JPH07267417A - Pressing force setting device for paper feeding device - Google Patents

Abstract

PURPOSE:To set the delivering action of a pickup roller and the separating performance of a paper separating device in response to the feature of a paper sheet in a paper feeding device arranged on the paper feed section of an image forming device. CONSTITUTION:This pressing force setting device is provided with a pickup roller arranged at the paper feed position of a paper feeding tray fitted to a paper feeding device 20 and a spring 8 exciting downward a retard roller constituting a paper separating device 25. The spring 8 is supported on a support bar member 6 vertically movable against the leg member 4 of a support base 3 arranged below a paper feed section, and the pressing force by the spring 8 is changed when the support bar member 6 is vertically moved. An operation arm member is arranged on the front side of the paper feeding tray, the support bar member 6 is lowered when the paper feeding tray is fitted, and the performance of the paper feeding device can be automatically set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device arranged in a sheet feeding portion of an image forming apparatus such as an electrophotographic copying machine, and more particularly,
The present invention relates to a pressing force setting device for a sheet feeding device, which is provided with means for controlling the force for pressing the pickup roller against the sheet and the nip pressure in the sheet separating device so that the sheet feeding performance matched with the characteristics of the sheet can be exhibited.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine or a printer, a paper accommodating device such as a plurality of paper feeding trays is arranged in a paper feeding section, and paper is fed to the paper feeding trays. The respective devices are arranged to configure a mechanism for feeding the paper from the paper feed tray. As a sheet feeding device arranged corresponding to the sheet feeding tray, for example, a device as disclosed in JP-A-2-231324 is known. In the paper feeding device of the conventional example, a pickup roller arranged corresponding to the leading end of the paper feeding side of the paper feeding tray and a paper separating device arranged at a predetermined interval downstream of the pickup roller are combined. I am configuring. Then, the sheet carried out from the paper feed tray by the pickup roller is subjected to a sorting action in the sheet sorting apparatus, and is sent out toward the sheet transport path arranged at the downstream portion thereof.

In the conventional sheet feeding device, the action of pressing the pickup roller against the sheet is set by its own weight including the supporting member of the pickup roller, and the sheet is loaded by the weight of the pickup roller. By pressing and rotating the pickup roller, the performance of feeding the paper is set. In the paper separating device arranged downstream of the pickup roller, a feed roller arranged on a fixed shaft and driven in a paper feeding direction,
It is configured by combining retard rollers that are driven in the opposite direction to the paper feeding direction. Then, when two sheets of paper enter the nip portion of the sheet separating device, the upper sheet is sent out toward the sheet conveying path, and the lower sheet is returned to the tray side. Further, between the retard roller and the feed roller, a mechanism for pressing the retard roller shaft against the feed roller shaft is provided so that a nip pressure of a predetermined value is set.

In the paper feeding device as described above, for example, as disclosed in Japanese Patent Laid-Open No. 3-98923,
With the paper feed tray attached to the paper feed unit of the image forming device,
BACKGROUND ART Roller members in a sheet feeding device are set so as to be capable of delivering a sheet and treating a sheet.
And by pulling out the paper feed tray from the paper feed section,
The pressing posture with respect to the roller member is released to prevent the pickup roller from interfering with the attachment / detachment of the paper feed tray. Further, it is possible to prevent the inconvenience such as the deformation of the roller member due to the constant pressing of the feed roller and the retard roller in the state where the paper feeding operation is not performed.

[0005]

However, when the conventional paper feeding device as described above is used and the properties of the papers stored in the paper feeding trays are different, when the pressing force by the pickup roller is constant, the paper is fed. There arises a problem that the paper movement cannot be performed accurately. For example, if the paper feed performance by the pickup roller is set to correspond to plain paper used for general copying, it may not be possible to exhibit sufficient feed performance for thick paper, and paper feed failure may occur. Is concerned. In the case of very thin paper such as tracing paper, the pickup roller slides strongly, which causes problems such as excessive rubbing of the paper. In addition to the problem of the pickup roller, the nip pressure between the two rollers is set to a constant value when the retard roller forming the sheet separating device is pressed against the feed roller to perform the separating operation on the sheet. However, depending on the thickness of the paper and the like, there is a problem that the separating action cannot be performed in a good state.

