JPH09216741A - Paper sheet carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attach/detach a roller used for carrying a paper sheet easily and safely without the disassembly of respective parts. SOLUTION: A roller 8 is installed so as to be put in or taken out freely and a drive shaft B9 combined by a turning stop is supported in a cantilever state and its free end 23 is extended upto a part beyond the maximum paper passing width PWMAX of a paper passing passage 6. A holding part 27 extended to near its free end 23 along the drive shaft B9 is fixed to the end surface of the roller 8 so as to hold this holding part 27 and attach/detach the roller 8 to the drive shaft B9. The falling off of the roller 8 combined by a turning stop to the drive shaft B9 is stopped by a falling off stop mechanism 31 and the falling off of the roller 8 can be released by an operation near the free end 23 of the drive shaft B9. Thereby, the roller 8 can be attached/detached only near the free end 23 of the drive shaft B9 with a wide space without the arrangement of the other parts and the easiness and safety of the work can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device used in an image forming apparatus such as a copying machine, a facsimile and a printer. The concept of the paper transport device includes a device for transporting the paper in the paper passage and a paper feed device for feeding the paper in the paper passage.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile, and a printer, it is general to use a roller to convey a sheet on which an image is formed. For example, a paper feed roller is used to feed the paper to the paper passage, and a pair of rollers is used to convey the fed paper. Further, in order to prevent double feeding of paper and feed only the topmost paper, a paper separating mechanism including a feed roller and a reverse roller may be used. In other words, the reverse roller pushes back the second and subsequent sheets of paper that are fed and overlapped with the topmost sheet by rotating in the same direction as the feed roller, and when it comes into contact with the feed roller after that, it acts on the feed roller by the action of the torque limiter. On the other hand, it is a structure that is driven to rotate. In any case, the image forming apparatus uses a plurality of rollers to convey the paper.

As the number of passing sheets increases, the peripheral surface of the roller for conveying the sheet wears and the coefficient of friction decreases. Therefore, replacement is required at a predetermined time. However, in order to replace the roller, the drive shaft and the bearing of the roller must be removed from the main body of the apparatus, which requires extremely troublesome work. In view of the above, a sheet conveying device in which the drive shaft of the roller is cantilevered so that the roller can be inserted and removed from its free end is conceivable. For example, Japanese Patent Publication No. 2-33609 or Japanese Utility Model Publication No. 7-12352. It is published in.

[0004]

[Problems to be solved by the invention]
In the paper transporting device disclosed in Japanese Patent No. 33609 or Japanese Utility Model Publication No. 7-12352, the roller is attached near the free end of the drive shaft supported in a cantilever state. Therefore, in order to attach and detach the roller, it is necessary to put a hand inside the main body of the apparatus, which makes it difficult to attach and detach the roller, and there is a problem in that the attaching and detaching work of the roller is dangerous. Moreover, since the free end of the drive shaft is arranged in the central portion of the apparatus body, other parts are arranged around the roller attached to the drive shaft, which further deteriorates workability.

[0005]

According to the first aspect of the present invention,
A drive shaft which is rotatably supported in a cantilever state and whose free end extends to a portion exceeding the maximum sheet passing width in the sheet passing path,
A roller that is attached to the drive shaft so as to be detachable in the axial direction and that is arranged at a position in contact with the paper passage, and a gripping body that is fixed to the end surface of the roller and that extends along the drive shaft to the vicinity of its free end. , A coupling part for locking the roller to the drive shaft at a predetermined position, a retaining mechanism for restricting the axial movement of the roller coupled to the drive shaft by this coupling part to prevent the roller from coming off, and the freedom of the drive shaft. A release mechanism that receives an operation near the end and releases the retainer of the roller with respect to the drive shaft. Therefore, by the operation in the vicinity of the free end of the drive shaft, the stopper mechanism for releasing the roller from the drive shaft is released. Therefore, it is possible to pull out the roller from the drive shaft by pinching the gripping portion in this state.
In this case, since the free end of the drive shaft extends to the part that exceeds the maximum paper-passing width in the paper-passing path, a wide working space is secured without arranging other parts around it, and the roller mounting / demounting work is performed. Will be easier. For example, it is possible to expose the free end of the drive shaft to the outside of the image forming apparatus in which the sheet conveying device is used. In this case, the work of attaching and detaching the roller becomes extremely easy.

