JPH0229066Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention consists of a paper loading table on which paper to be fed is placed, a paper feed roller that contacts the uppermost sheet of paper on the loading table and feeds it, and a The present invention relates to a paper feeding device having a friction member fixed to a recessed part of the mounting table recessed from the surface of the mounting table, located opposite to the paper feeding roller, and in contact with the lowest paper on the paper mounting table.

PRIOR ART It has been well known that paper feeding devices of the above type are used in image forming devices such as electronic copying machines, printers, and printing machines to feed paper such as copying machines, recording paper, manuscripts, or printing paper. be. FIG. 3 shows an example of a conventional paper feeding device, in which 1 is a box-shaped cassette that accommodates a stack of paper 2 to be fed, and a paper mounting table 3 on which the paper 2 is placed is provided at the bottom of the cassette. ing. In this mounting table 3, a tongue piece 4 protruding from the rear part (right side in FIG. 3) fits into a notch 5 formed in the bottom part 1a of the cassette 1, and the placing table is centered around this tongue piece 4. 3 is supported rotatably in the direction of arrow A. A pressure member (not shown) that is tiltably supported on the main body side of an image forming device (for example, a copying machine) protrudes from the hole 6 formed in the bottom plate 1a, and lifts the mounting table 3 upward and presses the mounting table 3 upwardly. Therefore, the uppermost sheet comes into pressure contact with the sheet feed roller 7 above it.

When feeding the paper 2, the paper feed roller 7 that contacts the uppermost paper on the paper loading table 3 rotates clockwise in FIG. Sent out.

When the sheets are fed sequentially and the number of sheets remaining on the mounting table 3 decreases, the lowest sheet is fed on the loading table 3.
If this is left unattended, multiple sheets of paper may be fed at the same time, causing a double feeding phenomenon. For this reason, as shown in FIGS. 4 and 5, a mat-shaped friction member 9 made of a high-friction material is adhered and fixed in a recess 8 of the mounting table 3 that is deeper than the general surface 3a. ing. The friction member 9 comes into contact with the lowest sheet of paper to increase the frictional force acting on this sheet, thereby preventing the sheet from slipping and preventing double feeding of sheets. Friction member 9
is provided at a position facing the paper feed roller 7 in order to enhance its function (FIG. 5).

By the way, if the above-described paper feeding device is used for a long period of time, it is inevitable that the friction member 9 will wear out over time due to contact with the paper feeding roller 7 or the paper 2. When this wear becomes significant, as shown in FIG. This results in a sharp step difference between the upper surface 9a and the upper surface 9a. Therefore, the paper pressed by the paper feed roller 7, especially the lowest paper, is pushed into the recess, and the paper portion 2a that hits the corner or side of the recess is deformed and folded. Put it away. If the paper is deformed in this way, it may not be conveyed correctly when it is fed, causing so-called skew, which may lead to paper conveyance troubles. Conversely, when the rigidity of the paper is high, the paper may lift the paper feed roller 7 upward. Therefore, conventionally, Figures 4 and 5
As shown in the figure, the upper surface 9a of the friction member 9 before wear is
The thickness of the friction member 9 is set to be thick so that it protrudes upward more than the general surface 3a of the mounting table 3, and the time it takes for the friction member 9 to wear out is increased, thereby extending the life of the friction member 9. However, if the upper surface 9a of the friction member 9 protrudes more than the surface 3a of the mounting table 3, when setting the paper 2 on the mounting table 3, the paper gets caught on the protruding friction member 9, causing the paper to be set. This creates a drawback that makes it difficult to use. Furthermore, when the paper is set, the paper may come into contact with the friction member 9 and the member 9 may peel off. In order to eliminate this drawback, the upper surface 9a of the friction member 9 is connected to the surface 3 of the mounting table 3.
If the height is set to be the same as a, the friction member 9 will wear out quickly as shown in FIG.

Purpose The purpose of the present invention is to provide a paper feeding device that reduces the above-mentioned conventional drawbacks.

Configuration In order to achieve the above object, the present invention provides the paper feeding device described at the beginning with a recess in the paper mounting table portions located on both sides of the friction member with respect to the paper feeding direction. However, we propose a configuration in which a recessed portion is formed that is shallower than the recessed portion.

Embodiments of the present invention will be described below with reference to the drawings.

The paper feeding device in this embodiment has the same structure as that shown in FIG. 3 except for the points explained below, so redundant explanation will be omitted.
In the following description, reference will be made to FIG. 3 as necessary.