Therefore, in order to solve the above-mentioned problems, for example, as shown in Japanese Utility Model Laid-Open No. 2-75430, a means for adjusting the height of pressing the paper against the pickup roller is used. It may be possible to adjust the paper feeding performance by the pickup roller. In the above conventional example, with respect to the plate member that supports the paper inside the paper feed tray, a means for adjusting the rising position in a plurality of stages is configured,
A height corresponding to the properties of the sheets to be accommodated can be set through an adjusting member arranged outside the sheet feeding section. Therefore, when the mechanism for adjusting the height of the sheet as described above is used, the force for pressing the pickup roller against the sheet can be controlled, so that the sheet feeding performance corresponding to the sheet quality and the like can be exhibited. It will be possible. In addition to the conventional example, in the example disclosed in Japanese Patent Laid-Open No. 56-151950, the mechanism for pressing the paper against the pickup roller is configured by combining a spring and an adjusting screw member, and the property of the paper is obtained. In this configuration, the force in the upward direction of the paper by the spring is adjusted so that the optimum pressure can be set.

However, in the above-described conventional paper feeding apparatus, it is considered to adjust the pressure between the paper and the feed roller with respect to the paper stored in the paper feeding tray or the like. Nothing is taken into consideration regarding the nip pressure in the separating device. However, in order to make the paper feeding performance of the paper feeding device satisfactorily exhibited, it is necessary to satisfy the two conditions of the feeding performance by the pickup roller and the sorting performance in the paper sorting device. As the performance of the sheet conveying apparatus in the forming apparatus is improved, it is the current situation that it is desired to use a sheet feeding apparatus having better sheet feeding performance.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional paper feeding device, and is to press the pickup roller against the paper feeding device arranged in the paper feeding portion of the image forming apparatus. The purpose of the present invention is to provide a device for adjusting the nip pressure in the paper separating device.
By providing a means for controlling the pressure of the pickup roller and the retard roller, when the paper feed tray is attached to the paper feed section, the performance of the paper feed device is improved according to the conditions set for the paper feed tray. The purpose is to provide a configurable device.

[0009]

According to the present invention, there is provided a pickup roller arranged at a sheet feeding position in correspondence with a sheet feeding tray mounted in a sheet feeding section of an image forming apparatus, and a pickup roller disposed downstream of the pickup roller. The present invention relates to a paper feeding device configured by a paper separating device. In the present invention, means for changing the pressing force is arranged with respect to the pickup roller and the retard roller of the paper separating device, and the means for changing the pressing force with respect to the roller member is operated by an operating member provided in the paper feed tray. The mechanism that enables the above is configured. Further, in the present invention, the means for changing the pressing force applied to the pickup roller and the retard roller of the paper feeding device is such that a vertically movable support bar member is arranged with respect to the supporting means arranged at the lower part of the paper feed tray mounting portion. Then, a spring member is arranged between the pick-up roller and the retard roller with respect to the support bar member, and the paper feed tray is attached to the paper feed unit of the image forming apparatus to operate the paper feed tray. A member may be configured to control the up and down movement of the support bar member. Further, in the present invention, the operating arm member is swingably provided to the bracket provided so as to project at the front end portion in the mounting direction of the paper feed tray, and means for setting the inclination angle of the operating arm member is provided. By mounting the paper feed tray in the paper feed unit of the image forming apparatus, the operation member of the paper feed tray may be configured to control the vertical movement operation with respect to the support bar member.

