JPS63258335A - Automatic sheet feed device - Google Patents

Abstract

PURPOSE:To prevent the feed of sheets in a state to be overlapped with each other, by a method wherein a press member is pressed against a friction piece in a state to be rockable around an axis parallel to the axis of a feed roller through the force of a spring. CONSTITUTION:Since a press member 11 is rockable around a support rod 12, a press force exerted through the force of a spring 15 for regulating a press force is divided in a given ratio irrespective of the angle position of the press member 11 to transmit the divided press forces to two projections 11a and 11b. Thus, the press force of each of the projections 11a and 11b is normally kept at a specified value irrespective of the presence of a sheet between a friction piece 10 and a feed roller 9. Thus, the friction piece 10 is pressed against the feed roller 9 throughout a wide area, a sheet 7 is reliably selected, and the sheets can be fed one by one. For example, even when the rear end of a feed sheet 7a is positioned at the projection 11b between the friction piece 10 and the feed roller 9, at the projection 11a, the friction piece 10 is brought into contact with the feed roller 9, and overlap with a subsequent sheets 7b and 7c is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic paper feeder used in a facsimile copying machine and the like.

2. Description of the Related Art As shown in FIG. 5, a conventional automatic paper feeder is arranged at the lower end of a paper feed tray 2 on which paper 1 such as a document to be fed is placed.
A paper feed roller 3 is rotated by a drive source (not shown), and two grooves are provided on the outer peripheral surface of the paper feed roller 3.

It has a friction piece 4 made of an elastic body such as a rubber plate that is pressed against it, and a suppressing piece 5 that presses the friction piece 4 against the paper feed roller 3, and the leading edge of the paper feed roller 3 holds a plurality of sheets of paper 1. By setting the paper feed roller 3 so that it is inserted between the roller 3 and the friction piece 4, and rotating the paper feed roller 3 in the direction of the arrow, a plurality of sheets of paper 1 can be fed.
is conveyed in the direction of the arrow and moves from the contact point 6 between the paper feed roller 3 and the friction piece 4 to the end of the friction piece.
friction coefficient between and paper 1, friction coefficient between papers, paper 1
The paper is sorted based on the difference in the friction coefficient between the paper feed roller 3 and the friction piece 4, and only the lowest paper that comes into contact with the paper feed roller 3 is fed out.

Problems to be Solved by the Invention However, with this configuration, there is a problem in that the lowest paper is not sorted smoothly and the paper may be fed out while still being polymerized.

The above problem arises for the following reasons. That is, if the paper is thick and the gap between the friction piece 4 and the paper feed roller 3 is large, or due to plastic deformation of the friction piece 4, the contact between the friction piece 4 and the paper feed roller 3 at the contact point 6 is insufficient by 3 degrees. In some cases, subsequent sheets of paper may enter deeply at the same time, resulting in overlapping and being fed out without being sufficiently sorted.

The present invention has been made in view of the above-mentioned problems, and provides an automatic paper feeder that allows stacked sheets of paper to be fed out sequentially from the lowest one without stacking the sheets of paper while being fed out. The purpose is to

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention uses a friction piece as a pressing member that presses the friction piece against the paper feed roller at two locations separated in the circumferential direction of the paper feed roller. A member shaped to press is used, and the pressing member is pressed against the friction piece by a spring in a swingable state about an axis parallel to the axis of the paper feed roller.

Effect of the Invention With the above-described configuration, the present invention has two contact points between the pressing member and the friction piece, making it possible to increase the area of pressure contact between the friction piece and the paper feed roller. It can swing around an axis parallel to the axis, so when it is pressed against the friction piece by a spring,
The pressing forces of the two contact points are always at a constant ratio, and the balance can be automatically adjusted.
It becomes possible to reliably sort a plurality of sheets of paper and feed them one by one.

