JPS5882933A - Paper feed roll - Google Patents

Abstract

PURPOSE:To stabilize the pressure of paper feeding due to a paper feed roll, as well to increase the carrying force thereof, and as well to reduce the operating sound thereof, by disposing an intermediate layer made of vibration absorbing rubber material between a roll shaft and an outer surface layer made of high wear-resistant material. CONSTITUTION:A paper feed roll 3 consists of such a multilayer structure that an intermediate layer 32 made of vibration absorbing rubber material is applied, by fitting or bonding, to the outer periphery of a core metal 31 fitted onto a roll shaft 4, and an outer peripheral layer 33 made of high wear-resistant rubber material is applied, by fitting or bonding, to the outer periphery of the intermediate layer 32. High hardness rubber material such as, for example, neoprene rubber, urethan rubber or EPDM rubber, having a rubber hardness of 40 deg. to 60 deg. may be used as the outer peripheral layer 33 of the paper feed roll 3. Further, rubber material such as, for example, foam polyurethane, foam NBR or low hardness rubber, having a C-scale ASCAR sponge hardness of 30 deg. to 60 deg. may be used as the intermediate layer 32.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a paper feed roller employed in a paper feed device of a copying machine, a printing machine, etc., and more specifically, to a paper feed roller for preventing two sheets of paper placed in a stacked state from being fed. The present invention relates to a paper feeding roller to which a separating roller is pressed, a so-called separating roller pressure contact type paper feeding roller.

BACKGROUND ART Since this type of paper feed roller is in pressure contact with a separating roller that rotates in forward and reverse directions or in reverse, the roller surface is subject to significant wear. Therefore, conventionally, a paper feed roller is used in which the outer peripheral layer is made of a hard rubber material with high wear resistance.

However, the paper feeding roller has unstable and small paper feeding pressure, and has problems in its conveyance performance.

Additionally, there was a problem in that a noise was generated when paper was fed.

Purpose/Summary of the Invention An object of the present invention is to provide a paper feed roller that solves the above problems.

In order to study the problem of conveyance performance of the paper feed roller, the present inventor used a conventional highly wear-resistant paper feed roller as the separation roller pressure contact type paper feed roller of the separation type paper feeding device shown in FIG. 2, which will be described later. When we investigated the frictional slip characteristics of this paper feed roller with the paper, we found that the change state of the friction coefficient (6) of the paper feed roller (
5 seconds), as shown in FIG. 1, a large amplitude was drawn around p=1.0.

The present inventor focused on the fact that the large change in the coefficient of friction (b) is due to the vibrations coming from the sorting roller, and found that the inside of this highly wear-resistant paper feed roller is made of a low-hardness rubber material with good vibration absorption properties. When a rubber material or foam rubber material is provided as an intermediate layer,
It was confirmed that the object of the present invention was achieved.

trespassing Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 2 shows a schematic configuration of a separating type sheet feeding device employing a sheet feeding roller according to the present invention.

In the figure, (1) Fi feeding roller is used to connect the paper feeding cassette (
2) Press against the top surface of the top layer of paper (FI) stored in 2) with a relatively small pressure force, and send out the upper layer of paper P) in the direction of the arrow (3) by rotating in the direction of the arrow. It is something.

(3) is a paper feed roller according to the present invention, and its structure is as follows:
As shown in the figure, a core bar (31) is fixed to the roller shaft (4), and an intermediate layer 2 made of a vibration-absorbing rubber material is provided on the outer periphery of the core bar (31) by fitting or pasting. It has a multi-layered structure in which an outer peripheral layer (33) made of a highly wear-resistant rubber material is provided on the outer periphery of the intermediate layer (33) by fitting or pasting.

Here, the outer peripheral layer (33) of the paper feed roller (3) is as follows:
High hardness neoprene rubber, urethane rubber, EPDM rubber, etc. with a rubber hardness of 40° to 60' can be used.Also, as the intermediate layer (32), the Asker sponge hardness C scale is 30° to 60.0. Low-hardness foamed polyurethane, foamed NBR, or low-hardness rubber can be used.

