JP2996003B2 - Paper transport device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electronic copying machine, which is provided with an opening / closing mechanism for a guide plate constituting a sheet feeding path so that a jam in the sheet feeding path can be easily performed. In particular, the present invention relates to a sheet conveying path opening / closing apparatus of an image forming apparatus capable of opening a guide plate and releasing a nip of a conveying roller device by pulling out a sheet stopped in a sheet feeding path.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine or a printer, or a printing apparatus using cut paper, a sheet fed from a sheet feeding unit is moved to an image transfer position,
There is provided a mechanism for temporarily stopping the sheet immediately before the printing position, positioning the leading end of the sheet, and then feeding the sheet to an image transfer section or the like. The paper transport mechanism,
As used in an apparatus such as a general electronic copying machine, a paper transport path is regulated by two guide plates, and a transport roller device is disposed at a predetermined interval with respect to the paper transport path, and the transport roller device is used. The sheet is transported. Then, a driving unit is arranged for each of these transport roller devices, and the paper is transported from the paper feed unit to the print unit.

As the above-described apparatus, for example, a transfer apparatus as shown in FIG. 6 can be configured.
The image forming apparatus 1 shown in FIG. 6 is a part of a color electronic copying machine, and forms a color toner image formed on a photosensitive drum 3 while holding a sheet on a transfer drum 2. An apparatus for transferring to paper is configured. The photosensitive drum 3 arranged corresponding to the transfer drum 2 includes:
As in the case of a general electronic copying machine, a toner image forming unit using an electrophotographic method is arranged, a plurality of developing devices are arranged corresponding to the photosensitive drums, and a plurality of developing devices are used. The formed color toner image is superimposed on a sheet and transferred, and the sheet is passed through a fixing device to form a color copy.

The image forming apparatus 1 is provided with a mechanism for feeding paper from the paper feed tray 10 and the manual feed tray 17, and includes a paper feed roller 11 provided on the paper feed member.
The paper is fed out one by one toward the paper transport path 13 by using the paper 18. In the paper transport path 13, transport roller devices 12, 14, and 15 are arranged at predetermined intervals. A paper feed path 20 is provided downstream of the transport roller apparatus 15, and a downstream of the paper feed path 20 is provided. Registration roller device 30
Has been arranged. The sheet feeding path 20 is configured to be greatly curved downward, and the sheet is conveyed to the transport roller device 15 while the leading end of the sheet is nipped by the registration roller device 30.
The sheet is curved by feeding the sheet. Then, when the registration roller device 30 is driven to feed the paper toward the transfer drum 2 by using the pressing force due to the bending of the paper, the feeding operation can be sufficiently exhibited.

[0005]

However, when the paper feed path is configured as described above, if a jam occurs in the paper feed path, there arises a problem that taking out the paper is troublesome. Therefore, the guide plate of the curved paper feed path is
For example, as shown in Japanese Utility Model Laid-Open Publication No. 2-52865, a mechanism is provided for opening and closing via a support shaft arranged at one end, and the guide plate is rocked to release the paper feed path. It is conceivable to provide a mechanism for removing paper. However, when the conventional mechanism is used, if the leading end of the sheet is nipped by the transport roller device, there is a problem that the sheet is torn when the sheet is pulled out.

Accordingly, for example, Japanese Utility Model Laid-Open No. 60-24473.
As disclosed in Japanese Patent Laid-Open Publication No. 6 (1994) -6, for example, it has been proposed that when the guide plate is released, the nip by the transport roller device is released so that the jam paper can be easily removed. However, it is necessary to manually move the guide plate in the paper transport path and release the nip of the transport roller device, and to return the members to their original positions after removing the jammed paper. However, there is a problem that the operator needs to perform a troublesome operation, and the work efficiency is deteriorated.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned drawbacks of the conventional apparatus, and it is possible to simultaneously swing the guide plate and release the nip of the transport roller apparatus by pulling out jammed paper. It is another object of the present invention to provide a device that can automatically return each member to a transport state thereafter.

