JPH0544348Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a paper feeding cassette for supplying transfer paper to an image forming apparatus such as an electrophotographic copying machine or a laser printer.

2. Description of the Related Art In FIG. 8, a paper feed cassette 1 containing a plurality of transfer papers 2 stacked therein has a pair of claws 3a and 3b for pressing the front end corners of the transfer papers 2 from above. When the cassette 1 is set in the image forming apparatus, the paper feed roller 4 and guide plates 5a and 5b attached to the image forming apparatus are positioned as shown. When the paper feed roller rotates and the paper feed roller 4 rotates accordingly, the uppermost transfer paper receives a force that pushes it forward (in the direction of arrow B). At this time, the uppermost transfer paper has a gap between the guide plate 5a and the claw part 3a.
In addition, deflection occurs between the guide plate 5b and the claw portion 3b. Furthermore, when the pushing force continues to be applied to the transfer paper 2, the deflection causes the transfer paper to bend into the claw portions 3a,
The paper is separated from 3b and fed.

By the way, the positions of the guide plates 5a and 5b are, for example,
It is set to match a specific size, such as setting it to match A4 size transfer paper, so for example
When the paper feed cassette for B5 size transfer paper is set, the distance between the guide plate and the claw part is l.
will be smaller than for A4 size. In such a case, the above-mentioned deflection is formed to be small, so that the transfer paper is not separated and causes a paper feeding failure.

On the other hand, in Utility Model No. 52-41865, a spherical body is provided in place of the claw. However, such a spherical body not only requires a complicated holding structure, but also has disadvantages in that the number of transfer sheets that can be accommodated in the cassette is reduced, and it is disadvantageous to downsizing the cassette.

Problems to be solved by the invention As mentioned above, in the conventional example, there were problems such as the problem that the transfer paper did not move away from the cassette properly during paper feeding, the complexity of the transfer paper holding structure, and the reduction in storage capacity. However, the present invention attempts to solve these problems.

Means for Solving the Problem The present invention has a claw part that presses the front end corner of the stored transfer paper from above, and when feeding the paper, the uppermost transfer paper is pushed forward by the paper feed roller of the image forming apparatus. Pressing the transfer paper to cause a deflection in the vicinity of the claw portion,
In a paper feeding cassette configured such that the transfer paper can be removed from the claw portion by the bending, an elastic member larger than the claw portion and having lower frictional resistance is provided on the surface of the claw portion that presses the transfer paper.

Function: Due to the deflection of the transfer paper that occurs when the transfer paper is fed from the cassette, the elastic member provided on the claw portion warps along the transfer paper. As a result, the edges of the claws become smooth, and the transfer paper can be easily removed from the claws. Further, since the frictional resistance of the elastic member is small, the friction between the elastic member and the transfer paper is also small.

Embodiment Figure 1 shows a paper feed cassette 10 in which the present invention is implemented.
2 is a perspective view showing one front corner of the claw piece 13, one end of which is rotatably mounted on the side plate 11 by a mounting means 12. The claw piece 13 extends forward along the side plate 11 and is partially bent at the front end. It is parallel to the front plate 14, and its upper part is further folded back to form a claw part 15a. An elastic member 1 with low frictional resistance made of polyester film is provided on the lower surface of the claw portion 15a.
6 is attached. Then, this elastic member 16
is formed slightly larger than the claw portion 15a. FIG. 2 is a plan view of the claw piece 13, side plate 11, etc. viewed from above, and FIG. 3 is a view viewed from the direction of arrow A in FIG. 1.

As described above, since the elastic member 16 is attached to the claw portion so that the elastic member 16 contacts the transfer paper 2, the guide plates 5a, 5b and the claw portion 15a are attached during the sheet feeding operation shown in FIG. , 15b, the elastic member 16 is slightly warped upward, and in combination with the small frictional resistance between the two, the transfer paper 2 is bent away from the claws 15a, 15b. The withdrawal will be carried out smoothly.

Next, FIG. 6 shows the results of an actual test using the configuration of the claw portion shown in FIG. 5a. Here, 50 sheets of transfer paper were set in the paper feeding cassette 10, and this process was repeated several times in succession to feed a total of 1300 sheets. As a result, only one jam (feeding failure such as a paper jam) occurred between 201 and 250 sheets, and the results were very good. Note that J ₁ indicates that jam occurred once. On the other hand, when the conventional example shown in Fig. 8 was tested, as shown in Fig. 7, once between 701 and 800 sheets, and once between 1101 and 1200 sheets
The jam occurred four times between sheets and twice between sheets 1201 and 1300. In Fig. 7, 100 sheets are set in each cassette. From these results, the effect of the elastic member 16 of the present invention can be seen.

In addition, even when the dimensions of the present invention were selected as shown in FIG. 5b, jamming occurred only once out of 1300 sheets, and the results were good. However, when the dimensions of the elastic member 16 were chosen to be exactly the same as the claws, the number of jams increased slightly, and paper folds occurred on the left and right sides of the leading edge of the transfer paper.

It goes without saying that the material of the above-mentioned elastic member is not limited to polyester film, and may be any elastic body as long as it has the same effect as above.

Effects of the invention According to the invention, since the transfer paper is smoothly released from the claw, paper feeding defects almost never occur even when the deflection formed between the guide and the claw is small. effective. Further, since it has an extremely simple structure and only requires the addition of a relatively thin member, it does not impair the accommodating capacity of the cassette.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a part of the paper feed cassette in which the present invention is implemented, FIG.
It is a figure when seen from the direction. FIG. 4 is a view from the front side showing the state of the cassette and its related parts during paper feeding operation. FIG. 5 is a diagram showing the sizes of the claw portion and the elastic member, and FIG. 6 is a diagram showing the test results in that case. FIG. 7 shows the test results of the conventional example, and FIG. 8 is a diagram illustrating the paper feeding mechanism of the conventional example. 2...Transfer paper, 5a, 5b...Guide plate, 10
...Cassette, 15a, 15b...Claw part, 16...
...Elastic member, 17...Deflection.

Claims (1)

[Claims for Utility Model Registration] (1) It has a claw portion that presses the front end corner of the stored transfer paper from above, and when feeding the paper, the uppermost transfer paper is pushed forward by the paper feed roller of the image forming device. In a paper feeding cassette configured to generate a deflection in a portion of the transfer paper near the claw portion so that the transfer paper can be removed from the claw portion due to the deflection, a surface of the claw portion that presses the transfer paper is bent. A paper feeding cassette characterized by being provided with an elastic member that is larger than the claw portion and has lower frictional resistance. (2) Utility model registration claim 1, characterized in that the elastic member is a polyester film.
Paper cassette as described in section. (3) The paper feeding cassette according to claim 1, wherein the elastic member is attached to the claw portion.