JP6729038B2 - Sheet stacking apparatus and image forming apparatus - Google Patents

Description

The present invention relates to a sheet stacking device and an image forming apparatus including the same.

An image forming apparatus such as a copying machine is a sheet stacking apparatus that sequentially conveys and stacks sheets by using a plurality of trays arranged side by side in the sheet conveying direction in order to convey sheets such as printed sheets in an orderly manner. May be prepared. The sheet stacking apparatus is used, for example, when a plurality of copies of the same document is printed in one print job, and when it is desired to bundle and output the copies. Patent Documents 1 and 2 disclose examples of the related art of such a sheet stacking apparatus.

The sheet stacking device described in Patent Document 1 is a device that transports the sheets on the mounting surface of the first tray and stacks the sheets on the second tray, and a gripping unit that can grip the sheets on the first tray. A rail member for movably supporting the grip means in parallel with the sheet mounting surface of the first tray along the sheet conveying direction, and a mechanism for swinging the rail member vertically to the sheet mounting surface of the first tray. With. In this sheet stacking apparatus, after gripping means for gripping a sheet at the upstream end of the first tray in the sheet transport direction is moved to the downstream end in the sheet transport direction in parallel with the sheet mounting surface of the first tray using a rail member, The grip means is moved vertically downward with respect to the sheet mounting surface of the first tray via the rail member, and further, the grip means is utilized in parallel with the sheet mounting surface of the first tray using the rail member and upstream in the sheet conveying direction. After moving to the end, the grip means is moved vertically upward with respect to the sheet mounting surface of the first tray via the rail member to return to the sheet gripping position. This allows the sheet stacking device to stack the sheets in the first tray on the second tray in an orderly manner.

The sheet processing apparatus described in Patent Document 2 is an apparatus that carries out a sheet bundle to a stack tray arranged on the downstream side of the processing tray, and is a sheet engaging member (gripper means) that engages with the sheet bundle on the processing tray. ), a carrier member on which the sheet engaging member is movably mounted along the sheet bundle carrying-out direction, and a loop guide groove for guiding the movement of the carrier member. The loop guide groove has an upper traveling path and a lower traveling path, and is formed in a loop shape. This sheet processing device uses the loop guide groove to move the sheet engaging member along the upper traveling path from the standby position to the sheet bundle unloading position on the outward path, and waits for the sheet engaging member from the sheet bundle unloading position on the return path. Move along the lower travel path to the position. As a result, this sheet processing apparatus can orderly carry out the sheet bundle of the processing tray to the stack tray.

JP, 2005-9962, A JP, 2009-263028, A

However, in the sheet stacking device described in Patent Document 1, when the grip means descends at the downstream end of the first tray in the sheet transport direction, the upstream side in the transport direction of the sheet gripped by the grip means places the sheet on the first tray. It descends while maintaining a state parallel to the surface. As a result, the problem is that the sheet bundle buckles. It was feared that the buckling of the sheet would make it impossible to convey the sheet in an orderly manner.

On the other hand, in the sheet processing apparatus described in Patent Document 2, when the sheet engaging member (gripper means) descends at the downstream end of the processing tray in the sheet conveying direction, the upstream portion in the conveying direction of the sheet gripped by the sheet engaging member is The posture is downward. However, since the sheet is released in a state where the upstream portion of the sheet engaging member in the conveying direction is facing downward at the sheet release position, the problem is that the sheet becomes cluttered at the time of release.

The present invention has been made in view of the above points, and an object of the present invention is to provide a sheet stacking apparatus and an image forming apparatus that can suppress the buckling of the sheet and can convey the sheet in an orderly manner. ..

In order to solve the above problems, the present invention provides a sheet stacking device that conveys a sheet placed on a first tray to a second tray provided on the downstream side of the first tray in the sheet conveying direction,
A grip portion for gripping the sheet placed on the first tray, a grip position of the sheet provided at the upstream end of the first tray in the sheet transport direction, and a sheet provided at the downstream end of the sheet transport direction of the first tray. A slide portion that moves in parallel to the sheet mounting surface of the first tray with respect to the release position of the first tray, and a grip portion that moves via the sliding portion with respect to the sheet mounting surface of the first tray. A plurality of engaging members that are supported by the grip portion and that are arranged side by side in the sheet conveying direction; and a slide portion that extends in parallel with the sheet mounting surface of the first tray. And a rail member having a guide portion with which the plurality of engaging members are movably engaged in the sheet conveying direction, and the rail member is provided at a downstream portion in the sheet conveying direction, and a part of the guide portion is provided. And a rotation guide member rotatably supported around a support shaft extending in a direction intersecting the sheet conveyance direction at a downstream end, and an upstream portion of the rotation guide member in the sheet conveyance direction is placed on the sheet tray of the first tray. A rotation guide urging member that urges the rotation guide member to rotate around the support shaft in a direction approaching the surface, and the rotation guide in a state where the rail member is closest to the sheet mounting surface of the first tray. The rotation preventing portion that prevents the member from rotationally displacing from the posture parallel to the sheet mounting surface of the first tray against the urging force of the rotation guide urging member, and the rail member of the first tray. The rotation guide member resists the urging force of the rotation guide urging member in a posture in which the rotation guide member is parallel to the sheet mounting surface of the first tray in a state of being separated from the sheet mounting surface and approaching the release position of the sheet. And a rotation return unit for rotating and displacing the rotation and returning the rotation return unit.

According to this configuration, when the grip portion moves to the downstream end of the rail member in the sheet conveying direction and the rail member is separated from the sheet mounting surface of the first tray, the gripping of the sheet of the grip portion is performed by the urging force of the rotation guide urging member. The area tilts downward. Accordingly, when the sheets are placed on the second tray and the grip by the grip portion is released, the buckling of the sheet bundle is suppressed. Furthermore, since the posture of the grip portion returns to the original position at the seat release position, the seat is released in an orderly state.

Further, in the sheet stacking apparatus having the above-described configuration, the slide portion is provided with a crankshaft extending in a direction intersecting a sheet conveying direction and a crankpin extending in parallel to the crankshaft while being separated from the crankshaft. And a first arm member rotatably supported by a crank portion rotatable around the crank shaft in a plane extending in the vertical direction, a support shaft having a lower end parallel to the crank shaft, and the grip portion on the upper end. A second arm member that is attached to the first arm member and is relatively displaced with respect to the first arm member , the crank arm having a groove portion that movably engages the crank pin with the second arm member. And

Further, in the sheet stacking apparatus having the above-mentioned configuration, the plurality of engaging members are arranged in parallel with a gripping surface facing the lower surface of the sheet formed in the grip portion.

Further, in the sheet stacking apparatus having the above configuration, the guide portion is provided at an upstream end in the sheet conveying direction, and the guide portion is provided in a direction away from the sheet mounting surface of the first tray as it goes upstream in the sheet conveying direction. It is characterized in that it is provided with an enlarging portion for enlarging.

Further, in the sheet stacking apparatus having the above-mentioned configuration, the first tray is configured such that the sheet mounting surface is inclined so as to rise toward the downstream side in the sheet conveying direction.

Further, in the sheet stacking apparatus having the above-described configuration, the grip portion includes a lower grip, which has a gripping surface facing the lower surface of the sheet and contacts the sheet from below, and a connecting shaft extending in a direction intersecting the sheet transport direction. The upper grip that is rotatably connected to the lower grip and comes into contact with the seat from above, and the connecting shaft that connects the upper grip in a direction in which a downstream portion of the upper grip in the sheet conveying direction approaches the grip surface of the lower grip. And a grip urging member that urges rotation around.

Further, in the sheet stacking apparatus having the above-described configuration, the elevating unit is rotatable about a cam shaft extending in a direction intersecting the sheet conveying direction in a plane extending in the sheet conveying direction and the vertical direction, and a cam portion of the cam unit. A follower member that is swingable around a support shaft that extends in parallel with the cam shaft in conjunction with a cam shape, and is connected between the slide portion and the follower member, and is linked to swing of the follower member. And a link mechanism for moving the sliding portion in the vertical direction.

