JP2001206604A - Sheet transport apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply remove a driven roller pressed to a driving roller from the removing surface side in the case of providing the driven roller removably from a holding mechanism. SOLUTION: A spur roller 12-2 as a driven roller is rotatably provided on a coil-like spring shaft 13, and the spring shaft 13 is inserted from the insert opening 19 of a holding body 17 of a holding mechanism 14, and held by a holding part formed by a holding member 23 and an opposite member 24. The holding body 17 is provided with holding clicks 20a, 20b opposite to each other with the insert opening 19 interposed between them to cover a part of the spring shaft 13, the holding clicks 20a, 20b are shifted from each other, whereby the spring shaft 13 is easily mounted and removed through the insert opening 19 to prevent the shaft from slipping off in the held state.

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 characterized by a support structure of a roller shaft which is driven and rotated by a driving roller to convey a sheet.

[0002]

2. Description of the Related Art A recording apparatus (printer) forms a visible image on a sheet as a recording medium so that image data obtained by reading an image of a document, image data input from another apparatus, and the like can be viewed. This is output as a hard copy. This recording device is, for example, an electrophotographic system,
In general, an ink jet system in which ink is selectively discharged to perform recording, a thermal recording system having a thermal head having thermal paper or thermal transfer ink, or the like is used.

If the recording apparatus is provided with an image reading apparatus for reading an image of a document, that is, a scanner, it can be used not only as a printing function as a printer, but also as a reading function and a copying function obtained by combining these functions. Becomes

A scanner irradiates a document conveyed or placed on a platen surface mainly composed of a transparent flat member such as glass with light emitted from a light source, and optically irradiates the document. After scanning, the obtained reflected light is read by a reading element CC.
An image is formed on the light receiving section of a photoelectric conversion element (reading element) such as D,
An electric signal (analog signal) corresponding to the amount of received light is output. The analog signal is converted into a digital signal, and this is output as image data that can be reproduced and output as a visible image by a recording device.

As described above, in an image forming apparatus or the like,
A transport device for transporting a sheet to a target position is provided, and a transport device is also provided in a scanner for transporting a document to a target position.

As the sheet conveying device, a device provided with a conveying roller for nipping and conveying the sheet is generally used. That is, the driven roller is configured to have a driven roller that is pressed against and driven by the driven roller, and the sheet that is sent to the nip portion that is a pressing portion of the driving roller and the driven roller is further fed to a target position. Is configured.

Therefore, the above-described driven roller is configured to be in pressure contact with the driving roller, and in the related art, the shaft is formed in a coil shape so that the shaft of the driven roller has a pressing action on the shaft itself. Is proposed and implemented. For example,
As described in Japanese Utility Model Laid-Open Publication No. 62-151549,
The shaft of the driven roller pressed against the driving roller is constituted by a coil spring shaft (hereinafter, referred to as a spring shaft), and the spring shaft is fixedly supported on a support frame. Thus, by utilizing the spring action of the spring shaft, particularly the elastic action, an appropriate pressing force is applied to the drive roller, so that the sheet can be conveyed satisfactorily.
This configuration not only greatly simplifies the configuration of the sheet transport device itself, but also enables stable transport of the sheet and helps to reduce the cost of the sheet transport device.

[0008] Further, as a further development of the one described in the above-mentioned gazette, Japanese Patent Laid-Open Publication No. Hei 3-10198 is disclosed.
As disclosed in Japanese Patent Publication No. 0, publication No. 0, for example, a configuration as shown in FIG. 8 has been proposed. In the configuration of FIG. 8, the spur roller 80, which is a driven roller that is driven and rotated, is configured by a coil-shaped spring shaft 81, and a regulating member 8 is configured to regulate both sides of the spur roller 80.
2 and a support portion 83 for supporting both ends of the coil spring constitute a holding mechanism.

The opening of the support portion 83 and the regulating member 82
Are provided opposite to each other. Therefore, the spring shaft 81 is bent by utilizing elasticity, and is held by the support portion 83 through the respective openings.
It is possible to easily replace or remove the spur roller 80 and the like.

In the sheet conveying apparatus described in the above-mentioned publication, the driven roller is a spur roller 80. Since the spur roller 80 is provided at a paper discharge portion in an ink jet printer, undried ink adheres to the roller, and this is transferred again to the sheet. A spur (star-shaped) structure is provided in order to prevent the occurrence of an offset. Therefore, as long as it is a mere sheet conveyance, there is no particular problem if the roller for the drive roller is not a spur structure but a driven roller having a normal roll structure.

[0011]

According to the driven roller holding structure as shown in FIG. 8, the spring shaft 81 is firstly moved from the lower side to the first holding portion (restriction) having a U-shaped groove as described above. In order to support the shaft end from above on the second holding portion (supporting portion) 83, the shaft end is largely bent and inserted into the second holding portion 83 from the upper opening. Thus, the spur-shaped driven roller 80 can be rotatably held.

