JP2007204281A - Sheet stack device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive sheet stack device superior in stacking quality, by increasing a stack quantity, without requiring a large motor. <P>SOLUTION: When performing stapling (postprocessing), a sheet P ejected from an ejecting roller (a sheet ejecting means) 7 is received by a jogger and a sheet support 46 of a sheet support means 40. The stapling is performed after registering by the jogger by returning to a postprocessing position by contacting a return roller 21. Then, the sheet support means composed of a pantograph mechanism is lowered in a state of being placed on the sheet support by pushing out by a sheet pushing-out means 35. A sheet bundle P is delivered to an ejecting try 6 by retreating the sheet support 46 by rotating an advance-retreat support holder 54. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet post-processing apparatus that is attached to an image forming apparatus such as a copying machine, a printer, and a facsimile machine and performs post-processing such as stapling and punch punching on an image-formed sheet from the image forming apparatus. The present invention also relates to a sheet stacking apparatus that stacks post-processed sheets in preparation for such a sheet post-processing apparatus.

  Conventionally, in a sheet stacking device provided in a sheet post-processing device or the like, a fixed discharge tray (discharge tray means) is provided, and sheets discharged by discharge rollers (sheet discharge means) are stacked on the discharge tray. There is something to stack.

  In such a sheet stacking apparatus, when it is desired to increase the amount of sheet stack on the discharge tray, the height from the discharge tray to the discharge roller is increased. However, when the height is increased, there is a problem that the dropping distance becomes longer and the stack quality of the sheet deteriorates.

  For this reason, as disclosed in, for example, Japanese Patent Publication No. 8-5260 and Japanese Patent Application Laid-Open No. 10-279168, in the conventional sheet stacking apparatus, as the amount of sheets stacked on the discharge tray increases, There are those that descend the discharge tray gradually.

  However, in this type of sheet stacking device that raises and lowers the discharge tray, since the discharge tray must be moved to a fixed position at a constant speed with a large number of sheets stacked, the movement load becomes large and a large motor There is a problem that it is expensive and expensive.

  SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide an inexpensive sheet stacking apparatus having a large stack amount and good stack quality without requiring a large motor.

  A second object of the present invention is to provide an inexpensive sheet stacking apparatus that has a simple and simple configuration as much as possible, increases the stack amount, and has a good stack quality.

  Therefore, in order to achieve the first object, the invention according to claim 1 is a sheet stacking apparatus for stacking the sheets discharged from the sheet discharge means on the discharge tray means, the sheet discharged from the sheet discharge means. It is characterized by comprising sheet support means for receiving, placing, descending, retreating and delivering to the discharge tray means.

  The invention according to claim 2 is characterized in that, in order to achieve the second object, in the sheet stacking apparatus according to claim 1, a pantograph mechanism is used for raising and lowering the sheet support means.

  According to a third aspect of the present invention, in order to achieve the second object, in the sheet stacking apparatus according to the first or second aspect, the sheet support means is supported together with the advance / retreat support holder, and the advance / retreat support holder is rotated. Thus, the sheet supporting means is advanced and retracted to deliver the sheet to the discharge tray means.

  According to the first aspect of the present invention, there is provided a sheet supporting means for receiving the sheet discharged from the sheet discharging means, placing it, descending, retreating and delivering it to the discharge tray means, and the sheet supporting means is much more. It is possible to provide an inexpensive sheet stacking apparatus having a small stacking load and a high stacking quality because the driving load is reduced to reduce the driving load. it can.

  According to the second aspect of the invention, since the pantograph mechanism is used for raising and lowering the sheet support means, the sheet support means can be raised and lowered with a simple and simple structure to provide an inexpensive sheet stack apparatus with a large stack amount and good stack quality. Can be provided.

