JPH01247337A - Paper feeder - Google Patents

Abstract

PURPOSE:To enable printing paper to be surely fed preventing a paper feed roller from wearing by racing a slip roller so as to prevent transmission of drive torque from a printer to the paper feed roller when friction torque not less than a predetermined value acts on the paper feed roller. CONSTITUTION:A paper feeder, when it is mounted to a printer, transmits drive torque to a paper feed roller 3 of an angular shaft 1, connecting a gear 2d, from the printer through a rotation transmitting system 2. A slip clutch 4 races when transmitted torque to the roller 3 increases to a value not less than the specified, that is, when printing paper is present in a hopper, the clutch 4 generates no racing for the printing paper in its feed torque, rotating with a gear 2a transmitting the torque to paper feed rollers 3a, 3b. However, the hopper provides no printing paper with the rollers 3a, 3b coming into direct contact with a pressure plate 12, when friction torque acts on the rollers 3a, 3b, the clutch races transmitting no torque to the rollers 3a, 3b from the printer. Accordingly, a surface is prevented from wearing because the rollers 3a, 3b are not rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding device that is attached to a printer and is used to supply printing paper to the printer according to a command from the printer.

[Conventional technology]

This type of conventional paper feeding device (sheet feeder) transmits torque from a drive source to a paper feeding roller via a rotation transmission system including gears and belts, and then feeds printing paper into a hopper inside the sheet feeder. The configuration is such that the image is sent to the printer.

[Problem to be solved by the invention]

In the conventional sheet feeder as described above, when there is printing paper in the hopper, the paper feed roller is in contact with the printing paper to send out the printing paper. Therefore, the frictional force of the paper feed roller is small, but when the hopper runs out of print paper, the paper feed roller comes into direct contact with a suppressing plate provided to apply a pressing force to the print paper. This increases the frictional force of the paper feed roller, but since the paper feed roller continues to rotate, the surface of the paper feed roller wears out, resulting in an unreliable feeding of the printing paper.

An object of the present invention is to eliminate the drawbacks of the conventional paper feeding device as described above, and to prevent the paper feeding roller from rotating when friction torque exceeding a specified value is applied to the paper feeding roller. It is an object of the present invention to provide a paper feeding device that can prevent wear of the paper and reliably feed printing paper.

[Means to solve the problem]

The paper feeding device of the present invention includes two pressure plates arranged side by side on which print paper is loaded, and two springs that apply a pressing force to each of the pressure plates. a hopper, two paper feed rollers provided corresponding to each of the two pressure plates and in contact with the printing paper mounted on the pressure plate, and a shaft that supports the paper feed roller and rotates the rotating slide. A rotating shaft having a gear train for transmitting the drive torque to the paper feed roller is provided, so that when a friction torque of a predetermined value or more is applied to the paper feed roller, the sliding roller idles and drive torque from the printer is not transmitted to the paper feed roller. It is composed of

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing the main parts of an embodiment of the present invention, and FIG.
The figure is a sectional view of the gear having the sliding clutch 7 of the embodiment shown in FIG. 1, and FIG. 3 is a side view of the hopper of the eleventh embodiment.

In FIGS. 1 to 3, the rotation transmission system 2 includes gears 2a, 2b, 2c, and 2d. A slip clutch 4 is provided between the shaft 5 and the rotating shaft 5, and the rotation of the rotary shaft 5 is transmitted to the gear 2aK via the slip clutch 4. As shown in FIG. 3, the flopper 83 has a pressure plate 12a and a spring 10 for applying a pressing force to the paper feed roller 2a on the printing paper.
The printing paper stacked above is pressed against the paper feed roller 3a. When the sheet feeder configured as described above is installed in a printer, driving torque is transmitted from the printer via the rotation transmission system 2 to the paper feed roller 3 provided on the square shaft 1 to which the gear 2d is connected. Ru. The sliding clutch 4 idles when the torque transmitted to the paper feed roller exceeds a specified value. In other words, when there is printing paper in the hopper, the slipping clutch 4 cannot handle the torque required to feed the printing paper. 4 rotates with the gear 2a without idling and transmits torque to the paper feed rollers 3a and 3b, but when the printing paper in the hopper runs out, the paper feed rollers 3a and 3
b and the pressure plate 12 are in direct contact and when there is friction between them, they rotate idly and act to prevent torque from the printer from being transmitted to the paper feed rollers 3a and 3b. Therefore, since the paper feed rollers 3a and 3b do not rotate,
Abrasion of its surface is prevented.

Although the above embodiment is an example in which the slip clutch is provided on the gear 2a, the same effect can be obtained even if the slip clutch is provided on any of the gears 2b, 2C, and 2d.

〔Effect of the invention〕

As explained above, the paper feeding device of the present invention includes a slipping clutch in the rotation transmission system, so that when a friction torque exceeding a specified value is applied to the paper feeding roller, the torque is transmitted to the paper feeding roller. This has the effect of preventing the paper feed roller from rotating while in direct contact with the pressure plate, thereby preventing wear on the paper feed roller. Therefore, it is possible to obtain a highly reliable paper feeding device that prevents malfunctions in the printing paper feeding operation due to wear of the paper feeding roller.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figure 1 is a perspective view showing the main parts of an embodiment of the present invention;
1 is a sectional view of a gear having a slipping clutch according to the embodiment shown in FIG. 1, and FIG. 3 is a side view of the hopper according to the embodiment shown in FIG. 1... Square shaft, 2... Rotation transmission system, 2a/2b
・2C・2d...Gear, 3a, 3b...Paper feed roller, 4...Sliding clutch, 2...Rotating shaft, 8a, 8b...
...Hopper, 10...Spring, 12a/12b
...Pressure plate. Agent: Patent Attorney Susumu Uchihara Group

Claims (1)

[Claims] a hopper having two pressure plates for loading printing paper arranged side by side on the left and right, two springs for applying a pressing force to each of the pressure plates; and the two pressure plates. two paper feed rollers provided corresponding to each of the plates and in contact with the printing paper mounted on the pressure plate;
A rotation transmission system including a gear train that is connected to a shaft that rotates while supporting the paper feed roller and transmits rotational torque from the printer to the shaft, wherein any gear in the gear train A slip clutch is provided between the rotating shaft and the gear, and when a friction torque of a predetermined value or more is applied to the paper feed roller, the slip roller idles and drive torque from the printer is not transmitted to the paper feed roller. A paper feeding device characterized in that it is configured as follows.