the space SPU above the sheet discharge port 400A in the space SP formed in the side portion of the apparatus main body 500A is also a sheet stacking space. As a result, a large amount of sheets can be stacked.

  However, the stack trays 421 and 422 can be moved up and down by simply removing one of the stack trays so that the stack tray has a single-stage specification, or the stack tray does not wait above the sheet discharge port 400A. It can also be expanded to enable continuous mass loading on a single stack tray. That is, as shown in FIG. 4 to be described later, the stack trays 421 and 422 are equally mounted with the lifting device 507, and the lifting devices 507 have gears 539 and 544 connected to the tray motor 530, respectively. The racks 540 and 545 fixed to the main body side of the processing apparatus 400 are engaged with each other. The stack tray is configured to be moved upward along with the lifting device and easily removable from the rack. Then, the removed stack tray can be easily attached again in the field work.

  Similarly, the sheet processing apparatus can be easily changed to the two-stage stack tray specification by adding another stack tray based on the one-stage stack tray specification.

<Sheet processing device>
2 is a cross-sectional view of the main body side of the sheet processing apparatus, FIG. 3 is a perspective view of the main body of the sheet processing apparatus, FIG. 4 is an explanatory view of a lifting device for a stack tray, and FIG. 6 to 9 are explanatory diagrams of the control procedure of the stack tray switching operation. The sheet processing apparatus 400 of the present embodiment includes, for example, a tray motor 530 that is a prime mover, a lifting device 507 that is a driving unit, stack trays 421 and 422 that are sheet stacking units, and a sheet clamp member 412 that is a discharge unit. And a torque limiter mechanism A that is a limiter mechanism, and a set screw 549 (or a pin member 565) that is a connecting member.

  As shown in FIG. 2, the sheet processing apparatus 400 finally stacks a processing tray 410 for temporarily stacking sheets sequentially discharged from the apparatus main body 500 of the copying machine, and a sheet bundle that has been stapled by the processing tray 410. A self-propelled stack tray (lower bin) 421 and a stack tray (upper bin) 422 are provided. The stack trays 421 and 422 are individually moved up and down, and can be stacked separately using the stack trays 421 and 422 when outputting a printer or facsimile other than a copy job. In addition to the two-stage specification described here, the sheet processing apparatus 400 can be changed in specifications by setting the stack tray to one stage to support continuous mass stacking, or prioritizing sorting to three or more stages. .

  The processing tray 410 stacks the sheets by switching back the sheets using the offset roller 407. The sheet receiving unit 401 receives a sheet discharged from the copying machine main body 500A. The sheet received by the sheet receiving unit 401 is detected by the entrance sensor 403, and is then transported and stacked on the processing tray 410 by the transport roller 405 and the offset roller 407. Sheets stacked on the processing tray 410 are detected by a sheet bundle discharge sensor 415.

  The offset roller 407 is a roller member that conveys a sheet by forward rotation, reverse rotation, and offset movement (axial movement), and an outer peripheral portion is formed of an elastic body having elasticity close to rubber, such as rubber or foam. It has a cylindrical appearance. The offset roller holder 406 is movable along the offset shaft 511 and is rotatable with the offset shaft 511 as a fulcrum, and is rotated in the vertical direction from the pickup solenoid 433 via the solenoid arm 512 and the separation lever 514. Is done. As the pickup solenoid 433 is turned on / off, the offset roller 407 is raised / lowered.

  As shown in FIG. 3, the offset roller 407 includes a timing belt 523, a roller gear 524, an idler gear 525, an offset gear 526, an offset pulley 527, and a conveyance motor 431 that can drive the conveyance roller 405 (FIG. 2) in common. It is rotationally driven via a timing belt 522. The offset roller 407 rotates forward to convey the sheet downstream, and reversely conveys the sheet upstream according to the rotation direction of the conveyance motor 431.