In this case, when the work for holding the driven roller 80 by the holding mechanism is performed, it is necessary to open the upper and lower sides and one surface side of the holding mechanism. That is, the work of holding the driven roller 80 can be performed in a state where the front part indicated by the reference numeral a and the upper and lower parts indicated by the reference signs b and c are all opened.

Therefore, it is necessary to provide a mechanism for holding the driven roller 80 so that the above-mentioned at least three open portions are secured. However, since the driven roller is pressed against the driving roller, the above-described open portion cannot be easily secured. Therefore, in the holding mechanism having the structure as shown in FIG. 8, the holding mechanism for the driven roller 80 is provided on the lid 84 or the like which can be opened and closed, and the lid 84 is opened to secure the above-described open portion. You need to be able to do it.

As a result, in the driven roller 80 held by the holding mechanism as shown in FIG. 8, the place where the driven roller 80 is installed is limited, and a protruding end (tip) ), And is limited to a paper discharge unit and the like.

In addition, since the spring shaft 81 needs to be supported in the vertical direction (or the horizontal direction in the horizontal direction), the holding operation, that is, the operation for attaching and detaching the spring shaft 81 from the holding mechanism is troublesome.

The present invention has been made in view of the above-described problems,
At least the operation for holding the shaft of the driven roller and the operation for removing the driven roller are performed in one direction, for example, in FIG.
It is an object of the present invention to provide a sheet conveying apparatus including a holding mechanism that can be operated from a direction (or any one of b and c).

In particular, an object of the present invention is to provide a sheet conveying apparatus in which a driven roller is rotatably provided on a shaft formed by a coil-shaped spring shaft, which can be easily attached to and detached from a holding mechanism. It is to provide a holding mechanism.

[0018]

According to a first aspect of the present invention, there is provided a sheet conveying apparatus comprising a driven roller pressed against a driving roller to convey a sheet. The rotating shaft of the driven roller has a coil-shaped spring shaft structure, and a holding mechanism for holding the spring shaft and pressing the driven roller against the driving roller is provided. Equipped with an insertion port on the surface side to insert the spring shaft,
A holding portion communicating with the insertion port and holding the spring shaft is provided, covers a part of the insertion port, and is provided with a plurality of holding claws for preventing the spring shaft of the holding portion from dropping off. The holding claws facing each other are provided at positions shifted from each other without facing each other.

According to such a configuration, for example, FIG.
As shown in (a), a spring shaft (13) rotatably supporting a driven roller (12-2) is inserted from an insertion opening (19) formed in the front surface of a holder (17). . At the time of insertion, the spring shaft (13) is flexed to a position where it comes off the tip of the upper holding claw (20a), and the spring shaft is pushed into the lower portion of the holding claw (20a). Then, with respect to the lower holding claw (20b) shifted from the holding claw (20a), the spring shaft (13) is bent to the opposite side to a position disengaged from the tip of the holding claw (20b),
The insertion is completed by pushing in, and the spring shaft can be held in the holding portion.

As described above, the spring shaft and the driven roller can be attached from one open side, and the position where the transfer device including the drive roller and the driven roller is provided is not restricted, and at least one side can be opened. Can be provided. In addition, the insertion, that is, the attachment, and the reverse removal can be performed from the same surface side, so that the work is simplified, and the structure of the holding mechanism for that purpose is not complicated, and the simple structure is sufficient.

In the sheet transporting apparatus according to the first aspect of the present invention, the holding member provided corresponding to the insertion port and forming a holding portion for holding a spring shaft has the insertion port side, If the inclined surface is formed so as to be guided to the holding portion, the operation of inserting the spring shaft into the holding portion using the inclined surface becomes easier. For example, as shown in FIG. 2C, a holding member (23) constituting a holding portion is provided at a portion corresponding to the insertion opening (19), and the insertion opening (19) side of the holding member is connected to the holding portion. To form a slanted surface so as to guide the spring shaft (13). Therefore, when the spring shaft is inserted from the insertion opening on the holding member, the spring can be easily formed along the inclined surface into a holding portion, for example, a holding portion constituted by an opposing member (24) provided opposite to the holding member. Can be inserted.

Further, in the sheet transporting apparatus having the above-described configuration, the side opposed to the holding member having the inclined surface may be
A holding claw is provided, and if the inclined surface is formed such that the shortest distance between the holding claw and the inclined surface is equal to or slightly larger than the spring axis, when inserting as described above, The work becomes easier, and the holding claws can prevent the spring shaft from falling off.

According to a second aspect of the present invention, there is provided a sheet conveying apparatus in which a driven roller is pressed against a driving roller to convey a sheet. The rotary shaft has a coil-shaped spring shaft structure, and a holding mechanism for holding the spring shaft and pressing the driven roller against the driving roller is provided. The holding mechanism includes the spring on one surface side. An insertion port through which the shaft can be inserted is provided, and a groove formed in communication with the insertion port is bent in the middle, and the bent portion is configured as a holding portion of a spring shaft. A driven roller rotated by a roller is arranged so as to regulate a direction in which the spring shaft is moved.