Embodiment FIG. 1 is a side view showing a schematic configuration of an automatic paper feeder according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts thereof. In the figure, 7 is the paper to be fed, 8 is a paper feed tray on which many sheets of paper 7 are stacked, and 9 is a paper feed roller provided at the lower end of this paper feed tray 8. It is connected to a drive device (not shown) for rotation. 10 is a friction piece made of an elastic body such as a rubber plate, and 11 is a pressing member that presses this friction piece 10 against the paper feed roller 9. This pressing member 11 is
It is provided with two protrusions 11a and 11b so as to press the friction piece 10 at two locations separated in the circumferential direction of the paper feed roller 9, and one protrusion 11c is provided on the opposite side. Ru. Further, an elongated hole lid is formed in the center, and is held by a support rod 12 that passes through the elongated hole 11d. With this structure, the pressing member 11 is movable relative to the paper feed roller 9 and swingable about an axis parallel to the axis of the paper feed roller. 13 is an auxiliary pressing member;
It is rotatably held by the support shaft 14 and placed in a position to press the protrusion 11c of the pressing member 11. Reference numeral 15 denotes a pressing force adjustment spring, which applies a force in the direction of arrow B to the auxiliary pressing member 13.

With this structure, the auxiliary pressing member 13 presses the protrusion 11c of the pressing member 11 to press the pressing member 11 against the friction piece 10, and the pressing member 11 presses the friction piece 11 with the two protrusions 11a and llb.
0 to the paper feed roller 9. Here, since the pressing member 11 is swingable around the support rod 12, the pressing force applied by the pressing force adjustment spring 15 is applied to the pressing member 1.
Regardless of the angular position of the projection 11a, it is divided into a predetermined ratio and transmitted to the two projections 11a and llb, and therefore the projection 11a
, llb are kept constant regardless of whether there is paper between the friction piece and the feeding roller. In this way, the friction piece 10 is pressed against the paper feed roller 9 over a wide area of 6 blades, and the paper 7 can be reliably sorted and fed one by one. For example, as shown in FIG. Even if the rear end of the paper feed sheet 7a is located between the friction piece 10 and the paper feed roller 9 at the protrusion 11b, the friction piece 10 contacts the paper feed roller 9 at the protrusion 11a, resulting in an island. It is possible to prevent the subsequent sheets 7b and 7c from overlapping.

Although it is necessary to change the pressing force of the pressing member 11 depending on the thickness of the paper, this adjustment can be made by adjusting the spring force of the spring 15.

Note that depending on the paper thickness, paper quality, etc., it may be desirable to change the ratio of the pressing forces of the two protrusions 11a and llb of the pressing member 11. In that case, Fig. 4(a),(b)
The shape of the pressing member 11 may be changed as shown in FIG. The pressing member 11 in FIG. 4(a) is an example in which a projection 11c that contacts the auxiliary pressing member 13 is provided near the projection 11a, and the pressing force of the projection 11a can be made larger than that of the projection 11b. Further, the pressing member 11 in FIG. 4(b) is an example in which a projection 11C that contacts the auxiliary pressing member 13 is provided near the projection 11b, and the pressing force 7 to -7 of the projection 11b is larger than that of the projection 11a. can do.

Effects of the Invention As is clear from the above explanation, the present invention uses a pressing member that presses a friction piece against a paper feed roller, and presses the friction piece at two locations separated in the circumferential direction of the paper feed roller. The contact point i between the pressing member and the friction piece is determined by pressing the pressing member against the friction piece with a spring while being able to swing around an axis parallel to the axis of the paper feed roller. - can be set at two locations, and the pressing force at each of the two contact points can be kept constant at all times,
This has the effect that the friction piece stably contacts the paper feed roller over a wide area, making it possible to reliably sort the paper, and preventing the paper from being fed out while still being polymerized.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a schematic configuration of an automatic paper feeding device according to an embodiment of the present invention, FIG. 2 is an enlarged view of the main parts thereof, and FIG. 3 is a side view showing the paper passing through the device in FIG. 1. Figure, Figure 4 (
FIG. 5 is a side view showing a schematic configuration of a conventional automatic paper feeder. 7...Paper, 8...Paper feed stand, 9...Paper feed roller,
10...Friction piece, 11...Press member, 11 a
, 11 b , 11 c - projection, 11 d... elongated hole, 12... support rod, 13... auxiliary pressing member, 15
... Spring for adjusting pressing force. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 5
Figure 12 only n-

Claims (1)

[Claims] A paper feed roller, a friction piece made of an elastic body pressed against the outer circumferential surface of the paper feed roller, and a single friction piece having a shape such that the friction piece is pressed at two circumferentially apart locations of the paper feed roller. An automatic sheet feeder comprising: a pressing member that is swingable about an axis parallel to the axis of the sheet feeding roller; and a spring that presses the pressing member against the friction piece.