[0010]

As described above, in the present invention, the operating member for controlling the pressing force of the pickup roller and the retard roller is arranged for the paper feed tray, and the properties of the paper stored in the paper feed tray are set. Therefore, the actuating member is adjusted. In addition, in the paper feeding unit of the image forming apparatus,
Corresponding to the position of the operating member provided in the paper feed tray,
An actuated member such as a support bar member is arranged, and an urging member such as a spring is provided between the pickup bar of the sheet feeding device and a bracket member provided on the retard roller of the support bar member. Keep it. Then, by mounting the paper feed tray in the paper feed section, the operating member provided on the tray acts to push down the support bar member, and the two members of the pickup roller and the retard roller are respectively connected via the springs. To be able to exert the action of applying a predetermined pressing force. Therefore, in the apparatus of the present invention, by adjusting the operation arm member of the tray according to the property of the paper stored in the paper feed tray, the paper feeding action and the sorting action corresponding to the paper are automatically set. Will be possible.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A pressing force setting device for a sheet feeding device according to the present invention will be described with reference to the illustrated example. The example shown in FIG.
The case where the paper feed tray 10 is attached to the paper feed unit of the image forming apparatus and the paper is fed out by the paper feed device 20 is shown. The paper feed tray 10 is provided at a position corresponding to the front portion of the paper feed side of the paper feed tray 10. The pickup roller 21 is arranged, and the paper is fed in the paper feeding direction by pressing it on the paper P and rotating it. Then, the paper sent out from the paper feed tray passes through the feed roller 26 and the retard roller 30 which constitute the paper separating device 25, and is carried toward the downstream portion by the carrying roller device 35 arranged in the paper carrying path. The feed roller 26 arranged in the paper separating device 25 is supported by a shaft arranged at a fixed position and is rotated in a paper feeding direction. The shaft for driving the retard roller 30 has a rotation control like a torque limiter. A means is provided, and the roller is rotated in the opposite direction to the sheet conveying direction to return the sheet to the tray side.

As shown in FIG. 2, the sheet feeding device as described above is provided with means for pressing the pickup roller 21 against the paper and means for pressing the retard roller 30 against the feed roller 26. ing. In the paper feeding device 20 of the present invention, the link 24 supporting the pickup roller 21 is swingably attached to the support shaft 27 of the feed roller 26 constituting the paper separating device 25, and is attached to the shaft 22 of the pickup roller 21. And a bracket 23 is provided below. And the bracket 2
3 and the support bar member 6 arranged at the lower part between the spring 7
And a mechanism for pressing the pickup roller toward the paper by the spring 7 is configured. As will be described later, the support bar member 6 is provided so as to be vertically movable along a long hole provided in the leg member of the support base 3, and by vertically moving and positioning the support bar member 6,
The means for changing the pressing force of the pickup roller by the spring can be adjusted.

Further, a retard roller 30 arranged to face the feed roller 26 of the sheet separating device 25.
Is a support shaft 33 with respect to the main body frame 1 of the image forming apparatus.
It is provided on a support frame 32 that is swingable via a bracket, and a bracket 34 is provided at the rear of the support frame 32.
Is installed. Then, the spring 8 is arranged between the bracket 34 and the support bar member 6 arranged in the lower part,
The retard roller 30 is supported by the spring 8 as a support shaft 33.
The nip pressure in the paper sorting device can be set via the. A support bar member 6 for setting a pressing force on the retard roller 30 and the pickup roller 21 of the sheet separating device by using two springs.
Is provided so as to be movable in the vertical direction with respect to the leg members 4 and 4a of the support base 3, and is pushed down by the operation arm members 15 and 16 provided in the paper feed tray to be pressed by the spring, as described later. You can set.

The support bar member 6 for swinging the two roller members and the operating member provided on the paper feed tray are constructed as shown in FIGS. In the support base 3 that supports the support bar member 6, the support bar member 6 is provided so as to be movable up and down by the diagonal elongated holes 5 provided in the leg members 4 and 4a. The springs 7 and 8 are connected to the section. Then, the support bar member 6 is swung by the operation arm members 15 and 16 provided on the paper feed tray, so that the pressing force to the pickup roller and the retard roller can be adjusted via the spring. Further, in the example shown in FIG. 3, the sheet separating device of the sheet feeding device is viewed from the front side in the sheet feeding direction, and the sheet feeding tray is provided along the tray guide surface provided on the body frame. 10 is moved in the direction of the arrow X to be mounted on the sheet feeding section of the image forming apparatus, and the operation arm member 15 is engaged with the support bar member 6 at the final part of the operation for mounting the tray. . Further, the example shown in FIG. 4 is shown as an explanatory view of a state of the apparatus of the present invention when viewed from the top, and the relationship between the pickup roller 21 and the retard roller 30 of the sheet feeding apparatus and the operation arm provided on the sheet feeding tray. The relationship between the members 15 and 16 is shown.