  The offset roller 407 moves in the width direction of the sheet by driving an offset motor 432 capable of forward and reverse rotation, and approaches and separates from the width direction positioning wall 416. The rotation of the offset motor 432 is transmitted from the offset motor gear 432a to the offset pinion 516, and is converted into a linear motion along the offset shaft 511 by the offset rack 515.

  When the pickup solenoid 433 (FIG. 2) is turned off, the normally rotating offset roller 407 descends by its own weight and lands (contacts) on the sheet. The offset roller 407 once transports the sheet to the downstream side and then reverses, pulls back the sheet to the upstream side, and pushes the trailing end of the sheet against the sheet trailing end stopper 411 provided on the upstream end of the processing tray 410. By applying, the rear end of the sheet S is aligned.

  The sheet whose rear end is aligned is moved so as to be dragged by the frictional force of the offset roller 407 that is in contact with the offset roller 407 that has stopped rotating along the offset shaft 511, The side edges of the sheets are aligned by touching the width direction positioning wall 416 through the bottom.

  The sheet whose side edges are aligned is rotated again by rotating the offset roller again and repeatedly aligned at the trailing edge. Then, the sheet is sandwiched by the sheet clamp member 412 and fixed on the processing tray 410. Rear end alignment, side end alignment and stacking. A sheet bundle formed by stacking a predetermined number of sheets is stapled (stitched) at an angle at the rear end by operating the stapler 420.

  The stapled sheet bundle is discharged to the stack tray 421 by moving the sheet clamp member 412 to the stack tray 421 (FIG. 2) side and releasing the sheet clamp member 412 while being sandwiched between the sheet clamp members 412.・ It is loaded. At this time, since the stacked sheet bundle on the stack tray 421 is pressed by the pressing member 421A (FIG. 2), it is not dragged by the sheet bundle moving on the stacking surface.

  As shown in FIG. 2, each of the stack trays 421 and 422 includes an independent lifting device 507 (FIG. 4), and can individually lift and lower the space below the sheet discharge port 400A to stop positioning at an arbitrary height position. It is. In addition, the upper stack tray 422 can move to the upper side of the sheet discharge port 400A and stand by.

  In the process of stacking and aligning sheets on the processing tray 410 described above, the stack tray 421 (422) rises to a position near the sheet discharge port 400A and supports the leading end side of the sheet bundle on the processing tray 410.

  In the process of discharging the sheet bundle from the processing tray 410 to the stack tray 421 (422), the stack tray 421 (422) is positioned at the sheet bundle receiving height by once descending and rising. Then, after discharging the sheet bundle, the sheet bundle is once lowered and then immediately raised so that the uppermost surface of the discharged sheet bundle is positioned at the sheet bundle receiving height, and the stack tray 421 (422) It descends to a lower height position by the thickness of. In this way, the stack tray 421 (422) is lowered every time the sheet bundle is discharged, and the sheet bundle is stably discharged and stacked on the stacking surface (the uppermost surface of the stacked sheet bundle) positioned at a certain height. The

  As shown in FIG. 4, the lifting device 507 equally mounted on the stack trays 421 and 422 includes racks 540 and 545 in which gears 539 and 544 driven by a tray motor 530 are fixed to the main body side of the sheet processing apparatus 400. , The stack trays 421 and 422 are moved up and down.

  The rotation of the tray motor 530 is transmitted from the belt 531 to the pulley 532, and the rotation of the pulley 532 is transmitted from the knob 562 to the worm gear 534 through the rotation shaft 533. The rotation decelerated by the worm gear 534 and the worm wheel 536 is transmitted from the gear 537 to the gear 538, and the rotation of the gear 539 formed integrally with the gear 538 is converted into a linear motion by the rack 540.

  The rotation of the gear 538 is transmitted from the gear 541 via the belt 542 to the gear 543, and the rotation of the gear 544 formed integrally with the gear 543 is converted into a linear motion by the rack 545.

