JPH06144619A - Paper feeding device - Google Patents

Abstract

PURPOSE:To provide a paper feeding device capable of preventing sheets from being caught on both ends of a friction pad part at the time when the sheets are separated and occurrence of jamming, non-delivery, overlapped delivery and others as they become a load and easily changing length of a guide to slide the sheets. CONSTITUTION:In a paper feeding device of a friction pad system to carry out separation of sheets by a paper feeding roller and a friction pad, a friction pad part 1, a friction pad holder 2 to hold the friction pad part 1, a head end front surface part 3 on the paper feeding side of a sheet 4 of the friction pad holder 2 and a guide plate 5 covering both ends of a paper feeding surface of the sheet 4 of the friction pad part 1 and the head end front surface part 3 on the paper feeding side of the friction pad holder 2 are furnished, and catching of the sheet 4 at the time of paper feeding is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for recording paper in an image forming apparatus or the like, and more particularly to an improvement of a friction pad type sheet feeding device used in copying machines, facsimiles, printers and the like. It is about.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a facsimile machine, a printer or the like, a friction pad type feeding mechanism is used as a mechanism for feeding one by one from recording sheets or originals in a stacked state. A paper machine is used. FIG. 3 is a perspective view of a main part of a conventional paper feeding device, and FIG. 4 is a perspective view for explaining the catching of the paper. The friction pad portion 101 is abutted and stuck to the lower surface 102a of the friction pad holder 102. Has been.
The front end surface portion 103, which is a protrusion located immediately in front of the lower surface 102a, is in sliding contact with the surface of the sheet 104 and serves as a guide for sliding the sheet. The friction pad holder 102, which is rotatably supported about the shaft 102b, is constantly pressed by a separation spring (not shown) against a paper feed roller (not shown) located above. By the rotation of the paper feed roller, the paper 104 is passed in the direction of arrow A, and the front end of the paper 104 slides on the front surface 103 of the front end of the portion serving as the guide, and the paper feed roller not shown. Is conveyed to the nip between the friction pad 101 and
The friction pad section 101, the sheet 104, and the sheet feed roller (not shown) are separated and sent out according to the relationship of the friction coefficient.

In FIG. 4, a place and a state where the sheet 104 is easily caught when passing over the friction pad portion 101 will be described. The sheet 104 is fed by being sandwiched between a paper feed roller (not shown) and the friction pad section 101, but the sheet 104 is fed by the friction pad section 101.
As shown in the drawing, when passing through, the friction pad holder 102 has a mountain shape curved in the width direction, and both ends in the width direction of the friction pad holder 102 hang down. At this time, the paper 104 is
It was easy for the friction pad portion 101 to be caught at both end corners or to act as a load to cause a jam or a non-feed. When the friction pad portion 101 is attached to the friction pad holder 102, the friction pad holder 102 is attached to a position slightly lower than the paper passing surface of the friction pad holder 102. At this time, the friction pad holder 10 is attached.
2 and the friction pad portion 101 have a gap 105 between them.
If there is such a problem, the leading edge of the paper sheet 104 digs into it and is caught, causing a problem such as jamming or non-feeding.

Further, at the front end of the paper passing surface of the friction pad holder 102, there is provided a front end surface portion 103 which serves as a guide for sliding the paper 104 in order to convey the paper 104 to a nip portion (not shown) to some extent. is there. If the length of the front end front face portion 103 (the length in the conveying direction) is large, the paper 104 slides on the front end front face portion 103 and always enters deep inside the nip portion, so that a multi-feed of multiple sheets is likely to occur. . On the contrary, if the length of the front end front surface portion 103 that functions as a guide for sliding the sheet 104 is short, the non-feeding is likely to occur. Further, the relationship between double feeding and non-feeding becomes complicated depending on the type of paper, and the length of the front end front surface portion 103 (the length in the carrying direction) of the portion that functions as a guide for sliding the paper 104 is set. Whether to do so is an extremely important factor to prevent double feeding and non-feeding. However, since the front end front surface portion 103 of the portion which functions as a guide for sliding the conventional paper 104 is made by die casting, the length of the front end front surface portion 103 can be changed by the friction pad holder 102. There was a problem that it took a lot of trouble because it had to be changed. The places (a) and (b) shown in the figure are places that are easily caught.