[0008]

According to the present invention, there is provided a paper sheet comprising a transport roller device comprising two rollers in contact with each other, a paper transport path formed by a swingable guide plate and a fixed guide plate. It relates to a transport device. In the invention according to claim 1 of the present invention, the swing-side guide plate swings in conjunction with an operation of pulling out a sheet in the direction of the extension of the sheet transport path,
The two rollers of the transport roller device are separated from each other in accordance with the swing of the swing-side guide plate. According to a second aspect of the present invention, one of the rollers of the transport roller device is supported by the swing-side guide plate, and the swing-side guide plate is interlocked with the operation of pulling out the sheet in the direction of the extension of the sheet transport path. And swings.

According to a third aspect of the present invention, there is provided a transport roller device including two rollers that are in pressure contact with each other, a guide plate that can swing through a support shaft of one of the transport roller devices, and a fixed guide plate. And a sheet conveying path formed by the swinging side, wherein the swinging side guide plate is provided with a cam member that performs a pressing action on a side opposed by the swinging operation, and the swinging side The guide plate of (1) swings in conjunction with the operation of pulling out the sheet in the direction of the extension of the sheet transport path.

As described above, the paper conveyance path can be released and the nip in the conveyance roller device can be released only by pulling out the jammed paper, so that a paper jam occurs in the paper conveyance path. Even in this case, the operation of removing the jammed paper can be easily performed. Further, the opening / closing mechanism of the paper transport path according to the present invention can use a relatively simple mechanism. After the jammed paper is removed, each member automatically returns to the original position, and the operation of the paper transport apparatus operates. Can be continued, so that the burden on the operator can be reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given of a sheet conveying path opening / closing device of an image forming apparatus according to the present invention with reference to the illustrated example. The example shown in FIG. 1 shows a case where a guide plate swinging mechanism and a nip release mechanism of a transport roller device are provided in a paper feeding path of a color electronic copying machine as shown in FIG. In order to supply paper and the like to the transfer drum 2, a paper feed path 20 is arranged. The paper feed path 20 is configured to have a largely curved shape, and a transport roller device 15 is disposed at the entrance of the paper feed path 20, and a registration roller is provided at a portion where paper is fed toward the transfer drum 2. The device 30 is arranged.

The transport roller device 15 and the registration roller device 30 are provided with a drive roller and a pinch roller facing each other, like a transport roller device disposed in a paper transport path of a general copying machine. By pressing the roller toward the driving roller, a predetermined nip pressure can be set between the two rollers. Further, in the registration roller device 30, the pinch roller 32 is provided so as to be able to be separated from and brought into contact with the drive roller 31 disposed at the fixed position. This will be described in detail.

In the portion of the paper feed path, the transport roller device 1
In a state where the leading end of the paper fed by 5 is locked by the registration roller device 30, the transport roller device 15 still applies a feeding action to form a loop on the paper. In other words, the leading end of the paper fed into the paper feed path is slightly inserted into the nip portion of the registration roller, and while the leading end of the paper is regulated, a loop is formed on the paper, thereby forming the loop of the paper. The leading end of the sheet is positioned by using the pressing force to return the loop. When the registration roller device 30 is driven, the action of pushing the sheet toward the registration roller device 30 is applied by the pressing force of the loop portion of the sheet, so that the action of the sheet nip can be favorably exhibited. To do.

A pressing roller 5 is provided downstream of the paper feeding path 20.
And the pressing roller 5 is provided with a roller supporting bracket 6.
The transfer drum 2 is provided so as to be able to be separated from and brought into contact with the transfer drum 2. In the transfer drum 2, the pressing roller 5 is brought into contact with the transfer drum 2 to send out the sheet only when the sheet is adhered, and uniform charging is performed by a charging member (not shown). The paper is held on the surface of the transfer drum 2 by static electricity. The transfer drum 2 is used to form a color copy by superimposing and transferring a color toner image on a sheet while holding the sheet on the surface thereof.