According to a second aspect of the present invention, in the first aspect of the present invention, the sheet guide further comprises a sheet guide which is disposed at a position that interferes with the movement trajectory of the roller at the time of inserting / removing the drive shaft, The paper guide is divided into a plurality of parts, and the attachment / detachment portion of the portion that interferes with the movement trajectory of the roller is arranged near the free end of the drive shaft. Therefore, even if the paper guide interferes with the movement trajectory of the roller, the roller can be attached and detached by removing only the part of the divided paper guide that interferes with the roller. At this time, since the attachment / detachment portion of the paper guide is located near the free end of the drive shaft outside the maximum paper passage width, work can be performed in a wide space where no other parts are arranged, and workability is good.

According to a third aspect of the present invention, in the first aspect of the present invention, a sheet guide which is disposed at a position that interferes with the movement path of the roller at the time of inserting / removing the drive shaft and forms a sheet passing path, and the sheet guide. And a retracting mechanism for rotating the drive shaft about its support end side to a position where the movement locus of the roller does not interfere with the guide. Therefore, even if the paper guide interferes with the movement trajectory of the roller, the roller can be attached and detached without interfering with the paper guide by rotating the drive shaft by the retracting mechanism. In this case, if the interlocking mechanism that switches the position of the drive shaft between the retracted position and the set position in association with the attachment / detachment operation of the sheet feeding cassette is provided, it is necessary to operate the retracted mechanism. Workability is getting better and better as it disappears.

[0008]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. The present embodiment is an example applied to a sheet feeding device of a copying machine.

FIG. 2 shows the external structure of the copying machine 1. This copying machine 1 is a front loading type having a paper feed cassette 2 that can be pulled out at the lower front portion. A document cover 3 for opening and closing a contact glass (not shown) and an operation panel 4 are provided on the upper surface, and a front cover 5 is openably and closably attached to the front surface. By opening this front cover 5, various maintenance work can be performed. Further, a side cover 7 for opening a sheet passage 6 to be described later is attached to the right side surface in FIG. Further, a reverse roller 8 as a roller is provided at a position adjacent to the sheet feeding cassette 2 arranged on the front surface of the drive shaft B9.
A roller attaching / detaching hole 10 for detachably setting the roller is provided. These will be described later in detail.

The copying machine 1 of the present embodiment has a paper separating mechanism 12 including a feed roller 11 and a reverse roller 8.
With a built-in paper feeding device 13 as a paper transporting device,
The sheet feeding device 13 feeds the uppermost sheet P among the sheets P stacked in the sheet feeding cassette 2 to the sheet passing path 6. 1 is a perspective view in which a part of the paper feeding device 13 is cut away, and FIG. 3 is a vertical side view of the paper feeding device 13.

The paper feeding device 13 includes a pair of side frames 1.
Various parts are assembled to a frame body 17 formed by screwing the lower frame 4, the lower frame 15, and the upper frame 16 into a rectangular shape. First, the frame body 17
A drive shaft A18 of the feed roller 11 is rotatably attached to the. The drive shaft A18 is hung from the center of the upper frame 16 and fixed to the upper sub-frame 1.
6a and the left side frame 14 are attached via a bearing BB. Such a feed roller 1
One drive shaft A18 is divided into two and is connected to each other via a one-way clutch A19. And the drive shaft A18
An electromagnetic clutch EC that applies a driving force to the drive shaft A18 is connected to the power input side 18a of the drive shaft A18, and the feed roller 11 is coaxially fixed to the power output side 18b of the drive shaft A18. The one-way clutch A19 has a pickup roller 2 for picking up the paper P in the paper feed cassette 2.
0 is rotatably attached. The pickup roller 20 includes a gear train A22 including an idler gear A21.
Is connected to the feed roller 11 via a power transmission path.