  According to the third aspect of the invention, the sheet support means is supported together with the advance / retreat support holder, and the sheet support means is advanced / retracted by rotating the advance / retreat support holder to deliver the sheet to the discharge tray means. By rotating the advancing / retracting support holder with a simple and simple configuration, it is possible to provide an inexpensive sheet stacking apparatus having a large stack amount and good stack quality.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a sheet is fed from an image forming apparatus (not shown) to the sheet post-processing apparatus 1 of the present invention.

  The sheet sent to the sheet post-processing apparatus 1 is sent along the conveyance guide by the entrance roller 2 and the vertical conveyance roller 3 in the sheet post-processing apparatus 1, and is detected by the conveyance sensor 4 during the conveyance, The switching claw 5 is divided into a sheet going upward and a sheet going to the discharge tray (discharge tray means) 6. A discharge roller (discharge unit) 7, a sheet lateral alignment assembly 8, and the like are arranged in the conveyance path in the direction of the discharge tray 6, and the conveyance path in the direction of the discharge tray 6 is of a stapling device (not shown) that binds the sheet bundle. It is configured to be located at the top.

  In FIG. 1, an alignment tray 12 is installed below the discharge roller 7. The alignment tray 12 is a horizontal support that supports the upstream reference portion 12a on the upstream end surface of the sheet on the discharge tray 6 and supports the upstream portion of the sheet in the width direction when binding in the staple mode or in the shift mode. And a stapling (shift) reference surface 12c on the upstream end surface of the seat. It is desirable that the width in the conveyance direction of the support portion 12b that supports the upstream portion of the sheet is almost the same as that of the front end of the stapler and is the minimum necessary. The entrance roller 2, the vertical conveyance roller 3, and the discharge roller 7 are each driven by a conveyance motor (not shown).

  In FIG. 2, the staple device 9 is driven by the staple moving motor 10 via the staple belt 11 and moves laterally. The pair of sheet lateral alignment assemblies 8 includes a front jogger 13 and a rear jogger 14 for performing lateral alignment of the sheets. The rear jogger 14 is driven by the jogger motor 15 via the jogger belt 16 and moves laterally, whereas the front jogger 13 is connected to the staple device 9 and moves laterally as the staple device 9 moves. .

  Since the front jogger 13 and the rear jogger 14 are configured to enclose a pair of sheet vertical alignment assemblies 17 described later, the pair of sheet vertical alignment assemblies 17 move laterally together with the joggers 13 and 14 respectively. can do. Each of the joggers 13 and 14 and the sheet longitudinal alignment assembly 17 is configured such that the shaft 7a of the discharge roller 7 is inserted through a bearing and moves along the shaft 7a. Each of the front jogger 13 and the rear jogger 14 has support portions 13a and 14a for supporting the side edge portions of the seat on the lower side.

  In FIG. 3, the sheet longitudinal alignment assembly 17 is configured to perform a pendulum motion by turning on and off the solenoid 20 with the shaft 7 a of the discharge roller 7 as a rotation fulcrum. The sheet longitudinal alignment assembly 17 includes a tapping bracket 22 having a return roller 21 for aligning sheets in the longitudinal direction. The return roller 21 includes a gear 23 attached to the shaft 7a of the discharge roller 7, It is driven via a gear 24 that meshes with it, a pulley that is coaxial with it, and a return roller belt 25 that is wound around the pulley that is coaxial with it and the pulley that is coaxial with the return roller 21.

  The hitting bracket 22 penetrates a link rod 26 extending in the lateral direction, and performs a pendulum motion by rotating in the vertical direction about the link rod 26. The link rod 26 is linked to the solenoid 20 via the lever 27. When the solenoid 20 is ON, the hitting bracket 22 rotates in the direction of the jogger support portions 13a and 14a to bring the return roller 21 into contact with the sheet. A similar effect can be obtained by using a paddle instead of the return roller 21.