In the paper feed tray 10 of the present invention, the front bracket 11 is provided so as to project at the tip end in the mounting direction, and the operating arm members 15 and 16 are provided to the front bracket 11 via the support shaft 17. It is swingable. And
As shown in FIG. 3, when the actuating arm member is swung via the support shaft and is pushed into the support base 3 to a position,
The operating arm member 15 engages with the support bar member 6,
The support bar member 6 is pushed down by the operating arm member. In the support bar member 6, springs 7 and 8 are connected to both ends of the support bar member 6. When the support bar member is lowered in a parallel state, the pressing force against the two roller members is increased. can do.
Further, when the operation of pushing down only one of the support bar members is performed, the pushing force can be increased against either the pickup roller or the retard roller.

As described above, as a means for changing the pressing force provided in the paper feeding device of the present invention, when a mechanism for pressing two roller members via springs is arranged at both ends of the support bar member, the feeding is performed. The actuating arm member provided on the paper tray 10 may be configured as shown in FIG.
In the example shown in FIG. 5, the support bracket 17 is attached to the front bracket 11 that is provided so as to project at the tip of the paper feed tray 10.
The holes 12, 12a are arranged in an arc shape corresponding to the above, and when the paper is loaded in the paper feed tray, the inclination angle of the operating arm member is set according to the conditions such as the nature of the paper. By mounting the tray in the paper feeding unit, the conditions for paper transportation in the paper feeding device can be automatically set. When the operation arm member is to be positioned, the stop pin 18 is inserted with the hole provided in the front bracket of the paper feed tray being overlapped with the hole provided in the operation arm member 15 to operate. Arm member 15,
By fixing 16 respectively, the inclination angle of the operating arm member can be set arbitrarily. Further, in the positioning mechanism for the operating arm member shown in FIG. 5,
When the operating arm member is fixed in the upright position,
The support bar member does not act, and the operating arm member does not engage with the support bar member. On the other hand, if the tilt angle of the actuating arm member is tilted to a state close to horizontal, the supporting bar member is greatly lowered, so that the force of pulling the spring acts largely and the force of pressing the roller member is strengthened. can do.

Therefore, as described above, the inclination angle of the operating arm member that projects toward the front side of the paper feed tray is
By setting the operating arm members independently, it is possible to add the action of lowering the support bar member in a horizontal state and the action of lowering one of the support bar members. Then, in the paper feeding device of the present invention, the strength with which the pickup roller is pressed against the paper and the nip pressure in the paper separating device are set in accordance with the nature of the paper, and the paper is fed from the paper feeding tray. Can be performed in a good condition in accordance with the characteristics of the paper. As described above, in the sheet feeding device of the present invention, the force for pressing the pickup roller against the sheet and the force for pressing the retard roller against the feed roller are adjusted separately, and the force from the sheet feeding tray is adjusted. When the paper is sent out, it is possible to exhibit the paper feeding performance corresponding to the properties of the paper.

Then, a spring is arranged between the two roller members and both ends of the support bar member so as to lower the support bar member in parallel and to lower one of the support bar members. Can be appropriately performed depending on the nature of the above. Therefore, by providing a means for changing the pressing force with respect to the two roller members forming the paper feeding device, the paper feeding action of an appropriate value can be made to correspond to the paper stored in the paper feeding tray. It is possible to add a judgment action. By configuring as described above,
In the present invention, for plain paper that can be fed relatively easily, the feeding operation can be performed without changing the pressing force of the pickup roller and the retard roller.
On the other hand, in the case of a paper such as tracing paper which has a high adhesion between the papers, the pressing force of the pickup roller is increased, but the pressing force of the retard roller is not changed. Further, it is possible to set a large pressing force of each roller for thick paper or the like. Then, as described above, it is possible to improve the paper feeding performance from the paper feeding tray by setting the pressing force of the roller member according to the characteristics of the paper.

