JPH0676148B2 - Sheet material feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a sheet material feeding device, more specifically, for example, a copying machine,
A device for feeding a sheet material in an image forming apparatus such as a printer, a printing machine, etc.
The present invention relates to a sheet material feeding device that feeds sheets one by one.

<Prior Art> A conventional device of this type will be described. As shown in FIG. 9, the paper feed roller 2 is in a position in contact with the sheet material P and the separation pad 7. The sheet material P is stacked on the middle plate 22,
It is lifted up from below by a middle plate lifting spring 23. As a result, the sheet material P is always in contact with the paper feed roller 2.

Then, when a start key (not shown) is pressed, the paper feed roller 2 rotates (clockwise in the illustrated example) to feed the uppermost sheet material P ₁ . At this time, the second sheet material P ₂ tries to move together due to the frictional force with the sheet material P ₁ ,
As shown in FIG. 10, the sheet material P after the sheet material P ₂ is stopped by the separating pad 7. The frictional force between the sheet feeding roller 2 and the sheet material P ₁ is F, the frictional force between the sheet materials P is G,
This is because when the repulsive force between the sheet material P and the separation pad 7 is H, the frictional force is F>H> G.

Accordingly, the sheet material P ₂ ~Pi was Zuido with the sheet material P ₁ is stopped by sequential separation pads 7 from the lowermost sheet material Pi, is conveyed only sheet P ₁ the uppermost, is fed to the transport roller 20.

In this way, the sheet materials P on the stacking table 21 are separated and conveyed one by one. In order for the sheet material P to be conveyed by the conveying roller 20 at a regular speed, the one-way clutch 5 is inserted in the sheet feeding roller shaft 6 so that the sheet feeding roller 2 does not become a load at the time of conveyance. This one-way clutch 5 drives the paper feed roller 2 when the roller shaft 6 rotates in the conveying direction relative to the paper feed roller 2, that is, in the clockwise direction in FIG. 9, but when it rotates counterclockwise. (When the paper feed roller 2 rotates faster than the paper feed roller shaft 6), it is incorporated so as to be free. That is,
The sheet feeding roller 2 is driven only when the sheet material P is fed and separated, and when the sheet material P is transported by the transport roller 20,
In order to prevent the subsequent double feeding of the sheet material P, the sheet material P is pressed against the separation pad 7.

However, when the sheet material P remains between the paper feed roller 2 and the separation pad 7 due to a jam or the like, the sheet material P is sandwiched between the paper feed roller 2 and the separation pad 7, and the paper feed roller 2 is reversed. Since the structure is not (counterclockwise in the illustrated example), it is difficult to pull out the sheet material P, and there are cases in which the sheet material P is torn and remains between the paper feed roller 2 and the separation pad 7.
As a countermeasure against this, a mechanism for releasing the pressure of the separation pad 7 is required, which causes problems such as cost increase and compactness.

Further, since the paper feed roller 2 and the separation pad 7 are always in contact with each other, until the sheet material enters between the paper feed roller 2 and the separation pad 7, the roller and the pad rub directly against each other, so that the load is heavy. However, the load fluctuation before and after the entering of the paper becomes large, which causes the unevenness of the image in the image and the durability.

<Purpose of the invention> The present invention has been made in view of the above-mentioned drawbacks of the conventional example, has a simple structure and is excellent in durability, does not exert an extra load during sheet material conveyance, or takes out the sheet material. An object of the present invention is to provide a sheet material feeding device that can be easily made.

<Means for Solving Problems> In order to achieve the above-mentioned object, a sheet material feeding device according to the present invention is configured such that a plurality of sheet materials are frictionally separated one by one between a sheet feeding roller and a separating member. In the sheet material feeding device for feeding, the paper feeding roller has a notch in part, and is configured such that the outer peripheral surface and the separating member are in pressure contact with each other to separate the sheet material, A pressing member for pressing the sheet material in the process of being separated and sent out to the auxiliary separating member arranged in the vicinity of the separating member when the paper feeding roller rotates and the cutout portion faces the separating member. And a load applied to the sheet by the pressing member and the auxiliary member is smaller than a load applied to the sheet material by the sheet feeding roller and the separating member.

