JPH0940258A - Paper reversing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper reversing device that can perform switch back conveyance of high reliability. SOLUTION: A conveying face of a reversing roller 11 on the reversing claw 12 side, that is, the conveying face of the reversing roller 11 for reversing paper together with the reversing claw 12, is formed of a high friction member, so that the paper is positively fed into the sheet reverse-feeding means side on the lower reaches. A conveying face of the reversing roller 11 not facing the reversing claw 12 is formed of a low friction member, so that this part does not become paper resistance at the time of switch back. The paper is thereby reversed smoothly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet reversing device used in copying machines, facsimiles, printers and the like.

[0002]

2. Description of the Related Art A technique for reversing a sheet using a reversing claw and a reversing roller is disclosed in Japanese Utility Model Laid-Open Nos. 3-107454 and 3-118964.

This is because a reversing roller that always rotates in a predetermined sheet conveying direction and the tip of the reversing claw intersect the circumferential surface of the reversing claw, and the paper reversing unit is utilized by utilizing the friction force between the waist of the sheet and the reversing roller. The paper is sent to and switchback inversion is performed.

[0004]

Generally, in the sheet reversing device of the type described above, since the reversing roller always rotates in a constant direction, after the trailing edge of the sheet has passed through the reversing claw, Even when switching back, the paper is rotating in the opposite direction to the paper transport direction. Not only does curl and the stiffness of the paper reduce transport resistance, but the edge of the paper comes into contact with the reversing roller, which causes folds and the like. The probability of will tend to be very high.

In particular, the conventional reversing roller is entirely made of EP rubber or the like, and has a large resistance when the paper is switched back, so that there is a problem that the edge of the paper is frequently broken.

Since the conveying force for conveying the sheet is generated on the outer peripheral surface (conveying surface) of the reversing roller on the side intersecting with the reversing claw, the remaining portion of the reversing roller only has to serve as a guide. The present invention focuses on the point.

A first object of the present invention is to provide a sheet reversing device capable of highly reliable switchback conveyance.

It is a second object of the present invention to provide a paper reversing device which is simple, can be manufactured at low cost, and can have high conveyance stability.

[0009]

The first object is to always provide a reversing roller that rotates in a predetermined direction, a sheet reversing unit that is located on the downstream side of the reversing roller and that switches back the sheet, and the reversing unit. The roller has a first guide surface that guides the paper to the roller, and the downstream side of the first guide surface is formed so as to intersect with the circumferential surface of the reversing roller. A reversing claw having a second guide surface for guiding, wherein the first guide surface of the reversing claw is pressed toward the reversing roller and retracts in the tangential direction as the sheet enters. In the sheet reversing device, the first reversing roller has a high friction member on the reversing claw side and a low friction member on the opposite side of the conveying surface of the reversing roller.
This is achieved by the following means.

The above first object is, in the first means,
This is achieved by the second means in which the area of the high-friction member is set to 1/2 or less of the area of the conveying surface of the entire reversing roller.

The above-mentioned first object is, in the first means,
This is achieved by the third means in which the conveyance surface of the high friction member and the conveyance surface of the low friction member are flush with each other.

The above-mentioned second object is, in the first means,
A reversing roller is composed of an integrally molded structure including a low friction member and a fitting portion having a diameter smaller than the outer diameter of the low friction member, and a ring-shaped high friction member press-fitted into the fitting portion. 4 means.

In the above-mentioned first to third means, since the conveying surface of the reversing roller on the reversing claw side, that is, the conveying surface of the reversing roller for reversing the sheet between the reversing claws is a high friction member, the sheet is surely fed. Is fed to the sheet reverse feeding means side downstream. Further, since the conveying surface of the reversing roller which does not face the reversing claw is a low friction member, this portion does not become a resistance of the sheet at the time of switchback.

In the fourth means, a reversing roller in which a ring-shaped high friction member is press-fitted into the fitting portion of the integrally molded structure having the low friction member is adopted, thereby simplifying and reducing the cost. Has been realized.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a sheet post-processing apparatus according to the embodiment.