  In the sheet processing apparatus 400 of the present embodiment, discharged sheet bundles can be selectively delivered to or sorted into one of the stack trays 421 and 422. When sheets are stacked on the stack tray 421, FIG. As described above, the stack tray 422 is retracted above the sheet discharge port 400A. When the stack tray 422 is moved from the lower side to the upper side of the sheet discharge port 400A, the sheet discharge port 400A is closed by the shutter 521.

  As shown in FIG. 5A, the shutter 521 is supported by a shutter lever 520 so as to be movable up and down, and the driving force of the conveyance motor 431 that drives the offset roller 407 and the conveyance roller 405 in common is an electromagnetic clutch 517, an electromagnetic wave. By moving the shutter lever 520 through the gear portion 517a of the clutch 517, the idler gear 518, and the cam gear 519, the shutter 520 is raised and lowered. As shown in FIG. 5B, the shutter 521 can be lowered to a position adjacent to the processing tray 410 to close the front surface of the offset roller 407.

  In the sheet processing apparatus 400 of the present embodiment, as shown in FIG. 1, the two-stage stack trays 421 and 422 are moved up and down in the sheet stacking space SP1 secured between the upper reader unit 120 and the lower apparatus main body 500A. Therefore, an upper limit sensor 547 (FIG. 6) is provided corresponding to the upper limit position of the sheet stacking space SP1, and a lower limit sensor 546 is provided corresponding to the lower limit position of the sheet stacking space SP1, and the sheets are stacked on the upper stack tray 422. When the upper limit sensor 547 detects the sheet bundle, the raising of the stack tray 422 is stopped, and when the lower stack tray 421 is detected by the lower limit sensor 546, the lowering of the stack tray 421 is stopped.

  As shown in FIG. 6A, the stack tray 421 is in a position where it can receive sheets, and the stack tray 422 is retracted to the upper side, and the stack tray 422 is a sheet below the sheet discharge port 400A. The operation of moving to a position where it can be received is started.

  A lower limit sensor 546 capable of detecting a lower limit is provided below the stack tray 421. As shown in FIG. 6B, the stack tray 421 is lowered to a position detected by the lower limit sensor 546, and the pressing member 421A is Then, it moves to the retracted position indicated by the solid line below the processing tray 410.

  Next, as shown in FIG. 5A, the pickup solenoid 433 (FIG. 3) is turned on, the offset roller holder 406 rotates upward, and the offset roller 407 moves to the upper standby position. In this state, the electromagnetic clutch 517 is turned on, the transport motor 431 is connected to the idler gear 518, and the transport motor 431 is rotated by a predetermined amount, whereby the shutter 521 is lowered to the position shown in FIG.

  When the shutter 521 descends and closes the sheet discharge port 400A of the processing tray 410, a guide surface at the trailing edge of the sheet is formed by the shutter 521 and is already loaded on the stack tray 422 as shown in FIG. When the stack tray 422 moves up and down, the sheet that has been placed does not flow back into the space of the processing tray 410 and does not enter.

  If the lowering of the shutter 521 is completed, the stack tray 422 starts to lower. Then, as shown in FIG. 7B, the stack tray 422 stops at a position where it passes through the pressing member 421A. Thereafter, the transport motor 431 rotates by a predetermined amount in the reverse direction, the shutter 521 moves up, and stops at the position shown in FIG.

  Then, when the pressing member 421A that has been retracted under the processing tray 410 rotates to a position where the sheet can be pressed, the stack tray 422 is raised to a position where the sheet is received, as shown in FIG. Then stop. Thereafter, the stack tray 422 can receive sheets in the same manner as the stack tray 421.

  Next, as shown in FIG. 8A, the stack tray 422 is in a position where the stack tray 422 can receive a sheet, and the stack tray 421 is in a position where the stack tray 421 is retracted downward. The ascending operation is started.