<Embodiment> FIGS. 1 to 5 show an embodiment of the present invention in which P is a sheet material (hereinafter referred to as "paper sheets"), 2 is a half-moon-shaped paper feed roller for feeding paper sheets, and 6 Is a paper feed shaft, 7 is a separation pad, and is a separation pad 7a, which is a separation member that comes into contact with the separation roller 7 when the paper feed roller 2 rotates, and auxiliary separation members having a higher friction coefficient than the separation pad 7a. It consists of a separation aid pad 7b. 8 is a spring that elastically supports the separation pad 7, 9 is on the paper feed shaft 6, slightly smaller than the radius of the paper feed roller 2, and when the paper feed roller 2 is not in contact with the separation pad 7a. , A separation idler roller which is a pressing means that freely rotates in contact with the separation auxiliary pad 7b, 10 is a lower guide, 11 is an upper guide, 20
Is a pair of conveying rollers, 21 is a cassette for storing the paper sheets P, 22
Is a middle plate for pushing up the paper sheets P upward, and 23 is a spring for pushing up the middle plate 22 upward.

If the frictional forces of the paper feed roller 2 and the paper sheet P, the separating pad 7a and the paper sheet P, and the paper sheets P are F, G, and H, respectively, the sizes are F>G> H. There is.

The paper feed shaft 6 incorporates a one-turn clutch (not shown). The positional relationship among the paper feed roller 2, the separation pad 7a, the separation assistance pad 7b, the separation idler roller 9 and the paper sheet P is normally stopped at the paper feed roller 2 in a convex state. The separation assisting pad 7b is elastically in contact. Further, the separation idler roller 9 is also in contact with the paper sheet P lifted by the middle plate pushing spring 23 from below through the middle plate 22. The radius of the separation idler roller 9 is slightly smaller than the radius of the paper feed roller 2. When a start key (not shown) is pressed, the paper feed roller 2 rotates and the paper feed roller 2 contacts the paper sheet P. When the paper feed roller 2 further rotates, as shown in FIG.
7a is pushed down and the paper sheet P is sent between the separating pads 7a, but only the uppermost paper sheet P ₁ is fed due to the difference in frictional force between the separating pad 7a and the paper feed roller 2. Since the paper feed roller 2 has a one-rotation clutch incorporated therein, the paper feed roller 2 is rotated once during paper feed to convey the paper sheet for a certain distance and then stop (FIG. 4).
The conveying distance by one rotation of the sheet feeding roller 2 is set longer than the distance between the conveying roller 20 and the sheet feeding roller 2.
Therefore, since the transport roller 20 is stopped until the feeding is completed, the paper sheet P ₁ is stopped by forming a loop as shown in FIG. At this time, the separation pad 7 is pushed up by the spring 8 and the separation auxiliary pad 7b is spared by the separation idler roller 9 to clamp the paper sheet P ₁ , so that the loop is maintained. When the paper feeding is completed, as shown in FIG. 5, the paper sheet P ₁ is transported by the transport roller 20 at a regular speed. At this time, the separation idler roller 9 is lightly rotated together with the paper sheet P _1, and therefore does not affect the conveyance of the paper sheet P ₁ . After the conveyance is completed, the paper feed roller 2 starts to rotate again, and thereafter, the paper feed separation is repeated in the same manner as described above.

The above is the description of one embodiment of the sheet material feeding device according to the present invention, but it goes without saying that the present invention is not limited to this embodiment.

For example, it may be one that includes a roller that is constantly rotating and that swings up and down to feed the sheet material. That is, it descends in response to the feeding signal and rises when feeding is completed.

Further, for example, the separation idler roller 9 does not necessarily have to be a roller, and may be a fixing material as long as the surface is smooth.

FIG. 6 shows the separation idler roller 9 with the paper feed shaft 6 of the paper feed roller 4.
The case where it is attached to a shaft provided at the tip of a lever that also serves as the upper guide 11 is shown. 3 is a stopper for keeping the highest height of the paper sheets constant.

FIG. 7 is a view showing an embodiment in which a pressing member which also serves as an upper guide 11 is provided in place of the separation idler roller 9 provided on the sheet feeding shaft 6 of the sheet feeding roller 4. It is a figure where the separation guide which doubled as a conveyance guide was provided.

