JPH0388647A - Automatic supplier device for sheet-state member - Google Patents

Abstract

PURPOSE:To effectively prevent a double feed by setting pressing force relatively larger in a pressing point in the downstream side. CONSTITUTION:The first and second pressing means 11 and 12, which are brought into contact with two parts different in a curving direction of a guide member (friction pad) 3 and for pressing curved parts of the guide member 3 to the peripheral surface side of a supply roller 1, are arranged. Here the first pressing means 11 is arranged relatively in the upstream side for the moving direction of a sheet-state member P, and the second pressing means 12 is arranged relatively in the downstream side for the moving direction of the sheet-state member P. Further pressing force of the second pressing means 12 is set relatively larger than pressing force of the first pressing means 11.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to sheet-like members applied to devices that use sheet-like members such as plain paper and OHP sheets, such as copying machines, laser printers, facsimile machines, etc. This invention relates to an automatic feeding device.

<Prior Art> For example, as an automatic paper feeder for automatically feeding paper, there has conventionally been a structure shown in FIG. 5 or FIG. 6.

In FIG. 5 or 6, 1 is a paper feed roller that rotates in the direction of arrow A1 during operation, and 2 is a transport guide for transporting paper P. A curved end portion of a friction pad 3 serving as a guide member is in contact with the paper feed roller 1 .

When the paper feed roller 1 is rotated in the direction of arrow A1, a large number of sheets P set on the conveyance guide 2 are started to be fed one by one from the bottom. The friction pad 3 acts so that the paper feed roller 1 sequentially feeds the paper P one sheet at a time without double feeding.

In order to cause the friction pad 3 to have the above-mentioned effect, in the conventional device, as shown in FIG. Also, as shown in FIG. 6, there is one in which a pad fixing plate 5 and a leaf spring 6 are used to press a friction pad 3 against a paper feed roller 1.

<Problems to be Solved by the Invention> By the way, in order for the friction pad 3 to perform its original function and reliably prevent double feeding of sheets, the friction pad 3 must be configured as shown in FIG. 5 or 6. It is necessary that the sheet feeding roller 1 is pressed against the paper feed roller 1 with sufficient pressing force at points A and B.

However, in the conventional mechanism shown in FIG. 5, the base of the long presser plate 4 is rotatably held around the fulcrum 7, and a pressing force is applied to the tip by the coil spring 8. Because of this configuration, one of the two holding parts at the tip of the holding plate 4 comes into contact with the friction pad 3 first, and the pressing force at point A or B, which came into contact first, increases, and the other point contacts the friction pad 3 first. The III pressure at the point was small, and there was a drawback that sufficient pressing force was not applied to the image point.

Further, in the conventional mechanism shown in FIG. 6, a sufficient pressing force is applied to point B pressed by the leaf spring 6, but the pressing force at point A is insufficient.

Furthermore, in the mechanism shown in FIG. 5 or 6, the seventh
As shown in the figure, when the leading edge of the paper P reaches the platen roller pair 9 located downstream of the paper feed roller 1 after paper feeding starts, the leading edge of the paper P is pulled by the platen roller pair 9, so that In some cases, the paper P is tensioned between the paper roller 1 and the platen roller pair 9, and the tension of the paper P causes the tip of the friction pad 3 to rise above the circumferential surface of the paper feed roller 1.

For this reason, the conventional mechanism for applying pressing force cannot sufficiently suppress the friction pads 3, and as a result, there is a drawback that the friction pads 3 cannot effectively prevent double feeding of sheets.

Therefore, the present invention was made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide an automatic feeding device for sheet-like members that can effectively prevent double feeding using a guide member such as a friction pad. shall be.

Means for Solving the Problems> The present invention provides a supply roller for feeding the sheet-like member, a part of which is curved along the circumferential surface of the supply roller, and the curved portion is in contact with the circumferential surface of the supply roller. A guide member is provided to bring the sheet-like member applied to the supply roller into close contact with the circumferential surface of the roller, and the guide member is brought into contact with two points in different curved directions, and the curved portion of the guide member is brought into contact with the circumferential surface of the supply roller. a first pressing means and a second pressing means for pressing against the
The first suppressing means is disposed relatively upstream with respect to the moving direction of the sheet-like member, and the second suppressing means is disposed relatively downstream with respect to the moving direction of the sheet-like member. Furthermore, a second pressure force is applied to the pressure force of the first pressure means.
This is an automatic feeding device for sheet-like members, characterized in that the pressing force of the pressing means is relatively large.

It is desirable that a light pressing force is applied to the pressing point on the upstream side relative to the moving direction of the sheet-like member to take in the sheet-like member and to prevent double feeding of the sheet-like member. . On the other hand, a strong pressing force is applied to the relatively downstream pressing point because it is necessary to prevent double feeding by separating sheet-like members that have started to be fed when they are being fed in duplicate. is necessary. In this invention, in view of such circumstances, the pressing force at the pressing point on the downstream side is relatively increased.