As shown in FIGS. 1 and 2, the paper mounting table 3 in this example also has a mat-like friction member 9 fixed to a recess 8 that is deeper than the general surface 3a by gluing or the like. . This friction member 9 is made of a high friction material such as cork-containing rubber or synthetic resin, as in the conventional case. What is different from the conventional method is that the paper mounting table portions located on both sides of the friction member 9 in the paper feeding direction are recessed from the general surface 3a of the mounting table, but are shallower than the recessed portions 8 and are flat. recessed portion 10 having a surface
is formed. When the friction member 9 fixed in the recess 8 is not worn out yet, its upper surface 9a protrudes upwardly from the surface of the recess 10, but it protrudes more than the upper surface 3a of the mounting table 3. In this example, they are at the same height level. The paper feed roller 7 is also located opposite the friction member 9 in this case.

The friction member 9 can also prevent the inconvenience of the lowest sheet slipping against the loading table 3 when the sheets 2 are fed as shown in FIG. 3 and the number of stacked sheets decreases. Moreover, since this friction member 9 protrudes from the upper surface of the recessed portion 10 and has a large thickness, it will not wear out prematurely as shown in FIG. 6.

The upper surface 9a of the friction member 9 according to the present invention does not protrude much more than the surface 3a of the mounting table 3, and in this example is at the same level. When setting as shown,
The inconvenience of the paper strongly hitting the friction member 9 can be suppressed, the paper can be easily set, and the friction member 9 can be prevented from peeling off.

Further, even when the friction member 9 rubs over time and there is a difference in height between the top surface 9a and the surface 3a of the paper mounting table, the paper 2 is When pressurized by the paper feed roller 7, the paper is not subjected to excessive external force as shown in FIG. There will be no creases or step-like wrinkles.

Furthermore, since the friction member 9 is fixed to the recess 8, when it is attached to the recess 8, the paper feed roller 7
The position of the friction member can be set correctly.

Note that if the width of the recess 10 is too large, there is a risk that the paper will get caught in the recess 10 itself when the paper is set.On the other hand, if the recess 10 is too narrow, when the friction member wears out, the recess 10 may become stuck. Since there is a possibility that paper may enter the recess 10 and cause a phenomenon similar to that shown in FIG. 6, the width of the recess 10 should be set taking both of these into consideration. Similarly, if the recess 10 is too deep, there is a risk that the paper 2 that has entered the recess may be deformed, and if it is too shallow, the friction member 9 may protrude from the surface of the recess 10. Since a sufficient height cannot be achieved, the depth of the recessed portion 10 should be determined in consideration of these factors. According to experiments, when the depth from the surface 3a of the mounting table 3 to the bottom of the recess 8 is 1 mm, the depth of the recess 10 is set to about 0.5 mm, and the recesses located on both sides of the friction member 9 are When the length L of section 10 (Fig. 1) is set to about 5 mm,
Favorable results were obtained.

The present invention can be widely applied to image forming apparatuses such as copying machines, printing machines, and various printers.

Effects According to the present invention, it is possible to prevent the problem of folds and step-like wrinkles in the paper, and it is also possible to suppress the inconvenience of the paper and the friction member coming into strong contact when setting the paper, without shortening the life of the friction member. It is possible.

[Brief explanation of drawings]

FIG. 1 shows the configuration of a paper feeding device according to the present invention,
3 is a cross-sectional view corresponding to the - line cross section in FIG. 3, FIG. 2 is a partial perspective view showing the friction member removed from the paper loading table, and FIG. 4 is a partial perspective view showing the conventional structure; FIG. 5 is a sectional view similar to FIG. 1 showing the conventional structure; FIG. 6 is a sectional view similar to FIG. 5 for explaining the conventional drawbacks. 2...Paper, 3...Paper mounting table, 3a...Surface, 7...Paper feed roller, 8...Recessed portion, 9...Friction member, 10...Recessed portion.

Claims (1)

[Claims for Utility Model Registration] A paper loading table on which the paper to be fed is placed, a paper feed roller that contacts the uppermost sheet of paper on the loading table and sends it out, and a roller that is concave from the surface of the sheet loading table. a friction member that is fixed to a recessed part of the paper mounting table, is located opposite to the paper feeding roller, and contacts the lowest paper on the paper mounting table, the friction member being fixed to the recessed part of the paper mounting table; The paper feeding device characterized in that a recessed portion is formed in the paper mounting table portions located on both sides of the member, which is recessed from the surface of the paper mounting table but shallower than the recessed portion.