  As shown in FIG. 8B, when the pressing member 421A returns to the retracted position and the transport motor 431 (FIG. 5) is rotated by a predetermined amount, the shutter 521 is lowered to block the sheet discharge port 400A of the processing tray 410. Thus, the sheets already stacked on the stack tray 422 are prevented from flowing backward from the sheet discharge port 400A to the space of the processing tray 410. Thereafter, the stack tray 422 starts to rise. The stack tray 422 passes through the sheet discharge port 400A and ascends to a space SPU provided above the sheet discharge port 400A as shown in FIG. The stack tray 422 moves up the space SPU provided above the sheet discharge port 400A and is detected by an upper limit sensor 547 provided near the upper limit of the space SPU (in the present embodiment, near the bottom surface of the reader unit 120). Then, since the stack tray lifting / lowering motor 530 stops, the rising is stopped.

  Next, the conveyance motor 431 rotates by a predetermined amount in the reverse direction, and as shown in FIG. 9B, the shutter 521 is raised to the position shown in FIG. 5A to open the sheet discharge port 400A. Stop.

  Finally, the holding member 421A that has been retracted rotates to a state where the sheet can be pressed, and as shown in FIG. 6A, the stack tray 421 is raised to the first position to receive the sheet and stopped. To do. By moving to this position, the stack tray 421 can receive sheets.

  By the way, the process of returning from the state shown in FIG. 8A to the state shown in FIG. 6A, that is, the stack tray 422 at the position for receiving the sheet is retracted above the sheet discharge port 400A, In the process in which the stack tray 421 that has been evacuated to the position where the sheet is to be received, normally, when the uppermost sensor 547 detects the uppermost surface of the sheet bundle stacked on the stack tray 422, the stack tray 422 is stopped rising. Thus, the collision with the lower surface of the reader unit 120 and the tray motor 530 of the elevating device 507 (FIG. 4) are prevented from being overloaded.

  However, if the upper limit sensor 547 is not put on the sheet bundle stacked on the stack tray 422 and the coffee cup or the like is not put on the upper limit sensor 547, the coffee cup or the like collides with the bottom surface of the reader unit 120 (FIG. 1). Even after the lift of 422 stops, the tray motor 530 of the lifting device 507 (FIG. 4) may continue to rotate, leading to overload of the tray motor 530 and damage to mechanical components.

  In addition, when the coffee cup is left on the sheet bundle stacked on the stack tray 421, the coffee cup or the like collides with the lower surface of the stack tray 422 in the process in which the stack tray 421 moves up to a position where the sheet is received. There is a possibility that the tray 421 is prevented from rising and an overload of the tray motor 530 or a mechanical component is damaged in the lifting device 507 (FIG. 4) of the stack tray 421.

  Therefore, in the sheet processing apparatus 400 of the present embodiment, the torque limiter mechanism A is provided in the lifting device 507 shown in FIG. 4 so that the rotation transmission is idled when a torque exceeding the upper limit is applied.

<First Embodiment>
10 is a cross-sectional view for explaining the configuration of the torque limiter mechanism, FIG. 11 is a perspective view of a limiter spring, FIG. 12 is a perspective view of a pulley, and FIG. 13 is an explanatory view of a direct connection structure in the torque limiter mechanism of the first embodiment. .

  As shown in FIG. 10, in the torque limiter mechanism A, the boss portion 562a of the knob 562 fixed to the rotating shaft 533 and the boss portion 532a of the pulley 532 are connected by a limiter spring 561, and the limiter spring 561 is connected to the boss portion. The transmission torque is limited by idling around 562a.

  A cylindrical boss portion 532 a is integrally formed inside the pulley 532, and a boss portion 562 a is integrally formed inside the knob 562. One end of a limiter spring 561 is inserted into the boss portion 532 a of the pulley 532, and the other end of the limiter spring 561 is press-fitted into the boss portion 562 a of the knob 562, respectively.

