JPH0445418B2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a device for preventing double feeding of sheet-like or booklet-like paper, and in particular, it is used in copying machines, electronic files, facsimile machines, printing machines, etc., to ensure that paper is fed one by one. This invention relates to a double-feed prevention device for feeding or changing pages.

<Prior Art> Conventionally, a system using air suction has generally been used as a device for pulling sheet-like or booklet-like paper up to a predetermined position for feeding or page changing. However, with these devices, there is a disadvantage that the frequency of so-called multi-feeding, in which multiple sheets of paper are pulled up at once, becomes extremely high, especially when the adhesion force between sheets is increased due to electrostatic charging, etc. . For this reason, there is a method that blows air between the sheets to separate them into groups of sheets to be lifted, but this method only makes it difficult to reliably separate the sheets when they are strongly charged. However, this method requires large-scale equipment, and also has the drawback of becoming a source of noise.

In addition, as another method, JP-A-55-51815
In this publication, there is a method in which a friction member is brought into contact with the edge of the paper when the paper is pulled up by air suction, and the double-fed paper is brushed off.

However, with this method, it is difficult to completely remove double-fed paper, and the friction member may cause an obstruction to the paper that is separated after passing through the friction member or the paper that has come off the air suction for some reason. This has disadvantages such as the paper becoming unable to return to the original paper tray and causing poor suction when feeding the paper next time.

<Object of the Invention> In view of the above-mentioned matters, the present invention has a simple mechanism that can reliably separate paper even in cases where it is strongly charged without damaging it, and also allows for friction-free separation. Paper that has peeled off after passing over the member and paper that has come off the suction can be returned to its original position without being disturbed by the friction member, thereby reliably eliminating double feeding of paper, and reducing the size and noise of the paper. The purpose of the present invention is to provide a highly reliable double-feed prevention device that eliminates the need for concerns.

<Example> The configuration of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic perspective view of the double feed prevention device of this embodiment, and FIG. 2 is a schematic side view of the same double feed prevention device.

In the figure, reference numeral 1 denotes friction members for preventing double feeding, and a pair of them are located near both corners of the sheet P to be pulled up. The friction member 1 is formed into an arched shape and has a flexible structure using, for example, a film-like resin as a substrate, and is fixed to a friction member mounting plate 2. The friction member mounting plate 2 is provided via a bearing member 6 (FIG. 2) so that it can rotate within a certain range around a shaft 5 attached to a fixed member (not shown). A driving solenoid 9 for rotating the friction member mounting plate 2 is attached to a fixed member (not shown) below the friction member mounting plate 2. Moreover, this drive is performed by the friction member mounting plate 2.
The friction member mounting plate 2 is connected to the friction member mounting plate 2 by a latch 4 passed between an angle 3 provided in a part of the solenoid 9 and a solenoid 9.
It is supposed to be communicated to Further, the friction member mounting plate 2 is moved by a spring member 20 provided around the shaft 5 so that the uppermost paper on the base plate 30 is in the position shown by the solid line in FIGS. The position is such that the trajectory A (Fig. 2) of the leading edge of the paper when it is pulled up by the paper 10 intersects a part of the friction member 1 for preventing double feeding, and the ON operation of the solenoid 9 causes It is possible to move to the position shown by the broken line in FIG. 2, that is, to a position that does not intersect with the trajectory A of the leading edge of the paper.

The double feeding prevention device of this embodiment constructed as described above will be explained using the sheet paper feeding device shown in FIGS. 3a, 3b and 3c as an example. Parts that are the same as those described above are given the same numbers.

Reference numeral 10 denotes a paper pulling device for pulling up the paper by means such as air suction, 30 a base plate for loading the paper to be fed, and 11 the leading edge of the paper stacked on the base plate 30. The regulating guide 33 is a pressure roller that presses a portion of the stacked sheets.

First, when an instruction is given to start feeding, the paper lifting device 10 rises to a position where it can pull up the uppermost sheet of sheets stacked on the base plate 30, and then stops. Then, the paper pulling device 10 attracts the uppermost paper by means such as air suction, and rotates upward in the direction shown by arrow E in the figure to a predetermined position about a point 35 on the pressure roller 33.