The paper feed path 20 has an outer guide plate 21 and an inner guide plate 22 arranged at a predetermined interval, and constitutes a mechanism for guiding a sheet between the two guide plates. It is fixed and held on the body frame or the like in a state where it cannot swing. On the other hand, the inner guide plate 22 is supported by the shaft of the pinch roller 32 of the registration roller device 30,
It is provided so as to be swingable about the axis. The paper feed path 2
2 and 3 are arranged as shown in FIGS. 2 and 3, and the outer guide plate 21 is supported in a state fixed to the main body frame.

The inner guide plate 22 is supported by a shaft 33 of a pinch roller 32 via brackets 23 on both sides thereof, and is provided so as to be swingable about the shaft 33. Further, means for urging the inner guide plate 22 toward the outer guide plate side by a spring 27 is provided, and the upstream end of the inner guide plate 22 is locked to the stopper member 26, The space between the two guide plates is maintained.

A cam member 25 is provided integrally with the bracket 23 for supporting the inner guide plate 22, and when the inner guide plate 22 is closed to guide a sheet, the cam member 25 is closed.
As shown in FIG.
Is pressed against the stopper member 26. In the paper feed path 20, the guide plates 2 on both sides
In a state where the interval between 1 and 22 is kept constant, the positioning operation for the sheet is performed.

In the state shown in FIG. 2, when the paper jams in the paper feed path 20 during the operation of positioning and feeding the paper, as shown in FIG. Then, the rear end of the sheet P is pulled out in the direction of the arrow. Then, by pulling out the sheet P to the upstream side, the force applied to the sheet overcomes the holding force of the spring 27 and swings the inner guide plate 22 counterclockwise about the shaft 33. Is done.

As shown in FIG. 3, when the inner guide plate 22 is swung counterclockwise, the cam member 25 provided on the bracket 23 is pressed inside the outer guide plate 21, and The pinch roller 32 is separated from the drive roller 31 by the cam member 25, and a slight gap is formed between the two rollers. Therefore, the paper that has been nipped by the registration roller device 30 can be freely pulled out while the nip by the roller device is released.

Further, in the state shown in FIG. 3, there is no force for swinging the inner guide plate 22 by the sheet. Therefore,
When the paper is pulled out from the paper feed path 20, the inner guide plate 22 is swung clockwise about the shaft 33 by the force of the spring 27 until the end is locked by the stopper member 26. A state is set in which the sheet is automatically returned, performs a registration operation on the sheet in the sheet feeding path, and guides the sheet.

As described above, when a paper jam occurs in the paper feed path, the inner guide plate is oscillated by applying only an operation of pulling out the paper, and the registration roller device 30 is rotated.
The mechanism for releasing the nip at is configured as shown in FIGS. The example shown in FIG.
3 shows a relationship between a driving roller 31 and a pinch roller 32 that constitute the registration roller device 30 and a cam member 25 provided on the inner guide plate 22.

As shown in the figure, a bracket 23 is formed on the side of the inner guide plate 22 arranged corresponding to the outer guide plate 21, and the cam member 25 is integrally formed on the bracket 23. Provided. The cam member 25
2 is not in contact with the outer guide plate 21 in the state shown in FIG. 2, but in the state shown in FIG. 3, it is pressed by the outer guide plate 21 and acts in a direction to separate the shaft 33 from the drive roller. I do.

Therefore, as shown in FIG.
When the inner guide plate 22 is swung by pulling out the paper, the cam member 25 is pressed against the outer guide plate 21, and the action of the cam causes the registration roller device 3.
The nip at 0 is released so that a slight gap is formed between both rollers. As described above, when the nip in the registration roller device 30 is released, the pinch roller 3
In the present invention, in order to allow the swing of FIG.
As shown in FIG. 5, a long hole 29 is provided in the support frame 28, and the shaft 33 of the pinch roller 32 is supported through the long hole 29.

Further, the spring 3
The urging means 4 is arranged to press the pinch roller toward the drive roller. Then, by providing means for pressing the springs 27 and 34 between the driving roller 31 disposed at the fixed position and the pinch roller 32, the nip pressure between both rollers is set,
It is possible to maintain the conveyance operation for the sheet in a good state. Paper feed path 20 of the present invention configured as described above
Then, even if a jam occurs in the paper feed path, the operation of swinging the inner guide plate and releasing the nip pressure by the registration roller device is performed only by performing an operation of pulling out the paper, thereby removing the jammed paper. Can be withdrawn.