  As shown in FIG. 11, the tip of one end side of the limiter spring 561 is a projection 561a that functions as a stopper, and the outer diameter of the boss 532a of the pulley 532 is slightly smaller than the inner diameter of the limiter spring 561. However, as shown in FIG. 12, the protrusion 561 a is inserted into the insertion hole 532 b of the pulley 532, thereby serving as a detent for the limiter spring 561 with respect to the pulley 532.

  As shown in FIG. 10, the pin 548 that passes through the rotation shaft 533 is held in a groove formed on the end surface of the knob 562, so that the knob 562 and the rotation shaft 533 are integrally connected. The rotating shaft 533 rotates together. Further, since the outer diameter of the boss portion 562a of the knob 562 is larger than the inner diameter of the limiter spring 561, the boss 562a is always fastened to the limiter spring 561, and the boss 562a and the inner surface of the limiter spring 561 are constantly frictioned. It is in a relationship that generates power.

  As shown in FIG. 4, the driving force of the tray motor 530 is transmitted to the worm gear 534 fixed to the rotating shaft 533 via the torque limiter mechanism A assembled in this way. As shown in FIG. 10, the output torque of the tray motor 530 is transmitted to the pulley 532 via the belt 531, transmitted from the pulley 532 to the knob 562 via the limiter-spring 561, and connected to the knob 562. 533 is transmitted.

  Here, the boss portion 562a of the knob 562 is normally tightened by a limiter spring 561. However, when a certain load torque is generated downstream of the rotating shaft 533, the limiter is rotated when the spring is rotated in the loosening direction side. Slack occurs between the spring 561 and the boss portion 562a of the knob 562, causing slippage, and it becomes impossible to transmit more torque from the rotary shaft 533 to the pulley 532. In this embodiment, the winding direction of the limiter spring 561 is set so that the limiter spring 561 rotates in the loosening direction when the tray is raised.

  And even if the raising of the stack tray 421 (422) is prevented by setting the slip torque value to a desired torque value, the tray motor 530 is overloaded in the elevating device 507 (FIG. 4) or the mechanical parts are damaged. It is trying not to cause. Further, when the stack tray 422 is raised, the upper limit sensor 547 does not detect the stack tray 422 even when a predetermined time elapses. When the stack tray 421 is raised, the stack tray 421 is raised even if the predetermined time elapses. 4 does not reach the sheet receiving height, the operation of the tray motor 530 in the lifting device 507 (FIG. 4) is forcibly stopped to stop the raising of the stack trays 422 and 421, and then the stack tray 422, 421 is lowered.

  Incidentally, as described above, the sheet processing apparatus 400 has a configuration in which the number of stack trays can be changed as necessary. In other words, the stack trays 421 and 422 are attached to the apparatus main body of the sheet processing apparatus 400 so that they can be easily attached and detached, and the stack tray of any number of stages can be controlled to rise and fall by a simple setting change through a touch panel (not shown). It is. As shown in FIG. 4, the stack tray is the same as the stack tray to which the configuration of the lifting device 507 is added, and can be added by engaging gears 539 and 544 with racks 540 and 545.

  So far, the embodiment in which two trays are mounted has been described. Next, differences in the case where “only one tray” is installed in the present embodiment will be described. The difference is the number of sheets that can be stacked per tray. When stack trays are arranged in two stages, there is a state where both stack trays stand by in a space below the sheet discharge port 400A, so that the space corresponding to the thickness of the stack tray + α is consumed, and one stage is arranged. Compared to, the number of sheets that can be loaded per stage is less than half.

  In other words, if only one stage is arranged, the number of stacked sheets can be more than doubled and substantially three times larger than that in the case where two stages are arranged. Continuous discharge and loading are possible.

  However, if only one stack tray with the slip torque value (upper limit value) of the torque limiter mechanism A described above is arranged on the premise of a two-stage arrangement, stacking heavy sheets such as A3 paper will stack in space. The torque value due to the load weight exceeds the slip torque value long before the upper limit number of sheets that can be reached is reached, and it is not possible to load the number of sheets that was initially expected. In addition, when the time is over, the image forming apparatus 400 may interrupt an error, which may cause a complicated return operation or reprinting.