Further, in the sheet stacking apparatus having the above-described configuration, the link mechanisms are arranged side by side in the sheet transport direction of the first tray and are provided at positions parallel to the sheet transport direction and extend in a direction intersecting the sheet transport direction. A first link member and a second link member that are rotatably supported via a shaft; and a connecting link that connects the first link member and the second link member, and the follower member swings. It is transmitted to the first link member, and the second link member performs the same operation as the first link member via the connecting link.

In the sheet stacking apparatus having the above structure, a common power transmission unit that transmits power to both the slide unit and the elevating unit is provided, and the power transmission unit has a single rotating body. The body is formed with the crank portion and the cam portion, and a rotation axis of the rotating body coincides with an axis of the crank shaft and an axis of the cam shaft.

Further, the sheet stacking apparatus having the above-mentioned configuration is characterized by including a sheet post-processing apparatus disposed upstream of the sheet gripping position in the sheet conveying direction.

Further, in order to solve the above problems, an image forming apparatus of the present invention is characterized by including the sheet stacking apparatus having the above configuration.

According to the configuration of the present invention, when a sheet is placed on the second tray and the grip of the sheet is released, it is possible to suppress the buckling of the bundle of sheets. Further, since the posture of the grip portion returns to the original position at the seat release position, the seat can be released in an orderly state. Therefore, the buckling of the sheet can be suppressed, and the sheet can be conveyed in an orderly manner.

1 is a front view of a partial vertical cross section of an image forming apparatus according to an exemplary embodiment of the present invention. It is a schematic block diagram of the sheet stacking apparatus of the embodiment of the present invention. FIG. 3 is a front view showing an intermediate tray, a grip portion, and a drive portion thereof of the sheet stacking apparatus according to the embodiment of the present invention. FIG. 3 is a perspective view showing an intermediate tray, a grip portion, and a drive portion thereof of the sheet stacking apparatus according to the embodiment of the present invention. FIG. 3 is a front view of the grip portion, the slide portion, and the power transmission portion of the sheet stacking device according to the embodiment of the present invention. FIG. 3 is a perspective view of a grip portion, a slide portion, and a power transmission portion of the sheet stacking device according to the exemplary embodiment of the present invention. FIG. 3 is a front view of a slide unit, a lifting unit, and a power transmission unit of the sheet stacking device according to the embodiment of the present invention. FIG. 3 is a rear view of the slide unit, the lifting unit, and the power transmission unit of the sheet stacking device according to the embodiment of the present invention. It is the perspective view seen from the front side of the slide part of the sheet stacking device of the embodiment of the present invention, the raising/lowering part, and the power transmission part. FIG. 3 is a perspective view of the slide unit, the elevating unit, and the power transmission unit of the sheet stacking device according to the exemplary embodiment of the present invention as viewed from the back side. FIG. 3 is a front view of the sheet stacking apparatus according to the embodiment of the present invention, showing a state in which the grip portion is in the sheet gripping position. FIG. 3 is a front view of the sheet stacking device according to the embodiment of the present invention, and is a diagram showing a state in which the grip portion is moving toward the release position of the sheet. FIG. 3 is a front view of the sheet stacking device according to the embodiment of the present invention, and is a diagram showing a state in which a grip portion is in a sheet release position. FIG. 3 is a front view of the sheet stacking device according to the embodiment of the present invention, and is a diagram showing a state in which the grip portion is moving toward the sheet gripping position. FIG. 3 is a front view of the sheet stacking apparatus according to the embodiment of the present invention, showing a state in which the grip portion has reached below a sheet gripping position. FIG. 4 is an enlarged front view showing a state in which the grip portion of the sheet stacking device according to the exemplary embodiment of the present invention has reached below a sheet gripping position. FIG. 6 is an enlarged front view showing a state in which the grip portion of the sheet stacking device according to the exemplary embodiment of the present invention has reached above the sheet release position. FIG. 6 is an enlarged front view showing a state in which the grip portion of the sheet stacking apparatus according to the exemplary embodiment of the present invention is in the middle of changing the posture above the sheet release position. FIG. 6 is an enlarged front view showing a state in which the grip portion of the sheet stacking apparatus according to the exemplary embodiment of the present invention has completed the posture change above the sheet release position. FIG. 6 is an enlarged front view showing a state where the grip portion of the sheet stacking device according to the embodiment of the present invention is in the process of descending toward the sheet release position. FIG. 4 is an enlarged front view showing a state in which the grip portion of the sheet stacking device according to the exemplary embodiment of the present invention has reached the sheet release position.

Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to the contents below.

<First Embodiment>
First, with respect to the image forming apparatus of the embodiment of the present invention, the image output operation will be described while explaining the outline of the structure using FIG. FIG. 1 is an example of a partial vertical sectional front view of an image forming apparatus. The two-dot chain line with an arrow in the drawing indicates the sheet conveyance path and the sheet conveyance direction.

The image forming apparatus 100 is a so-called tandem type color copying machine as shown in FIG. 1, and includes an image reading unit 102 that reads an image of a document, a printing unit 103 that prints the read image on a sheet such as paper, and a printing unit. An operation unit 104 for inputting conditions and displaying the operating status and a main control unit 105 are provided.

The image reading unit 102 is a known unit that reads an image of an original placed on the upper surface of a platen glass (not shown) by moving a scanner (not shown). The image of the original is separated into three colors of red (R), green (G), and blue (B), and converted into an electric signal by a CCD (Charge Coupled Device) image sensor (not shown). As a result, the image reading unit 102 obtains image data for each color of red (R), green (G), and blue (B).

The image data for each color obtained by the image reading unit 102 is subjected to various processes in the main control unit 105, and image data for each reproduction color of yellow (Y), magenta (M), cyan (C), and black (K). And stored in a memory (not shown) of the main control unit 105. The image data for each reproduced color stored in the memory is processed for positional deviation correction, and thereafter, in order to perform optical scanning with respect to the photoconductor drum 121 that is an image carrier, the image data for each scanning line is synchronized with the sheet conveyance. Read out.

The printing unit 103 forms an image by an electrophotographic method and transfers the image to a sheet. The printing unit 103 includes an intermediate transfer belt 111 in which the intermediate transfer body is formed as an endless belt. The intermediate transfer belt 111 is wound around a driving roller 112, a tension roller 113, and a driven roller 114. The tension is applied to the intermediate transfer belt 111 by urging the tension roller 113 upward in FIG. 1 by a spring (not shown). The intermediate transfer belt 111 is rotationally moved counterclockwise in FIG. 1 by the drive roller 112.

The drive roller 112 presses and contacts the secondary transfer roller 115 that faces the intermediate transfer belt 111 with the intermediate transfer belt 111 interposed therebetween. At the position of the driven roller 114, the intermediate transfer cleaning unit 116 provided so as to face the driven roller 114 with the intermediate transfer belt 111 interposed therebetween contacts the outer peripheral surface of the intermediate transfer belt 111. After the toner image formed on the outer peripheral surface of the intermediate transfer belt 111 is transferred to the sheet S, the intermediate transfer cleaning unit 116 removes and cleans adhered substances such as toner remaining on the outer peripheral surface of the intermediate transfer belt 111.

Below the intermediate transfer belt 111, image forming units 120Y, 120M, 120C and 120K corresponding to respective reproduced colors of yellow (Y), magenta (M), cyan (C) and black (K) are provided. In this description, the identification symbols “Y”, “M”, “C”, and “K” are omitted, unless otherwise specified, and are collectively referred to as, for example, “image forming unit 120”. Sometimes. The four image forming units 120 are arranged in a line along the rotation direction of the intermediate transfer belt 111 from the upstream side to the downstream side in the rotation direction. The four image forming units 120 have the same configuration, and a charging unit, an exposing unit, a developing unit, a drum cleaning unit, and a primary transfer roller are arranged around the photosensitive drum 121 that rotates clockwise in FIG. Prepare

A scanning optical device 123, which is an exposure device, is arranged below the image forming unit 120. The scanning optical device 123 corresponds to four image forming units 120 by one unit, and has four light sources such as semiconductor lasers (not shown) individually corresponding to each of the four photosensitive drums 121. The scanning optical device 123 modulates four semiconductor lasers according to image gradation data of each reproduced color, and individually emits laser light corresponding to each reproduced color to the four photoconductor drums 121.

