JPH02178128A - Paper feeding device - Google Patents

Abstract

PURPOSE:To perform paper feeding so stably without entailing any noise by unifying a cylindrical driver with a paper feeding means or locking it to a drive shaft of this paper feeding means, while constituting another rotor free of rotation with a drive shaft of a friction roller so as to be pressed or approximated to the said driver in an opposed manner. CONSTITUTION:When paper feeding for a sheet or the like large in friction force with a friction rollers 5 for an OHP sheet, etc., is carried out, each rotor 8 installed in a drive shaft 6 of the friction roller 5 comes into contact with each cylindrical driver 7 installed in one side or both sides of a paper feeding means 1, and in this case, a pressing force of more than the specified one is not added to the friction roller 5. With this constitution, the sheet is stably feedable without entailing any noise. In addition, a tip of the sheet culed downward is guided into the rotor 8 set up in one side or both sides of the friction roller 5, and it enters a pressure-contact position between the paper feeding mean 1 and the friction roller 5. Consequently, such a possibility that this sheet tip might be bent is thus eliminable.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a paper feeding device for a copying machine.

BACKGROUND OF THE INVENTION Conventional paper feeding devices for copying machines use various methods to feed paper one sheet at a time from the paper storage section. The most stable method for feeding paper is to feed the paper one sheet at a time by rotating a friction roller pressed against the means in the opposite direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The conventional paper feeding device for a copying machine described above will be described below with reference to the drawings.

FIG. 5 shows a cross-sectional view of important parts of a paper feeding device of a conventional copying machine.
In the figure, l is a paper tray, 2 is a pickup roller for feeding out the top paper of the paper placed on paper tray 1, 3 is a paper feed roller for feeding the paper into the inside of the copying machine, and 4 is a paper feed roller. 3 is a paper feed roller drive shaft that drives the paper feed roller 3 , 5 is a friction roller provided in pressure contact with the paper feed roller 3 , and 6 is a friction roller drive shaft that drives the friction roller 5 .

Next, the operation will be explained in detail.

The top paper of a plurality of sheets of paper placed in a paper tray 1 is sent out from above the paper tray 1 by a pickup roller 2. Paper feed roller 3 further feeds the paper into the copying machine. At this time, the friction roller 5 feeds the sheets one by one.

When two or more sheets of paper enter between the paper feed roller 3 and the friction roller, the lower paper is returned to the paper tray 1 side by reverse rotation of the friction roller.

If a certain amount of torque is applied between the friction roller 5 and the friction roller drive shaft on the friction roller 5 side, slippage occurs and the friction roller 5 rotates in the same direction as the paper feed roller 3, resulting in stable paper feeding. It will be done as follows.

Problems to be Solved by the Invention However, in the above configuration, when the frictional force between the OHP sheet and the friction roller is large, the force that presses the friction roller toward the paper feed roller increases due to the frictional force, and the friction roller The pressure contact force increases, which may cause abnormal noise during paper feeding, impair paper feeding performance, and cause paper feeding failures.

In addition, if the paper curls downward (which tends to occur when copying the back side of a paper that has been copied - times or when making overlapping copies), the leading edge of the paper may hit the friction roller, causing the back of the paper to curl. Because the paper is sent out by a pickup roller, the leading edge of the paper may be bent.

The present invention solves the above problems and provides a paper feeding device for a copying machine that stably feeds paper.

Means for Solving the Problems In order to solve the above problems, the paper feeding device of a copying machine according to the present invention includes a paper feeding means for feeding paper into the inside of the copying machine, and a friction member provided so as to be in pressure contact with the paper feeding means. A roller and a cylindrical drive body provided on one or both sides of the paper feed means, the cylindrical drive body being integral with the paper feed means or fixed to a drive shaft of the paper feed means and facing the paper feed means. The friction roller is configured such that a rotatable body is pressed into contact with or brought close to the drive shaft of the friction roller.

Effect With the above-described configuration of the present invention, when feeding paper such as an OHP sheet that has a large frictional force with the friction roller, the rotating body rotatably provided on the drive shaft of the friction roller is attached to one side of the paper feeding means. Or, it comes into contact with the cylindrical drive bodies provided on both sides, and -
Pressure force greater than the chamber pressure is not applied to the friction roller, and paper feeding performance is stabilized.

Furthermore, the leading edge of the downwardly curled sheet of paper is guided by the rotary body installed on one or both sides of the friction roller and enters the pressure contact position between the paper feeding means and the friction roller, so that the leading edge of the sheet will not be bent.

EXAMPLE An example of the present invention will be described below with reference to the drawings. Note that the same reference numerals are given to the same parts as those of the conventional example.

FIG. 1 shows a sectional view of essential parts of a paper feeding device of a copying machine according to a first embodiment of the present invention.