Next, the drive shaft B9 of the reverse roller 8 is rotatably attached to the frame body 17.
The drive shaft B9 is attached in a cantilever state via a bearing BB between a lower sub-frame 15a formed by cutting and raising in the center of the lower frame 15 and a left side frame 14, and its free end 23 is The roller attachment / detachment hole 10 described above is exceeded by exceeding the maximum sheet passing width PW _MAX in the sheet passing path 6.
It is exposed to the outside. The drive shaft B9 of such a reverse roller 8 is divided into two and is connected to each other via a one-way clutch B24. And drive axis B
The power input side 9a of 9 is connected to the drive shaft A18 of the feed roller 11 via a gear train B26 including an idler gear B25. Therefore, the feed roller 11 and the reverse roller 8 which receive the driving force rotate in the same direction as each other.

The reverse roller 8 is detachably attached to the power output side 9b of the drive shaft B9 of the reverse roller 8. The reverse roller 8 has an elongated grip portion 27 having elasticity on its end surface.
Is fixed, and this grip portion 27 extends along the drive shaft B9, and its end portion reaches the vicinity of the free end 23 of the drive shaft B9. Further, a coupling portion 28 is provided which couples the reverse roller 8 and the one-way clutch B24 which are inserted into the drive shaft B9 and have reached a predetermined position, and the coupling portion 28 is provided.
Thus, the reverse roller 8 is fixed to the drive shaft B9 by rotation prevention. Further, the groove 2 is formed at the free end 23 of the drive shaft B9.
9 is cut, and a claw 30 that fits into the groove 29 is formed at the end of the grip 27. As a result, the connecting portion 28
The retaining mechanism 3 that regulates the axial movement of the reverse roller 8 that is rotationally coupled to the drive shaft B9 to prevent it from coming off.
1 and a release mechanism 32 for releasing the retaining of the reverse roller 8 with respect to the drive shaft B9.

Next, in the frame body 17, a large hole 33 is formed in the right side frame 14. This hole 33 is for avoiding interference of the reverse roller 8 with the side frame 14 when the reverse roller 8 is attached to or detached from the drive shaft B9. The paper guide 34, which constitutes a part of the paper passage 6 described above, is attached to the frame body 17 at a position between the feed roller 11 and the reverse roller 8. The paper guide 34
Is divided into two, a paper guide 34a attached to the left side frame 14 and a paper guide 34b attached to the right side frame 14. The paper guide 34b includes a mounting portion 35 screwed to the side frame 14 near the hole 33 formed in the right side frame 14. In FIG. 3, the paper guide 34a is omitted.

In such a structure, the electromagnetic clutch E
The driving force is applied via C to the drive shaft A18 of the feed roller 11.
, The feed roller 11 and the pickup roller 20 are driven and rotated. Drive shaft A1
The rotational force of 8 is transmitted to the drive shaft 9a of the reverse roller 8, but is not transmitted to the reverse roller 8 itself by the action of the one-way clutch B24, and the reverse roller 8 is rotated by the feed roller 11. At this time, since the one-way clutch A19 is rotated by the rotation of the drive shaft A18a, the pickup roller 20 that is integral with the one-way clutch A19.
Comes into contact with the uppermost sheet P in the sheet cassette 2. After the contact, the position of the pickup roller 20 is fixed by the action of the one-way clutch A19. As a result, the paper feed cassette 2
The uppermost sheet P among them is picked up by the pickup roller 20 and fed to the sheet passing path 6. At this time, the paper P
When the sheet P is double-fed, the sheet P is conveyed between the feed roller 11 and the reverse roller 8, and the second and subsequent sheets P contact the reverse roller 8. Then, the feed roller 1
The resistance applied to the reverse roller 8 is reduced by 1 and the reverse roller 8 rotates in the reverse direction to push the second and subsequent sheets of paper P back toward the paper feed cassette 2. As a result, the paper P is separated and fed, and only the uppermost paper P is fed.