Therefore, in the first embodiment, as shown in FIG. 13A, a screw fixing portion 532c is formed on the pulley 532 as a setting portion, and a screw hole is formed at a position corresponding to the screw fixing portion 532c of the rotating shaft 533. 533a is formed. Then, the set screw 549 is inserted by superimposing the screw stopper 532c and the screw hole 533a, so that the pulley 532 and the rotary shaft 533 can be directly connected by bypassing the torque limiter mechanism A. That is, the set screws 549, the order of driving the tray motor 530 → the belt 531 → pulley 532 → next rotation shaft 533, limiters spring 561 and the knob 562 will not participate at all in the drive. Therefore, the maximum torque to be transmitted becomes the starting torque of the tray motor 530 and is transmitted to the downstream, and large capacity loading is possible.

  In addition, when one stage is added to the specification of the one-stage arrangement and a two-stage stack tray is used, it is possible to remove the set screw 549 from the state shown in FIG. Thus, the direct connection can be canceled and torque transmission by the torque limiter mechanism A can be performed.

  As shown in FIG. 1, in the case of one-stage arrangement, the stackable range of the stack tray 421 is between the sheet receiving position and the lower limit sensor 546 (SP1), and a coffee cup is placed above the stack tray 421. Even if misplaced or the like, there is sufficient space so that it does not collide with the bottom surface of the reader unit 120. Therefore, the torque limiter mechanism A described above may not be provided in the specification of the one-stage arrangement.

  According to the torque limiter mechanism A of the first embodiment, for example, the set screw 549 that is a connecting member can be easily attached and detached with only a simple tool such as a screwdriver, and the upper limit torque transmitted by the attachment and detachment of the set screw 549 is 2 Since it is switched to the stage, it is possible to stack a large amount of heavy sheets by using the possible lifting range, regardless of whether it is a one-stage specification or a two-stage specification. In addition, the old stack tray (tray device) can be used as it is simply by attaching and detaching the set screw 549, regardless of the specification change of the two-stage specification → the one-stage specification → the one-stage specification → the two-stage specification. It is no longer necessary to prepare multiple types of stack trays with different torques, reducing the cost of preparing and managing multiple types of stack trays. No longer purchase new stack trays.

Second Embodiment
FIG. 14 is a partial perspective view of the torque limiter mechanism of the second embodiment. In the first embodiment, since a set screw 549 is used, a tool is required for attachment. On the other hand, in 2nd Embodiment, since the rotating shaft 533 and the pulley 532 are directly connected using the pin member 565 which can be mounted | worn easily by hand, a tool is unnecessary.

  FIG. 14 is a perspective view showing a state where the pin 548 of the torque limiter mechanism A shown in FIG. 10 is removed and the knob 562 and the limiter spring 561 are removed. As shown in FIG. 14, the rotation shaft 533 and the pulley 532 are formed with through holes at overlapping positions, and the rotation shaft 533 and the pulley 532 are directly connected to each other by inserting a pin 565 into the through hole. It is designed to rotate as a unit. The pin 565 is formed with an arc portion 565a that substantially wraps around the cross section following the side surface of the rotation shaft 533, so that the arc portion 565a restrains the cross section of the rotation shaft 533 and prevents the pin 565 from falling off.

  According to the torque limiter mechanism of the second embodiment, when switching the upper limit torque, the pin 565 can be attached by manually pushing in without using a tool, and the workability of changing the number of stack trays is further improved.