In the pressing force setting device for the sheet feeding device of the present invention constructed as described above, the means for changing the pressing force arranged on the pickup roller and the retard roller is provided at both ends of one supporting bar member. In addition to constituting the means for attaching the spring to the portion, it is possible to construct the means for arranging the support bar members independently of the leg members arranged on the support base. The actuating arm member provided on the paper feed tray acts on the two support bar members to vertically move each of the support bar members independently to control the pulling force of the spring. . Further, in the apparatus of the present invention, the means for setting the inclination angle can be arbitrarily configured with respect to the operation arm member provided on the paper feed tray. Further, it is possible to configure two kinds of adjusting means at a position where the actuating arm member is tilted and a position where the actuating arm member is not in contact with the supporting bar member, and the setting of operating conditions for these supporting bar members is often done in the image forming apparatus. It can be appropriately set according to the type of paper used.

[0020]

Since the paper feeding apparatus of the present invention is constructed as described above, an operating member for controlling the pressing force of the pickup roller and the retard roller is arranged on the paper feeding tray. Since the operating member can be adjusted according to the properties of the paper stored in the paper feed tray, the paper feeding action can be favorably performed on any type of paper. Further, an operated member such as a support bar member is arranged in the sheet feeding unit of the image forming apparatus in correspondence with the position of the operating member provided on the sheet feeding tray.
By providing an urging member such as a spring between the pickup bar of the sheet feeding device and the bracket member provided on the retard roller for the support bar member,
The means for changing the pressing force can be easily configured. Then, by mounting the sheet feeding tray provided with the operating member in the sheet feeding section, the operating member provided on the tray acts to push down the support bar member, and two members of the pickup roller and the retard roller are connected via the spring. With respect to each, it is possible to exert the action of applying a predetermined pressing force. Therefore, in the apparatus of the present invention, by adjusting the operation arm member of the tray according to the property of the paper stored in the paper feed tray, the paper feeding action and the sorting action corresponding to the paper are automatically set. Will be possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship between a sheet feeding tray and a sheet feeding device according to the present invention.

FIG. 2 is an explanatory view of means for changing the pressing force arranged in the paper feeding device of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between an operation arm member provided on a sheet feeding tray and a unit that changes a pressing force of a sheet feeding device.

FIG. 4 is a plan view of the device of FIG.

FIG. 5 is an explanatory view of a fixing means of an operation arm member provided on a paper feed tray.

[Explanation of symbols]

1 body frame, 3 support base, 6 support bar member, 10 paper feed tray, 11 front bracket, 12 holes, 15 and 16 working arm member,
18 stop pins, 20 paper feeding device, 21 pickup roller, 23 bracket, 25 paper separating device, 26 feed roller, 30 retard roller, 32 support frame, 34 bracket.

Claims (3)

[Claims] 1. A pickup roller arranged at a paper feeding position corresponding to a paper feeding tray mounted in a paper feeding portion of an image forming apparatus, and a paper separating device arranged downstream of the pickup roller. In the paper feeding device, a means for changing the pressing force with respect to the pickup roller and the retard roller of the paper separating device is arranged, and the means for changing the pressing force with respect to the roller member is operated by an operating member provided in the paper feeding tray. A pressing force setting device for a sheet feeding device. 2. The means for changing the pressing force applied to the pickup roller and the retard roller of the sheet feeding device is such that a vertically movable supporting bar member is arranged with respect to a supporting means arranged at the lower part of the sheet feeding tray mounting portion. A spring member is arranged between the pick-up roller and the retard roller with respect to the support bar member, and the paper feed tray is attached to the paper feed unit of the image forming apparatus, so that the operation member of the paper feed tray is provided. 2. The pressing force setting device for the sheet feeding device according to claim 1, wherein the pressing force setting device is configured to control the vertical movement of the support bar member. 3. An operating arm member is provided so as to be swingable with respect to a bracket provided so as to project at a tip end portion in the mounting direction of the paper feed tray, and means for setting an inclination angle of the operating arm member is provided. 3. The mounting member for a sheet feeding tray of an image forming apparatus is configured so that an operating member of the sheet feeding tray controls a vertical movement operation with respect to the support bar member. The pressing force setting device for the paper feeding device according to [1].