Below the scanning optical device 123, a sheet stacking device 140 for stacking and accommodating a plurality of sheets S such as sheets is provided inside. The sheets S accommodated in the sheet stacking device 140 are sequentially sent to the sheet conveying path Q one by one from the uppermost layer. The sheet S sent from the sheet stacking device 140 to the sheet conveying path Q reaches the position of the registration roller pair 154. Then, the registration roller pair 154 corrects the skew feeding of the sheet S (skew correction), and in synchronization with the rotation of the intermediate transfer belt 111, the contact portion (secondary transfer) between the intermediate transfer belt 111 and the secondary transfer roller 115. The sheet S is sent out toward the (nip portion).

In the image forming unit 120, an electrostatic latent image is formed on the surface of the photoconductor drum 121 by the laser light emitted from the scanning optical device 123, and the electrostatic latent image is visualized as a toner image by the developing unit. The toner image formed on the surface of the photoconductor drum 121 is primarily transferred to the outer peripheral surface of the intermediate transfer belt 111 at a position where the photoconductor drum 121 faces the primary transfer roller with the intermediate transfer belt 111 interposed therebetween. Then, as the intermediate transfer belt 111 rotates, the toner images of the image forming units 120 are sequentially transferred to the intermediate transfer belt 111 at a predetermined timing, so that yellow, magenta, cyan, and black are formed on the outer peripheral surface of the intermediate transfer belt 111. A color toner image is formed by superposing the four color toner images.

The color toner image primarily transferred onto the outer peripheral surface of the intermediate transfer belt 111 is formed by contacting the intermediate transfer belt 111 and the secondary transfer roller 115 with the sheet S sent in synchronization by the registration roller pair 154. And is transferred at the secondary transfer nip portion.

A fixing unit 155 is provided above the secondary transfer nip portion. The sheet S to which the unfixed toner image is transferred at the secondary transfer nip is sent to the fixing unit 155 and is sandwiched by the heating roller and the pressure roller, and the toner image is heated and pressed to be fixed on the sheet S. It The sheet S that has passed the fixing unit 155 is discharged to a sheet discharge unit 156 provided above the intermediate transfer belt 111.

The operation unit 104 is provided on the front side of the image reading unit 102. The operation unit 104 inputs settings such as printing conditions such as the type and size of the sheet S used for printing by the user, enlargement/reduction, presence/absence of double-sided printing, and settings such as fax number and sender name in facsimile transmission. Accept. In addition, the operation unit 104 also serves as a notification unit for notifying the user of the device status, cautions, and error messages by displaying them on the display unit 104w.

Further, the image forming apparatus 100 is provided with a CPU, an image processing unit (not shown), and a main control unit 105 including other electronic components (not shown) for controlling the entire operation of the image forming apparatus 100. The main control unit 105 uses a CPU, which is a central processing unit, and an image processing unit, and controls the components such as the image reading unit 102 and the printing unit 103 based on a program and data stored in a memory and input, to perform a series of operations. The image forming operation and the printing operation are realized.

The image forming apparatus 100 includes the sheet stacking device 1. The sheet stacking apparatus 1 is detachably connected to the main body 101 on the left side of the main body 101 when the image forming apparatus 100 is viewed from the front side in FIG. The sheet S that has passed through the fixing unit 155 reaches the sheet stacking apparatus 1 via the transport path below the sheet discharge unit 156.

The sheet stacking apparatus 1 can bundle and discharge the sheets S for which the toner images have been fixed, for example, when printing a plurality of copies of the same document in one print job. Further, the sheet stacking apparatus 1 can perform post-processing such as punching processing, stapling processing, and half-folding processing. It should be noted that the sheet stacking device can be installed in the place of the broken line in FIG. 1 of the sheet discharging unit 156 by limiting the function.

Subsequently, a schematic configuration of the sheet stacking device 1 of the image forming apparatus 100 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the sheet stacking apparatus.

As shown in FIG. 2, the sheet stacking apparatus 1 includes a sheet carry-in port 2, a first sheet discharge path 3, a second sheet discharge path 4, an intermediate tray (first tray) 5, a discharge tray (second tray) 6, and a sub tray. 7, a post-processing device 8 and a grip portion 20.

The sheet carry-in port 2 is provided on the side surface facing the main body 101 of the image forming apparatus 100 and opens. The sheet S passing through the fixing unit 155 is carried into the sheet stacking apparatus 1 through the sheet carry-in port 2.

The first sheet discharge path 3 extends from the sheet carry-in port 2 to the intermediate tray 5. The second sheet discharge path 4 branches from the middle of the first sheet discharge path 3 and extends to the sub tray 7. A discharge tray 6 is provided on the downstream side of the intermediate tray 5 in the sheet conveying direction. The sub tray 7 is arranged above the sheet stacking apparatus 1, and the discharge tray 6 is arranged below the sub tray 7.

The intermediate tray 5, the discharge tray 6 and the sub-tray 7 are inclined such that the sheet mounting surface rises toward the downstream side in the sheet conveying direction. The user can take out the sheet S discharged onto the discharge tray 6 or the sub tray 7.

The post-processing device 8 is arranged on the upstream side of the intermediate tray 5 in the sheet conveying direction. The post-processing device 8 is composed of, for example, a stapling device. The sheet stacking device 1 can perform post-processing such as stapling on the bundle of sheets S conveyed to the intermediate tray 5 by using the post-processing device 8.

The grip portion 20 is provided on the intermediate tray 5. The sheet stacking device 1 is provided on the downstream side of the intermediate tray 5 in the sheet conveying direction by gripping the sheet S using the grip portion 20 with respect to the sheet S that is placed on the intermediate tray 5 and subjected to post-processing. The sheet S is conveyed to the discharge tray 6.

Next, detailed configurations of the intermediate tray 5, the grip portion 20, and the driving portion of the grip portion 20 of the sheet stacking apparatus 1 will be described with reference to FIGS. 3 to 10. 3 and 4 are a front view and a perspective view showing the entire intermediate tray 5, the grip portion 20, and the drive portion of the grip portion 20, respectively. 5 and 6 are a front view and a perspective view of the grip portion 20, the slide portion, and the power transmission portion. 7 and 8 are a front view and a perspective view of the slide portion, the elevating portion, and the power transmission portion. 9 and 10 are a perspective view of the slide portion, the elevating portion, and the power transmission portion as seen from the front side and a perspective view as seen from the back side.

The intermediate tray 5 is provided with a sheet mounting surface 5b on the upper surface of its housing 5a. As described above, the sheet placing surface 5b is inclined so as to rise toward the downstream side in the sheet conveying direction. That is, the intermediate tray 5 is configured with an inclination such that the grip position G1 of the sheet S on the sheet mounting surface 5b is located below the release position G2 of the sheet S. Further, the intermediate tray 5 is provided with a sheet rear end member 5c at the central portion in the sheet width direction intersecting the sheet conveying direction. The sheet rear end member 5c receives the sheet S that freely falls from the first sheet discharge path 3 and moves the sheet S to the grip position G1.

The intermediate tray 5 includes, in addition to the grip portion 20, a slide portion 30, which is a driving portion of the grip portion 20 shown in FIGS. 3 and 4, an elevating portion 40, and a power transmission portion 50.

The grip portions 20 form a pair having the same configuration and are arranged side by side in the sheet width direction with the intermediate tray 5 sandwiched therebetween. When the sheet S is conveyed from the intermediate tray 5 to the discharge tray 6, the grip portion 20 appears above the sheet mounting surface 5b of the intermediate tray 5. The grip portion 20 includes a lower grip 21, an upper grip 22 and a grip biasing member 23 shown in FIGS. 5 and 6.

The lower grip 21 has a gripping surface 21a that is formed below the grip portion 20 and faces the lower surface of the sheet S. The grip surface 21a contacts the sheet S from below. Further, the lower grip 21 is provided with a wall portion 21b which is perpendicular to the grip surface 21a and extends upward. The wall portion 21b contacts the sheet S from the upstream side in the sheet conveying direction.