In the figure, 1 is a paper tray, 2 is a pickup roller for feeding out the top paper of the paper placed on paper tray 1, 3 is a paper feed roller for feeding the paper into the inside of the copying machine, and 4 is a paper feed A paper feed roller drive shaft that drives the roller 3; 5 is a friction roller provided in pressure contact with the paper feed roller 3; 6 is a friction roller drive shaft that drives the friction roller 5; 7 is a paper feed roller drive It is a cylindrical driving body provided with a fixed shaft 4, and is arranged on both sides of the paper feed roller 3. Reference numeral 8 denotes a rotary body that is rotatably provided on the friction roller drive shaft 6 in pressure contact with or in close proximity to the cylindrical drive body 7 .

Next, the operation will be explained in detail.

When paper is fed by the paper feed roller 3, the friction roller 5 rotates in the opposite direction, so that the paper is fed one by one. At this time OH
When feeding paper that has a large frictional force with the friction roller 5, such as a P sheet, the force is transmitted to the friction roller drive shaft 6 in the direction of pushing up the friction roller 5. In the case of the configuration of the embodiment, the rotating body 8 is provided facing the cylindrical driving body 7 in close proximity or in pressure contact with it, so that when it is in pressure contact with it, it is not pushed up any further and the friction roller 5 is pushed up. Pressure force does not increase. In addition, when the rollers 5 are provided close to each other, the friction rollers 5
The paper feed roller 4 bends and the friction roller 5 is pushed up, and the pressure contact force increases, but it does not increase beyond the point of contact, and the gap between the cylindrical drive body 7 and the rotating body 8 is set to an appropriate value. By doing so, it is possible to prevent the influence on paper feeding performance due to an increase in pressure contact force. Further, since the rotating body 8 is rotatably provided on the friction roller drive shaft 6, it rotates together in the paper feeding direction by contact with the cylindrical drive body 7, and does not affect paper passing properties.

FIG. 2 is a side view and a sectional view of a main part of a paper feeding device of a copying machine in a second embodiment. In the figure, by making the outer diameter of the rotating body 8 larger than the outer diameter of the friction roller 5, even when the paper is curled downward, the leading edge of the paper is
The leading edge of the sheet is guided by the friction roller 5 and can be fed without being bent.

FIG. 3 is a side view of essential parts of a paper feeding device for a copying machine according to a third embodiment, in which a groove is provided on the outer circumference of a cylindrical drive body 7 to improve paper feeding performance.

FIG. 4 is a side view and a cross-sectional view of a main part of a paper feeding device of a copying machine according to a fourth embodiment. The circumferential speed of the outer periphery of the body 7 is increased, improving paper feeding performance, and the paper is shaped to cover the friction roller 5, so that the effect of preventing double feeding of paper is also improved.

Effects of the Invention As detailed above (according to the present invention, when feeding paper such as an OHP sheet that has a large frictional force with a friction roller, abnormal noises or paper feeding failures occur during paper feeding). Furthermore, even when feeding downwardly curled paper, the leading edge of the paper is prevented from being folded by a portion of the friction roller, and stable paper feeding performance can be obtained.

[Brief explanation of the drawing]

1 and 3 are the first and third embodiments of the present invention, respectively.
2 and 4 are main part sectional views of the embodiment, FIG. 2 and FIG.
FIG. 5 is a schematic configuration diagram of a conventional paper feeding device. 1... Paper feed roller 4... Paper feed roller drive shaft, 5... Friction roller, 6...
... Friction roller drive shaft, 7 ... Cylindrical drive shaft, 8 ... Rotating body. Name of agent: Patent attorney Shigetaka Awano Idiot 1 person 3・-tξ
η-near gs- in the scabbard D-ra 4-in! h 7...Cylindrical drive body 8- Turn body Fig. 2

Claims (4)

[Claims] (1) a paper feeding means for feeding paper into the copying machine;
It includes a friction roller provided so as to be in pressure contact with the paper feeding means, and a cylindrical driving body provided on one or both sides of the paper feeding means, and the cylindrical driving body is integrated with the paper feeding means or A paper feeding device, characterized in that a rotating body is fixed to a drive shaft of a paper means and is rotatable with respect to the drive shaft of the friction roller, and is pressed against or close to the cylindrical drive body. (2) The paper feeding device according to claim (1), wherein the outer diameter of the rotating body which is rotatably mounted on the drive shaft of the friction roller is larger than the outer diameter of the friction roller. (3) The paper feeding device according to claim 1 or 2, characterized in that a groove is provided on the outer periphery of the cylindrical drive body. (4) The paper feeding device according to any one of claims (1) to (3), characterized in that the outer diameter of the rotating body that is rotatable with respect to the drive shaft of the friction roller is smaller than the outer diameter of the friction roller.