According to the sheet conveying apparatus having such a configuration, for example, as shown in FIG. 6, the holding body (17) constituting the holding mechanism is inserted into the insertion opening (17) into which the spring shaft (13) can be inserted. The holding portion (26) communicating therewith is formed by providing an L-shaped groove (25), and one side wall (26a) of the holding portion (26) is formed on the sheet conveying direction side, particularly on the drive roller (12-1). When the sheet (S) is conveyed in the direction of the arrow, the driven roller (12-2) is rotated, and the rotational moment at that time restricts the spring shaft (13) from moving in the conveying direction. It is arranged to be.

Therefore, when the sheet is being conveyed, the driven roller is always in pressure contact with the drive roller at a predetermined position, so that the sheet can be conveyed satisfactorily, and the spring shaft does not fall off the insertion slot. Therefore, the work of attaching and detaching the spring shaft and the like can be performed from one side, and the work is very simple.

Further, in the configuration of the sheet conveying apparatus according to the second aspect of the present invention, as shown in FIG. 7, for example, as shown in FIG. By providing the protrusion (27),
When the sheet is not conveyed, dropout prevention can be performed.

[0027]

Embodiments of the present invention will be described in detail below with reference to the drawings. 1A and 1B show a holding mechanism of a driven roller constituting a sheet conveying apparatus for explaining a first embodiment of the present invention. FIG. 1A is a plan view viewed from an operation surface side on which a driven roller is attached and detached. , (B) is a plan view viewed from the opposite surface. FIG. 2 is a view showing a cross-sectional state along the line AA, the line BB, and the line CC shown in FIG. 1. In particular, FIG. 2 shows a shaft holding portion for rotatably supporting a driven roller. It is sectional drawing which shows the detail.

FIG. 3 is a perspective view showing the appearance of an image forming apparatus having a sheet conveying device having a holding mechanism as shown in FIG. 1, and FIG. 4 is a perspective view showing the sheet conveying device of the image forming apparatus shown in FIG. Configuration diagram showing the internal structure of the image forming unit including,
FIG. 5 is a front view showing a state in which a sheet is conveyed in the sheet conveying apparatus according to the present invention.

First, an image forming apparatus according to the present invention and a conveying apparatus for conveying a sheet to an image forming section of the image forming apparatus will be described with reference to FIGS. FIG.
The image forming apparatus shown in FIG. 1 is an ink jet printer that ejects ink onto a sheet S as a recording medium as appropriate according to image data, and forms a visible image according to the image data. The present invention is not limited to a sheet conveying apparatus using an ink jet printer, but includes an image forming apparatus using an electrophotographic method, and a thermal printing method for thermally reproducing and recording an image using a thermal head or the like. The present invention can be directly applied to the sheet conveying device of the adopted image forming apparatus. Further, the apparatus of the present invention can be applied as it is to not only the sheet conveyance but also a document conveyance apparatus for conveying a sheet document or the like to a target position.

Therefore, in FIG. 3, sheets as recording media are placed so that an appropriate number of sheets are stacked on a sheet feed tray 2 provided so as to protrude from the main body of the image forming apparatus 1. The paper feed tray 2 is provided with a regulating guide 3 for regulating at least one edge in a width direction orthogonal to the paper feeding direction of the sheets to be placed. One end edge of the sheet is aligned with the regulation guide 3 and the required number of sheets are placed on the sheet feed tray 2. The loaded sheet is fed, for example, from the top sheet, and after passing through the recording position, a discharge sheet, which will be described later with reference to FIG. It is discharged to the tray 4.

In the main body of the image forming apparatus 1, as shown in FIG. 4, a pickup roller 5 for feeding the sheet S placed on the sheet feed tray 2 from the uppermost sheet is provided at the upper end of the sheet. They are arranged facing each other. The pickup roller 5 sends out the uppermost sheet S by one rotation. The fed sheet S is picked up by a pickup roller 5.
Is fed to the paper feed roller 6 provided in correspondence with.

The paper feed roller 6 has a reverse path (U-shaped path).
The sheet S is sent to a registration roller 8 disposed in front of the recording position via the recording sheet 7. The registration roller 8 temporarily stops the sheet S, and starts conveying the sheet S in synchronization with the start of recording at the recording position. In addition, according to the ink jet printing, when image formation of one line or a plurality of lines is completed, sheet feeding of an amount corresponding to the line is started.

At the recording position, an ink head 10 for appropriately ejecting ink is provided so as to face a platen 9 having a flat portion for receiving the back surface of the inverted sheet. The ink head 10 is mounted on an ink carriage (not shown).
For example, it is slidably provided on two slide shafts 11 which are provided flat in a direction perpendicular to the sheet feeding direction. In this way, the ink head 10 scans the sheet S conveyed at the start of recording, in a direction orthogonal to the transport direction, and records a necessary line. At this time, the sheet S is stopped when the ink head 10 scans,
Ink ejection control is performed in accordance with the image data, and by the end of recording of that line, sheet feeding control is performed for the sheet S in an amount corresponding to the recording line. By sequentially repeating this, reproduction and recording of an image according to the image data can be performed.