<Effect of the sheet processing apparatus of the present embodiment>
In the sheet processing apparatus 400 of this embodiment, the sheet bundle SA is pushed out to the stack tray 421 (422) by the sheet clamp member 412, and the rear end of the sheet bundle SA is aligned with the upstream end of the stack tray 421 (422). Therefore, it is unnecessary to conventionally tilt the stack tray by about 30 degrees in order to pull back the discharged sheet bundle SA. Further, since the pressing member 421A presses the sheet bundle SA against the stack tray 421 (422), it is possible not only to prevent a decrease in the stacking amount due to the curl of the sheet, but also the preceding sheet already stacked is pushed by the succeeding sheet and advanced. It is possible to prevent a decrease in stacking performance such as a shift of the sheet stacking position. As a result, the sheet processing apparatus 400 can secure a stable stacking performance at a stack tray angle of about 9 degrees, and thus the stack tray 421 (422) even in the space SP (FIG. 1) where the height direction is limited. A large number of sheets can be stacked.

  The sheet processing apparatus 400 of this embodiment can align the trailing ends of the sheets S stably with a simple configuration that does not require many members. Further, since the sheet is not discharged so as to be skipped, the sheet can be stably conveyed with little fluctuation.

  Further, when stacking sheets on the processing tray 410, the stacking tray 421 (422) supports the front end side of the sheet bundle so that the processing tray 410 is shortened, so that the entire length of the sheet processing apparatus 400 is shortened. Compared with the sheet processing apparatus of Patent Document 2 that supports a sheet only by the processing tray, the copying machine 500 can be configured more compactly.

  Further, after the sheet S is moved in the width direction on the processing tray 410 and the side edge alignment is performed, the offset roller 407 is reversely rotated again to perform the trailing edge alignment again in order to correct the deviation of the sheet trailing edge alignment. Therefore, it is possible to perform highly accurate rear end alignment and side end alignment of the sheet.

  Further, when the alignment process for the designated number of sheets is completed, the sheet clamp member 412 is closed and the sheet bundle is held, so that the sheet bundle is not disturbed during the stapling process.

  Further, the rotation amount of the offset roller 407 when the rear end of the sheet is abutted against the sheet rear end stopper 411 is slightly larger than the distance from the point where the conveyance of the sheet S is stopped and switched back to the sheet rear end stopper 411. Since the rotation amount is such that the sheet can be conveyed, in other words, the offset roller 407 is reversely rotated for a predetermined time even after the sheet S is conveyed by a distance for contacting the sheet trailing edge stopper 411 by the reverse rotation of the offset roller 407. S can be reliably brought into contact with the sheet trailing edge stopper 411.

  In the above description, the case where the two-stage stack tray is provided has been described. However, the stack tray is provided in n stages, and the (n-1) -th stack tray in the n stages is provided in the space SPU above the sheet discharge port 400A. Can be used, the limited sheet stacking space SP1 can be efficiently used, and a large number of sheets can be sorted and stacked in n stages.

  Further, when the sheet discharge port 400A is a common sheet discharge port 400A in a mode such as a copying machine, a printer, and a facsimile, and sheets are selectively discharged from the common sheet discharge port 400A to the n-stage stack tray, Space saving is possible and the overall height can be reduced.

  In addition, when the sheet discharge port 400A is a common sheet discharge port and the sheets are discharged from the sheet discharge port 400A to the stack tray by one sheet bundle discharge member 413, the configuration can be simplified. Cost can also be reduced.

  The offset roller 407 moves the sheet in the width direction and abuts against the positioning wall 416 in the staple processing mode, but performs alignment in the width direction when the staple roller is not in the staple processing mode (the sheet is not bound). The sheet bundle may be discharged as it is without being stacked.

  The stapler unit 420 is a fixed type and is disposed in the vicinity of the width direction positioning wall 416. However, the stapler unit 420 is not limited to this, and is movable so that it can move in the sheet conveying direction or the width direction. Also good. When the stapler unit 420 is made movable in this way, the stapler unit 420 can perform a stapling process for binding different portions or a plurality of locations in the sheet conveyance direction or width direction of the sheet bundle SA.