In this embodiment, a separating pad is used, but this is exactly the same even if it is a separating roller.

This sheet feeder can be used for a copy sheet feeder of a copying machine or a sheet document automatic feeder (ADF).

The separating pad may be a roller instead of a plate.

Further, as shown in FIG. 8, the paper feed roller may have a partially different outer radius. That is, the paper feed roller 10 has an outer periphery formed by a radius R that is larger than the radius of the separation idler roller 9 and a radius r that is equal to or smaller than the radius of the separation idler roller 9.

The material of the separation pad 7a and the separation auxiliary pad 7b may be the same.

As explained above, the paper feed roller is made into a half moon shape, and the separation idler roller that comes into contact with the separation pad when the paper feed roller does not come into contact with the separation pad is provided. It became. The configuration is simplified.

Also, since the paper feed roller is convex upward and stopped, even if a paper sheet is caught in the paper feed section and jammed, the paper sheet is sandwiched between the separation idler roller and the separation pad, and the separation idler roller Since it is light and rotates freely, it is possible to smoothly remove jams without damaging the paper sheets. It is convenient not only when removing jams, but also when taking out a bundle of paper sheets (because the uppermost paper sheet is generally held by a separation pad).

Further, since the separation idler roller is coaxial with the paper feeding shaft, the positional relationship between the paper feeding roller and the paper sheets is always kept constant.

Since the paper feed roller first contacts the paper sheets and then presses against the separation pad, the roller and the pad do not rub each other directly. As a result, the load and load fluctuation are reduced, the unevenness in the image pitch is reduced, and the durability is improved.

By providing separation auxiliary pads on both sides of the separation pad in contact with the separation idler roller and not in contact with the paper feed roller, it is possible to make the friction coefficient higher than that of the separation pad. It became possible to stably separate and feed.

<Effects of the Invention> Since the sheet material feeding apparatus according to the present invention has the above-described configuration, the configuration is simplified and the sheet material can be easily conveyed and the sheet material can be easily taken out. .

[Brief description of drawings]

FIG. 1 is a sectional view of the present invention, FIG. 2 is a perspective view of the present invention, FIGS. 3 to 5 are views showing sheet feeding and conveyance of the present invention, and FIGS. 6 to 8 are other embodiments. FIG. 9 to FIG. 11 are diagrams showing a conventional example. P is a paper sheet, 2 is a paper feed roller, 6 is a paper feed shaft, 7 is a separation pad, 9 is a separation idler roller, and 20 is a conveyance roller.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Tadashi Yagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Innovator Shinwa Adachi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Takeshi Totoriyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (7)

[Claims] 1. A sheet material feeding device for feeding a plurality of sheet materials by frictionally separating a plurality of sheet materials one by one between a paper feeding roller and a separating member, wherein the paper feeding roller has a cutout portion in a part thereof. The outer peripheral surface and the separating member are in pressure contact with each other so as to separate the sheet material between them, and when the paper feed roller rotates and the cutout portion faces the separating member, the separating member separates. Is provided with a pressing member for pressing the sheet material in the process of being fed out to the auxiliary separating member disposed in the vicinity of the separating member, and the pressing member is more than the load applied to the sheet material by the sheet feeding roller and the separating member. A sheet material feeding device, characterized in that the load applied to the sheet is reduced by the auxiliary separating member and the auxiliary separating member. 2. The sheet material feeding device according to claim 1, wherein a separating plate is used as the separating member. 3. The sheet material feeding device according to claim 1, wherein a roller is used as the separating member. 4. The sheet material feeding device according to claim 1, wherein a rotatable idler roller is used as the pressing member. 5. The sheet material feeding device according to claim 4, wherein the idler roller is provided on a paper feed roller shaft. 6. A friction coefficient of a separation member that is in pressure contact with the paper feed roller and a friction coefficient of an auxiliary separation member that is in pressure contact with the pressing member are different from each other.
The sheet material feeding device according to any one of (5). 7. The sheet material feeding device according to claim 1, wherein the separating member and the auxiliary separating member are made of the same material. .