<Embodiments> Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an illustrative diagram showing the configuration of an automatic paper feeder according to an embodiment of the present invention.

In the figure, 1 is a paper feed roller for feeding the recording paper P, and 2 is a conveyance guide for the recording paper P. 3 is a friction pad as a guide member. The tip of the friction pad 3 is curved along the circumferential surface of the paper feed roller 1, and the curved portion is in contact with the circumferential surface of the paper feed roller. The paper feed roller 1 is rotated in the direction of arrow A1 during operation to feed the recording paper P.

These paper feed roller 1, conveyance guide 2 and friction pad 3
The components are similar to those of a conventional automatic paper feeder.

The feature of this embodiment is that the pressing means for pressing the tip portion of the friction pad 3 includes two pressing members, a first pressing member 11 and a second pressing member 12, and a common pressing force generating unit connected to both of them. The structure includes a tension spring 13 as an elastic member.

The first pressing member 11 is a crank-shaped longitudinal member whose bent position at the center in the longitudinal direction is held at a fulcrum 14 and is rotatable about the fulcrum 14 . A pressing force is applied to point A of the friction pad 3 by the protruding tip portion 15.

The second pressing member 12 also has a longitudinal crank shape, and is rotatably held in a bent position at the center in the longitudinal direction by a fulcrum 16. Then, the tip convex portion 17 allows the friction pad 3 to
A pressing force is applied to the point.

A common tension spring 13 is hung between the rear end portions of the first pressing member 11 and the second pressing member 12 . The tension spring 13 is an example of an elastic member for generating pressing force, and acts to bring the rear end portions of the first suppressing member 11 and the second pressing member 12 closer to each other. Therefore, a counterclockwise moment is applied to the first pressing member 11 about the fulcrum 14, and the tip convex portion 15 presses the point A of the friction pad 3 with a constant force. Further, the same moment is applied to the second pressing member 12 on the right side, and the tip convex portion 17 presses the point B of the friction pad 3. The magnitude relationship between the pressing force applied to point A and the pressing force applied to point B in this state is the length from the fulcrum 14 of the first pressing member 11 to the tip protrusion 15 and the length from the fulcrum 14 to the rear end. It is determined based on the so-called lever principle based on the length ratio, the length from the fulcrum 16 to the tip protrusion 17, and the length from the fulcrum 16 to the rear end of the second pressing member 12.

In the above state, it is preferable to make the pressing force at point B larger than the pressing force at point A. This is because point A is located on the upstream side relative to the paper conveyance direction, and
The pressing force at point B is preferably a light force that does not double feed the paper when the paper feed roller 1 takes in the recording paper P, whereas at point B, the pressure is such that the paper feed is started by the paper feed roller 1. This is because, when recording sheets are being fed in duplicate, a larger pressing force is required to prevent the double feeding by separating the sheets being fed in duplicate.

FIG. 2 is a diagram for explaining the actions of the first suppressing member 11 and the second pressing member 12, which are the pressing means according to this embodiment.

To explain with reference to FIG. 2, feeding of the recording paper P is started by the paper feed roller 1, and when the recording paper P enters below the friction pad 3 along the circumferential surface of the paper feed roller 1 (the first 2
(see figure), a counter-pressing force is first applied to point A of the friction pad 3 by the paper P, and the first pressing member 11 tries to lift up and rotate clockwise around the fulcrum 14. When the first pressing member 11 rotates clockwise around the fulcrum 14, the tension spring 13 is pulled toward the first pressing member 11, and the rear end of the second pressing member 12 changes from the state shown by the broken line to the state shown by the solid line. A force is applied to the second pressing member 12, and the second pressing member 12 attempts to rotate clockwise around the fulcrum 16. Then, the tip convex portion 17 of the second pressing member 12 presses the point B of the friction pad 3, and more pressing force than before is applied to the point B.

Therefore, when the paper P is transported by the paper feed roller 1 and the leading edge of the paper reaches point B, a sufficient pressing force is applied to the paper by the friction pad 3, so that double feeding can be effectively prevented.

Furthermore, when the leading edge of the paper reaches point B and a counter-suppressing force acts on point B of the friction pad 3, that force is transmitted from the second pressing member 12 to the tension spring 13, and the force is transmitted to the point A of the first pressing member 11. A pressing force is applied.

In this way, when point A of the friction pad 3 is about to rise, the pressure at point B is applied, and when point B is about to rise, the pressure at point A is applied, and so on. When a counter-pressing force acts on a pressing point, the pressing force on the other pressing point is applied, which is effective in preventing double feeding.

FIG. 3 is an illustrative view of an automatic paper feeder according to another embodiment of the invention. The feature of the embodiment shown in FIG. 3 is that the suppressing means for pressing the friction pad 3 has the following structure.