Thereby, the roller surface hardness of the paper feed roller (3) as a whole can be maintained at 40° to 50°.

(5) is a separating roller, which is composed of reversing rollers (7), (7) attached to a roller shaft (6) and a driven roller (8), and the roller shaft (6) feeds the separating roller (5). It is supported by a frame υ which is biased by a spring (■) in the direction of pressing against the roller (3). Reversing roller (7)
, (7) is made of a rubber material whose outer peripheral surface friction coefficient and outer peripheral hardness are smaller than those of the outer peripheral layer (33) of the paper feed roller (3), such as foamed rubber materials such as foamed polyurethane and foamed polypropylene. The driven roller (8) is fixed to the outer peripheral surface of a core (not shown) attached to the shaft (6) via a one-sided clutch (not shown), and the driven roller (8) has a friction coefficient on its outer peripheral surface that is higher than that of the reversing roller (7). The outer periphery is made of a hard material that does not easily deform due to the pressure applied to the paper feed roller (3), such as polyacetal or a material whose surface is treated with Teflon, and the outer circumference is made of a material (not shown) of the core material of the reversing roller (7). It is rotatably provided on the outer peripheral surface of. Also, the reversing rollers (7), (7) and the driven roller (8) are collars (9), (9), and end collars (10).

Cl0). The roller shafts (4) and (6) are gears (11) that mesh with each other.
, (12) , connected in country 0, paper feed roller (3)
The reverse rollers (7) and (7) are configured to rotate in the direction of the arrow, respectively, and the driven roller (8) is configured to rotate in the direction of the arrow due to the rotation of the paper feed roller (3).

(14), α4Fi paper feed roller (3) and separation roller (5)
), which is a pair of conveying rollers that convey the old paper sent out by
) and the paper CP), we found that the change state of the friction coefficient (JL) of the paper feed roller (3) (
5 seconds), it stabilizes at μ=1.0 as shown in Figure 4.
It was confirmed that the amplitude was significantly reduced, and even after long-term operation, the paper feeding pressure was stable and large, and its conveyance performance was good.

In addition, the sound of paper separation during paper feeding was kept to a very low level.

In addition, in the present invention, the middle layer (32J is thick) and the outer layer (32J is thick)
It was better to make 3) thinner.

Effects As described above, the present invention provides a paper feed roller having an outer circumferential layer made of a highly wear-resistant rubber material, and an intermediate layer made of a vibration-absorbing rubber material is provided between the roller shaft and the outer circumferential layer. Since this paper feed roller is characterized by
This has the effect of stabilizing the paper feeding pressure, increasing the conveying force, and significantly reducing handling noise.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the frictional slip characteristics of a conventional separation roller pressure-contact paper feeding roller with paper, and FIG. 2 is a diagram showing a schematic configuration of a separation type paper feeding device employing a paper feeding roller according to the present invention. FIG. 3 is a sectional view of the paper feed roller of the present invention, and FIG.
FIG. 2 is a diagram showing the frictional slip characteristics of the paper feed roller of the apparatus with respect to paper. (3)... Paper feed roller, c31)... Core metal, (32
3... Middle layer, (33)... Outer layer, (4)...
Roller shaft, (5)... Sorting roller, P)... Paper applicant Minolta Camera Co., Ltd.

Claims (1)

[Scope of Claims] 1. In a paper feed roller equipped with an outer circumferential layer made of a highly wear-resistant rubber material, an intermediate layer made of a vibration-absorbing rubber material is provided between the roller shaft and the outer circumferential layer. Characteristic paper feed roller. 2. A patent characterized in that the intermediate layer is made of a low hardness rubber material. 3. A patent characterized in that the intermediate layer is made of a foamed rubber material. The paper feed roller described in range 1.