JP2001019209A - Sheet transport device - Google Patents

Abstract

(57) [Problem] To provide a sheet conveying apparatus which does not require accuracy and has few members and does not skew the sheet. The driving roller includes a driving roller fixed to a shaft, a driven roller paired with the driving roller, a mounting plate for supporting the driven roller, and two pairs of guide members for guiding a conveyed sheet. In the sheet conveying apparatus, the mounting plate is rotatably mounted to the guide member in the sheet advancing direction, and the driven roller supported by the mounting plate is pressed against the driving roller by elastic force. The sheet conveying device is configured such that the driven roller is driven by the driven roller to follow the driven roller and rotate in the sheet advancing direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus used for an image forming apparatus such as a copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional sheet conveying apparatus comprises a roller 11 and a driven roller 12 having a fixed axial position, and two pairs of guides 13, 14.
The roller shaft 11a and the shaft 12a of the driven roller are set in parallel. If the parallelism between the roller shaft 11a and the driven roller shaft 12a is not accurately maintained, the sheet skews. For this reason, the shaft position of the driven roller 12 is directly fixed to the guide 13, and the shaft is pressed against the roller 11 by the elastic member 15.

[0003]

However, the sheet conveying performance in this case depends on the accuracy in mounting the guides 13 and 14, and the driven roller shaft 12a provided on the guide 13.
Depends on the accuracy of the part that fixes the

As shown in FIG. 4, when the driven roller 22 is mounted on a mounting plate 25 made of an elastic member and the mounting plate 25 is fixed so as to press against the roller 21, the mounting plate 25 is There is a high possibility that it will be installed obliquely with respect to 21.

On the other hand, as shown in FIG. 5, when a guide 33 to which a driven roller 32 is attached can be opened and closed,
The relationship between the roller 31 and the driven roller 32 becomes unstable, and the relationship changes each time the guide 33 is opened and closed.

That is, in the case of FIG. 3, the method of directly fixing the shaft position of the driven roller requires the precision of parts, and in the case of FIG. 4, the precision of assembly when fixing the mounting plate is required. An assembling jig is also required. FIG.
In this case, when the guide is movable, an additional member for positioning the guide is required.

An object of the present invention is to solve these problems of the prior art and to provide a sheet conveying apparatus which does not require precision and has few members and does not skew the sheet.

[0008]

In order to solve the above problems, the present invention provides a driving roller fixed to a shaft, a driven roller paired with the driving roller, and a mounting plate for supporting the driven roller. In a sheet transport device configured by two pairs of guide members for guiding a sheet to be transported, the mounting plate is rotatably attached to the guide member in a sheet advancing direction, and is attached to the mounting plate. The sheet conveying device is configured such that the supported driven roller is pressed against the driving roller by elastic force, and the driven roller is driven to rotate by following the driving roller to be directed in the sheet advancing direction.

Therefore, the direction of the driven roller follows the direction of rotation of the drive roller. Therefore, when the drive roller is in pressure contact with the driven roller, the drive roller rotates even if the parallelism of the rotating shafts is deviated. The driven roller always faces in the traveling direction of the sheet and does not disturb the straightness of the sheet. In addition, when the machine is on standby, it is not necessary to maintain the parallelism of the rotation axes of the rollers and rollers, so that assembly and operation can be easily performed.

[0010]

1 and 2 are views showing the structure and operation of a sheet conveying apparatus according to the present invention.
The same parts are indicated by the same reference numerals.

FIG. 1 is a schematic sectional view of a sheet conveying apparatus according to the present invention. FIGS. 2A and 2B are perspective views for explaining the operation of the sheet conveying apparatus of the present invention. FIG. 2A shows a state in which a driven roller mounting plate rotates, and FIG. This shows a state where the sheet is oriented in the sheet advancing direction.

In the sheet conveying apparatus shown in FIG. 1, a driving roller 1 has a driving rotary shaft 1a fixed to a frame of the apparatus main body.
, And a driving force is transmitted by a driving source (not shown) during sheet conveyance. Reference numeral 2 denotes a driven roller 2 which is provided so as to be paired with the driving roller 1, is pressed against the driving roller 1, and rotates by the pressing force. Reference numeral 3 denotes a mounting plate 3 which supports the driven roller 2 and presses the driven roller 2 against the drive roller 1 itself, and a pair of guides 4 for conveying a sheet, 5
It is constituted by.

As shown in FIG. 2A, when the driving roller 1 and the driven roller 2 are not in pressure contact with each other, the mounting plate 3 is rotatable about the fulcrum A in the sheet advancing direction. Therefore, the direction of the driven roller 2 is not determined. Although the drive roller 1 and the driven roller 2 can be pressed against each other even when they are pressed, the direction of the driven roller 2 is not determined at this time.

As shown in FIG. 2B, when a driving force is transmitted to the driving roller 1, the driving roller 1 rotates in the sheet advancing direction, and accordingly, the driven roller 2 is oriented in the sheet advancing direction. Start spinning.

By this operation, the driving roller 1 and the driven roller 2
Will face in the same direction. The mechanism for transporting the transfer paper described above includes the transport process of the image forming apparatus, that is, the transport path from the cassette where the transfer paper is set to the image transfer section, the transport path from the fixing section to the discharge section, the reversing section, and both sides. The present invention can be applied to a device for transporting transfer paper, such as a unit transport path.

[0016]

As described above, according to the configuration and method of the present invention, when driving is applied, the rollers and rollers of the sheet conveying apparatus automatically align themselves, so that the driving rollers always convey the sheet. Sometimes the sheet is directed in the sheet advancing direction, so there is no skew of the sheet. Therefore, assembling efficiency is not required and the assembling efficiency is increased because the assembling accuracy is not required. Not affected by component accuracy. Since there is a margin in the mounting position and the like, the yield of the members is improved. Even if the relationship between the rollers changes each time the operation is performed without being affected by the operability, the direction in the sheet direction is corrected each time the drive is transmitted, so that the operability can be easily made.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a sheet conveying apparatus according to the present invention.

FIGS. 2A and 2B are perspective views for explaining the operation of the sheet conveying apparatus according to the present invention, in which FIG. 2A is a perspective view showing a state in which a driven roller mounting plate rotates, and FIG. FIG. 7 is a perspective view illustrating a state in which a driven roller is oriented in a sheet advancing direction during sheet conveyance.

FIG. 3 is a cross-sectional view illustrating a conventional sheet conveying device.

FIG. 4 is a cross-sectional view illustrating a conventional sheet conveying device.

FIG. 5 is a cross-sectional view illustrating a conventional sheet conveying device.

[Explanation of symbols]

 1, 11, 21, 31 Drive roller 1a, 11a Drive rotation shaft 2, 12, 22, 32 Followed roller 2a, 12a Followed roller shaft 3, 13, 33 Mounting plate 4, 14 Guide 5, 15, 25 Guide

Claims (1)

[Claims] 1. A driving roller fixed to a shaft, a driven roller paired with the driving roller, a mounting plate for supporting the driven roller, and two pairs of guide members for guiding a conveyed sheet. The mounting plate is rotatably attached to the guide member in the sheet advancing direction, and the driven roller supported by the mounting plate is pressed against the driving roller by elastic force. And a driven roller driven by the driven roller to follow the driven roller and rotate in a sheet advancing direction.