Further, the lower grip 21 is provided with a locking piece 21c on the side of the grip surface 21a on the side of the intermediate tray 5. On the other hand, the intermediate tray 5 includes a locking plate 5d below the sheet mounting surface 5b at the grip position G1 of the sheet S and above the locking piece 21c. The locking piece 21c comes into contact with the lower surface of the locking plate 5d when the grip portion 20 rises toward the gripping position G1 of the sheet S in the upstream portion of the intermediate tray 5 in the sheet conveying direction. As a result, at the grip position G1 of the sheet S, the grip surface 21a of the lower grip 21 is prevented from being displaced above the sheet mounting surface 5b.

The upper grip 22 is arranged above the grip portion 20. As shown in FIG. 5, the upper grip 22 has a substantially crescent shape in which the upstream end and the downstream end in the sheet conveying direction are curved downward as viewed in the sheet width direction. The downstream end of the upper grip 22 in the sheet conveying direction contacts the sheet S from above.

The lower grip 21 is provided with a connecting shaft 21d extending in the seat width direction at a position of the wall portion 21b corresponding to a substantially central portion of the upper grip 22 in the sheet conveying direction. The upper grip 22 is rotatably connected to the lower grip 21 via a connecting shaft 21d.

The grip urging member 23 is provided at the location of the connecting shaft 21d. The grip urging member 23 is formed of, for example, a torsion coil spring, and urges the upper grip 22 to rotate around the connecting shaft 21d in a direction in which the downstream portion of the upper grip 22 in the sheet conveying direction approaches the grip surface 21a of the lower grip 21.

A contact portion 22a for the casing 5a of the intermediate tray 5 is provided at the upstream end of the upper grip 22 in the sheet conveying direction. The contact portion 22a comes into contact with the housing portion 5a when the grip portion 20 moves to the most upstream side in the sheet conveying direction of the intermediate tray 5. As a result, the upper grip 22 is rotationally displaced about the connecting shaft 21d in the direction in which the downstream portion of the upper grip 22 in the sheet conveying direction resists the biasing force of the gripping biasing member 23 and moves away from the gripping surface 21a of the lower grip 21 ( (See FIG. 11). As a result, when gripping the sheet S, the lower grip 21 and the upper grip 22 of the grip portion 20 are sufficiently expanded.

The slide portion 30 is individually provided for each of the pair of grip portions 20. The slide portion 30 is arranged substantially below the grip portion 20. The slide portion 30 includes a roller 31, a rail member 32, a crank portion 33, and a crank arm 34 shown in FIGS. 3 to 10.

The roller 31 is arranged outside the grip portion 20 with respect to the central portion of the intermediate tray 5 in the sheet width direction. The roller 31 is rotatably supported by a support shaft provided in a support member 35 attached to the outside of the lower grip 21 in the seat width direction and extending in the seat width direction. Two rollers 31 are arranged side by side in parallel with the grip surface 21a of the lower grip 21 along the sheet conveying direction.

The rail member 32 is arranged outside the grip portion 20 with respect to the central portion of the intermediate tray 5 in the sheet width direction. The rail member 32 includes a guide portion 32a extending parallel to the sheet mounting surface 5b of the intermediate tray 5.

The guide portion 32a is formed in a gutter shape that is recessed from the inner side in the sheet width direction (on the side of the intermediate tray 5) toward the outer side in the sheet width direction and extends parallel to the sheet mounting surface 5b. Two rollers 31 supported by the grip portion 20 are inserted inside the guide portion 32a. The roller 31 is an engaging member that engages with the guide portion 32a so as to be movable along the sheet conveying direction. Most of the area including the central portion to the downstream portion of the guide portion 32a in the sheet conveying direction has a width that does not cause rattling with respect to the outer diameter of the roller 31. Accordingly, the roller 31 can smoothly move inside the guide portion 32a.

The guide portion 32a includes an enlarged portion 32b provided at the upstream end in the sheet conveying direction (see FIG. 8). In the expanding portion 32b, the guide portion 32a expands in a direction away from the sheet mounting surface 5b of the intermediate tray 5, that is, in the downward direction as the sheet conveying direction goes upstream. In the enlarged portion 32b, the roller 31 is movable in the up-and-down direction intersecting the sheet conveying direction, which is the direction in which the guide portion 32a extends.

Further, the rail member 32 includes a rotation guide member 321, a rotation guide biasing member 322, and a rotation blocking portion 323.

The rotation guide member 321 is provided at a downstream portion of the rail member 32 in the sheet conveying direction and includes a part of the guide portion 32a. That is, the downstream portion and the downstream end of the guide portion 32a in the sheet conveying direction are formed on the rotation guide member 321. The rotation guide member 321 is rotatably supported at a downstream end of the rail member 32 in the sheet conveying direction around a support shaft 32c extending in the sheet width direction. The rotation guide member 321 is rotationally displaced relative to the main body of the rail member 32.

The rotation guide member 321 includes a protrusion 32d that projects radially outward with respect to the support shaft 32c and that protrudes outward in the sheet width direction with respect to the central portion of the intermediate tray 5 in the sheet width direction. On the other hand, the rail member 32 is provided with a restriction groove 32e, which is curved in an arc shape in the circumferential direction around the axis of the support shaft 32c and penetrates in the seat width direction, at a position corresponding to the protrusion 32d. The projection 32d is inserted into and engaged with the restriction groove 32e, and the restriction groove 32e restricts the rotatable range of the projection 32d, that is, the rotatable range of the rotation guide member 321.

The rotation guide biasing member 322 is provided at the location of the support shaft 32c. The rotation guide urging member 322 is composed of, for example, a torsion coil spring, and the rotation guide member 321 is rotated around the support shaft 32c in a direction in which the upstream portion of the rotation guide member 321 in the sheet conveying direction approaches the sheet mounting surface 5b of the intermediate tray 5. Energize the rotation.

The rotation blocking portion 323 is provided on the upper surface of the rotation guide member 321 and the surface at the downstream end in the rotation direction of the rotation guide member 321 biased by the rotation guide biasing member 322. The rotation blocking portion 323 comes into contact with the housing portion 5a of the intermediate tray 5 when the rail member 32 is closest to the sheet mounting surface 5b of the intermediate tray 5. As a result, the rotation blocking portion 323 blocks the rotational displacement of the rotation guide member 321 from the posture parallel to the sheet conveyance direction against the biasing force of the rotation guide biasing member 322. That is, when the rail member 32 is closest to the sheet placing surface 5b of the intermediate tray 5, the guide portion 32a is linear from the upstream portion in the sheet conveying direction to the downstream end in the sheet conveying direction provided on the rotation guide member 321. The roller 31 can linearly move from the upstream end to the downstream end of the guide portion 32a in the sheet conveying direction.

The rotation guide member 321 is provided with an engaging piece 324, which is a rotation returning portion, at its lower portion. The elevating part 40 comes into contact with the engaging piece 324 when the rail member 32 moves downward and is separated from the sheet mounting surface 5b by a predetermined distance. As a result, in the state where the rail member 32 is below the sheet mounting surface 5b, the rotation guide member 321 is rotationally displaced against the urging force of the rotation guide urging member 322, and the guide portion 32a is in the sheet conveying direction. Is returned to a form that extends linearly from the upstream portion to the downstream end.

The crank portion 33 is provided below the sheet mounting surface 5b of the intermediate tray 5. The crank portion 33 includes a crank shaft 33a and a crank pin 33b. The crankshaft 33a extends in the sheet width direction and is rotatably supported by the housing portion 5a of the intermediate tray 5. The crank pin 33b is spaced radially outward from the crank shaft 33a and extends parallel to the crank shaft 33a.

The crank portion 33 is formed on the disk member 51, which is the rotating body of the power transmission unit 50. The disk member 51 is arranged such that its rotation plane extends in the sheet conveying direction and the vertical direction. The crank portion 33 is rotatable about the crank shaft 33a within a plane extending in the sheet conveying direction and the vertical direction.

The crank arm 34 is arranged outside the crank portion 33 with respect to the center portion of the intermediate tray 5 in the sheet width direction. The crank arm 34 is formed in a generally elongated shape extending in the vertical direction and is composed of a first arm member 341 and a second arm member 342.