That is, a U-shaped pressing member 21 is provided, and a pressing force is applied to points A and B of the friction pad 3 by two tips 22 and 23 of the U-shaped pressing member. The center portion of the U-shaped pressing member 21 is rotatably held by a fulcrum 24, and the fulcrum 24 is allowed to vibrate in the distance direction relative to the center portion of the paper feed roller 1. Further, a coil spring 25 is connected to the fulcrum 24, and the pressing member 24 is elastically urged toward the center of the paper feed roller 1 by the coil spring 25.

Therefore, when the friction pad 3 floats at point A and an upward force (reverse pressing force) is applied to the tip 22 of the pressing member 21, the pressing member 21 swings about the fulcrum 24 and the other tip 23 presses point B with a pressing force. vice versa,
When the friction pad 3 is about to rise at point B, the pressing member 21 swings around the fulcrum 24 and the other tip 22
A pressing force is applied to press point A.

The rest of the structure in the embodiment of FIG. 3 is similar to that of FIG. 1, and the same parts are given the same numbers.

Further, in FIG. 3, numeral 9 represents a pair of platen rollers.

In the embodiment shown in FIG. 3 as well, the lengths of the arms extending left and right from the fulcrum 24 are changed, and the right side of the fulcrum 24 in the figure is relatively short and the left side is relatively long. It is preferable to make the pressing force applied to point B relatively stronger than the pressing force applied at point B.

FIG. 4 is an illustrative view of an automatic paper feeder according to still another embodiment of the invention.

A feature of the embodiment shown in FIG. 4 is that completely independent suppression means are used to press points A and B of the friction pad 3, respectively.

That is, at point A, a pressing force is applied by the pressing member 32 elastically biased by the coil spring 31, and at point B, the pressing force is applied by the suppressing member 32 elastically biased by the coil spring 33.
The pressing force is applied by 4.

In this embodiment, the coil spring 33 has a larger tensile force than the coil spring 31, and B
A relatively larger pressing force is applied to the point than at the A point.

The reason for this is the same as that explained in the embodiment of FIG.

In other words, the spring pressure is relatively weak on the A point side, so that the paper P can easily enter between the friction pad 3 and the paper feed roller. On the other hand, at point B, the spring pressure is relatively strengthened to increase the pressing force, thereby reliably preventing double feeding of the sheets when the sheets P pass.

In addition, as in this embodiment, the pressing force applied to point A and point B is applied to independent coil springs 31 and 33, respectively.
This has the advantage that the pressing force can be accurately set and controlled.

The rest of the structure is similar to the embodiment shown in FIG. 3, and the same parts are given the same numbers.

The above description has been made by taking as an example an automatic paper feeder for feeding recording paper in a copying machine, but the present invention is also applicable to an automatic paper feeder for feeding paper money, for example, and a paper feeder for feeding a cloth-like sheet member. It can also be used as a supply device, etc.

<Effects of the Invention> Since the present invention is configured as described above, it is possible to provide an automatic feeding device that can reliably prevent double feeding when conveying sheet-like members.

[Brief explanation of drawings]

FIG. 1 is an illustrative diagram showing the configuration of an automatic paper feeder according to an embodiment of the present invention. FIG. 2 is an illustrative view showing the operation of the pressing means in FIG. 1. FIG. 3 is an illustrative diagram showing the configuration of an automatic paper feeder according to another embodiment of the invention. FIG. 4 is an illustrative diagram showing the configuration of an automatic paper feeder according to still another embodiment of the present invention. FIG. 5 is an illustrative diagram showing the configuration of a conventional automatic paper feeder. FIG. 6 is an illustrative diagram showing another example of a conventional automatic paper feeder. FIG. 7 is an illustrative diagram for explaining problems in a conventional automatic paper feeder. In the figure, 1... paper feed roller, 3... friction pad, 11... first pressing member, 12... second pressing member, 1
3...Tension spring, 21...Press member, 25...Coil spring, 31.33...Coil spring, 32.33.
... indicates a pressing member. Fig. Fig. 3 Fig. Fig. Fig. 3 Fig. Fig. Fig. 3 Fig. Fig. Fig. 3

Claims (1)

[Claims] 1. Supply roller for feeding sheet-like materials and, A part of it curves along the circumferential surface of the supply roller. The curved part touches the circumferential surface of the supply roller. is in contact with the supply roller and is fed to the supply roller. The sheet-like member is brought into close contact with the circumferential surface of the roller. a guide member for At two locations with different bending directions of the guide member. The supply roller contacts the curved part of the guide member. First pressing means for pressing against the peripheral surface side and a second pressing means, The first pressing means moves the sheet-like member. placed on the upstream side relative to the direction The second pressing means is a sheet-shaped portion. Relative to the downstream side with respect to the direction of material movement The first pressing hand Pressure of the second pressing means against the pressing force of the stage The special feature is that the force is relatively large. Automatic supply for sheet-like parts Feeding device.