JPH07257759A - Paper feed device - Google Patents

Abstract

PURPOSE:To provide a mechanism being also excellent in operating ability with the positioning of paper carried out surely in a paper feed device which can position the paper sheets of a paper feed cassette in a rack and pinion system. CONSTITUTION:The second pinion 9 attached coaxially with the first pinion 7 is connected to the first pinion 7 through an elastic member being deformable in the direction of rotation of the pinion, and the second rack 11 attached to a device body in attaching a paper feed cassette engages with the second pinion 9 for energizing a guide member 4 in a direction where it is pushed against paper sheets.

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 mounted on an image forming apparatus such as a copying machine, a facsimile or a laser printer.

[0002]

2. Description of the Related Art A paper feed cassette loaded in an image forming apparatus is provided with a member for positioning the edges of the paper in accordance with the size of the paper to be loaded.

It is necessary to prepare various kinds of paper feed cassettes according to all paper sizes to be used.
Since there are many paper feed cassettes that are not used, not only the cost problem but also the securement of the storage place is hindered. Therefore, in these days when efficient use of equipment is required, a member for locating the edge of the paper of the paper feed cassette is flexible so that it can accommodate paper other than the specific size paper such as B5 and A4. Many are configured to slide into.

However, such a movable guide member needs to remain at a predetermined position after the edge of the sheet is positioned. Therefore, conventionally, when fixing or releasing the fixation of the guide member, for example, a predetermined part of the guide member is pressed or released by operating a separate lever or the like.

There is also a structure in which a friction member or the like is used to increase the resistance to the sliding movement of the guide member to make it difficult to move, so that the guide member set at the edge portion of the paper is not easily displaced. .

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention For example, in FIG.
When stacking the sheet bundle 2 on the sheet feeding cassette 1, after the sheet bundle 2 is accommodated in the sheet feeding cassette 1, the side guide 4 that regulates the position of the sheet edge portion 3 parallel to the sheet conveying direction. Is slid in a direction perpendicular to the sheet conveying direction to fix the position of the sheet bundle 2. At this time, as shown in FIG. 8, the side guide 4 is slid by engagement of a rack 5 fixed to the guide and a pinion 7 rotatably attached to the cassette body.

In such engagement, as understood from the drawings, the slidability of the rack 5 is lowered by pressing it with the pressing members 12, such as leaf springs arranged at both outer ends of the rack 5, The side guide 4 is held at a predetermined position. Alternatively, as can be seen in FIG. 9 showing the cassette cross section, a member 13 having a high friction coefficient, such as rubber, is pressed against the pinion 7 by using a screw 14, and the pressing force reduces the rotatability of the pinion 7 and thus the side guide. It is also practiced to hold 4 in place.

However, in any of the methods, if an attempt is made to increase the force for holding the side guide 4, there is a problem that when the guide is slid, the resistance becomes great and the operability is significantly deteriorated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to devise a mechanism which is excellent in operability while surely performing sheet positioning in a sheet feeding device which positions a sheet in a sheet feeding cassette by a rack and pinion system.

[0010]

In order to solve the above problems, according to the present invention, there is provided a paper feed cassette which is attachable to and detachable from the main body of the apparatus, and a guide member which regulates the position of the paper edge is provided in the cassette. The guide member is provided with a rack (first rack) attached to the guide member and a pinion (first rack) rotatably attached to the cassette body so that the guide member is perpendicular to the attachment / detachment direction of the sheet feeding cassette. In the paper feeding device that slides at, the second pinion mounted coaxially with the first pinion is connected to the first pinion via an elastic member that is deformable in the rotation direction of the pinion, The second rack attached to the apparatus main body and the second pinion are engaged with each other at the time of mounting, and the guide member is configured to be urged in the direction of pressing the sheet.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in the drawings.

In FIG. 1 showing the characteristic portion of the sheet feeding cassette according to the present invention from the bottom side, a side guide 4 for regulating the position of the edge portion of the sheet parallel to the sheet conveying direction is perpendicular to the sheet conveying direction. It is configured to be slidable, and in each of the side guides 4, as seen in FIG.
The first racks 5 are integrally mounted via the cassette body bottom 6 while being staggered in parallel with each other. The first pinion 7 meshing with the first rack 5 is the second pinion 9
At the same time, it is rotatably attached to the bottom 6 of the cassette body. As shown in FIG. 2, the first pinion 7 and the second pinion 9 are arranged so that the first pinion 7 abuts on the cassette body bottom 6 on a stud 14 protruding on the lower side surface of the cassette body bottom 6. There is.

On the other hand, a second rack 11 is attached to the apparatus main body 10 at a position where it does not mesh with the second pinion 9 until just before the completion of loading the paper feed cassette.