The first arm member 341 is provided below the crank arm 34. The lower end of the first arm member 341 is rotatably supported by the housing 5a via a support shaft 341a that is parallel to the crank shaft 33a. The first arm member 341 is configured in a rectangular tube shape having a rectangular cross section. Inside the first arm member 341, the second arm member 342 is inserted and fitted into the first arm member 341 through the opening at the upper end opposite to the lower end provided with the support shaft 341a.

The second arm member 342 is provided above the crank arm 34. The lower portion of the second arm member 342 is inserted inside the first arm member 341 and can be displaced relative to the first arm member 341 . The grip portion 20 is attached to the upper end of the second arm member 342 so as to be rotatable about an axis extending in the seat width direction.

The second arm member 342 has a groove portion 342a extending in the longitudinal direction and recessed in the seat width direction. The groove portion 342a has a width into which the crank pin 33b can be inserted, and the crank pin 33b engages so as to be movable along the longitudinal direction of the crank arm 34.

The elevating part 40 is provided separately for each grip part 20 forming a pair, similarly to the slide part 30. The elevating part 40 is arranged substantially below the grip part 20. The elevating part 40 includes a cam part 41, a follower member 42, and a link mechanism 43 shown in FIGS. 3, 4, and 7 to 10.

The cam portion 41 is provided below the sheet mounting surface 5b of the intermediate tray 5. The cam portion 41 includes a cam shaft 41a and a cam groove 41b. The cam shaft 41a extends in the sheet width direction and is rotatably supported by the housing portion 5a of the intermediate tray 5. The cam groove 41b is formed radially outward of the axis of the cam shaft 41a, and has a ring shape surrounding the axis.

The cam portion 41 is formed on the disc member 51 of the power transmission unit 50. The cam groove 41b is formed on the other flat surface of the disk member 51 opposite to the one flat surface on which the crank pin 33b is formed. The cam portion 41 is rotatable around the cam shaft 41a within a plane extending in the sheet conveying direction and the vertical direction.

The follower member 42 is arranged adjacent to the cam portion 41 in the seat width direction. The follower member 42 has a longitudinal shape, and one end of the follower member 42 is rotatably supported by the housing portion 5a via a support shaft 42a that is parallel to the cam shaft 41a. The support shaft 42a is provided radially outside the disc member 51. A follower portion 42b is provided at the other end of the follower member 42. The follower portion 42b projects in the seat width direction toward the cam groove 41b and is inserted into the cam groove 41b. The follower member 42 is swingable around the axis of the support shaft 42a in conjunction with the shape of the cam groove 41b.

The link mechanism 43 is disposed below the rail member 32 and is connected between the rail member 32 and the follower member 42. The link mechanism 43 includes a first link member 431, a second link member 432, a connecting link 433, and an interlocking gear 434.

The first link member 431 and the second link member 432 have substantially the same shape and are arranged side by side in the sheet conveying direction of the intermediate tray 5. The first link member 431 and the second link member 432 are rotatably supported by the housing portion 5a via support shafts 431a and 432a that extend in the sheet width direction and that are provided at positions parallel to the lower sheet conveying direction. To be done.

Further, the first link member 431 and the second link member 432 are respectively provided with engaging pins 431b and 432b at their upper ends. On the other hand, the rail member 32 is provided with two slits 32g and 32h below the guide portion 32a. Each of the two slits 32g and 32h extends in parallel with the sheet transport direction of the intermediate tray 5, and is arranged in parallel with each other in the sheet transport direction. The engagement pin 431b of the first link member 431 is inserted into and engaged with the slit 32g arranged on the upstream side of the rail member 32 in the sheet conveying direction. .. The engagement pin 421b of the second link member 432 is inserted into and engaged with the slit 32h arranged on the downstream side of the rail member 32 in the sheet conveying direction.

The connection link 433 is disposed below the first link member 431 and the second link member 432 and between them. The connection link 433 connects the first link member 431 and the second link member 432.

The interlocking gear 434 is arranged below the first link member 431. The rotation center of the interlocking gear 434 is connected to the support shaft 42 a of the follower member 42. That is, the interlocking gear 434 can rotate around the axis of the support shaft 42a as the follower member 42 swings. The interlocking gear 434 meshes with a gear portion 431c provided below the support shaft 431a of the first link member 431.

In the link mechanism 43, the swing of the follower member 42 is transmitted to the first link member 431 via the interlocking gear 434, and the second link member 432 performs the same operation as the first link member 431 via the connecting link 433. As a result, the link mechanism 43 interlocks with the swing of the follower member 42 to move the rail member 32, that is, the slide portion 30 in the vertical direction.

The power transmission unit 50 is arranged below the slide unit 30 and the elevating unit 40. The power transmission unit 50 has a disc member 51 that is a single rotating body. As described above, the disc member 51 is arranged so that its rotation plane extends in the sheet conveying direction and the vertical direction. A crank portion 33 is formed on one rotation plane of the disc member 51, and a cam portion 41 is formed on the other rotation plane.

The crankshaft 33a is formed on the central axis of the disc member 51. The crank pin 33b is formed on one rotation plane of the disc member 51, and projects from the rotation plane toward the seat width direction outer side. The crank portion 33 is rotatable about the crank shaft 33a within a plane extending in the sheet conveying direction and the vertical direction.

The cam shaft 41a is formed on the central axis of the disc member 51. The cam groove 41b is formed in the other rotation plane of the disc member 51, and is formed in a gutter shape that is recessed from the rotation plane toward the inside in the seat width direction. The cam portion 41 is rotatable around the cam shaft 41a within a plane extending in the sheet conveying direction and the vertical direction.

In this way, the disc member 51 is formed with the crank portion 33 and the cam portion 41, and the rotation axis of the disc member 51 coincides with the axis of the crank shaft 33a and the axis of the cam shaft 41a. The power transmission unit 50 commonly transmits power to both the slide unit 30 and the elevating unit 40.

Next, an outline of a sheet conveying operation from the intermediate tray 5 to the discharge tray 6 by the sheet stacking device 1 will be described with reference to FIGS. 11 to 15. FIG. 11 is a front view of the sheet stacking apparatus 1 and shows the state in which the grip portion 20 is at the grip position G1 of the sheet S. FIG. 12 is a front view of the sheet stacking apparatus 1 and shows the state in which the grip portion 20 is moving toward the release position G2 of the sheet S. FIG. 13 is a front view of the sheet stacking apparatus 1 and shows the state where the grip portion 20 is at the sheet S release position G2. FIG. 14 is a front view of the sheet stacking apparatus 1 and shows the state where the grip portion 20 is moving toward the grip position G1 of the sheet S. FIG. 15 is a front view of the sheet stacking apparatus 1 and shows a state in which the grip portion 20 reaches below the grip position G1 of the sheet S.

The detailed configuration of the sheet stacking device 1 is based on the description with reference to FIGS. 3 to 10, and the reference numerals may be omitted in FIGS. 11 to 15.

In the state where the grip portion 20 is at the grip position G1 of the sheet S, the grip portion 20 appears above the sheet mounting surface 5b of the intermediate tray 5 as shown in FIG. At this time, the locking piece 21c of the lower grip 21 comes into contact with the locking plate 5d of the intermediate tray 5 from below, and the gripping surface 21a is not displaced above the sheet mounting surface 5b. Further, since the two rollers 31 of the slide portion 30 are arranged parallel to the sheet mounting surface 5b along the guide portion 32a, the grip surface 21a of the lower grip 21 is parallel to the sheet mounting surface 5b of the intermediate tray 5. And, it becomes almost flush.

On the other hand, the contact portion 22a of the upper grip 22 contacts the housing portion 5a of the intermediate tray 5, and the downstream portion of the upper grip 22 in the sheet conveying direction is separated from the grip surface 21a against the urging force of the grip urging member 23. It is displaced in the direction, that is, in the upward direction. As a result, the lower grip 21 and the upper grip 22 of the grip portion 20 are sufficiently expanded, and the preparation for gripping the sheet S is completed.