[0005]

In the above-mentioned paper feeding device, the paper is caught on both ends of the friction pad portion, or becomes a load to cause jamming, non-feeding or double feeding. There has been a problem that the friction pad holder itself needs to be remade in order to make the front surface of the tip end of the portion that serves as a guide to slide to an appropriate length.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention is intended to solve such a problem. That is, the present invention prevents the occurrence of jams, non-feeds, or double feeds that may occur when the paper is caught at both ends of the friction pad portion or acts as a load when the paper is separated. An object of the present invention is to provide a paper feeding device in which the length of a guide to be guided can be easily changed.

[0007]

In order to achieve the above object, the present invention provides a friction pad type sheet feeding device in which a sheet is separated at a nip portion between a sheet feeding roller and a friction pad. It is held by a friction pad holder and has a front end front surface on the paper passing side of the friction pad holder and a guide plate that covers both ends of the paper passing surface of the friction pad section at the same time, and prevents the paper from being caught when passing the paper. The surface of the guide plate is made of a material on which the paper easily slips, and the guide plate has a U-shaped planar shape and can be fitted over the friction pad holder.

[0008]

In the sheet feeding device constructed as described above, the friction pad portion guides at both ends in the width direction of the sheet passing surface of the friction pad portion and the front end portion of the friction pad holder on the sheet passing side are made of a slippery material. By covering with a plate, when the sheets are separated, it is possible to prevent the both ends of the friction pad portion from being caught or being a load to cause jamming, non-feeding, or double feeding. Furthermore, since the guide plate has a U-shaped planar shape, it can be easily inserted into the friction pad holder or easily removed in the opposite direction, so the length of the guide that slides the paper should be an appropriate length. You will be able to easily change to one.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 (a) and 1 (b) are a cross-sectional view showing a schematic configuration of a sheet feeding device to which the present invention is applied, and a perspective view of a main part thereof. The base 6 supported by the main body of the image forming apparatus has a structure in which a paper base 7 for stacking paper 4 is moved up and down by a fulcrum shaft 8 provided on the base 6. The paper tray 7 is always biased upward by the paper feed spring 9, and the paper tray 7 or the paper on the paper tray 7 is pressed by the paper feed roller 10 located in the nearest position. The friction pad holder 2 is also always fed by the separation spring 11 to the feed roller 1.
Pressed to 0. This state is the set state,
In this state, the paper 4 is not fed.

A lever 13 whose one end is attached to the left and right shafts 12 of the base 6 is rotatably supported by the shaft 12, and a hole 14 of the lever 13 is used to move the paper tray 7 up and down. A shaft 16 at one end of the arm 15 is attached, and at the other end of the shaft 16 of the arm 15, a shaft 17 for pushing down the paper tray 7 and a square hole 1 provided in the base 6.
There is a shaft 19 which is fitted to the No. 8 and moves up and down with this as a guide (see (b)). As a result, when the lever 13 is lifted upward, the shaft 19 of the arm 15 linearly moves downward along the square hole 18 of the base 6. Further, the shaft 17 of the arm 15 is also moved downward at the same time and the paper table 7 is pushed down, so that the pressing between the paper feed roller 10 and the paper table 7 is eliminated, and a gap is formed between them so that the paper 4 can be set. it can. Next, when the lever 13 is lowered, the operation opposite to the above is performed and the paper tray 7 is moved up to raise the paper 4 and the paper feed roller 1.
The pressure is applied to 0, and the sheet is fed.

Here, when the paper feed roller 10 rotates clockwise, the set uppermost paper 4 is fed, and the front end front surface portion 3 of the guide on the front surface of the friction pad holder 2 is fed.
Slip on and go to friction pad section 1. Further, due to friction between the respective sheets 4, even if several sheets are continuously fed to the uppermost sheet 4 and the plural sheets 4 are simultaneously fed, the sheet 4 that has entered the sheet hits the friction pad portion 1 earlier and the uppermost sheet 4 is fed. Is always pulled by the paper feed roller 10, and since the frictional force between the respective sheets 4 is smaller than the frictional force between the friction pad portion 1 and the sheet 4, the uppermost sheet 4 is always
Is transported.