The sheet S for which recording has been completed is discharged to the above-described discharge tray 4 via a discharge roller 12 provided immediately after the recording position. The discharge roller 12 or the registration roller 8 is a driving roller for driving and rotating one of the rollers, and a driven roller that is driven and rotated with respect to this driving roller is provided so as to be pressed against the driving roller, and the sheet is conveyed. The device is configured.

(First Embodiment of the Present Invention) The sheet conveying apparatus described with reference to FIGS. 3 and 4 according to the present invention sends out the sheet S on the sheet feed tray 2 by the pickup roller 5 as described above. This is conveyed to a recording position via a paper feed roller 6 and a registration roller 8, and is discharged to a discharge tray 4 via a discharge roller 12 after recording.

For example, the discharge roller 12 constituting the sheet conveying device as shown in FIG. 4 is configured so that the driving roller 12-1 which is driven to rotate is pressed against the driving roller 12-1 with an appropriate pressure. And the following driven roller 12-2. Although not shown, the drive roller 12-1 has a drive gear or the like fixed to one end of the rotary shaft 12a as shown in FIG. 5, and rotation of a motor or the like is transmitted to the drive gear, and the drive roller 12-1 is driven via the rotary shaft 12a. Driven to rotate.

On the other hand, the driven roller 12-2 has a simple configuration and a spring shaft 13 or the like formed in a coil shape in order to impart an action of pressing the driving roller 12-1 with an appropriate pressure. The spring shaft 13 is held at both ends by a holding mechanism 14 according to the present invention. Therefore, the spring shaft 1
The driven roller 12-2 can be brought into pressure contact with the drive roller 12-1 without providing any special urging means, by utilizing the elastic force of 3 itself. Therefore, the configuration is simplified.

A specific example of the holding mechanism 14 according to the present invention will be described in detail below with reference to FIGS. The holding mechanism 14 is designed to easily perform the work of attaching and detaching the driven roller 12-2 in a small space.

In the ink jet printer shown in FIG. 4, the driven roller 12-2 is a sheet S which is a recording medium.
Since the ink dots adhere to the surface, if the ink is not dried, it is formed in a spur (star) shape in order to avoid offset. However, if there is no problem such as offset, the driven roller 1 having a roll structure
It may be 2-2.

The holding mechanism 14 separates the driving roller 12-1 and the driven roller 12-2, and for example, a support member provided to be openable and closable in order to secure a space for mounting and dismounting, or a conventional technology. As described in the section, it is provided on the lid 15 and the like. The lid 15 is composed of an exterior of the main body of the device 1 and the like.

As shown in FIG. 1, a spur roller 12-2, which is a driven roller, is axially moved by a regulating member 16 provided substantially at the center of a coil-shaped spring shaft 13 rotatably provided. It is provided rotatably so that movement is regulated. The holding mechanism 14 has a space portion for holding a spring shaft 13 described later, and is provided with a holding body 17 formed in a frame structure having a portion for regulating the movement of the regulating member 16. .

FIG. 1A is a plan view of the spur roller 12-2 viewed from the direction in which the spur roller 12-2 is attached and detached.
FIG. 6B is a plan view seen from the lid 15 shown in FIG. 5.

The holder 17 has, for example, a housing structure, and the side on which the spur roller 12-2 is mounted is shown in FIG.
For example, as shown in FIG.
As shown in FIG. 5, the bottom is, for example, a necessary portion is appropriately cut away, and a holding portion for holding the spring shaft 13 is provided inside the housing. Therefore, the center part of the surface and the bottom surface of the holding body 17, especially the spring shaft 13
A cut-out portion 18 for restricting the movement of the regulating member 16, particularly the movement in the axial direction, is formed in a portion corresponding to the regulating member 16 provided at the center of the notch. The restricting member 16 is inserted into the notch 18 and the restricting member 1
6 is restricted from moving in the axial direction, thereby enabling movement toward the drive roller 12-1. Thereby, the spur roller 1
In 2-2, the movement in the axial direction is restricted by the elastic action of the spring shaft 13, and the movement in the direction orthogonal to the shaft 13 can be freely performed.

First, in FIG. 1 (a), the notch for inserting or detaching the spring shaft 13 is provided on the surface facing the bottom surface of the holder 7, that is, the surface on which the spur roller 12-2 is attached and detached. An insertion port 19 is formed so as to be orthogonal to 18 and communicated therewith. The length of the insertion port 19, that is, the length in the longitudinal direction is substantially the same as the length in the axial direction of the spring shaft 13, and the opening width on the side orthogonal to the length is determined by the shaft diameter (diameter) of the spring shaft 13. Are formed long enough.