When the separating / feeding operation is repeated, the reverse roller 8 is worn and the frictional resistance thereof is lowered, so that the separating operation failure frequently occurs. Therefore, in such a case, it is necessary to replace the reverse roller 8. To replace the reverse roller 8, open the front cover 5 of the copying machine 1 and open the right side frame 1
4 is attached to the paper guide 34b attached to the mounting portion 35
Remove it by releasing the screwing in. Then, the end portion of the grip portion 27 is picked up, and the drive shaft B of the reverse roller 8 is
The grip portion 27 for the groove 29 formed in the free end 23 of
The engagement of the claw 30 is released. In other words, the release mechanism 32 releases the retainer mechanism 31 from retaining the reverse roller 8 with respect to the drive shaft B9. In this state, when the grip portion 27 is pulled out while being gripped, the reverse roller 8 integrated with the grip portion 27 is pulled out from the drive shaft B9. Therefore, the new reverse roller 8 to be replaced is inserted into the drive shaft B9 and pushed until it hits the one-way clutch B24. At this time, the reverse roller 8 and the feed roller 1
Since both 1 have elasticity, the reverse roller 8 is smoothly pushed in by mutual elastic deformation. Then, the replaced reverse roller 8 is connected to the drive shaft B by the connecting portion 28.
9 is fixed to the drive shaft B9 by the engagement action of the claw 30 with the groove 29 in the retaining mechanism 31. After that, the paper guide 34b is attached to the right side frame 14 again, and the front cover 5 of the copying machine 1 is closed, whereby the replacement work of the reverse roller 8 is completed.

Such replacement work of the reverse roller 8 is performed only near the free end 23 of the drive shaft B9 of the reverse roller 8. In this case, the free end 23 of the drive shaft B9
Is extended to a portion exceeding the maximum paper passing width PW _MAX in the paper passing path 6, so that no other parts are arranged unlike the copying machine 1 illustrated in FIG. Therefore, it is possible to work in a wide space, and the work is easy and safe. Moreover, in the paper feeding device 13 of the present embodiment, the paper guide 34 interferes with the movement trajectory of the reverse roller 8, whereas the paper guide 34 is divided into two parts and interferes with the movement trajectory of the reverse roller 8. (Paper guide 34b)
Is mounted near the free end 23 of the drive shaft B9.
It can be easily attached and detached by work at. Therefore, the paper guide 34b does not interfere with the attachment / detachment of the reverse roller 8, and the work of attaching / detaching the paper guide 34b itself can be performed in a wide space, which is easy and safe.

The second embodiment of the present invention is shown in FIGS.
The same parts as those in the first embodiment described with reference to FIG. The sheet feeding device 13 according to the present embodiment includes a retracting mechanism 42 that rotates the drive shaft B9 about the support end 41 side thereof to a position where the movement trajectory of the reverse roller 8 does not interfere with the sheet guide 34, and a sheet feeding cassette. An interlocking mechanism 43 that switches the position of the drive shaft B9 between the retracted position and the set position in association with the attachment / detachment operation of No. 2 is provided.

The retracting mechanism 42 will be described. The drive shaft B9 of the reverse roller 8 is attached to the left side frame 14 via the bearing BB on the side of the support end 41 thereof, but this attachment is made with some flexibility. In the lower sub-frame 15a, which is another fulcrum of the drive shaft B9 and supports the drive shaft B9 via the bearing BB, a U-shaped support groove 44 for supporting the drive shaft B9 in the bearing BB is deeply formed. . Therefore, the left side frame 14 and the lower sub-frame 15
The drive shaft B9 supported only by a rotates on its free end 23 side by its own weight with the support end 41 side as a fulcrum.
It is in a state of being positioned at the retracted position as illustrated in FIG. At this retracted position, the movement locus L of the reverse roller 8
The ofRR (see FIG. 5) does not interfere with the paper guide 34. On the other hand, when the paper feeding device 13 is used, it is necessary to dispose the drive shaft B9 at the set position as illustrated in FIG. 4 in which the reverse roller 8 contacts the feed roller 11. Therefore, in the present embodiment, a biasing structure for raising the drive shaft B9 is provided. This urging structure includes an urging member 46 rotatably attached to the lower sub-frame 15a around a horizontally oriented shaft 45, and a spring A47 for rotating the urging member 46 in the a direction in FIG. , A push-up lever 48 which is provided on the urging body 46 and pushes up the bearing BB of the drive shaft B9. That is, the biasing member 46
Spring A hung between the lower frame 15 and the lower frame 15.
The biasing member 46 is rotated by 47 in the direction a in FIG.
As a result, the push-up lever 48 of the urging body 46 moves the drive shaft B9.
The bearing BB is pushed up.