Prior to the movement of the grip portion 20 to the grip position G1 of the sheet S, in the intermediate tray 5, the sheet trailing end member 5c receives the sheet S that freely falls from the first sheet discharge path 3 (the retracted position). 12 (see 12) to the grip position G1 along the sheet conveying direction.

Then, in FIG. 11, when the disc member 51 rotates counterclockwise, the crank pin 33b also rotates counterclockwise. As a result, the crank arm 34 that engages with the crank pin 33b rotates about the axis of the support shaft 341a, and the grip portion 20 moves toward the downstream side in the sheet conveying direction. In this way, the slide portion 30 that receives power from the power transmission portion 50 moves the grip portion 20 from the grip position G1 of the sheet S toward the downstream side in the sheet conveying direction.

At the start of the movement of the grip portion 20 to the downstream side in the sheet conveying direction, the contact portion 22a of the upper grip 22 is separated from the housing portion 5a of the intermediate tray 5. As a result, the urging force of the grip urging member 23 acts on the upper grip 22, and the downstream portion of the sheet conveying direction approaches the grip surface 21 a of the lower grip 21. As a result, at the grip position G1, the grip part 20 can firmly grip the sheet S placed on the intermediate tray 5 with the lower grip 21 and the upper grip 22.

When the grip portion 20 moves toward the downstream side in the sheet conveying direction, the cam groove 41b also rotates with the rotation of the disk member 51, but the follower member 42 is swung based on the shape of the cam groove 41b. In addition, the link mechanism 43 is not displaced. That is, the engagement pins 431b and 432b of the first link member 431 and the second link member 432 do not displace. The rail member 32 is not displaced in the vertical direction, and the slide portion 30 keeps the grip surface 21a parallel to the sheet mounting surface 5b of the intermediate tray 5 between the grip position G1 and the release position G2 of the sheet S. In this state, the grip portion 20 is moved to the downstream side in the sheet conveying direction.

Further, when the disc member 51 rotates counterclockwise, the crank arm 34 is displaced along with the rotation of the crank pin 33b, and the grip portion 20 moves above the sheet mounting surface 5b of the intermediate tray 5 as shown in FIG. At, the sheet reaches the downstream end in the sheet conveying direction. Here, the crank arm 34 has a configuration in which the second arm member 342 is sufficiently extended.

Then, when the disc member 51 rotates counterclockwise, the follower member 42 and the link mechanism 43 are displaced based on the shape of the cam groove 41b, and the grip portion 20 moves downward as shown in FIG. At this time, the elevating part 40, which receives power from the power transmitting part 50, moves the grip part 20 via the slide part 30 and hides it from the sheet mounting surface 5b of the intermediate tray 5.

More specifically, the elevating unit 40 moves the grip unit 20 below the sheet mounting surface 5b of the intermediate tray 5 and upstream in the sheet conveying direction in a direction that is inclined with respect to the sheet mounting surface 5b, and the grip unit 20 is made to reach the release position G2 of the sheet S. Here, the crank arm 34 has a configuration in which the second arm member 342 is relatively contracted.

Then, when the disc member 51 rotates counterclockwise, the crank arm 34 is displaced in accordance with the rotation of the crank pin 33b, and the grip portion 20 causes the sheet mounting surface 5b of the intermediate tray 5 to move as shown in FIG. It reaches the upstream portion in the sheet conveying direction below.

When the grip portion 20 moves toward the upstream side in the sheet conveying direction, the cam groove 41b also rotates with the rotation of the disk member 51, but the follower member 42 and the link mechanism 43 are based on the shape of the cam groove 41b. Does not displace. That is, the rail member 32 is not substantially displaced in the vertical direction, and the slide portion 30 makes the grip portion 20 hidden below the sheet mounting surface 5b of the intermediate tray 5 parallel to the sheet mounting surface 5b in the sheet conveying direction. Move it to the upstream side.

Then, when the disc member 51 rotates counterclockwise, the crank arm 34 is displaced in accordance with the rotation of the crank pin 33b, and the grip portion 20 moves the sheet mounting surface 5b of the intermediate tray 5 as shown in FIG. The sheet reaches the upstream end in the sheet conveying direction below. At this time, in the grip portion 20, as described above, the contact portion 22a of the upper grip 22 contacts the housing portion 5a, whereby the downstream portion of the upper grip 22 in the sheet conveying direction is displaced upward, and the lower grip 21 and the upper grip 21 are displaced. 22 is fully expanded.

Thereafter, when the disc member 51 rotates counterclockwise, the follower member 42 and the link mechanism 43 are displaced based on the shape of the cam groove 41b, and the grip portion 20 moves upward as shown in FIG. More specifically, the elevating part 40 moves the grip part 20 to the grip position G1 of the sheet S above the sheet mounting surface 5b of the intermediate tray 5 in a direction substantially perpendicular to the sheet mounting surface 5b. ..

In the sheet conveying operation from the intermediate tray 5 to the discharge tray 6, the sheet stacking device 1 realizes one cycle in which the grip portion 20 is moved from the grip position G1 of the sheet S to the grip position G1 again via the release position G2 as described above. To do.

Next, the detailed configuration and operation of the sheet stacking apparatus 1 at the upstream portion in the sheet conveying direction will be described with reference to FIG. FIG. 16 is an enlarged front view showing the state where the grip portion 20 has reached below the grip position G1 of the sheet S. Note that, in FIG. 16, for convenience of description, the guide portion 32a and the roller 31 that are formed or arranged on the back side in the depth direction of the paper of the rail member 32 and cannot be seen from the front side are shown by solid lines.

The guide portion 32a of the rail member 32 includes an enlarged portion 32b at the upstream end in the sheet conveying direction as shown in FIG. In the enlarged portion 32b, one surface of the gutter-shaped guide portion 32a on the lower side has a downward slope that separates from the sheet mounting surface 5b as the sheet conveying direction moves toward the upstream side.

In the sheet conveying operation from the intermediate tray 5 to the discharge tray 6, when the grip portion 20 moves from the downstream portion to the upstream portion in the sheet conveying direction below the sheet mounting surface 5b, two rollers 31 are formed in the guide portion 32a. Reach the enlarged portion 32b. At this time, the weight of the grip portion 20 or the urging force of the grip urging member 23 acts in a direction in which the two rollers 31 follow one surface on the lower side of the enlarged portion 32b. As a result, the grip portion 20 is inclined to the upstream side in the sheet conveying direction so that the gripping region of the sheet S by the lower grip 21 and the upper grip 22 faces upward.

Next, a detailed configuration and operation of a downstream portion of the sheet stacking device 1 in the sheet conveying direction will be described with reference to FIGS. FIG. 17 is an enlarged front view showing a state where the grip portion 20 has reached above the release position G2 of the seat S. FIG. 18 is an enlarged front view showing a state where the grip portion 20 is changing the posture above the release position G2 of the seat S. FIG. 19 is an enlarged front view showing a state in which the grip portion 20 completes the posture change above the release position G2 of the seat S. FIG. 20 is an enlarged front view showing a state where the grip portion 20 is descending toward the release position G2 of the seat S. FIG. 21 is an enlarged front view showing a state where the grip portion 20 has reached the release position G2 of the seat S.

As shown in FIG. 17, when the grip portion 20 reaches the downstream end in the sheet conveying direction above the sheet mounting surface 5b of the intermediate tray 5, that is, above the release position G2 of the sheet S, the grip surface 21a of the grip portion 20 is reached. Are parallel to the sheet mounting surface 5b and are substantially flush with each other.

At this time, the two rollers 31 (see FIG. 5) supported by the grip portion 20 are set in the downstream portion of the guide portion 32a formed on the rotation guide member 321 in the sheet conveying direction. Then, the rotation blocking portion 323 comes into contact with the casing portion 5a (not shown) of the intermediate tray 5, and the rotation guide urging member 322 (FIG. 7) indicates that the rotation guide member 321 is rotationally displaced from the posture parallel to the sheet conveying direction. (See) blocking against the urging force.