After the spring shaft 13 is mounted through the insertion port 19, a plurality of holding claws 20 for preventing the spring shaft 13 from dropping are provided so as to project toward the insertion port 19. The holding claw 20 is provided so as to protrude so as to cover a part of an upper portion thereof in a state where the spring shaft 13 is held, and is particularly provided so as to face up and down with the insertion opening 19 interposed therebetween. In the figure, upper holding claws 20a and 20c cover a part on the spring shaft 13 in the lower direction with the insertion opening 19 interposed therebetween, and the lower holding claws 2
Ob protrudes upward and is provided so as to cover a part on the spring shaft 13. Also, the holding claw 20c
Are provided corresponding to both ends of the spring shaft 13. The upper and lower holding claws 20a, 20b
As shown in (a), the protruding portions are provided at positions shifted from each other.

Since the upper and lower holding claws 20a and 20b are provided at positions deviated from each other, the insertion opening 19 has a distance on the plane between the protruding tips smaller than the shaft diameter of the spring shaft 13. However, the actual spacing can be larger than the shaft diameter.

The back surface opposite to the front surface of the holder 17, that is, the surface (bottom surface) on the side of the lid 15, as shown in FIG. 1B, supports 21 for supporting the spring shaft 13 on the bottom surface.
Are provided substantially corresponding to both ends of the spring shaft 13. Further, on the bottom surface, supporting portions 22 for preventing the spring shaft 13 from falling off are further provided on both sides of the central cutout portion 18 and corresponding to the holding claws 20b on the surface. The holder 7 has a lid 15 having the bottom surface described above.
Attached and fixed.

On the other hand, with respect to the structure for holding the spring shaft 13 in the holding body 17, AA shown in FIG.
FIG. 2A is a cross-sectional view taken along line BB, line CC.
The structure of the holding function will be described in detail with reference to FIGS.

The holding mechanism 14 has a holding portion in the holding body 17 for holding the spring shaft 13. The holding portion is provided with an insertion port 19 formed on the surface of the holding body 17.
It is provided so that it may communicate with.

First, in FIG. 2 (c), at the portions corresponding to the holding claws 20c at both ends of the holding body 17, the holding members 2 are provided to facilitate the insertion of the spring shaft 13 and the like.
3 are provided so as to face the holding claws 20c. The holding member 23 is formed with an inclined surface such that the upper side of the insertion opening 19 is inclined downward and guided to the holding portion. That is, the end of the spring shaft 13 is
At the time of further insertion, it is inclined downward to facilitate the insertion.

In correspondence with the holding member 23,
An opposing member 24 is provided. The holding member 23, the opposing member 24, and the support 21, which is the bottom surface of the holder, constitute a holding portion for the spring 13 shaft. The distance between the holding member 23 and the facing member 24 provided opposite each other in the holding body 17 is substantially equal to or slightly larger than the diameter of the spring shaft 13. The movement of the spring shaft 13 in the left-right direction is regulated and held.

The inclined surface of the holding member 23 is formed such that the shortest distance between the inclined surface on the upper surface of the holding member 23 and the tip P of the holding claw 20c is slightly longer than the shaft diameter (diameter) of the spring shaft 13. Have been. Thereby, the spring shaft 1
3 can be inserted into the insertion opening 19 of the holding body 19 facing the holding member 23, and can be inserted between the holding member 23 as the holding section and the facing member 24 by sliding on the inclined surface.

Next, as shown in FIG. 2B, the spring shaft 13 can be inserted from the insertion port 19 in the same posture, and is held by the holding portions of the holding member 23 and the regulating member 24. In other words, the insertion port 19 at the intermediate portion between the spur roller 12-2, which is the driven roller, and both ends is sufficiently larger than the shaft diameter of the spring shaft 13, so that the insertion port 19 can be easily provided between the holding member 23 and the opposing member 24. It can be inserted. The holding member 23 at this position may have an upper surface formed as an inclined surface or a planar shape as shown in the drawing.

In the portion shown in FIG. 2A, the holding member 23 and the opposing member 24 are not provided in the holding body 17, and the spring shaft 13 can move freely. The movement of both ends is restricted by the holding portion, and the movement to the drive roller 12-1 side is enabled.
Further, the movement of the inserted spring shaft 13 is regulated by the holding claws 20a and 20b facing each other, and the falling off at the insertion position is regulated.

In the above configuration, the spur roller 12-2
An operation procedure for holding the spring shaft 13, which rotatably supports the above, on the holding body 17 will be described below.

First, the lid 15 on which the holding body 17 constituting the holding mechanism 14 shown in FIG.
-2 is rotated away from the drive roller 12-1,
As shown in FIG. 1A, the insertion opening 19 formed in the holder 17 is opened.

In this state, both ends of the spring shaft 13 are positioned on the holding member 23 from the insertion openings 19 facing the holding claws 20c, respectively, and guided into the inclined surface to be inserted into the holding portion. Then, the space between the spur roller 12-2 and the end is directly inserted into the holding portion from the insertion port 19.

