JPH0213406Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field of the invention This invention is a copying machine using a paper cassette;
This article relates to improvements to the brake seat of paper feeding mechanisms installed in printing devices such as OCR, OMR, and laser line printers.

(b) Background of technology Although the speed of printing equipment has been rapidly increasing in recent years, the last sheet (last sheet) of multiple sheets loaded on the hopper is difficult to reach due to friction with the brake sheet. This sometimes interferes with the smooth pick-feed (pick-up and transport) operation, resulting in jams, and this is a major factor that hinders the speeding up of the equipment. Therefore, there is a strong demand for the development of a paper feeding mechanism that can pick-feed the final paper smoothly and accurately.

(c) Prior art and problems Figure 1 is a perspective view for explaining a conventional paper supply mechanism, where a shows when there are multiple papers, and b shows when the last paper is the last one (last paper). It shows the time when

As shown in FIG. 1A, the conventional paper feeding mechanism includes a pick roller 2 for pick-feeding the paper 1, a bottom plate 4 installed in a hopper 3, and for pushing up the paper 1 loaded on the hopper 3 into contact with the roller 2. , attached to the bottom plate 4 to prevent a plurality of sheets 1 from being pick-fed at the same time.
and a brake sheet 5 that applies a brake to the last sheet (last sheet) of the sheet.

Then, the paper 1 pushed up in the direction of arrow A by the lift-up mechanism (not shown) comes into contact with the pick roller 2, and due to friction with the pick roller 2 rotating in the direction of arrow R, the paper 1 is pushed up in the direction of arrow A. Pick feed is given in the direction.

However, as shown in Figure b, most of the jamming phenomenon 10 in conventional printing devices occurs on the last sheet of paper 1 (last sheet) stacked on the bottom plate 4 of the paper hopper 3, as described above. are doing. This is the final paper 1 and the paper 1 loaded directly above it.
In order to prevent the paper 1 from being repeatedly pick fed (this phenomenon is referred to as double feed), the friction coefficient μ ₁ between the paper 1 and the friction coefficient μ 2 between the paper 1 and the pick crawler 2 is greater than the friction coefficient μ ₂ between the paper 1 and the brake. This is because the friction coefficient μ ₃ between the sheets 5 is set larger.

Therefore, when paper 1 is the last sheet, even if pick crawler 2 tries to pick feed paper 1,
The movement of the paper 1 is obstructed due to the large frictional force with the brake seat 5, and the paper 1 is no longer pick-fed smoothly, resulting in the jamming phenomenon 10. However, with the conventional structure, it is very difficult to adjust the balance between the frictional resistance between the sheets of paper 1 and the frictional resistance between the sheets of paper 1 and the brake sheet 5 to smoothly pick-feed the sheets of paper 1.

(d) Purpose of the invention This invention was made to correct the above-mentioned conventional drawbacks, and by changing the shape of the paper contact surface of the brake sheet facing the pit crawler,
The object of the present invention is to provide a paper feeding mechanism that enables smooth pick-feeding of paper.

(e) Structure of the invention According to the invention, the invention comprises a bottom plate having a brake seat and a hopper in which the bottom plate is housed, and the paper loaded in the hopper is moved to a pick crawler by the pushing force of the bottom plate. In the paper supply configuration in which the paper is sequentially pick-fed one by one by pressing and rotating the roller, a plurality of air flow paths parallel to the paper feeding direction are provided on a surface of the brake sheet facing the pick roller. This is achieved by providing a paper feeding mechanism characterized by providing a groove.

(f) Example of implementation of the idea Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a perspective view for explaining this embodiment, and in this figure, the same parts as in the previous figure are designated by the same reference numerals.

As shown in the figure, the paper feeding mechanism of this embodiment has a surface 5' of the brake sheet 5 facing the pick roller 2.
It has a plurality of grooves 15 parallel to the feeding direction of paper 1 (direction of arrow B). When such a groove 15 is provided, an air flow is constantly generated within the groove 15 due to various convection flows such as a cooling fan provided within the apparatus main body. On the other hand, when there are many sheets on the hopper, their weight creates a suction cup-like suction between the last sheet 1 and the brake sheet 5, effectively preventing double feeding.
As the remaining amount of paper decreases, the effect of pushing up the paper by the air flow in the groove 15 becomes active, and when the last paper 1 is reached, the excessive adhesion to the brake seat surface is canceled by the air flow. As a result, the frictional resistance between the paper 1 and the brake sheet 5 and the frictional resistance between the paper 1 and the pick roller 2 become in the originally desired relationship.

As a result, the last sheet of paper (last sheet) 1 on the bottom plate 4 is smoothly pick-fed, and jamming accidents are almost completely avoided.

Note that the width w and the number of grooves 15 provided on the paper contact surface 5' are determined from the width W with respect to the pick roller 2, the friction coefficient μ ₃ between the paper 1 and the brake sheet 5, the friction coefficient μ ₂ between the paper 1 and the pick roller 2, etc. It is determined.

(g) Effects of the invention As explained in detail above, the paper feeding mechanism of the present invention is extremely effective in that jamming accidents of paper, especially the final paper, can be almost completely avoided by simple improvement of the brake seat. It is.

[Brief explanation of the drawing]

FIG. 1 is a perspective view for explaining a conventional paper supply mechanism, in which a is a diagram showing a state when there is a plurality of papers, and b is a diagram showing a state when the last paper is the last one (last paper). FIG. 2 is a perspective view for explaining one embodiment of the present invention. In the drawing, 1 is paper, 2 is a pick crawler,
3 is the hopper, 4 is the bottom plate, 5 is the brake seat,
5' is the paper contact surface, 15 is the groove, w is the width of the groove provided on the paper contact surface 5' of the brake sheet, and W is the width of the pick roller.

Claims (1)

[Scope of utility model registration request] It is equipped with a bottom plate having a brake sheet and a hopper in which the bottom plate is housed, and the pushing force of the bottom plate pushes the paper loaded on the hopper against a pick roller, and the rotation of the roller moves the paper into one sheet. A paper feeding mechanism in which the paper feeding structure performs pick-feeding sequentially, characterized in that grooves serving as a plurality of air flow paths parallel to the feeding direction of the paper are provided on a surface of the brake sheet facing the pick roller.