Subsequently, when the elevating part 40 moves the grip part 20 downward through the slide part 30, the rotation guide urging member 322 causes the rotation guide member 321 to move its upstream side in the sheet conveying direction to the sheet mounting surface. It rotates counterclockwise around the support shaft 32c in the direction approaching 5b, that is, in FIG. As a result, the posture change of the grip portion 20 inclining so that the gripping region of the sheet S by the lower grip 21 and the upper grip 22 is directed downward is started.

Further, when the grip portion 20 moves downward, the protrusion 32d of the rotation guide member 321 is regulated by the regulation groove 32e of the rail member 32 as shown in FIG. 19, and the grip portion 20 interlocked with the rotation of the rotation guide member 321. Posture change stops. The posture of the grip portion 20 shown in FIG. 19 is maintained until the grip portion 20 further descends by a predetermined amount.

Here, the elevating part 40 operates the link mechanism 43 when moving the grip part 20 downward. At this time, in the link mechanism 43, as shown in FIGS. 18, 19 and 20, the engaging pins 431b and 432b of the first link member 431 and the second link member 432 are located inside the slits 32g and 32h of the rail member 32. Is moved from the upstream side to the downstream side in the sheet conveying direction.

When the grip portion 20 moving downward approaches the release position G2 of the seat S, the engagement pin 432b of the second link member 432 moving inside the slit 32h of the rail member 32 moves the rotation guide member 321 as shown in FIG. The engaging piece 324 of. As a result, the rotation guide member 321 rotates clockwise about the support shaft 32c in FIG. 20 against the urging force of the rotation guide urging member 322. Then, the posture of the grip portion 20 is returned so that the grip surface 21a of the grip portion 20 approaches a state parallel to the sheet mounting surface 6a of the discharge tray 6.

When the grip portion 20 reaches the release position G2 of the seat S, the protrusion 32d of the rotation guide member 321 is regulated by the regulation groove 32e of the rail member 32 as shown in FIG. 21, and the grip interlocked with the rotation of the rotation guide member 321. The posture change of the part 20 stops. The guide portion 32a returns to the form of linearly extending from the upstream portion to the downstream end in the sheet conveying direction. The grip surface 21a of the grip portion 20 is substantially parallel to the sheet mounting surface 6a of the discharge tray 6.

Subsequently, when the elevating part 40 operates, the grip part 20 moves to the upstream side in the sheet conveying direction via the rail member 32 as shown in FIG. As a result, the upstream end in the sheet transport direction of the bundle of sheets S gripped by the grip portion 20 comes into contact with and hooks on the wall portion 5e at the downstream end in the sheet transport direction of the housing 5a. As a result, the sheet S is released from the gripped state by the grip portion 20.

As in the above-described embodiment, in the sheet stacking apparatus 1, the rail member 32 is provided at the downstream portion in the sheet transport direction and includes a part of the guide portion 32a, and the spindle extends at the downstream end in the direction intersecting the sheet transport direction. The rotation guide member 321 rotatably supported around 32c, and the rotation guide member 321 around the support shaft 32c in the direction in which the upstream portion of the rotation guide member 321 in the sheet conveying direction approaches the sheet mounting surface 5b of the intermediate tray 5. When the rotation guide urging member 322 that urges rotation and the rail member 32 are closest to the sheet mounting surface 5b of the intermediate tray 5, the rotation guide member 321 is rotationally displaced from the posture parallel to the sheet conveying direction. The rotation blocking portion 323, which blocks the urging force of the rotation guide urging member 322, and the rail member 32 are separated from the sheet mounting surface 5b of the intermediate tray 5 and rotate in a state of approaching the release position G2 of the sheet S. The guide member 321 is provided with an engagement piece 324 which is a rotation return portion for returning the guide member 321 in a posture in which the guide member 321 is parallel to the sheet conveyance direction by rotationally displacing it against the biasing force of the rotation guide biasing member 322.

According to this configuration, when the grip portion 20 moves to the downstream end of the rail member 32 in the sheet conveyance direction and the rail member 32 descends, that is, when the rail member 32 is separated from the sheet mounting surface 5b of the intermediate tray 5, the rotation guide urging member 322. The gripping area of the sheet S of the grip portion 20 is tilted downward by the urging force of. Thereby, when the sheet S is placed on the discharge tray 6 and the grip by the grip portion 20 is released, the buckling of the bundle of sheets S can be suppressed. Further, at the release position G2 of the seat S, the posture of the grip portion 20 returns to the original position, so that the seat S can be released in an orderly state.

The slide unit 30 includes two rollers 31 supported by the grip unit 20 and arranged side by side in the sheet conveyance direction, and two rollers 31 extending in parallel with the sheet mounting surface 5b of the intermediate tray 5 so that the two rollers 31 extend in the sheet conveyance direction. A rail member 32 having a guide portion 32a that is movably engaged with the rail member 32, and a crank shaft 33a and a crank pin 33b extending in a direction intersecting the sheet conveying direction are provided in a plane extending in the sheet conveying direction and the vertical direction. The grip part 20 is attached to the first arm member 341 rotatably supported by a crank part 33 rotatable around the crankshaft 33a and a support shaft 341a whose lower end is parallel to the crankshaft 33a and the upper end. A second arm member 342 which is displaced relative to the first arm member 341, and a crank arm 34 having a groove portion 342a with which the crank pin 33b is movably engaged with the second arm member 342. Accordingly, the slide portion 30 can move the grip portion 20 in parallel from the grip position G1 of the sheet S toward the downstream side in the sheet conveyance direction, and further, moves the grip portion 20 from the release position G2 of the sheet S upstream in the sheet conveyance direction. It can be moved in parallel to the side.

Further, since the two rollers 31 are arranged in parallel with the grip surface 21a of the lower grip 21, the grip surface 21a is moved by moving along the guide portion 32a extending in parallel with the sheet mounting surface 5b. The grip portion 20 can be moved in a state of being parallel to the surface 5b.

Further, the guide portion 32a includes an enlarged portion 32b provided at the upstream end in the sheet conveying direction and expanding in the direction away from the sheet mounting surface 5b of the intermediate tray 5 in the sheet conveying direction toward the upstream side. According to this configuration, when the grip portion 20 moves from the downstream portion to the upstream portion in the sheet conveying direction, the weight of the grip portion 20 or the urging force of the grip urging member 23 causes the two rollers 31 to expand the enlarging portion 32b. It works in the direction to follow the lower surface. Then, the grip portion 20 is inclined so that the grip area of the sheet S faces upward. Thus, when the grip portion 20 is moved from below the sheet mounting surface 5b to the grip position G1 of the sheet S, the grip portion 20 is moved upstream of the sheet S in the conveying direction without contacting the upstream end of the sheet S in the conveying direction. Can be moved to the side.

Since the intermediate tray 5 is configured such that the sheet mounting surface 5b is inclined so as to rise toward the downstream side in the sheet conveying direction, the sheets S stacked on the intermediate tray 5 are automatically conveyed by the action of gravity. Move to the upstream side. As a result, the sheets S can be neatly aligned and arranged on the intermediate tray 5 upstream in the sheet conveying direction.

The grip portion 20 is rotatably lowered via a lower grip 21 having a gripping surface 21a facing the lower surface of the sheet S and coming into contact with the sheet S from below, and a connecting shaft 21d extending in a direction intersecting the sheet conveying direction. The upper grip 22 is connected to the grip 21 and comes into contact with the sheet S from above, and the upper grip 22 is rotated around the connecting shaft 21d in a direction in which a downstream portion of the upper grip 22 in the sheet conveying direction approaches the gripping surface 21a of the lower grip 21. The grip urging member 23 for urging. Thereby, the sheet S can be easily and firmly gripped.

The elevating part 40 is interlocked with the shapes of a cam part 41 rotatable around a cam shaft 41a extending in a direction intersecting the sheet conveying direction in a plane extending in the sheet conveying direction and the vertical direction, and a cam groove 41b of the cam part 41. The follower member 42 swingable around a support shaft 42a extending in parallel with the cam shaft 41a, and the slide part 30 is connected between the slide part 30 and the follower member 42 so as to move the slide part 30 in conjunction with the swing of the follower member 42. And a link mechanism 43 that moves in the vertical direction. As a result, the elevating part 40 can move the grip part 20 below the sheet mounting surface 5b of the intermediate tray 5 and upstream in the sheet conveying direction in a direction that is inclined with respect to the sheet mounting surface 5b. The grip portion 20 can be moved to a grip position G1 of the sheet S above the sheet mounting surface 5b in a direction substantially perpendicular to the sheet mounting surface 5b.

