Patent Grant
9809412
This application is based on and claims the benefit of priority from Japanese patent application No. 2013-224930 filed on Oct. 30, 2013, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a sheet folding apparatus which folds sheets of paper in two and a post-processing apparatus which includes the sheet folding apparatus.
At present, a sheet post-processing apparatus which has an apparatus which staples or punches sheets on which images are formed by an image forming apparatus, or a sheet folding apparatus which folds such sheets in two is spread.
In general, a sheet folding apparatus which folds sheets in two has a couple of two-folding rollers and a folding plate which can move forward to or backward from a nip between the two-folding rollers. The sheet folding apparatus folds the sheets by pushing the sheets upward with the folding plate so as to insert the sheets between the two-folding rollers and pressing the sheets between the two-folding rollers.
A roller with a column-shaped central shaft and a rubber layer surrounding the shaft is typically used as the two-folding roller. If the roller with such a construction is formed so as to have the uniform outer diameter in a longitudinal direction, the pressing force of each end part of the roller in a longitudinal direction tends to be stronger than that of the central part of the roller because of the deformation of the roller and the like when the two rollers are pressed each other. This causes the problem that force is applied to the sheets from the outer side to the inner side in a width direction when the sheets passes between the rollers, so that the sheets are creased.
In consideration of this, a two-folding roller whose outer diameter is set so as to gradually decrease from the central part to each end part in an axial direction is proposed. In the roller with such a shape, the pressing force is higher at the central part having the large diameter when the two rollers are pressed each other, and the above-described tendency is cancelled each other out, and therefore, a uniform pressing force can be obtained in an axial direction in the rollers.
In a sheet folding apparatus with such two-folding rollers, in the case where the edge of the folding plate does not go over the nip between the two-folding rollers when the sheets are folded in two, the bulging edge part of the folded sheets, which is formed when the sheets are pushed upward and are folded with the folding plate, cannot go over the nip. As a result, the sheets are pushed back from the nip, or, the most outer sheet goes over the nip, and thus, a paper jam occurs, or, if the sheets are stapled, the sheet is torn.
In the case where the edge of the folding plate goes over the nip between the two-folding rollers, the sheets are not pushed back. However, when the folding plate is pulled out from the nip, the friction between the folding plate and the most inner sheet increases between the central parts of the two-folding rollers each having a large diameter, and, as a result, gloss can be produced on the sheet and it causes defects in the images, or the most inner sheet may be pulled back together with the folding plate, so that a paper jam occurs, or the sheet is torn.
In consideration of this, a post-processing apparatus in which a cutout part which is not inserted into the nip is formed in the part of the edge of the folding plate corresponding to the central parts of the two-folding rollers each having a large diameter is proposed.
However, in the post-processing apparatus in which the cutout part is formed in the edge of the folding plate, when one sheet is set between the two-folding rollers and the folding plate, the central part of the sheet is placed on the edge of the folding plate, and, at this time, the part of the sheet corresponding to the cutout part can bend down because of its weight. If the sheet is inserted into the nip between the two-folding rollers with the folding plate in the state where the sheet is bending down, the bent part of the sheet is creased.
If a projected part is formed in the cutout part to prevent the crease of the sheet, the sheet can be set without bending down, and cannot be creased. However, since the projected part is inserted into the nip, gloss can be produced in the part of the sheet corresponding to the projective part when the folding plate is pulled out from the nip, as described above.
A sheet folding apparatus in accordance with one aspect of the present disclosure is an apparatus which folds a sheet of paper in two and has a couple of two-folding rollers each of whose outer diameter gradually decreases from the central part to each end part in a longitudinal direction thereof, a folding plate which can move forward to or backward from a nip between the two-folding rollers, and has a cutout part which is located in an edge part of the folding plate facing the nip between central parts of the two-folding rollers, wherein the cutout part does not reach the nip between the central parts of the two-folding rollers when the sheet is folded, and a folding plate support member which is placed at a position facing the nip between the central parts of the two-folding rollers, and can slide in a direction of moving closer to or away from the nip, wherein the folding plate support member projects from the cutout part when the sheet is set between the two-folding rollers and the folding plate, and does not reach the nip when the sheet is folded.