  4 to 6 show the configuration of the sheet pushing means 35. FIG. The push-out member 30 is connected to two push-out link levers 33a and 33b constituting the parallel movement mechanism 33, and one push-out link lever 33a is in contact with the eccentric cam gear 34 by an unillustrated urging member. The levers 33a and 33b and the eccentric cam gear 34 are mounted on bosses that protrude from the alignment tray 12, and can rotate and rotate. Therefore, when the driving force is transmitted from a driving source (not shown) and the eccentric cam gear 34 is rotated, the push-out link levers 33a and 33b of the parallel motion mechanism 33 are rotated by the eccentric cam 34A so that the push-out member 30 advances and retreats. It has become.

  In FIG. 4, the pressing member 31 is integrated with the guided member 32 and is held by the pushing member 30 so as to rotate about a shaft 30 a orthogonal to the moving direction A on the pushing member 30. It is lifted and biased in the direction of arrow U by a spring that does not. In FIG. 5, when the pushing member 30 moves in parallel in the A direction for pushing out the sheet, the guided member 32 contacts the guide member 12d of the alignment tray 12 in conjunction with it, and the holding member 31 resists the spring and pushes the sheet. The sheet is chucked by rotating in the pressing direction (arrow D direction). The guided member 32 is made of a spring material, and the pressing pressure is controlled by the thickness of the sheet bundle.

  Conversely, when the pressing member 31 is urged to be lowered in the D direction by the spring and the sheet is not pushed out, the guided member 32 is abutted against the guide member 12d to lift the pressing member 31 in the U direction. When the chucking is performed, the engagement with the guide member 12d may be released.

  Further, at the time of stapling, as shown in FIG. 6, the pushing member 30 is retracted from the staple reference surface 12c on the upstream end surface of the sheet, and the abutting portion 31a (see FIG. The sheet is abutted against the abutting part 12e (see FIG. 5), and the pressing member 31 is pushed down in the D direction to chuck the sheet.

  Next, the seat support means 40 will be described. FIG. 7 shows an elevating part of the seat support means 40 using a pantograph mechanism in which the first link bar 42, the second link bar 43, the third link bar 44, and the fourth link bar 45 cross each other in pairs. Yes. A seat support 46 is rotatably fitted to the end portion of the third link bar 44, and the seat support 46 is supported from below by the end portion of the fourth link bar 45. The stack sheet presser (stack sheet presser means) 47 is simultaneously connected by a chain portion of the first link bar 42 and the fourth link bar 45 so as to be rotatable.

  The first link bar 42 is supported at its end by a fixed fulcrum shaft 48 in the sheet post-processing apparatus, and rotates around the fixed fulcrum shaft 48. Further, the first link bar 42 has a boss 49, which is inserted into the receiving portion of the small cam 50, and the small cam 50 rotates, whereby the pantograph expands and contracts. A magnet 51 is attached to the lower side of the sheet support 46, and a metal bar 52 is attached to the upper side of the stack sheet presser 47. When the pantograph mechanism is contracted, the magnet 51 attracts the metal bar 52 to extend the pantograph mechanism. The presser holding means that can lift the stack sheet presser 47 is provided. Further, the upper portion of the sheet support 46 has a guide shape for guiding the sheet to the alignment tray 12.

  FIG. 8 shows an advance / retreat portion of the seat support means 40. The seat support means 40 is supported by a common fixed fulcrum shaft 48 of FIG. The advance / retreat support holder 54 moves the sheet support means 40 forward and backward by rotating about the fixed fulcrum shaft 48 to deliver the sheet to the discharge tray 6. The advance / retreat support holder 54 has a boss 55, which is inserted into the receiving portion of the large cam 56, and the advance / retreat support holder 54 rotates as the large cam 56 rotates.

  FIG. 9 is an overall view of the seat support means 40, and the boss 57 of the linkage portion of the second link bar 43 and the third link bar 44 and the boss 58 of the end portion of the fourth link bar 45 are elongated holes of the forward / backward support holder 54. And is restricted to move only in the vertical direction with respect to the advance / retreat support holder 54. The large cam 56 and the small cam 50 rotate by transmitting the driving force from the same driving source from the shaft 41 via the cam driving pulley 59 and the cam driving belt 60. As the respective cams rotate, the seat support 46 moves up and down, and the seat support 46 moves forward and backward by the advance / retreat support holder 54 in conjunction therewith.