In the holding claw 20a, the elasticity of the spring shaft 13 is used to bend downward in FIG. 1 to a position outside the tip of the holding claw 20a. In this state, the spring shaft 13 is
Into the bottom of Next, in FIG. 1A, the spur roller 12-2 is largely bent upward by using the elasticity of the spring shaft 13 to a position where the spring shaft 13 is disengaged from the tip of the lower holding claw 20b. By pressing the spring shaft 13 to the holding claw 20b.
Press into the bottom of Thereby, the holding operation of the spur roller 12-2 including the spring shaft 13 is completed.

Here, the spur roller 12-2 is restricted by the restricting member 16 in the range of the notch portion 18 so as to be able to move in the direction of the drive roller 12-1 and to move in the other direction of the spring shaft 13. Movement is regulated. Further, the spring shaft 13 can be moved between the holding portion to the rear side and the front side in FIG. 1, and the movement in the axial direction and the vertical direction is restricted. In particular, in the spur roller 12-2, the vertical direction in FIG. And it can bend elastically to the back and the front side.

Therefore, with the holding completed, the lid 15
Is closed, the spur roller 12-2 becomes the drive roller 12-
1 is press-contacted according to the elastic force of the spring shaft 13. That is, as shown in FIG.
The spur roller 12 is regulated by the support portion 21 of the holder 17.
-2 is pressed against the drive roller 12-1 with an urging force corresponding to the amount of deflection of the spring shaft 13.

On the other hand, when the spur roller 12-2 needs to be replaced, the spur roller 12-2 is separated from the drive roller 12-1 by opening the lid 15. This state is as shown in FIG. 1A as described above, and the spring shaft 13 is attached to the holder 1 from the insertion port 19 surface.
Remove from 7. For this reason, the spur roller 12-2 is pinched and pulled upward in the figure, and
3 is bent to a position disengaged from the lower holding claw 20b, and pulled toward the near side, thereby removing the spring shaft 13 from the lower holding claw 20b. That is, the spring shaft 13 on the lower surface of the holding claw 20b is pulled out onto the holding claw 20b.

Then, by pulling the spring shaft 13 downward while holding the spur roller 12-2 and the like, the spring shaft 13 is disengaged from the upper holding claw 20a, and the spring shaft 13 at both ends is pulled. 13 comes off the holding portion, and the whole can be easily removed.

As described above, the spur roller 12-2 rotatably provided on the spring shaft 13 is
Can be easily removed from the holding portion and attached to the holding portion from one side. Therefore, the holding mechanism 14
As described with reference to FIG. 8, it is not necessary to perform attachment and detachment in a state in which one side such as the upper and lower sides and the front side is opened, so that the workability is greatly improved and the spur roller 12
The position where the driven roller such as -2 is provided is not limited. In particular, according to the present invention, as long as at least one surface is open, the registration roller 8 and the sheet feeding roller 6 shown in FIG. In the following driven roller, it can be easily applied to a driven roller that is configured to be separated from the driving roller.

This is because, as shown in FIG. 1, the portion of the insertion slot 19 only needs to be opened, and the attachment and detachment from the insertion slot 19 becomes possible. In addition, since the attachment / detachment operation can be performed only from one surface side, a large space is not required, and it is necessary to protrude the spring shaft 13 or the like for the attachment / detachment operation to the opposite side, or to turn the hand or the like of the user. And workability is improved.

Further, after the mounting, each protruding end of the holding claws 20a and 20b for preventing the spring shaft 13 from being detached is inserted into the insertion slot 1
It is provided at a position deviated from each other with respect to 9 and is not at a position facing each other. Therefore, the operation of inserting and removing the spring shaft 13 is facilitated, and the attaching / detaching operation from one side is enabled. In addition, after attachment, the function of preventing detachment can be reliably exhibited.

(Second Embodiment of the Present Invention)
According to the embodiment, the spur roller 12 which is a driven roller
-2 can be attached and detached from one open surface side. Therefore, it is not necessary to secure a large work space.For example, without being limited to only the position of the discharge roller, even inside a sheet conveying device such as an image forming apparatus, if it can be separated and opened from the drive roller, and if one surface can be opened, It is possible to perform the attaching and detaching work.

The configuration of an embodiment different from the first embodiment, in which the operation of attaching and detaching the driven roller 12-2 can be easily performed, will be described below with reference to FIGS.

First, FIG. 6 shows that a holding member 17 constituting a holding mechanism 14 for holding a spring shaft 13 of a spur roller 12-2, which is a driven roller, has a groove having an L-shaped cross section at both ends of the spring shaft 13. 25, and one opening of the groove 25 is used as the insertion port 19. This holder 17 is
Portions corresponding to both ends of the spring shaft 13 are formed in a shape as shown in FIG.
As shown in FIG. 1, the central region is regulated via a regulating member 16 and the like.