In FIG. 1, discharge rollers 2 and 3 are provided in a paper discharge portion provided on the discharge side of the image forming apparatus 1. A sheet post-processing device (sorter) 100 is provided adjacent to the side surface of the main body of the image forming apparatus 1. In the figure, 1- to 3-bin delivery trays 4, 5, and 6 are provided on the left side, and the right side is provided on the right side. Inlet guide plates 37 and 38, which correspond to the ends of the sheet conveyance path 71, are provided so as to project, and are connected (inserted) to the main body side. A drive side entrance roller 7 and a driven side entrance roller 8 are provided on the downstream side of the entrance guide plates 37 and 38 in the sheet carrying direction, and an entrance sensor 9 is provided at a position close to the downstream side in the carrying direction. There is.

A sheet conveying path 71 extending directly to the discharge trays 4, 5 and 6 is formed in a substantially "C" shape in the drawing, and a curved conveying path for reversing extending to the reversing tray 16 side. (Hereinafter, also referred to as “reversing path”.) 72 and a switching claw 10 for switching the conveyance direction are installed, and a reversing roller 11 and a reversing claw 12 are provided below the switching claw 10. Below the reversing roller 11, a reversing guide plate 13 and a conveying roller 14 are provided.
Also, a beating roller 15 is provided.

A reversing sensor 17 is installed on the upstream side of the reversing claw 12 in the conveying direction when the reversing claw 12 is reversing, and a 3-bin sheet discharge is provided along the conveying path 71 above the reversing claw 12 at a position corresponding to the lower 3-bin sheet discharging tray 6. Sensor 18, 3 bin discharge roller 19, driven roller 2
A 2-bin paper ejection sensor 22 and a 2-bin paper ejection roller 2 are provided at locations where the 0- and 3-bin paper ejection claws 21 correspond to the middle-stage paper ejection tray 5.
3, a driven roller 24, a 2-bin paper ejection claw 25, and a 1-bin paper ejection sensor 26, a 1-bin paper ejection roller 27, a driven roller 28, and a lumbar guide 29 are arranged at locations corresponding to the upper paper ejection tray 4. It is set up.

The upper and lower guide rollers 30, the upper and lower guide rails 31, the front and rear guide rollers 32, the front and rear guide rails 33, the shift tray base 34, the tray upper surface detecting sensor 35, and the end fence 36 are provided along the vertically extending conveying path 71. The 1-bin paper ejection guides 39 are provided.

The sorter 100 described above is used in the image forming apparatus 1.
The sheets ejected by the ejection rollers 2 and 3 of the image forming apparatus 1 are attached to the side portions of the sheet as described above and are distributed to the sheet ejection trays 4, 5 and 6 and stacked in that state (straight). There are two types of modes: a straight paper discharge mode and a reverse paper discharge mode in which the front and back are reversed and distributed and stacked.

Hereinafter, the sorter 10 configured as described above
The operation of 0 will be described.

When the sorter 100 is activated by the activation information from the image forming apparatus 1, the entrance rollers 7 and 8 and the reversing roller 11 driven by the first driving means are at the same speed as the conveying speed of the main body discharge rollers 2 and 3. A transport roller 1 which rotates at a speed slightly higher than that or is driven by the second drive means 1.
4. The discharge rollers 19, 23, 27 rotate at a speed higher than the conveying speed of the image forming apparatus 1.

At the same time when the front end of the paper is ejected from the ejection rollers 2 and 3 of the image forming apparatus 1, the sorter 100 outputs the mode information indicating whether the paper is ejected straight from the image forming apparatus 1 or reversed. Then, the sorter 100 conveys and ejects the sheet by different operations based on the respective information.

Each part will be described below in accordance with the flow of paper.

(1) Straight paper discharge mode When the leading edge of the paper reaches the discharge rollers 2 and 3 of the image forming apparatus 1,
The image forming apparatus 1 sends to the sorter 100 information that the sheet is discharged in the straight sheet discharge mode. In this mode, the sheet is guided by the inlet guide plates 37 and 38 to the inlet rollers 7 and 8 driven by the first drive means. This time,
The peripheral speed of the entrance roller 7 is set to be equal to or slightly higher than the peripheral speed of the discharge rollers 2 and 3, and the paper can be smoothly carried into the sorter 100 without burdening the paper. At this time, the switching pawl solenoid (not shown) for operating the switching pawl 10 is turned on, the switching pawl 10 is at the position indicated by the solid line (position A), and the paper is ejected by the second drive means. , 23, 27.