FIG. 2 is an exploded enlarged view of the friction pad portion. The friction pad portion 1 is abutted and attached to the upper surface 2a of the friction pad holder 2 which is lower than the tip front surface portion 3. The friction pad holder 2 has an L-shaped side surface, is pivotally supported in a vertical direction by a shaft 2b at a lower end portion, and the friction pad portion 1 is bonded to an upper portion thereof. The sheet 4 is passed through the upper portion of the friction pad holder 2 in the direction of arrow A. Both ends of the paper passing surface of the paper 4 of the friction pad portion 1 and the front end front surface portion 3 of the friction pad holder 2 on the paper passing side are detachably covered with guide plates 5 made of a material on which the paper 4 slips easily. Has become. Since the guide plate 5 has a U-shaped planar shape, it can be easily fitted over the friction pad holder 2 in the direction of the arrow B, or can be easily removed in the opposite direction. Note that the guide plate 5 in FIG. 2 is shown in a state of being separated from the front surface portion 3, and when the guide plate 5 is assembled, the friction pad 1 is exposed in the void portion of the U-shaped guide plate 5. Become. By selectively mounting and using guide plates 5 having different shapes (particularly, the length of the portion covering the front surface portion 3 in the transport direction), good paper feeding that meets conditions such as paper quality is realized. be able to.

[0013]

Since the present invention is configured as described above, both ends of the paper passing surface of the paper 4 of the friction pad portion 1 and the front end front surface portion 3 of the friction pad holder 2 on the paper passing side are surfaced. Since the paper 4 is covered with the guide plate 5 made of a slippery material, when the paper 4 is separated, it is caught on both ends of the friction pad portion 1,
Alternatively, it is possible to prevent jamming, non-feeding, or double feeding as a load. Further, since the guide plate 5 is U-shaped, it can be easily fitted over the friction pad holder 2 or can be easily removed in the opposite direction. Therefore, the guide length for sliding the paper 4 can be set to an appropriate length. You can easily turn it into something. Even if a gap is formed between the holder and the pad portion, the guide plate can cover the gap, so that the sheet can be prevented from being caught.

[Brief description of drawings]

1A and 1B are side sectional views of a sheet feeding device to which the present invention is applied.

FIG. 2 is a perspective view of a main part of a paper feeding device showing an embodiment of the present invention.

FIG. 3 is a perspective view of a main part of a conventional paper feeding device.

FIG. 4 is a perspective view of a main part for explaining a catch of a sheet in a conventional sheet feeding device.

[Explanation of reference numerals] 1 ... Friction pad portion, 2 ... Friction pad holder, 3 ... Front end portion, 4 ... Paper, 5
... Guide plate, 6 ... Base, 7 ... Paper stand, 8
... fulcrum shaft, 9 ... paper feeding spring, 10 ... paper feeding roller, 11 ... separation spring, 12 ... shaft,
13 ... Lever, 14 ... Hole, 15 ... Arm,
16 ... Shaft, 17 ... Shaft, 18 ... Square hole, 19 ...
..Shafts, 101 ... Friction pad portions, 102 ...
..Friction pad holder, 103 ... front end portion, 104 ... paper, 105 ... gap

Claims (3)

[Claims] 1. A friction pad type sheet feeding device for separating sheets at a nip portion between a sheet feeding roller and a friction pad, wherein the friction pad portion is held by a friction pad holder, and the passage side of the friction pad holder. And a guide plate that covers both ends of the paper passing surface of the friction pad portion at the same time, thereby preventing the paper from being caught when the paper is passed. 2. The paper feeding device according to claim 1, wherein the surface of the guide plate is made of a material that allows the paper to slip easily. 3. The paper feeding device according to claim 1, wherein the guide plate has a U-shaped planar shape and can be fitted and covered on the friction pad holder.