As shown in FIG. 3, a mounting pin 16 formed at one end of a through groove formed on the circumference of the second pinion 9
And the mounting pin 1 projectingly formed on the surface of the first pinion 7
The first pinion 7 and the second pinion 9 are attached to each other by mounting the spring 8 on 5 and accommodating the spring 8 in the through groove of the second pinion. Instead of the spring, various elastic members such as rubber can be attached. First pinion 7 and second
Unless the external force acts on the second pinion 9 itself, the pinion 9 rotates integrally, and when the external force acts, it can rotate independently of each other while resisting the spring force. The first pinion 7 and the second pinion 9 thus mutually attached.
Is rotatably fitted into the stud 14 of the cassette body.

FIG. 4A shows a state before the paper feed cassette is loaded in the main body of the apparatus, that is, when the second pinion 9 and the second rack 11 are in the positional relationship shown in FIG. On the other hand, FIG. 4B shows the state after the paper feed cassette is pushed in the direction of the white arrow in FIG. 1 and the paper feed cassette is loaded. Unlike FIG. 4A, the spring 8 is stretched, and biases the first pinion 7 and the second pinion 9 in opposite rotation directions.

Such a spring force is generated by pushing the paper feed cassette from the position shown in FIG. 1 to the position shown in FIG. That is, the second pinion 9 of the paper feed cassette and the second rack 11 of the apparatus body 10 do not mesh with each other until just before the completion of loading the paper feed cassette, and at the time when the loading of the paper feed cassette is completed, the second pinion 9 and the second pinion 9 2 racks 1
The second pinion 9 is rotated independently of the first pinion 7 that meshes with the first rack 5 that meshes with the first rack 5. as a result,
Pins 15 and 1 of each of the first pinion 7 and the second pinion 9
Therefore, the spring 8 hung on 6 is stretched. The reaction force of the spring 8 acts in a direction in which both side guides 4 are pulled toward each other via the first pinion 7 and the first rack 5, but has a magnitude enough to eject the loaded sheet cassette. It's not there.

In the case where the paper feeding cassette is loaded by the front loading method, the paper feeding direction and the paper feeding cassette loading direction intersect each other. Therefore, instead of the side guides, a slidable guide member at the rear end of the paper is used. The technical idea of the present invention may be applied to.

[0018]

According to the sheet feeding device of the first aspect, the second pinion mounted coaxially with the first pinion is connected to the first pinion through the elastic member which is deformable in the rotational direction of the pinion. Since the second rack and the second pinion attached to the apparatus main body are engaged with each other when the paper feed cassette is mounted, the guide member is urged in the direction to press the paper. , The second pinion is rotated a certain amount by the operation of mounting the paper feed cassette on the main body of the apparatus,
Since the guide member is urged in the direction of pressing it against the paper, the end portion of the paper pressed by the guide member with a certain tension can be reliably held. Even if there is a gap between the guide member and the paper, the first pinion rotates when the cassette is mounted, so the guide member follows the end of the paper and reliably regulates the end of the paper.

[Brief description of drawings]

FIG. 1 is a schematic bottom view showing a characteristic part of a paper feed cassette according to the present invention.

FIG. 2 is a schematic side view corresponding to FIG.

FIG. 3 is an exploded view of a first pinion, a second pinion and a spring.

FIG. 4 is a schematic view of a first pinion, a second pinion and a spring after assembling, FIG.
(B) shows a state after the cassette is loaded.

5 is a schematic bottom view showing a characteristic portion after loading a paper feed cassette corresponding to FIG. 1. FIG.

FIG. 6 is a schematic side view showing a characteristic portion after loading a paper feed cassette corresponding to FIG. 2;

FIG. 7 is a schematic perspective view of a conventionally known paper feeding cassette.

FIG. 8 is a schematic bottom view showing a conventionally known mechanism for holding the engagement of the rack and pinion.

FIG. 9 is a schematic side view showing a holding mechanism having a configuration different from that of FIG.

[Explanation of symbols]

 4 Side Guide 5 1st Rack 6 Cassette Body Bottom 7 1st Pinion 9 2nd Pinion 10 Machine Body 11 2nd Rack 14 Stud

Claims (1)

[Claims] 1. An apparatus main body having a detachable paper feed cassette, a guide member for regulating a position of a paper end portion in the cassette, and a rack attached to the guide member and a cassette main body being rotatable. In a paper feeding device in which the guide member slides in a direction at right angles to the attachment / detachment direction of the paper feeding cassette by engagement with the attached pinion, the second pinion mounted coaxially with the pinion moves in the rotation direction of the pinion. The pinion is connected via a deformable elastic member, and the second rack attached to the apparatus main body and the second pinion are engaged with each other when the sheet cassette is attached,
A sheet feeding device, characterized in that the guide member is urged in a direction of pressing the sheet.