When the paper stopped in the paper feed path is removed and the force for swinging the inner guide plate is not applied, the inner guide plate is moved by the force of the spring disposed on the inner guide plate. It can be automatically returned to the original position. Therefore, the operator can perform the jam processing only by performing the operation of merely removing the jammed paper without releasing the paper transport path or performing the operation of releasing the nip of the transport roller device. .

Further, as shown in the embodiment, the sheet conveying path opening / closing apparatus of the image forming apparatus of the present invention configured as described above can not only cope with the jam processing in the curved conveying path, but also It can also be applied to jam clearance on roads. In this case, it is necessary to add an action for swinging the inner guide plate only by pulling out the jammed paper.Therefore, set the paper pulling direction to the direction in which the inner guide plate is released, and pull out the paper. Thus, the release of the inner guide plate and the release of the nip pressure in the transport roller device may be performed.

[0027]

As described above, in the sheet conveying path opening / closing device of the image forming apparatus according to the present invention, a mechanism for urging the inner guide plate toward the outer guide plate by a relatively weak spring and a registration roller device are used. A mechanism for interlocking the nip pressure of the inner guide plate with the swing of the inner guide plate is arranged, so that the paper conveyance path can be released and the nip can be released by the conveyance roller device only by pulling out the jammed paper. . Then, even if a paper jam occurs in the paper feed path, the operation of removing the paper can be easily performed only by pulling out the jammed paper. Further, the opening / closing mechanism of the paper transport path according to the present invention can use a relatively simple mechanism. After the jammed paper is removed, each member automatically returns to the original position, and the operation of the paper transport device is performed. Can be continued, so that the burden on the operator can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration of a paper feed path to which the present invention can be applied.

FIG. 2 is a side view illustrating a configuration of a sheet feeding path of the present invention.

FIG. 3 is an explanatory diagram of a state in which an inner guide plate is swung by pulling out jammed paper.

FIG. 4 is an explanatory view showing an operation of releasing the nip of the registration roller device by the cam member of the present invention.

FIG. 5 is a side view of a sheet feeding path in a registration roller device portion.

FIG. 6 is an explanatory diagram of a sheet conveying device in a conventional image forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Image forming apparatus, 2 Transfer drum, 10
Paper feed tray, 13 paper transport path, 15 transport roller device, 20 paper feed path, 21 outer guide plate,
22 inside guide plate, 23 bracket, 25
Cam member, 26 stopper member, 27 spring, 30 registration roller device, 31 drive roller, 32 pinch roller.

Claims (3)

(57) [Claims] 1. A paper transport device comprising: a transport roller device including two rollers that are in pressure contact with each other; a swingable guide plate; and a paper transport path formed by a fixed guide plate. The swing-side guide plate swings in conjunction with the operation of pulling out the sheet in the direction of the extension of the sheet transport path, and the two rollers of the transport roller device are adapted to swing the swing-side guide plate. A sheet transport device that is separated from the sheet transport device. 2. A paper transport device comprising: a transport roller device including two rollers that press against each other; a swingable guide plate; and a paper transport path formed by a fixed guide plate. One of the rollers of the transport roller device is supported by the swing-side guide plate, and the swing-side guide plate swings in conjunction with the operation of pulling out the sheet in the direction of the extension of the sheet transport path. Characteristic paper transport device. 3. A sheet formed by a transport roller device including two rollers that are in pressure contact with each other, a guide plate that can swing through a support shaft of one of the transport roller devices, and a fixed guide plate. A paper path comprising: a conveying path; and a guide member on the oscillating side provided with a cam member that performs a pressing action on a side facing the oscillating operation, wherein the oscillating side guide plate includes: A sheet conveying device which swings in conjunction with an operation of pulling out a sheet in the direction of an extension of the sheet conveying path.