The link mechanism 43 is rotatably supported via support shafts 431a and 432a that are arranged side by side in the sheet conveying direction of the intermediate tray 5 and that extend in a direction intersecting with the sheet conveying direction that is provided in a position parallel to the sheet conveying direction. The first link member 431 and the second link member 432 are provided, and the connection link 433 that connects the first link member 431 and the second link member 432. Then, the swing of the follower member 42 is transmitted to the first link member 431, and the second link member 432 performs the same operation as the first link member 431 via the connecting link 433. As a result, the rail member 32 of the slide portion 30 can be moved in the vertical direction while maintaining the state where the guide portion 32a is parallel to the sheet conveying direction of the intermediate tray 5.

The power transmission unit 50 has a disc member 51 which is a single rotating body, and the crank member 33 and the cam portion 41 are formed on the disc member 51, and the rotation axis of the disc member 51 is the crankshaft 33a. And the axis of the cam shaft 41a. With this structure, it is possible to easily form a structure in which power is transmitted from the single drive source to the slide unit 30 and the elevating unit 40.

Further, the sheet stacking device 1 includes a post-processing device 8 for the sheet S arranged upstream of the grip position G1 for the sheet S in the sheet conveying direction. According to this configuration, it is possible to perform the post-processing on the bundle of the sheets S that are neatly brought closer to the upstream side in the sheet conveying direction. Therefore, it is possible to suppress the positional deviation of the post-processing area and the occurrence of processing defects.

Although the embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. Further, a plurality of embodiments can be combined and implemented.

The present invention can be used in an image forming apparatus such as a copying machine.

1 sheet stacking device 5 intermediate tray (first tray)
5a Housing part 5b Sheet mounting surface 6 Ejection tray (second tray)
20 grip part 21 upper grip 21a gripping surface 21d connecting shaft 22 lower grip 23 gripping biasing member 30 sliding part 31 roller (engaging member)
32 rail member 32a guide portion 32b enlarged portion 33 crank portion 33a crank shaft 33b crank pin 34 crank arm 40 lift portion 41 cam portion 41a cam shaft 41b cam groove 42 follower member 42a spindle 43 link mechanism 50 power transmission portion 51 disc member 100 Image forming apparatus 321 Rotation guide member 322 Rotation guide biasing member 323 Rotation blocking portion 324 Engagement piece (rotation return portion)
341 First arm member 341a Support shaft 342 Second arm member 342a Groove portion 431 First link member 431a Support shaft 432 Second link member 432a Support shaft 433 Connection link S sheet G1 Grip position G2 Release position

Claims (11)

In a sheet stacking device for transporting a sheet placed on a first tray to a second tray provided on the downstream side of the first tray in the sheet transport direction,
A grip portion for gripping the sheet placed on the first tray,
The grip portion is provided on a sheet mounting surface of the first tray between a sheet gripping position provided at an upstream end of the first tray in the sheet transport direction and a sheet releasing position provided at a downstream end of the sheet transport direction. A slide part that moves in parallel,
An elevating part that moves the grip part via the slide part to move in and out of the sheet mounting surface of the first tray;
Equipped with
The slide part is
A plurality of engaging members supported by the grip portion and arranged side by side in the sheet conveying direction,
A rail member that has a guide portion that extends in parallel with the sheet mounting surface of the first tray and that engages with the plurality of engaging members so as to be movable along the sheet transport direction;
Equipped with
The rail member,
A rotation guide member that is provided at a downstream portion in the sheet conveying direction and includes a part of the guide portion, and that is rotatably supported around a spindle extending in a direction intersecting the sheet conveying direction at the downstream end,
A rotation guide urging member that urges the rotation guide member to rotate about the support shaft in a direction in which an upstream portion of the rotation guide member in the sheet conveying direction approaches the sheet mounting surface of the first tray;
The rotation guide urging member means that the rotation guide member is rotationally displaced from a posture parallel to the sheet mounting surface of the first tray when the rail member is closest to the sheet mounting surface of the first tray. A rotation blocking part that blocks against the urging force of
The rotation guide is in a posture in which the rotation guide member is parallel to the sheet mounting surface of the first tray in a state where the rail member is separated from the sheet mounting surface of the first tray and approaches the release position of the sheet. A rotation returning portion for rotating and displacing the urging member against the urging force,
A sheet stacking device comprising: The slide part is
A crankshaft extending in a direction intersecting the sheet conveying direction and a crankpin that is spaced apart from the crankshaft and extends parallel to the crankshaft are provided, and can rotate around the crankshaft in a plane extending in the sheet conveying direction and the vertical direction. Crank part,
The second arm member for relative displacement said grip portion is attached to the first arm member and the upper end which is rotatably supported with respect to said first arm member through a support shaft lower end forms a parallel to the crankshaft A crank arm having a groove portion configured to engage the second arm member with the crank pin so as to be movable;
The sheet stacking apparatus according to claim 1, further comprising: 3. The sheet stacking device according to claim 1, wherein the plurality of engaging members are arranged in parallel with a gripping surface of the grip portion that faces a lower surface of the sheet. The guide portion includes an enlargement portion that is provided at an upstream end of the sheet conveyance direction and that enlarges the guide portion in a direction away from the sheet mounting surface of the first tray as it goes upstream in the sheet conveyance direction. The sheet stacking device according to any one of claims 1 to 3. The sheet stacking device according to claim 1, wherein the first tray is configured such that the sheet mounting surface is inclined so as to rise toward the downstream side in the sheet conveying direction. The grip is
A lower grip that has a gripping surface formed on the lower surface of the seat and contacts the seat from below,
An upper grip that is rotatably connected to the lower grip and is in contact with the sheet from above via a connecting shaft that extends in a direction intersecting the sheet conveying direction,
A grip urging member that urges the upper grip to rotate about the connecting shaft in a direction in which a downstream portion of the upper grip in the sheet conveying direction approaches the gripping surface of the lower grip,
The sheet stacking device according to any one of claims 1 to 5, further comprising: The lifting unit is
A cam portion rotatable about a cam shaft extending in a direction intersecting the sheet conveying direction in a plane extending in the sheet conveying direction and the vertical direction;
A follower member that is swingable around a support shaft extending in parallel with the cam shaft in conjunction with the cam shape of the cam portion,
A link mechanism connected between the slide portion and the follower member to move the slide portion in the up-down direction in conjunction with the swing of the follower member;
The sheet stacking device according to any one of claims 1 to 6, further comprising: The link mechanism is
A first link member that is rotatably supported via a support shaft that is arranged side by side in the sheet transport direction of the first tray and that is provided in a position that is parallel to the sheet transport direction and that extends in a direction that intersects the sheet transport direction; A second link member,
A connection link connecting the first link member and the second link member,
Equipped with
The swing of the follower member is transmitted to the first link member, and the second link member performs the same operation as the first link member via the connecting link. Sheet stacking device. The slide part is
A crankshaft extending in a direction intersecting the sheet conveying direction and a crankpin that is spaced apart from the crankshaft and extends parallel to the crankshaft are provided, and can rotate around the crankshaft in a plane extending in the sheet conveying direction and the vertical direction. Crank part,
A first arm member whose lower end is rotatably supported via a support shaft parallel to the crankshaft, and a second arm member having the upper end to which the grip portion is attached and which is displaced relative to the first arm member. A crank arm having a groove portion configured to movably engage the crank pin with the second arm member;
A common power transmission unit that transmits power to both the slide unit and the elevating unit,
The power transmission unit has a single rotating body,
The crank part and the cam part are formed in the rotating body, and the rotation axis of the rotating body coincides with the axis of the crank shaft and the axis of the cam shaft. The sheet stacking device described in. The sheet stacking device according to claim 1, further comprising a sheet post-processing device that is disposed on an upstream side of the sheet gripping position in the sheet conveying direction. An image forming apparatus comprising the sheet stacking device according to any one of claims 1 to 10.