The interlocking mechanism 43 will be described. On the lower frame 15, a release lever 49 is rotatable about a vertically oriented shaft 50 at a position where it interferes with a movement locus LofPC (see FIG. 4) of a sheet feeding cassette 2 housed in the copying machine 1 so as to be freely drawn. It is installed. This release lever 49
The force of the spring B51 stretched between the release lever 49 and the lower frame 15 causes the biasing member 46 to rotate in the direction b in FIG. 4 and rotate in the direction opposite to the direction a in FIG. It is a structure. That is, the biasing member 46 is provided with the contact piece 50 that contacts the release lever 49, and the release lever 4 is provided.
9 is a structure in which the biasing member 46 is rotated in the direction opposite to the direction a in FIG. 4 by pushing the contact piece 50. In this case, the force of the spring B51 is set to be stronger than the force of the spring A47. Then, when the release lever 49 interferes with the sheet feeding cassette 2, the release lever 49 is rotated in the direction opposite to the direction b in FIG. 4 against the force of the spring B51, whereby the release lever 49 and the biasing member. It is configured so that the engagement with 46 is released.

In such a structure, when the paper feed cassette 2 is mounted on the copying machine 1, the release lever 49 rotates in the direction opposite to the direction b in FIG. 4, and the release lever 49 and the biasing member 46.
The engagement between and is released. As a result, the urging body 46 is rotated in the direction a in FIG. 4 by the force of the spring A47, whereby the push-up lever 48 pushes up the bearing BB of the drive shaft B9, and the reverse roller 8 contacts the feed roller 11. The drive shaft B9 is positioned at the position. And
When the sheet cassette 2 is pulled out, the release lever 49 is rotated in the direction b in FIG. 4 by the force of the spring B51,
The contact piece 50 of the urging body 46 is pushed in. At this time, the urging body 4
Release lever 4 is stronger than the force of spring A47 that urges 6
Since the force of the spring B51 for urging 9 is stronger, the urging body 46 rotates in the direction opposite to the direction a in FIG. 4 against the force of the spring A47. As a result, the push-up lever 48 retracts to a position where the drive shaft B9 of the reverse roller 8 cannot be pushed up, and the drive shaft B9 rotates by its own weight with the supporting end 41 side as a fulcrum, and the retract as illustrated in FIG. Move to position.

When the drive shaft B9 of the reverse roller 8 is at the retracted position, the movement locus LofRR of the reverse roller 8 does not interfere with the paper guide 34. Therefore, when the paper feed cassette 2 is pulled out, the reverse roller 8 can be easily inserted into and removed from the drive shaft B9. At this time, since the reverse roller 8 can be attached / detached through the roller attaching / detaching hole 10 formed on the front surface of the copying machine 1, it is not necessary to open / close the front cover 5 when attaching / detaching the reverse roller 8. Therefore, the replacement work of the reverse roller 8 becomes easier and safer.

FIG. 6 shows a modification of the retaining mechanism 31 and the releasing mechanism 32. That is, the grip portion 27 of the reverse roller 8
Is formed in a tubular shape that covers the drive shaft B9 up to its free end 23, a groove 61 is cut in the free end 23 of the drive shaft B9, and a retaining piece 62 is attached to this groove 61.
The retaining piece 62 has a U-shaped groove 63, and the U-order groove 63 is fitted in the groove 61 of the free end 23. Therefore,
The retaining piece 62 regulates the movement of the grip portion 27 to retain the reverse roller 8. So, if you remove the retaining piece 62,
By gripping the grip portion 27, the reverse roller 8 is driven by its drive shaft B9.
Can be easily removed from the.