A sheet post-processing apparatus in accordance with one aspect of the present disclosure has the above-described sheet folding apparatus.
The above and other objects, features, and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present disclosure is shown by way of illustrative example.
Embodiments of a sheet folding apparatus and a sheet post-processing apparatus in accordance with the present disclosure are described below and in the drawings.
The configuration of a sheet post-processing apparatus 100 is described.
A carry-in part 101, in which sheets ejected from an image forming apparatus are carried, is formed in a part of one side of the sheet post-processing apparatus 100, and a first ejection tray 102 is placed in apart of the other side of the sheet post-processing apparatus 100. In the inside of the sheet post-processing apparatus 100, a sheet conveyance path 103, which extends from the carry-in part 101 to the first ejection tray 102, is formed, and a punching apparatus 105, which performs a punching process on the sheets, and a stapling apparatus 106, which stacks the sheets and staples the sheets with staples, are arranged along with the sheet conveyance path 103.
A first branch path 108 and a second branch path 109 are separated from the sheet conveyance path 103 between the punching apparatus 105 and the stapling apparatus 106, and extend upward and downward, respectively. A second ejection tray 111 is placed at the downstream end of the first branch path 108. Further, a diverting drum 113, which temporarily diverts the sheets, is placed between the first branch path 108 and the second branch path 109. Furthermore, a diverting path 114, which joins the conveyance path 103, is formed along with the diverting drum 113.
A sheet folding apparatus 1 is placed on the downstream side of the second branch path 109 in the lower part of the sheet post-processing apparatus 100. The sheet folding apparatus 1 performs the staple process or the folding process on the supplied sheets in accordance with a user's selection.
The sheet folding apparatus 1 is described below and in
The case 3 has front and back side boards 3a, 3b shaped like a right triangle in a front view, a right side board 3c, and bottom side board 3d.
The sheet placing member 10 has an upstream sheet placing member 11A and a downstream sheet placing member 11B. Each of the sheet placing members 11A and 11B is formed by using, for example, a member shaped like a board. The upstream sheet placing member 11A and the downstream sheet placing member 11B are arranged between the slanting upper edges of the front and back side boards 3a and 3b of the case 3 in a straight line in a slanting downward direction. A gap D with a predetermined distance is formed between the sheet placing members 11A and 11B.
A push-out member 12 and a receiving member 13, which align the edges of the upstream side and the downstream side in a sheet conveying direction of the sheets placed in the sheet placing members 11A and 11B, are arranged in the sheet placing members 11A and 11B, respectively. Incidentally, in the explanation described below, “upstream side” and “downstream side” mean the upstream side and the downstream side in the sheet conveying direction, respectively.
The push-out member 12 is attached to an endless belt 14A placed below the upstream sheet placing member 11A in such a way as to project from the upstream sheet placing member 11A. The endless belt 14A is spanned between an upstream drive pulley 15A and an upstream driven pulley 16A. The receiving member 13 is attached to an endless belt 14B placed below the downstream placing member 11B in such a way as to project from the downstream sheet placing member 11B. The endless belt 14B is spanned between a downstream drive pulley 15B and a downstream driven pulley 16B.
The push-out member 12 and the receiving member 13 are moved in accordance with the lengths of the sheets in the sheet conveying direction, so that the position of the sheets placed on the sheet placing members 11A and 11B is adjusted in the sheet conveying direction.
A couple of width aligning members 18A and a couple of width aligning members 18B, each of which aligns the positions in a width direction (a direction perpendicular to the sheet conveying direction) of the sheets with the center, are placed on the sheet placing members 11A and 11B, respectively. The width aligning members 18A are arranged on the upper surfaces of the upstream sheet placing member 11A at a predetermined intervals in a width direction. The width aligning members 18B are arranged on the upper surfaces of the downstream sheet placing member 11B at a predetermined intervals in a width direction. The width aligning members 18A and the width aligning members 18B are arranged in the direction parallel to the sheet conveying direction. The width aligning members 18A and 18B move in accordance with the widths of the sheets so as to align the widths of the sheets and to correct oblique passing of the sheets.