The L-shaped groove 25 is provided in the spur roller 12
The insertion port 19 is provided so as to oppose the surface on which the " -2 " is attached and detached, and a space part which is communicated with the insertion port 19 and bent in the middle is configured as a holding portion 26 of the spring shaft 13. The insertion port 19 and the holding portion 25 are formed to have a diameter substantially equal to or slightly larger than the diameter of the spring shaft 13. Therefore, the driving roller 12-1 and the spur roller 12
-2 is separated, and the portion of the insertion port 19 is opened. In this case, in the holding mechanism of the spur roller 12-2, when the spur roller 12-2 is attached to a lid or the like, the lid is rotated. The pivot point is the right side in FIG. Then, by rotating clockwise, the insertion port 19 is at the upper position and the holder 26 is at the lower position. Thereby, the spur roller 12-2, particularly the spring shaft 13, can be easily attached and detached through the insertion port 19. That is, the spring shaft 13 can be easily attached or detached through the insertion port 19.

The holder 17 holds the spring shaft 13 by the holding portion 26. The holding state is such that a straight line connecting the axis of the drive roller 12-1 and the axis of the spring shaft 13 is a sheet. The position of the side wall 26a with which the spring shaft 13 of the holding portion 26 abuts is determined so as to intersect at a substantially right angle with respect to the transport direction of S. Therefore, the driving roller 12
When -1 is driven to rotate in the direction of conveying the sheet S, the spur roller 12-2 is driven to rotate. At this time, the spring shaft 13 attempts to move in the sheet conveying direction due to the rotational moment of the spur roller 12-2 or the like. However, the spring shaft 13 contacts the side wall 26a of the holding portion 26, and further movement is restricted.
In addition, the spur roller 12-2 is connected to the holding portion 2 of the holding body 17.
6, the upper wall 26b is restricted from moving upward, is pressed against the drive roller 12-1 with an appropriate pressure, and is driven to rotate, so that the sheet S can be conveyed favorably.

As described above, by arranging the side wall 26a of the holding portion 26 of the holding body 17 so as to be on the side of the sheet S in the conveyance direction, the pressure contact state is maintained when the driven roller 12-1 is driven to rotate. And the insertion port 19 located on the opposite side to the side wall 26a.
Can be prevented from falling off.

However, considering the case where the holding mechanism is left as it is in FIG. 6 and the sheet conveying direction is reversed, the spur roller 12-2 which is driven and rotated is rotated clockwise. Therefore, the spring shaft 13 tends to move in the sheet conveying direction. Because of this, there is no way to restrict the movement of the spring shaft 13, and it is conceivable that the spring shaft 13 falls off from the insertion port 19.

Therefore, it is preferable that the holding member 17 is provided with the L-shaped groove 25 so that the side wall 26a of the holding portion 26 is located on the sheet conveying direction side. Moreover, groove 2
In the case where the insertion port 19 is separated from the driving roller 12-1, the insertion port 19 may be located on the separated open space side.

Even in such a configuration, if a space on the side facing the insertion port 19 can be secured in the work of attaching and detaching the spring shaft 13 and the like, the work can be easily performed, and the position of the installation is limited. You will not receive it.

According to the holder 17 having the structure shown in FIG. 6, when the holding mechanism is separated from the drive roller 12-1, it is necessary to rotate the holder clockwise. If the rotation is reversed, the insertion port 19 will be at a lower value and the holding portion 26 will be at the upper position, so that the spring shaft 13 cannot be mounted and may fall by its own weight at the time of separation. In order to solve such a problem, as shown in FIG. 7, a retaining portion 26 formed by the groove 25 is provided with a separating portion, for example, a projection 27 for preventing falling off is provided near a bent portion. That is, the groove 25 is not substantially L-shaped but J-shaped. Therefore, if the spring shaft 13 inserted from the insertion port 19 is mounted on the holding portion 26 so as to get over the projecting portion 27, the projecting portion 27 fulfills the function of preventing falling off.

As a result, the position of the fulcrum for rotating the holding mechanism for separating the spur roller 12-2 from the driving roller 12-1 is not restricted, and the rotation fulcrum is provided on the left side in FIG. The spring shaft 13 can be prevented from falling off even if it is rotated clockwise so that the insertion port 19 is at the lower position. This gives you more design freedom.

In the above configuration, the spur roller 1
When 2-2 is driven and rotated, the side wall 26 of the holding portion 26 is always
The sheet is conveyed by being pressed by the drive roller 12-1 with an appropriate pressure. At this time, since the axis of the spring shaft 13 and the axis of the drive roller 12-1 are always positioned in a fixed state on the side wall 26a, the sheet S may be damaged, damaged, jammed, or the like. Eliminates and enables good transport.

