JPS6216951A - Paper feed device in copying machine - Google Patents

Abstract

PURPOSE:To surely prevent double-feed, by providing an upper guide for a plate-like paper feed tray, in the upper section of the latter, and by providing a rubber piece for resiliently pressing a preceding paper sheet against the upper guide together with the following paper sheet, to a manual insertion gate. CONSTITUTION:A first paper sheet P1 fed by a conveyer roller 6 and a second paper sheet P2 pulled to a position just before a pressing member 8, are pressed against a manual insertion gate 2 by means of a rubber piece 11 having a large friction coefficient and provided to the manual insertion gate 2, and therefore, they are introduced into the gate 2. Accordingly, the paper sheet P1 alone which does not make into contact with the rubber piece 11 is fed by the conveyer roller 6 while the paper sheet P2 which makes into contact with the rubber piece 11 is inhibited from moving. Accordingly it is possible to prevent double feed concerning the first and second paper sheets P1, P2.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a paper feeding device for a copying machine used to continuously feed cut sheets (copy paper) into a copying machine.

<Prior Art and Its Disadvantages> A conventional paper feeding device and its operation will be described with reference to FIGS. 2(A) to 2(E).

A conventional paper feed device is configured to feed paper P set in paper feed tray 1.
The manual feed gate 2 and 1. are opened and closed between an upper position that prevents the paper from being fed and a lower position that allows the paper to be fed. A feed roller 3, a pull-in roller 4 that is interlocked with the paper feed roller 3 and moves toward and away from the paper P, a reversing roller 5 that moves towards and away from the paper feed roller 3, and a paper P+ fed by the paper feed roller 3. A transport roller 6 that feeds the paper to a predetermined location, a plate-shaped paper feed guide 7 that guides the paper P sent by the paper feed roller 3 to the transport roller 6, and a paper P that is sent by the paper feed roller 3.
, to the paper feed guide 7 to prevent the subsequent paper P2 from moving together, the paper feed roller 3
The manual feed gate 2 is configured to be displaced to the above-mentioned upper position and protrude to the upper part of the paper feed tray 1 in synchronization with the movement of the reversing roller 5 away from the paper feed tray 1.

When the manual feed solenoid (not shown) is off, the manual feed gate 2 protrudes to the top of the paper feed tray 1 and is set at the upper position as shown in FIG. The leading edges of the multiple sheets of paper P are aligned, the feed roller 4 is separated from the paper P, and the reversing roller 5 is separated from the paper feed roller 3, creating a gap between the paper feed roller 3 and the paper feed roller 3. S is formed. The reason why the reversing roller 5 is separated from the paper feed roller 3 when the manual feed solenoid is off is because both rollers 3 and 5
If the rollers 5 and 3 are in contact with each other, the reverse rotation roller 5 will always be in contact with the paper feed roller 3 regardless of whether the copying machine is in copy mode or not. This is because if you do, you won't be able to pull it out. When the manual feed solenoid is turned on from this state, the manual feed gate 2 moves down around the support shaft 2a to open the paper feed tray 1, as shown by arrows a, b, and c in FIG. 2(B). At the same time when the paper retracts downward and is set at the lower position, the feed roller 4 contacts the paper P, and the reversing roller 5 contacts the paper feed roller 3 to be in a pressurized state. This completes the paper feeding preparation. After a certain period of time (several seconds) after the manual feed solenoid is turned on, the arrow d appears in Figure 2 (C).
, e.

As shown by f, the paper feed roller 3, the pull-in roller 4, and the reversing roller 5 start rotating. This allows paper feed tray 1
The topmost paper (hereinafter referred to as the first paper) P,
is fed into the paper feed guide 7.

At this time, the paper below (hereinafter referred to as the second paper) P2 is often dragged by the first paper P, but this second paper P2 is not connected to the paper feed roller 3. It is separated by a reversing roller 5 rotating in the opposite direction. Therefore, only the first sheet PI is fed into the sheet feed guide 7. The first sheet of paper P fed into the paper feed guide 7 in this manner turns on the transport roller starting switch 9 as shown in FIG. 2(D).

When this switch 9 is turned on, the conveyance roller 6 starts rotating. The conveyance roller 6 consists of an upper roller 6a and a lower roller 6b, and these rollers 6a and 6b transport the paper PI.
A message is sent to Furthermore, after a certain period of time has elapsed since the switch 9 was turned on, while the paper P1 is being fed by the conveyance roller 6, the manual feed solenoid is turned off.
The rotation of the paper feeding roller 3 and the drawing roller 4 is stopped. This kind of control is necessary because if the paper feed roller 3 continues to rotate at this point, the second sheet P2 will be fed by the pull-in roller 4 that is interlocked with the paper feed roller 3. This is because it causes the inconvenience of being caught. However, when the manual feed solenoid is turned off, the reversing roller 5 separates from the paper feed roller 3 as shown by arrow C' in FIG. It stops working on the second sheet of paper P2. Therefore,
Due to the handling action of the reversing roller 5, the second sheet P2, which has stopped without passing through the paper feed roller 3, is dragged by the first sheet PI, which is being fed by the transport roller 6, and is moved to the paper feed guide 7. may be derived. Further, the manual feed gate 2 is displaced to the above-mentioned upper position as indicated by the arrow a' in synchronization with the separation operation of the reversing roller 5, and projects to the upper part of the paper feed tray 1.

However, if the second sheet P2 is allowed to be dragged by the first sheet PI, double feeding will occur even if the manual feed gate 2 is set to the upper position in synchronization with the separation operation of the reversing roller 5. Conventionally, the paper feed guide 7 is composed of a lower guide 7a and an upper guide 7b, and the paper is introduced between these, and a member 8 is used to press the paper with a rubber piece or the like to elastically push the paper against the upper guide 7b. 3 of the second sheet of paper P2! ': This pressing of the 0 movement was stopped by the member 8, thereby preventing double feeding of the paper P2.