  10 to 15 show the operation sequence of the seat support means 40. First, in the seat support means 40 in the state shown in FIG. 10, the first link bar 42 is rotated counterclockwise with the rotation of the small cam 50, and the seat support 46 is moved as shown in FIG. The stack tray 6 is lowered. Thereafter, with the rotation of the large cam 56, the advance / retreat support holder 54 is rotated as shown in FIG. 13, and the sheet support means 40 is retracted to the retracted position. Further, before the sheet supporting means 40 is retracted, the stack sheet presser 47 is retracted to the non-pressing position, the magnet 51 attracts the metal rod 52, and the stack sheet presser 47 is lifted by the press holding means.

  Then, as the small cam 50 further rotates, the first link bar 42 is rotated clockwise, and the seat support 46 is raised as shown in FIG. Thereafter, when the advancing / retracting support holder 54 moves forward to the operating position as shown in FIG. 15 along with the rotation of the large cam 56, the stack sheet presser 47 hits the pin 49 and is released after being attracted by the magnet 51 of the presser holding means. The pressing position for pressing the sheet on the discharge tray 6 is set.

  As a result, the sheet support 46 can protrude above the sheet bundle on the stack tray 6 regardless of the height of the sheet bundle on the stack tray 6, and the alignment of the sheet bundle on the stack tray 6 is not impaired. .

  In the small cam 50 and the large cam 56, the number of link sets is n, the rotation angle α of the advancing / retracting support holder 54 with respect to the horizontal, and the rotation angle of the first link lever 42 with respect to the advancing / retreating support holder 54 are β. When the length of the first link bar 42 is L and the distance in the vertical direction from the rotation fulcrum shaft 48 to the end of the uppermost link (fourth link bar 44) is T, the illustrated example has two sets. Since it is a link, it is a front cam in which the relational expression of T = 2 × L × sin γ × cos α is established.

  FIG. 16 is a graph showing the relationship between the rotation angle α and the rotation angle β with respect to the rotation angle of the small cam 50 and the large cam 56.

  In the above configuration, first, the case where the shift mode of FIGS. 17 to 22 is selected will be described.

  When the shift mode is selected, the joggers 13 and 14 move from the home position and stand by at a position where the set distance is maintained from the sheet width. Further, the push-out member 30 moves to a home position (a state position where the sheet is received in the alignment tray 12).

  In FIG. 17, the sheet P sent from the image forming apparatus is received by the entrance roller 2, conveyed by the vertical conveyance roller 3, and when the conveyance sensor 4 detects the leading edge of the sheet, the sheet support 46 is in the center of the sheet P. The stack sheet presser 47 presses the sheet P on the discharge tray 6.

  Then, the sheet P is directed toward the discharge tray 6 by the switching claw 5 and discharged by the discharge roller 7. The discharged sheet P is supported on both side edges by the support portion 13a of the front jogger 13 and the support portion 14a of the rear jogger 14, and is placed on each of the joggers 13 and 14. At this time, the central portion of the rear end of the sheet P is received by the sheet support 46.

  Next, the solenoid 20 is turned on a predetermined time after the sheet P is discharged, the tapping bracket 22 is lowered, the return roller 21 is brought into contact with the sheet P, and the sheet P is conveyed in the upstream direction by the rotation of the return roller 21. The sheet P conveyed in the upstream direction by the return roller 21 is conveyed to a post-processing position where the upstream side of the sheet is supported on the support portion 12 b of the alignment tray 12.