At this time, if there is only one sheet of the highest sheet of paper P _-1 to be fed, the tip 15 of the sheet lifting device 10 and the stacked sheet of paper P are pulled up as shown in FIG. There is a distance 1 from the leading end 40 of the sheet, and the vicinity of the leading end of the paper is free, so that even if it comes into contact with the friction member 1 for preventing double feeding, it will not be damaged and will be pulled up to a predetermined position.
Furthermore, if the paper to be pulled up is thick, the double-feed prevention friction member 1 escapes so that the paper can be pulled up to a predetermined position without damaging the paper. At this time, the suction force of the paper pulling device 10 is sufficiently larger than the contact pressure between the paper and the friction member 1 for preventing double feeding, so that the paper does not fall due to contact between the paper and the friction member 1 for preventing double feeding. After the paper is pulled up to a predetermined position in the above manner, as shown in Figure c, the double-feed prevention friction member 1 is moved to a position where it does not intersect with the trajectory A drawn by the leading edge of the paper, as shown by the broken line in Figure 2. It is moved by the operation of the solenoid 9. This allows the paper to be smoothly returned to its original position in the event that the first sheet of paper is pulled up past the friction member and is peeled off due to bending or lifting speed, or in the event that the paper falls out of suction. This is an evacuation operation to return to normal. After the next sheet is fed by a device (not shown), the double-feed prevention friction member 1 returns to the position shown in FIG. 1A to handle the next sheet. On the other hand, when a plurality of sheets of paper are pulled up at once by the paper pulling device 10, as shown in FIG. Become. At this time, the topmost sheet of paper is pulled with sufficient force by the paper pulling device 10 as described above, so it does not fall, but the sheets below the topmost sheet (P _-2 and below) are shown in Figure b. As shown, the adhesion force between sheets is weakened by the contact pressure with the friction member 1 for preventing double feeding, and no longer increases with respect to the sheet pulling device 10. The friction member 1 for preventing double feeding may be provided over the entire width of the paper, but if it is provided near the corner of the paper as in this embodiment, peeling will begin at the corner of the paper. It is easy to allow air to flow between the sheets, and therefore the suction force between the sheets, which causes double feeding, can be effectively weakened.
In this way, when only the uppermost paper is pulled up to the predetermined position, the friction member 1 for preventing double feeding is moved to c in the same figure.
As shown in the figure, the sheets below the topmost sheet that were not pulled up to the predetermined position are moved to return to their original positions, and once the topmost sheet P _-1 has been fed, the paper is returned to the position a in the same figure.
The next step is to handle the paper.

Figure 4 shows an example in which the double feeding prevention device of this embodiment is installed in a booklet turning device, and as is clear from the figure, its operation is exactly the same as that of the sheet feeding device described above. Therefore, the explanation will be omitted.
Note that the same numbers are attached to the same parts as those described above.

<Effects> As described above, according to the double-feed prevention device of the present invention, double-feeding occurs when the paper that is being pulled up by the lifting device becomes an obstacle at a position near the corner that contacts the edge of the paper to be pulled up. By providing an elastic friction member formed into an arcuate shape to prevent
Although it is a simple mechanism, it is possible to effectively separate the paper without damaging it, and when the above-mentioned lifting device completes the lifting, it is able to separate the paper to a position where it does not touch the trajectory drawn by the edge of the paper being pulled up. It is possible to reliably return to the original position the paper that has been separated by crossing the friction member to move the friction member and the paper that has been removed from the suction. Therefore, it is possible to provide a small and highly reliable double feeding prevention device. can.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of a double feed prevention device according to the present invention, FIG. 2 is a schematic side view of the double feed prevention device,
Figures 3a, b, and c are explanatory diagrams of the operation process of the double-feed prevention device according to the present invention, taking a sheet paper feeding device as an example, and Figure 4 is an illustration of the double-feed prevention device according to the present invention installed in a booklet turning device. It is an explanatory diagram showing an example. 1...Friction member, 2...Friction member mounting plate, 4...
... Latch, 5 ... Shaft, 6 ... Bearing member, 9 ... Solenoid, 10 ... Paper pulling device, 11 ... Guide, 20 ... Spring material, 30 ... Base plate, P ...
...paper, B...booklet.

Claims (1)

[Scope of Claims] 1. In a device for pulling paper in the form of a sheet or a booklet to a predetermined position, an obstacle to the paper while being pulled up by the pulling device is placed near a corner touching an end of the paper to be pulled up. an elastic friction member formed in an arcuate shape to prevent folding and double feeding; and a friction member that moves the friction member to a position where it does not touch the trajectory drawn by the edge of the paper to be lifted when the lifting device completes the lifting. A double-feed prevention device, comprising a moving means, and capable of returning the paper that has passed through the friction member and been pulled up by double-feeding, and the paper that has come off the lifting device.