JPS5836835A - Paper feeder - Google Patents

Abstract

PURPOSE:To prevent a simultaneous feed of paper sheets, by setting an angle, provided in the reverse of a paper feed direction, of the contact angles, formed between a conveyer belt and double feed preventive member to a larger degree, and applying separative force between the simultaneously fed plural sheets. CONSTITUTION:A double feed preventive member 4, having a peripheral surface of radius of curvature R, is placed to the side of a driven pulley 2 from the middle of a driving pulley 1 and the drive pulley 2. Accordingly, a contact angle theta2 of the angles, that is, contact angles theta1, theta2, formed by a perpendicular h passing the center of a curvature A for a paper feed direction F and straight lines b, c passing contact points B, C, between a conveyer belt 3 and double feed preventive member 4, and passing the center of the curvature A, is inevitably formed larger. As a result, at a feed of paper, point end parts of the uppermost sheet X1 and the other sheet X2 are held between the conveyer belt 3 and the double feed preventive member 4 in a displaced state, and shear force, separating the both sheets X1, X2, is applied between the both sheets X1, X2. In this way, a simultaneously feeding frequency of the plural sheets X1, X2 can be decrease.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device used for feeding recording paper in a copying machine or the like.

Recently, in recording devices such as copying machines, paper feeding &if as shown in Fig. 1 has been used because it is suitable for sieving speed paper feeding. 1. ,! +1, etc., the paper feeding arrangement shown in the first diagram is the driving pulley/and the driven pulley VC,) JI) passed friction body 1- Large number t, c conveying belt 3, and the intermediate part of this conveying belt 3 It is equipped with a double-feed prevention member having a large coefficient of friction that is pressed against the belt, and by driving the conveyor belt 3 in the direction of the arrow, it peels off the uppermost sheet x1 and the other sheets X2.
Paper is fed by t+[Fl-. When I tried using a paper feeder with this structure, I found that several sheets of paper 1-'X1. There are often cases where X2 are fed at the same time. According to research conducted by the present inventors, this malfunction occurs when multiple sheets (Xl, The fact that no shearing force acts as a peeling force between X1° and x2 is considered to be J-.

Therefore, the present invention is based on a line perpendicular to the paper feeding direction VC passing through the center of curvature of the circumferential surface of the double-feed prevention member, and both sides f of this perpendicular line.
The angle between the contact point between the conveyor belt and the double-feed prevention member and the straight line that encloses the center of curvature of MiI (hereinafter referred to as 1)
It is called contact β [. ), it is recommended that the dose at the rear in the paper feeding direction be set larger than the other one.
Ru.

Hereinafter, details of embodiments embodying the present invention will be explained with reference to FIGS. 2 to 2.

Figure 1 shows the use of equal diameter driving booleans 11/1.2 and the center axes of these pulleys/1.2.

6 and the paper feeding direction I? This is an example in which H is set in parallel. In this example, the radius of curvature R
Double feeding prevention member 11 having a circumferential surface of 11. is biased towards the driven pulley side from the middle between the driving pulley and the driven pulley. Therefore, the angle i formed by a line perpendicular to the paper feeding direction F6C passing through the center of curvature A, contact points B and C between the conveyor belt 3 and the double-feed prevention member, and straight lines C and C passing through the center of curvature A. ,! 11 Contact angle θ1. Regarding θ2, the contact angle θ2 is inevitably larger. As a result, during sheet feeding, in A1), the leading edge of the second-most sheet X1 and the leading edge of the other sheet You will be caught. Therefore, there is a shear force I11 between both sheets x1 and X2! ! When multiple sheets of paper are fed at the same time, the degree of fineness decreases.
, 2 center 1η11. This is an example in which the straight line & connecting the two spaces and the paper feeding direction F are set parallel to each other. The feature of this embodiment is that the outer diameter of the driven pulley λ is the same as that of the driving pulley.
The outer diameter of the pulley is much larger than that of the pulley, and the double feed prevention member is located at the 11J1 position in the bald area of both pulleys. Even with such a tc configuration, the contact angle θ2 can be made smaller than the contact angle 01, so the same effect as in the case of FIG. 2 can be expected.

The double feed prevention member tag in Fig. V is located approximately in the middle of the 1-car boot Q/, , 2, as in the case of Fig. 3, and moreover,
Both boos 11/ and u are of equal diameter. The embodiment shown in FIG. V is characterized by the central axis S of both pulleys/2.

4 is at a point where the straight line a connecting the two points is oriented in one direction with respect to the paper feeding direction PK. Even with this L-shaped configuration, the contact angle θ2 can be set larger than the contact angle 01, so that malfunctions are reduced. In addition, in the present invention, tit, 11
Of course, it is also possible to implement a combination of the embodiments shown in FIGS.

After all, according to the present invention, it is possible to provide a highly reliable paper feeding device with fewer malfunctions without increasing the product cost.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional paper feeding device, Fig. 2 is an explanatory diagram of an embodiment of a paper feeding device + W according to the present invention, and Fig. 3 is an explanatory diagram of a third embodiment of the present invention. The figure is an explanatory diagram of a third embodiment according to the present invention. 3... Conveyor belt, G... Double feed prevention member, b, c.
... Straight line, h... Perpendicular line, θ1. θ2...Contact angle, A
...Curvature center, B, C...Contact point, F...Paper feeding direction. Patent applicant: Konishi Rokushani Kogyo Co., Ltd. Patent attorney: Ta 1) Akira Hiroshi 5- -IC.

Claims (1)

[Claims] 1) A conveyor belt driven in one direction and an arc-shaped li!
In the sheet feeding direction 1θVC, which is equipped with a double feeding prevention member whose i11 surface is pressed against this conveyor belt, iif the east line passing through the circumference ratio center 2 in the sheet feeding direction, and both fl of this perpendicular line.
Ill rank! i&l conveyor belt-double feed prevention member 1
Among the angles formed between the 1fto) contact point and the riJ center of curvature with the straight line, the rear angle in the paper feeding direction is made larger than the other.