In the first and second embodiments of the present invention, the spur roller 12-2 in the discharge roller 12 is used.
Was explained. However, in the driven roller separated from the driving roller as described above, if a space for opening one operation surface side for attaching and detaching can be secured, the attaching and detaching operation can be performed only from that surface side. For this reason, the present invention can be applied to any sheet conveying device in the apparatus, not in the vicinity of the sheet discharge section of the apparatus, but which can be separated from the drive roller and can secure a space where one surface can be operated.

Further, the sheet conveying apparatus is not limited to the one which feeds a sheet to the image forming section and conveys a sheet after recording as described above, but also a sheet conveying apparatus for conveying a sheet-shaped original, that is, a sheet original conveying apparatus. Of course, it can be applied to the apparatus as it is.

[0080]

In the sheet conveying apparatus of the present invention described above, the driven roller provided with the spring shaft can be easily attached and detached from the insertion port side in a state where the driven roller can be separated and opened from the driving roller.

Therefore, it is not necessary to secure a large open space when the driven roller is separated from the driving roller, so that the position of the conveying roller is not limited, and the driven roller and the driven roller can be used. It can be applied to everything that needs to be attached and detached.

Further, a sheet transporting apparatus which can be achieved with a simple configuration without requiring a special configuration for mounting and dismounting, and which can satisfactorily transport a sheet can be provided.

[Brief description of the drawings]

1A and 1B show an embodiment of a holding mechanism of a driven roller constituting a sheet conveying apparatus according to the present invention, wherein FIG. 1A is a plan view viewed from a surface on which a driven roller is attached and detached,
(B) It is the top view seen from the opposite surface side.

FIG. 2 is a cross-sectional view of each of the holding mechanisms along line AA, line BB, and line CC shown in FIG.

FIG. 3 is a perspective view illustrating an appearance of an image forming apparatus including the sheet conveying device according to the present invention.

4 is a configuration diagram showing a specific example of the internal structure of the image forming apparatus shown in FIG. 3 including a sheet conveying device.

FIG. 5 is a front view illustrating a sheet conveyance state by the sheet conveyance device according to the present invention.

FIG. 6 is a cross-sectional view for explaining a second embodiment of a holding mechanism of a driven roller constituting the sheet conveying apparatus of the present invention.

FIG. 7 is a cross-sectional view showing another aspect of the second embodiment of the holding mechanism of the driven roller constituting the sheet conveying apparatus of the present invention.

FIG. 8 is a perspective view showing an example of a conventional driven roller holding mechanism.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 image forming apparatus 2 paper feed tray 4 discharge tray 5 pickup roller 6 paper feed roller 7 reverse transport path 8 transport roller 12 discharge roller 12-1 drive roller 12-2 driven roller (spur roller) 13 spring shaft 14 holding mechanism 15 times Movable lid 16 Control member 17 Holder 18 Notch portion for control 19 Insertion opening 20 Holding claw 21 Support member 23 Holding member 24 Opposing member 25 Holding groove 26 Holding portion 27 Projecting portion

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Matsushita 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 2C059 CC03 CC24 3F049 AA01 CA02 CA21 DA12 LA07 LB01

Claims (5)

[Claims] 1. A sheet conveying device comprising a driven roller pressed against a driving roller to convey a sheet, wherein a rotating shaft of the driven roller has a coil-shaped spring shaft structure, and the spring shaft is A holding mechanism for holding and pressing the driven roller against the driving roller, the holding mechanism including an insertion port on one surface side into which the spring shaft can be inserted, and a spring shaft communicated with the insertion port. Is provided, which covers a part of the insertion port,
A seat provided with a plurality of holding claws for preventing the spring shaft of the holding portion from falling off, wherein the holding claws opposed to each other across the insertion opening are provided at positions shifted from each other without facing each other; Transport device. 2. The insertion port side of a holding member provided corresponding to the insertion port and constituting a holding portion for holding a spring shaft is formed in an inclined surface shape so as to guide the holding member to the holding portion. The sheet conveying device according to claim 1, wherein: 3. A holding claw is provided on a side facing the holding member having the inclined surface, and a shortest distance between the holding claw and the inclined surface is equal to or slightly larger than a spring shaft. 3. The sheet conveying device according to claim 2, wherein the inclined surface is formed. 4. A sheet conveying apparatus comprising a driven roller pressed against a driving roller for conveying a sheet, wherein the rotating shaft of the driven roller has a coil-shaped spring shaft structure, and the spring shaft is A holding mechanism for holding and pressing the driven roller against the driving roller is provided. The holding mechanism includes an insertion port on one surface side into which the spring shaft can be inserted, and communicates with the insertion port. The groove is bent in the middle, and the bent portion is configured as a holding portion of a spring shaft. One side wall of the holding portion is rotated by the driving roller. The direction in which the spring shaft of the driven roller is moved. A sheet conveying device, wherein the sheet conveying device is arranged so as to regulate the sheet feeding. 5. The sheet conveying device according to claim 4, wherein a protrusion for preventing the spring shaft from falling off is provided near a bending position in the middle of the groove communicating with the insertion port.