The staple apparatus 20 is placed above the end part of the downstream side of the upstream sheet placing member 11A.
The sheet folding part 30 is placed at the position corresponding to the gap D between the upstream sheet placing member 11A and the downstream sheet placing member 11B.
The sheet folding part 30 is described below and in
As shown in
As shown in
The rotation shaft of the upstream roller 31A is connected to a motor 32 through gear arrays (not shown), and rotates in a clockwise direction in
As shown in
A cutout part 36 is formed in the upper edge part of the folding plate 35. The cutout part 36 is formed in the position corresponding to the central part 31a of each two-folding roller 31. The cutout part 36 has a length, in a longitudinal direction, approximately the same as or slightly larger than the length L1 of the central part 31a of each two-folding roller 31, and has a depth that is set in such a manner that the cutout part 36 does not reach the nip N when the folding plate 35 is inserted into the nip N between the two-folding rollers 31.
Multiple (for example, three) projected piece parts 37 are formed on each side of the cutout part 36 of the folding plate 35. In the folding plate 35, the projected piece parts 37 each extend and are continuously arranged. Among the projected piece parts 37 on each side of the cutout part 36, one is an inside projected piece part 37a located on the outer side of the cutout part 36, another one is an intermediate projected piece part 37b located on the outer side of the inside projected piece part 37a, and the other is an outside projected piece part 37c located on the outer side of the intermediate projected piece part 37b and located on slightly inner side of the end of the folding plate 35. The arrangements of the projected piece parts 37 on both sides of the cutout part 36 have symmetry with respect to the center in a width direction of the folding plate 35.
Each projected piece part 37 has a height smaller than the depth of the cutout part 36, and the projected piece part 37 located near the end of the folding plate 35 is larger in width than the projected piece part 37 located near the center of the folding plate 35. Namely, the inside projected piece part 37a is the smallest, the outside projected piece part 37c is the largest, and the intermediate projected piece part 37b is intermediate between the inside projected piece part 37a and the outside projected piece part 37c, in width. The intervals between the projected piece parts 37 are approximately the same.
The folding plate 35 is supported by a support member 40. The support member 40 supports on the upstream side and the downstream side in the sheet conveying direction of the folding plate 35, and supports the part of the folding plate 35 located below the cutout part 36, and, as shown in
As shown in
As shown in
In the folding plate support member 50, the base end part 51a of the body part 51 is supported between the holding projected parts 48 formed in the upstream support plate 42. In such a manner, the folding plate support member 50 can slide with respect to the folding plate 35 in the height direction of the folding plate 35.
Further, a coil spring 55 is placed between the support part 52 of the folding plate support member 50 and the support part 42a of the upstream support plate 42. The coil spring 55 pushes the folding plate support member 50 toward the upper edge of the folding plate 35. As shown in
As shown in
The guide part 61 is a guide hole shaped like a long hole and formed in each of the front and back side boards 3a and 3b of the case 3 of the sheet folding apparatus 1. The guide part 61 is placed at the position corresponding to the nip N of the two-folding rollers 31 in each of the front and back side boards 3a and 3b, and extends in the direction along with the tangent line T of the nip N. The direction along with the tangent line T is the direction that the folding plate 35 moves forward or backward. The upper and lower pins 45 and 46 of the support member 40 enter each guide part 61.
One end of each crank arm 63 is rotatably connected to the upper pin 45 through the guide part 61. The other end of each crank arm 63 is rotatably connected to an axis part of the disk-shaped cam 65. Each disk-shaped cam 65 is supported so as to rotate around a rotation shaft 66. The disk-shaped cam 65 located on the back side is connected to the rotation shaft of a motor 68 though a gear array 67. In such a mechanism, when each disk-shaped cam 65 is rotated by the drive of the motor 68, the connection point of the crank arm 63 and the disk-shaped cam 65 moves along with the circular path. Then, through each crank arm 63, the folding plate 35 supported by the support member 40 reciprocates along with the guide part 61 between a retracting position, which is the lowest point of the connection point of the crank arm 63 and the disk-shaped cam 65 moving along with the circular path, and a progress position, which is the highest point of the connection point.