On the other hand, when the sorter 100 receives the mode information, the sheet discharge rollers 19, 23, 27 driven by the second driving means are provided before the leading edge of the sheet reaches the 3-bin sheet discharge roller 19. The conveyance speed is reduced to the same speed as the first driving means, and the paper conveyed from the entrance roller 7 driven by the first driving means is smoothly received and conveyed by the 3-bin paper ejection roller 19. .

Next, when the trailing edge of the sheet passes through the ejection rollers 2 and 3, the trailing edge of the sheet is ejected from the image forming apparatus 1 and 2.
A signal that the signal has passed through is sent, and this signal is sent to the sorter 10
When 0 is received, the first,
When the entrance sensor 9 detects that the trailing edge of the paper has passed through the entrance rollers 7 and 8, the speed of the second driving means increases, and after a certain time, the first driving means operates before the next paper enters. Return to the original transport speed (peripheral speed). At this time, the paper has been delivered to the discharge rollers 19, 23, 27 that are driven at high speed, and has passed through the 3-bin sensor 18 to be discharged upward to the discharge trays 4, 5, 6. Be transported.

Then, for example, when the paper is discharged to one bin according to the information from the image forming apparatus 1, the respective paper discharge rollers 19, 23 and 27 driven by the second driving means are kept at the speeds which have been previously accelerated. It is rotating and the 2-bin and 3-bin solenoids (not shown) that operate the 2-bin paper ejecting claw 25 and the 3-bin paper ejecting claw 21 are off.
1 is in the position of the solid line (C and E positions), so the paper is 1
It is guided in the direction of the bin discharge roller 27.

Next, the paper is discharged onto the 1-bin discharge tray 4 along the 1-bin discharge guide 39. The sheet is wavy in the transport direction by the waisting guide 29 protruding from the one-bin sheet discharging guide 39, and is driven by the second driving means when the trailing edge leaves the paper discharging roller 27. Since the bin discharge rollers 27 are decelerated, they are smoothly and accurately stocked in the 1-bin discharge tray 4.

The deceleration timing is determined by the 1-bin paper ejection sensor 26 determining whether the trailing edge of the paper has passed. When the trailing edge of the sheet has passed, it is decelerated to a speed suitable for discharging the sheet, and after a certain time calculated from the speed and the transport distance, it is determined that the trailing edge of the sheet has left the 1-bin discharging roller 27, and the second The drive means of No. 2 is accelerated to prepare for receiving the next sheet.

Next, for example, when discharging to a 2-bin according to the information from the image forming apparatus 1, the 2-bin discharging roller 23 driven by the second driving means is a 3-bin discharging roller 19 when discharging the 1-bin. In the same manner as above, the three-bin solenoid that operates the three-bin paper ejection pawl 21 is turned off while the three-bin paper ejection pawl 21 is in the position (E position) indicated by the solid line. Yes, a 2-bin solenoid (not shown) for activating the 2-bin paper ejecting claw 25 is turned on, and the 2-bin paper ejecting claw 25 ejects the paper onto the 2-bin paper ejection tray 5 at a position indicated by a chain double-dashed line (D). Position).

As a result, the sheet is ejected onto the 2-bin sheet ejection tray 5 along the 2-bin sheet ejection claw 25 and the 2-bin sheet ejection roller 23 that project onto the transport path 71.

It should be noted that the paper is wavy in the transport direction due to the overlap between the projection provided at the center of the 2-bin paper ejection claw 25 and the 2-bin paper ejection roller 23, and the rear end of the paper is When leaving the 2-bin delivery roller 23, the 2-bin delivery roller 23 driven by the second drive means is decelerated, so that the 2-bin delivery roller 5 is smoothly and accurately stocked in the 2-bin delivery tray 5.