  In this embodiment, the offset roller 407 is used to align the trailing edge and the side edge of the sheet. However, not the roller member but the member itself moves in the sheet conveying direction to convey the sheet. The same effect can be obtained for the sheet processing apparatus using the moving means and the sheet orthogonal direction moving means for moving the sheet in the width direction by moving in the direction orthogonal to the sheet conveyance direction (width direction).

1 is a front view of a copying machine including a sheet processing apparatus according to an embodiment of the present invention. It is sectional drawing by the side of the apparatus main body of a sheet processing apparatus. It is a perspective view of the apparatus main body of a sheet processing apparatus. It is explanatory drawing of the raising / lowering apparatus of a stack tray. It is explanatory drawing of a structure and operation | movement of a shutter. It is explanatory drawing of the control procedure of stack tray switching operation. It is explanatory drawing of the control procedure of stack tray switching operation. It is explanatory drawing of the control procedure of stack tray switching operation. It is explanatory drawing of the control procedure of stack tray switching operation. It is sectional drawing explaining the structure of a torque limiter mechanism. It is a perspective view of a limiter spring. It is a perspective view of a pulley. It is explanatory drawing of the direct connection structure in the torque limiter mechanism of 1st Embodiment. It is a partial perspective view of the torque limiter mechanism of the second embodiment.

Explanation of symbols

120 Reader unit 200, 500A Image forming means (printer unit, apparatus main body)
400 Sheet processing device 407 Offset roller 410 Processing tray 412 Sheet clamp member (discharge member)
421, 422 Sheet stacking means (stack tray)
500 Image forming apparatus 500A Image forming means (apparatus body)
507 Driving means (elevating device)
530 prime mover (tray motor)
532 Pulley 539, 544 Gear 549, 565 (Set screw, pin member)
561 Limiter spring 562 Knob 565 Pin member A Limiter mechanism (torque limiter mechanism)
SP, SPU space SP1 Sheet stacking space

Claims (5)

Sheet stacking means for transmitting rotation of the built-in power source to the driving means and moving up and down by the driving means;
Discharging means for discharging the sheet to the sheet stacking means,
In the sheet processing apparatus for stacking the sheet discharged by the discharge unit on the sheet stacking unit with the elevation of the sheet stacking unit,
A limiter mechanism is provided in the drive means to limit the rise of the sheet stacking means when the rising load of the sheet stacking means increases and the transmission torque reaches an upper limit value;
Before Symbol sheet stacking means I one-stage or multiple set-up with possible der,
The limiter mechanism, the sheet processing apparatus characterized by having said sheet stacking means one stage cases, setting unit capable of switching to increase the upper limit value than that of said sheet stacking means has multiple stages. Sheet stacking means for transmitting rotation of the built-in power source to the driving means and moving up and down by the driving means;
Discharging means for discharging the sheet to the sheet stacking means,
In the sheet processing apparatus for stacking the sheet discharged by the discharge unit on the sheet stacking unit with the elevation of the sheet stacking unit,
A limiter mechanism is provided in the drive means to limit the rise of the sheet stacking means when the rising load of the sheet stacking means increases and the transmission torque reaches an upper limit value;
What can der attaching said sheet stacking means to retract to a position higher than the previous SL discharge means,
The limiter mechanism increases the upper limit value when the sheet stacking means for retracting to a position higher than the discharge means is not provided, compared with the case where the sheet stacking means for retracting to a position higher than the discharge means is provided. A sheet processing apparatus having a switchable setting unit .   3. The sheet processing apparatus according to claim 1, wherein the limiter mechanism is a two-stage switching type capable of setting the maximum upper limit value by fixing relative rotation between the input side and the output side.   The sheet processing apparatus according to claim 1, wherein the sheet stacking unit is attached in a form in which the sheet stacking unit can be added and reduced. Image forming means for forming an image on a sheet;
A processing unit for processing a sheet image-formed by the image forming unit;
An image forming apparatus according to claim 1, wherein the processing unit is the sheet processing apparatus according to claim 1.

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