However, if the elastic force of the pressing member 8 is too strong, the so-called weak paper will not be able to overcome the pressing member 8 against its elasticity even if it is fed by the paper feed roller 3. This pressing causes a paper jam in front of the member 8. Conversely, if the elastic force of the pressing member is too weak, it will not be able to sufficiently separate paper with a large coefficient of friction, such as thin paper or paper with a rough surface, and the paper will be dragged by the preceding paper. When the subsequent paper is pressed against the elasticity of the member 8, the pressing easily overcomes the member 8.
resulting in double feed. That is, simply providing the pressing member 8 as in the prior art has the disadvantage that it cannot adequately deal with the quality and type of paper in preventing double feeding.

<Object of the Invention> The present invention was made to improve the above-mentioned conventional drawbacks, and provides a paper feeding device that can reliably prevent double feeding even if the quality or type of paper changes. The purpose is to

<Structure and Effects of the Invention> In order to achieve the above object, the present invention arranges a plate-shaped paper feed tray upper guide on the upper part of the paper feed tray, and also provides a guide for the preceding paper fed by a conveyance roller and the preceding paper. The manual feed gate is provided with a rubber piece that elastically presses and pinches the succeeding sheet dragged by the paper feed tray upper guide.

According to the above means, the preceding paper being fed by the conveyance roller and the succeeding paper being dragged by this are elastically pressed against the upper guide of the paper feed tray by the rubber piece provided on the manual feed gate and are sandwiched between them. Even if a gap is formed between the reversing roller and the paper feed roller, only the preceding paper that is not in contact with the rubber piece with a large friction coefficient will be fed by the conveyance roller, and the following paper that is in contact with the rubber piece will be fed. The paper is prevented from being sent to the transport rollers. Further, the movement of the sheet dragged by the following rollers is stopped by the rubber piece.

Therefore, double feeding is reliably prevented regardless of whether the paper is of low "stiffness" or has a large coefficient of friction.

<Example> An embodiment of the present invention will be described below with reference to FIG.

In the figure, reference numeral 10 denotes a paper feed tray upper guide, and reference numeral 11 denotes a rubber piece having a large friction coefficient, such as urethane rubber.The rubber piece 11 is provided at the tip of the manual feed gate 2.

FIG. 1 corresponds to FIG. 2(E) described in the conventional example.

That is, after the switch 9 in FIG. 2(E) is turned on and the conveying roller 6 starts rotating, the reversing roller 5 separates from the paper feed roller 3 after a certain period of time, and in synchronization with this separating operation, the manual feed gate 2 opens. is set at an upper position that prevents the paper P from being fed, and is shown projecting to the upper part of the paper feed tray 1.

In this state, the first sheet P, which is being fed by the transport roller 6, and the second sheet P2, which has been dragged to the front of the pressing member 8, are provided at the manual feed gate 2. The rubber piece 11 having a large friction coefficient is elastically pressed against the upper guide 10 of the paper feed tray and is sandwiched therein. Therefore, only the first sheet P1 that is not in contact with the rubber piece 11 is sent by the conveyance roller 6,
Even if the second sheet P2 in contact with the rubber piece 11 is pulled by the first sheet P, its valve movement is prevented by the friction with the rubber piece 11. Therefore, double feeding of the first sheet P1 and the second sheet P2 is prevented. In the above, if the contact surface of the paper feed tray upper guide 10 with the paper is subjected to a lubricating treatment, for example, a Teflon coating, the paper separation effect by the rubber piece 11 will be promoted, and double feeding will be more reliably prevented. .

In Figure 1, matters other than those mentioned above are shown in Figure 2 (A) ~
This is the same as explained in (E).

Further, the same elements as those described in FIGS. 2(A) to (E) are given the same reference numerals, and detailed explanations thereof are omitted.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing the main parts of a paper feeding device according to an embodiment of the present invention, and FIGS. 2(A) to (E) are schematic side views for explaining the operation of a conventional paper feeding device. . 1...Paper feed tray, 2...Manual feed gate, 3...
Paper feed roller, 4... Pick-up roller, 5... Reverse roller, 6... Conveyance roller, 7... Paper feed guide, 8...
・Pushing member: 10...Paper feed tray upper guide, 11...Rubber piece, P, PI+ p2...Paper.

Claims (1)

[Claims] (1) A manual feed gate that moves in and out between an upper position that prevents the paper set in the paper feed tray from being fed and a lower position that allows the paper to be fed, a paper feed roller, and a manual feed gate that is linked to the paper feed roller. and a pull-in roller that approaches and separates from the paper, a reversing roller that approaches and separates from the paper feed roller, a transport roller that feeds the paper fed by the paper feed roller to a predetermined location, and a paper fed by the paper feed roller. A plate-shaped paper feed guide that guides the paper to the transport roller, and a pressing member that elastically presses the paper fed by the paper feed roller against the paper feed guide to prevent double feeding of subsequent paper. In a copying machine paper feeding device configured such that the manual feed gate moves to the above-mentioned upper position and protrudes above the paper feed tray in synchronization with the separation operation of the reversing roller, a plate-shaped plate is provided at the top of the paper feed tray. In addition to arranging a paper feed tray upper guide, a rubber piece is provided on the manual feed gate to elastically press and sandwich the preceding paper fed by the conveyance roller and the subsequent paper dragged by the preceding paper against the paper feed tray upper guide. A paper feed device for a copying machine characterized by the following.