  Then, the sheet P abuts against the staple reference surface 12c on the upstream end surface of the sheet and abuts the upstream end surface of the sheet to perform vertical alignment (FIG. 18). At the time of front shift, the front jogger 13 is kept at the same position, the rear jogger 14 is moved to perform sheet lateral alignment, and the process is repeated until the last page. After the last page is completed, the pushing member 30 moves the upstream portion (rear end portion) of the sheet bundle to the position of the reference portion 12 a on the upstream end surface of the sheet on the discharge tray 6. At this time, in order to prevent inertia from acting on the sheet bundle P at the speed of the pushing member 30, the sheet member upstream portion (rear end portion) is chucked by the holding member 31 (FIG. 19).

  Subsequently, the front jogger 13 and the rear jogger 14 are opened so as to drop the sheet bundle (FIG. 20), and then the sheet bundle is dropped while the sheet support 46 is placed on the discharge tray 6. Deliver (FIGS. 21 and 22).

  At the time of the rear shift, the rear jogger 14 is kept at the same position, the front jogger 13 is moved to perform the sheet lateral alignment, and the above operation is repeated. The sheet bundle is sorted by alternately repeating the front shift and the rear shift.

  Next, a case where the staple mode is selected will be described. When the staple mode is selected, the joggers 13 and 14 move from the home position and stand by at a position where the set distance is maintained from the sheet width. Further, the push-out member 30 moves to a home position (a state position where the sheet is received in the alignment tray 12).

  The sheet P sent from the image forming apparatus is received by the entrance roller 2 and conveyed by the vertical conveyance roller 3. When the conveyance sensor 4 detects the leading edge of the sheet P, the sheet support 46 is in a position to support the sheet P. Then, the stack sheet presser 47 presses the sheet P on the discharge tray 6.

  Then, the sheet P is directed toward the discharge tray 6 by the switching claw 5 and discharged by the discharge roller 7. The discharged sheet P is supported on both side edges by the support portion 13a of the front jogger 13 and the support portion 14a of the rear jogger 14, and is stacked on the joggers 13 and 14. At this time, the central portion of the rear end of the sheet P is supported by the sheet support 46.

  Next, after discharging the sheet P, the solenoid 20 is turned on after a predetermined time, the tapping bracket 22 is lowered, the return roller 21 is brought into contact with the sheet P, and the sheet P is conveyed in the upstream direction by the rotation of the return roller 21. The sheet P conveyed in the upstream direction by the return roller 21 is conveyed to a position where the upstream side of the sheet can be supported on the support portion 12b of the alignment tray 12 (FIG. 18).

  Then, the sheet P abuts the sheet upstream side end surface against the sheet upstream side end surface staple reference surface 12c and performs alignment in the sheet vertical direction (FIG. 18). Thereafter, the front jogger 13 and the rear jogger 14 perform alignment in the sheet lateral direction. After the last page is completed, the pushing member 30 moves backward from the staple reference surface 12c on the upstream end surface of the sheet to rotate the holding member 31 to chuck the sheet bundle, and the stapling device 9 performs stapling (FIG. 19). . Thereafter, the upstream portion (rear end portion) of the sheet bundle is moved to the position of the reference portion 12a on the upstream end surface of the sheet on the discharge tray 6 by the pushing member 30 (FIG. 20), and then the front jogger 13 and the rear jogger 14 are moved to the sheet. The bundle is released so as to drop, and the sheet support 46 is lowered with the sheet bundle placed thereon, and the sheet bundle is dropped and delivered to the discharge tray 6 (FIGS. 21 and 22). Subsequently, when the sheet is accepted, the above operation is repeated.

  Next, with reference to FIGS. 23 and 24, the operation when the non-post-processing mode in which neither stapling nor shifting is performed is selected will be described.

  A sheet P sent from the image forming apparatus is received from the entrance roller 2 and conveyed by the vertical conveyance roller 3. It is directed toward the discharge tray 6 by the switching claw 5 and discharged onto the discharge tray 6 by the discharge roller 7. At this time, the push-out member 30 is in a position retracted from the reference portion 12a on the upstream end surface of the sheet on the discharge tray 6. That is, the presser member 31 is controlled to be substantially at the same position as the reference portion 12 a on the upstream end surface of the sheet on the discharge tray 6. That is, when the stapling is not performed, the pushing member 30 is moved so that the entrance to the post-processing position is closed by the holding member 31. As a result, the pressing member 31 has a shape capable of guiding the sheet, and the upstream side of the sheet discharged from the discharge roller 7 does not enter the opening of the alignment tray 12 but is guided to the discharge tray 6.