[0024]

According to the first aspect of the present invention, the free end of the drive shaft in the cantilever state in which the roller is removably attached is extended to a portion beyond the maximum paper-passing width in the paper-passing path, and such freeness is provided. Since the roller can be attached / detached by the operation near the end, the roller can be attached / detached only in the vicinity of the free end of the drive shaft, where other parts are not arranged and the space is large. The ease and safety can be improved. In this case, it is also possible to expose the free end of the drive shaft to the outside of the image forming apparatus in which the sheet conveying apparatus is used, and in this case, the ease and safety of the work of attaching / detaching the roller can be further enhanced. it can.

According to the second aspect of the present invention, the paper guide that interferes with the movement path of the roller is divided into a plurality of parts, and the attaching / detaching portion of the portion that interferes with the movement path of the roller is arranged near the free end of the drive shaft. Even if the paper guide interferes with the movement trajectory of the roller, the roller can be attached and detached by removing only the part of the divided paper guide that interferes with the roller. At this time, since the attachment / detachment part of the paper guide is located near the free end of the drive shaft outside the maximum paper passage width, it is possible to work in a wide space where other parts are not placed,
It is possible to improve the ease and safety of the work of attaching and detaching the roller.

According to the third aspect of the present invention, since the paper guide that interferes with the locus of movement of the roller is provided with the retracting mechanism for rotating the drive shaft about its supporting end side to a position where the locus of movement of the roller does not interfere. Even if the paper guide interferes with the movement path of the roller, the roller can be attached and detached by rotating the drive shaft by the retracting mechanism. In this case, if the interlocking mechanism that switches the position of the drive shaft between the retracted position and the set position in association with the attachment / detachment operation of the sheet feeding cassette is provided, it is necessary to operate the retracted mechanism. Therefore, the ease of attaching and detaching the roller and the safety can be further improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a sheet feeding device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a copying machine.

FIG. 3 is a perspective view in which a part of the sheet feeding device is cut away.

FIG. 4 is a perspective view in which a part of a paper feeding device according to a second embodiment of the present invention is cut away.

FIG. 5 is a vertical sectional side view thereof.

FIG. 6 is a vertical sectional side view of a sheet feeding device showing a modified example of the second embodiment of the present invention.

[Explanation of symbols]

6 Paper Passing Path 8 Roller 9 Drive Shaft 23 Free End 27 Gripping Body 28 Coupling Section 31 Stopping Mechanism 32 Release Mechanism 34 Paper Guide 35 Detaching Section 42 Evacuation Mechanism 43 Set Position PW _MAX Maximum Paper Width

Claims (4)

[Claims] 1. A drive shaft which is rotatably supported in a cantilever state and whose free end extends to a portion exceeding a maximum paper passing width in a paper passing path, and which is attached to the drive shaft so as to be detachable in the axial direction. A roller arranged at a position in contact with the sheet passing path, a gripping body fixed to an end surface of the roller and extending to a vicinity of a free end thereof along the drive shaft, and the roller at a predetermined position on the drive shaft. A coupling part for locking the rotation, a retaining mechanism for restricting the axial movement of the roller coupled to the drive shaft by the coupling part to prevent the roller from coming off, and an operation near the free end of the drive shaft. And a release mechanism that receives and releases the retainer of the roller with respect to the drive shaft. 2. A paper guide which is arranged at a position that interferes with the movement trajectory of the roller at the time of inserting / removing with respect to the drive shaft to form a paper passage, and the paper guide is divided into a plurality of parts to move the roller. 2. The sheet conveying apparatus according to claim 1, wherein the attaching / detaching portion of the portion that interferes with the locus is arranged near the free end of the drive shaft. 3. A paper guide that is disposed at a position that interferes with the movement trajectory of the roller during the insertion / removal operation with respect to the drive shaft to form a paper passage path, and the drive is performed to a position where the movement trajectory of the roller does not interfere with this paper guide. The sheet conveying apparatus according to claim 1, further comprising: a retracting mechanism that rotates the shaft around its support end side. 4. The sheet conveying apparatus according to claim 3, further comprising an interlocking mechanism that switches the position of the drive shaft between the retracted position and the set position in association with the attachment / detachment operation of the paper feed cassette.