The deceleration timing is determined by the 2-bin paper ejection sensor 22.
Is determined by detecting whether the trailing edge of the paper has passed, and when the trailing edge of the paper has passed, the speed is reduced to a speed suitable for ejecting the paper, and a fixed time period calculated by the speed and the transport distance has elapsed. After that, it is determined that the trailing edge of the sheet has left the 2-bin sheet discharge roller 23, the speed of the second conveying means is increased again by the second driving means, and preparation for receiving the next sheet is performed.

When the paper is discharged to the 3-bin, the 2-bin solenoid is off, and the 2-bin paper ejecting claw 25 is at the solid line position (C position).
The 3-bin solenoid is on and the 3-bin paper ejection claw 21
Is similar to the operation for discharging to two bins, except that is moved to the position of the chain double-dashed line (position F).

As a method of detecting that the trailing edge of the sheet has passed through the entrance roller 7, the discharging roller 2 is detected based on the information that the trailing edge of the sheet from the image forming apparatus 1 has passed through the discharging rollers 2 and 3. , 3 and the entrance rollers 7 and 8 of the sorter, there is a method of making a determination by the passage of time calculated from the carrying distance and the carrying speed. If this method is adopted, the detection means such as the entrance sensor 9 can be omitted.

(2) Reversed paper discharge mode In the reversed paper discharge mode, when the leading edge of the paper comes to the discharge rollers 2 and 3 of the image forming apparatus 1, the image forming apparatus 1 provides information about the reverse paper discharge mode. Sent to.

The sheet is guided to the entrance rollers 7 and 8 by the entrance guide plates 37 and 38. At this time, the peripheral speed of the entrance roller 7 is set to be equal to or slightly higher than the peripheral speed of the discharge rollers 2 and 3, and the sheet is smoothly conveyed into the sorter 100 without burdening the sheet. .

In the reverse sheet discharge mode, the sheet is directly conveyed from the entrance rollers 7 and 8 to the reverse roller 11 side, so
It is not conveyed across the drive system of the drive means of the second drive means and the drive system of the second drive means. Therefore, the transport roller 14 driven by the second drive means and the respective paper discharge rollers 19, 23, 27
Is rotating at a speed higher than the peripheral speed of the discharge rollers 2 and 3.

At this time, the switching pawl solenoid for operating the switching pawl 10 is off, the switching pawl 10 is at the position indicated by the chain double-dashed line (position B), and the paper is reversible by the reversing pawl 12 and the reversing roller 11. Entry into the constructed wedge-shaped part. The tip of the reversing claw 12 is set so as to overlap the reversing roller 11 and is pressed in the counterclockwise direction so that it can be rotated clockwise so as not to obstruct the entrance of the sheet. Is attached to. As a result, the sheet is conveyed along the reversal guide plate 13 onto the reversal tray 16 by the conveyance force generated by the reversal roller 11 and the reversal claw 12.

Next, when the trailing edge of the sheet passes through the discharge rollers 2 and 3, the trailing edge of the sheet is discharged from the image forming apparatus 1 to the discharging rollers 2 and 3.
A signal that the signal has passed through is sent, and this signal is sent to the sorter 10
When 0 is received, the first driving means speeds up the entrance roller 7 and the reversing roller 11 at a speed higher than the conveyance speed of the image forming apparatus 1 in order to make a space between the paper and the next paper, and the trailing edge of the paper enters the entrance. After a certain time has passed from the roller 7, the transport speed of the entrance roller 7 and the reversing roller 11 returns to the original peripheral speed before the next sheet enters.

Next, when the trailing edge of the sheet comes out of the portion in contact with the reversing roller 11 and the reversing claw 12, the reversing claw 12 is moved by the rotational force to the position of the two-dot chain line from the position of the solid line (G position) in the figure. H position).

At this time, since the paper has no carrying force,
The reversing claw 12 is stopped at a position slightly slipped from the tip. When the trailing edge of the sheet comes out of the tip of the reversing claw 12, the reversing claw 12 moves to the position of the chain double-dashed line (H position), the reversal sensor 17 is turned on, and the striking roller 15 is driven based on the signal. The reversing solenoid turns on and hits the roller 15
Moves from the position indicated by the solid line (the I position) to the position indicated by the chain double-dashed line (the J position) in contact with the conveying roller 14 which is being driven at high speed by the second driving means, and the sheet is conveyed in the front-rear reverse direction (switchback). Then, the sheet is conveyed along the reversing claw 12 at a high speed to the upper side of the paper (in the direction of 1, 2, 3 bins) and is driven at a high speed by the second driving means.
The sheet is discharged from the sheet 27, and the sheet is reversed.