  Further, the front jogger 13 and the rear jogger 14 stand by at a position where the sheet can be scooped up so that the front end (downstream portion) of the sheet does not hit the discharge tray 6 when the sheet is discharged, and each jogger 13 is simultaneously discharged. Retract 14 and drop the sheet onto the discharge tray 6.

  In the present embodiment, when receiving a large sheet in the width direction, the central portion hangs down and the sheet upstream end support portion 12b is provided on the alignment tray 12 in consideration of the case where the alignment property cannot be secured. In a system that does not handle a large seat, the seat upstream end support portion 12b need not be provided.

1 is an overall configuration diagram of a sheet post-processing apparatus. It is the fragmentary perspective view. It is the perspective view which looked at the further part from the bottom. It is a perspective view of the sheet | seat extrusion means used with the sheet | seat post-processing apparatus. It is a perspective view around the sheet pushing means. It is the perspective view which looked around the sheet pushing means from the reverse direction. It is a perspective view of the pantograph mechanism which comprises a sheet | seat support means. It is a perspective view of the advancing / retreating support holder supported with a pantograph mechanism. It is an assembly perspective view of a sheet support means and an advance / retreat support holder. It is an operation state figure in which a sheet support means is in a support position. FIG. 6 is an operation state diagram in which the seat support means starts to descend. It is an operation state diagram in which the seat support means is lowered. It is an operation | movement state figure which the advancing / retreating support holder started retreating. It is an operation state diagram in which the seat support means starts to rise. It is the operation | movement state figure which the advance / retreat support holder advanced to the operation position. It is a graph which shows the relationship between rotation angle (alpha) and rotation angle (beta) with respect to the rotation angle of a small cam and a large cam. FIG. 6 is an explanatory diagram illustrating a state where a sheet is discharged from a sheet post-processing apparatus onto a discharge tray. FIG. 6 is an explanatory diagram of a state in which a discharge sheet is returned to a post-processing position. FIG. 10 is a diagram illustrating a state in which stapling is performed at a post-processing position. FIG. 6 is a diagram illustrating a state in which a stapled sheet bundle is pushed out from a post-processing position. FIG. 6 is an explanatory diagram of a state in which a sheet bundle is lowered. FIG. 6 is an explanatory diagram of a state after a sheet bundle is delivered to a discharge tray. FIG. 6 is an explanatory diagram of a sheet discharge state in a non-staple mode. FIG. 6 is an explanatory diagram of a state in which a sheet is dropped onto the discharge tray.

Explanation of symbols

1 sheet post-processing device 6 discharge tray (discharge tray means)
7 Discharge roller (sheet discharge means)
13 Front jogger 14 Rear jogger 40 Sheet support means 46 Sheet support 47 Stack sheet presser (stack sheet presser means)
48 Fixed fulcrum shaft 51 Magnet 52 Metal rod 54 Advancing / retracting support holder P Sheet

Claims (3)

In the sheet stacking apparatus for stacking the sheets discharged from the sheet discharge means on the discharge tray means,
A sheet stacking device, comprising: a sheet supporting unit that receives a sheet discharged from the sheet discharging unit, places and lowers the sheet, retracts and transfers the sheet to the discharge tray unit.   2. The sheet stacking apparatus according to claim 1, wherein a pantograph mechanism is used for raising and lowering the sheet support means.   The sheet support means is supported together with an advance / retreat support holder, and the sheet support means is advanced / retracted by rotating the advance / retreat support holder to deliver the sheet to the discharge tray means. The sheet stacking apparatus according to 1 or 2.

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