As shown in
As shown in
As shown in
The operation of the sheet folding part 30 with the above-described configuration is described below and in
As shown in
Thereafter, the sheets are conveyed on the sheet placing members 11A and 11B by the push-out member 12 and the receiving member 13, and the central parts in a longitudinal direction of the sheets are positioned at a staple position of the staple apparatus 20, and are stapled.
Next, the stapled sheets are conveyed on the sheet placing members 11A and 11B to the sheet folding part 30 by the push-out member 12 and the receiving member 13, and the central parts in a longitudinal direction of the sheets are set at the position corresponding to the nip N between the two-folding rollers 31 of the sheet folding part 30.
As shown in
In this manner, as shown in
After the sheets S are set, the motor 68 of the drive mechanism 60 of the sheet folding part 30 shown in
The folding plate support member 50 moves forward together with the folding plate 35 toward the nip N at first. However, when the support part 52 of the folding plate support member 50 touches the caching part 71 of the catching member 70, the folding plate support member 50 moves downward with respect to the folding plate 35 against the pushing force of the coil spring 55, so that the folding plate support member 50 does not enter the nip N.
In the folding plate 35 located at the progress position show in
Further, approximately at the same time as driving the motor 68 of the drive mechanism 60, the upstream roller 31A is driven by the motor 32, and is rotated in a clockwise direction in
The folding plate 35 moves backward immediately after the folding plate 35 reaches the progress position, and the upstream roller 31A and the downstream roller 31B continue to rotate. In this manner, the folded sheets S are ejected from the nip N of the two-folding rollers 31 in such a manner that the folded central parts are ejected first.
As shown in
As described above, in the sheet folding apparatus 1 in accordance with an embodiment of the present disclosure, when the sheets are set, whereas the folding plate 35 does not touch the central part of the sheets (i.e., the central part of the lowest sheet among the sheets), the folding plate support member 50 touches the central part of the sheets (i.e., the central part of the lowest sheet among the sheets). Therefore, it is possible to support the sheets so as to prevent the central parts of the sheets from bending down. Further, the folding plate support member 50 moves forward to the nip N of the two-folding rollers 31 together with the folding plate 35 at first. Therefore, it is possible to insert the sheets into the nip N while keeping the sheets approximately straight. Consequently, it is possible to prevent the central parts of the sheets from being creased.
Further, when the sheets are folded in two, the folding plate 35 and the folding plate support member 50 do not enter the nip N between the central parts 31a of the two-folding rollers 31 with a large diameter. Therefore, it is possible to prevent gloss from being produced in the central part of the sheet when the folding plate 35 is moved backward. Consequently, it is possible to obtain a high quality two-folded sheets without any creases or any gloss.
Further, each of the two-folding rollers 31 is formed in such a manner that the outer diameter gradually decreases from the central part to each end part. Therefore, it is possible to make the pressure force in a longitudinal direction on the two-folding rollers 31 uniform and to reduce creases in the sheets. Furthermore, the multiple projected piece parts 37 are formed in the parts excepting the part corresponding to the central parts 31a of the two-folding rollers 31 in the edge of the folding plate 35, and the width of the projected piece part 37 located near the end of the folding plate 35 is larger than that of the projected piece part 37 located near the center of the folding plate 35. Therefore, it is possible to disperse the internal stress that the sheets receives when the folding plate 35 enters the nip N, and thereby, it is possible to prevent the sheets from being damaged.
While the present disclosure has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present disclosure.
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| 2013-224930 | Oct 2013 | JP | national |
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| An Office Action; “Notice of Reasons for Rejection,” issued by the Japanese Patent Office on Feb. 2, 2016, which corresponds to Japanese Patent Application No. 2013-224930 and is related to U.S. Appl. No. 14/510,361. |
| Number | Date | Country | |
|---|---|---|---|
| 20150119223 A1 | Apr 2015 | US |