At this time, the space between the sheets is sufficiently widened so that the trailing edge of the sheet does not overlap with the leading edge of the next sheet at the position of the reversal sensor 17. The discharge operation of the discharge rollers 19, 23, 27 to the discharge trays 4, 5, 6 is the same as in the straight discharge mode. FIG. 2 is an enlarged configuration diagram of a sheet reversing unit in the sheet post-processing apparatus according to the embodiment.

The reversing claw 12 has a first guide surface 12a for guiding the sheet to the reversing roller 11, a second guide surface 12b for guiding the reversed sheet in the sheet discharge direction, and both guide surfaces 1
It has a top portion 12c where 2a and 12b join.

The reversing claw 12 is normally located at the position indicated by the solid line, and the lever 101 and the spring 10 are rotated counterclockwise in the drawing.
It is pressurized by 2 etc. Further, the reversing claw 12 is rotatable in the clockwise direction of the drawing, and is set so as to be rotatable to a position indicated by a two-dot chain line in the drawing as a sheet enters.

The hitting roller 15 is usually the lever 10
Since 3 is pulled counterclockwise by the spring 104, it is separated from the transport roller 14, but the solenoid 10
When 5 is turned on, it is urged in the direction of the transport roller 14.

The reversing roller 11 is attached to the shaft 106, and the reversing claw 12 is attached to the shaft 107.

FIG. 3 is a front view showing the positional relationship between the reversing roller and the reversing claw.

A large number of disk-shaped reversing rollers 11 are fixed to the shaft 106 at equal intervals, while the reversing claws 12 are reversing rollers 1.
Many are fixed to the shaft 107 so as to be staggered with 1. However, at the central portion (on the center lines C and L), the reversing claws 12 and 1 are arranged so as to sandwich both sides of the reversing roller 11 at the center.
2 are provided.

As shown in the figure, the top 12c of the reversing claw 12
Intersects with the reversing roller 11.

In the present invention, of the outer peripheral surface (conveying surface) of the reversing roller 11, the portion on the reversing claw 12 side, that is, the reversing claw 1
The part on the side intersecting 2 is a high friction member 11a such as EP rubber.
The low friction member 1 made of thermoplastic resin or the like is formed on the opposite side.
1b. Therefore, only the reversing roller 11 at the center (on the center lines C and L) corresponds to the above-mentioned reversing claws 12 and 12 on both sides, and the high friction members 11a and 11 are provided on both sides thereof.
a is provided.

FIG. 4 is a partially cutaway front view of the reversing roller, FIG.
FIG. 3 is an exploded perspective view of the same.

As shown in FIG. 5, a stepped portion (fitting portion) 11c is provided in a part of a resin molded product, and a ring-shaped high friction member 11a is press-fit into the stepped portion to form the reversing roller 11. The outer peripheral surface of the high friction member 11a and the low friction member 11b are adjacent to each other.

The outer peripheral surfaces 11a and 11b are formed on the same plane (the outer peripheral surfaces have the same radius) (FIG. 4).
At C = D). When the width of the high friction member 11a is A and the width of the entire reversing roller 11 is B, A ≦ 1/2 (B). That is, the width of the high friction member 11a is suppressed to 1/2 or less of the whole.

In the above-described embodiment, the reversing roller 11 which always rotates in the predetermined direction, and the paper reversing means (14) located downstream of the reversing roller 11 for switching back the paper. , 15, 103, 104, 105)
And a first guide surface 12a for guiding the paper to the reversing roller 11, and the downstream side of the first guide surface 12a is the reversing roller 1
The first guide of the reversing claw 12 includes a reversing claw 12 that is formed so as to intersect with the circumferential surface of the first reciprocating member 1 and that has a second guide surface 12b that guides the sheet to the sheet discharge port after reversing the sheet. In the sheet reversing device in which the surface 12a is pressed toward the reversing roller 11 and can retreat in the tangential direction as the sheet enters, among the conveying surfaces of the reversing roller 11,
Since the reversing claw side is formed of the high friction member 11a and the opposite side is formed of the low friction member 11b, the conveying surface of the reversing roller 11 on the reversing claw side, that is, the conveying surface of the reversing roller 11 for reversing the sheet with the reversing claw 12 Since the high-friction member 11a is used as the high-friction member 11a, the paper is surely fed to the downstream paper feeding means (14, 15, 103, 10).
4,105) side. Further, since the conveying surface of the reversing roller 11 which does not face the reversing claw 12 is the low friction member 11b, this portion does not become the resistance of the paper at the time of switchback, and the curled paper, the thin paper, etc. are not broken or scratched. Can be reliably transported. Therefore, highly reliable switchback transportation can be performed.

Further, in the above-mentioned embodiment, an integrally molded structure comprising the low friction member 11b and the fitting portion (11c) having a diameter smaller than the outer diameter of the low friction member 11b,
Since the reversing roller 11 is composed of the ring-shaped high friction member 11a press-fitted into the fitting portion (11c), the reversing roller 11 is simple, and the cost can be reduced, and the transport stability can be improved.

[0059]

According to the inventions of claims 1 to 3,
Since the conveying surface of the reversing roller on the reversing claw side, that is, the conveying surface of the reversing roller for reversing the sheet with the reversing claw is a high friction member, the sheet is reliably fed to the downstream sheet reversing means side. Also, since the transport surface of the reversing roller that does not face the reversing claw is a low-friction member, this part does not become the resistance of the paper at the time of switchback, and curled paper, thin paper, etc. are not broken by the ears and scratches are securely made. Can be transported. Therefore,
Highly reliable switchback transportation can be performed.

According to the fourth aspect of the invention, since the reversing roller has the structure in which the ring-shaped high friction member is press-fitted into the fitting portion of the integrally molded structure having the low friction member, it is simple and low in cost. It is possible to improve the transport stability.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a sheet post-processing apparatus according to the present invention.

FIG. 2 is an enlarged configuration diagram of a sheet reversing unit in the sheet post-processing apparatus according to the present invention.

FIG. 3 is a front view showing a positional relationship between a reversing roller and a reversing claw.

FIG. 4 is a partially cutaway front view of a reversing roller.

FIG. 5 is an exploded perspective view of the same.

[Explanation of Codes] 11 Reversing Roller (Reversing Roller) 11a High Friction Member 11b Low Friction Member 12 Reversing Claw 12a First Guide Surface 12b Second Guide Surface 12c Top 13 Reversing Guide Plate 14 Conveying Roller 15 Tapping Roller 16 Reversing Tray 101 Lever 102 Spring 103 Lever 104 Spring 105 Solenoid 106 Shaft of Reverse Roller 11 107 Shaft of Reverse Claw 12

Claims (4)

[Claims] 1. A reversing roller that constantly rotates in a predetermined direction, a paper reversing unit that is located on the downstream side of the reversing roller to switch back the paper, and a first guide surface that guides the paper to the reversing roller. And a second guide surface that is formed so that the downstream side of the first guide surface intersects with the circumferential surface of the reversing roller and that guides the paper to the sheet discharge port after reversing the paper. In the sheet reversing device, which is provided with a claw, the first guide surface of the reversing claw is pressed toward the reversing roller and can be retracted in the tangential direction as the sheet enters, A sheet reversing device, wherein the reversing claw side of the surface is formed of a high friction member and the opposite side thereof is formed of a low friction member. 2. The sheet reversing device according to claim 1, wherein the area of the high friction member is set to ½ or less of the area of the conveying surface of the entire reversing roller. 3. The sheet reversing device according to claim 1, wherein the conveyance surface of the high friction member and the conveyance surface of the low friction member are flush with each other. 4. The integrally molded structure according to claim 1, comprising the low-friction member and a fitting portion having a diameter smaller than the outer diameter of the low-friction member, and a ring shape press-fitted into the fitting portion. The sheet reversing device, wherein the reversing roller is formed of the high friction member.