JPH0235707Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an automatic paper feeding device, and more specifically, the present invention relates to an automatic paper feeder. Relates to an automatic paper feeding device that separates and discharges paper sheets one by one by utilizing the difference in the coefficient of friction between the conveying roller and the paper sheets, between the paper sheets, and between the paper sheets and the paper sheet separation piece. It is.

[Technical background of the invention]

FIG. 1 conceptually shows an automatic paper feeder used in conventional facsimile machines, copying machines, and the like. This automatic paper feeder is capable of handling multiple sheets of paper 1
The paper sheet mounting table 2 is provided with a sheet mounting table 2 on which sheets are placed at an angle, a conveying roller 3 disposed at the tip of the sheet mounting table, and a sheet separating piece 4 disposed above the roller. The sheet separator 4 is made of a flexible material and is mounted on a bracket 6 which is fixed to a facsimile machine, copying machine, etc. by means of a holder 5. The holder 5 is rotatably supported by a bracket 6, supports the base end 4a of the sheet separating piece 4, and is supported by a compression spring 7 interposed between the tip of the arm 5a and the bracket 6. The leading end is brought into contact with the leading end (free end) 4b of the sheet separating piece 4, and the leading end 4b of the sheet separating piece 4 is brought into pressure contact with the circumferential surface of the conveyance roller 3. In the automatic paper feeder configured in this manner, a wedge-shaped gap A is formed by the conveying roller 3 and the sheet separation piece 4, as shown in FIG.

30 to 50 sheets of paper (for example, a manuscript) 1 are loaded into the wedge-shaped gap A and stacked on the sheet mounting table 2 with their leading edges arranged in a step-like manner. Therefore, when the conveyance roller 3 rotates in the direction of the arrow in FIG.
Paper leaf 1 ₁ is downward in Figure 1 (next processing section)
is discharged to. At this time, the sheets 1 ₂ to 1 _o are prevented from moving by the sheet separating piece 4 and remain at the initial position. When the sheet 1 ₁ is ejected and cut, the next sheet 1 ₂ comes into contact with the conveying roller 3 and is conveyed along with the roller. From then on, this operation is repeated one after another, and paper sheets 1 ₃
~1 _o are ejected one by one without overlapping.

Such an automatic sheet feeding device has a friction coefficient μ ₁ between the sheet 1 and the conveying roller 3, a friction coefficient μ ₂ between the sheet 1 and the sheet separation piece 4, and a friction coefficient μ ₃ between the sheets.
The relationship between the two is substantially set to μ ₁ >μ ₂ >μ ₃ , and the difference in these friction coefficients is utilized to separate and discharge the sheets 1 ₁ to 1 _o one by one.

[Problems with background technology]

By the way, in the automatic paper feeder described above, in order to reliably separate and eject the paper sheets 1 ₁ to 1 _o one by one, that is, to reliably prevent double feed, the tips of the paper sheets 1 ₁ to 1 _o should be As shown in Fig. 1, the sheets are loaded in a stepwise manner into the wedge-shaped gap A, and the tip of the lowest sheet ₁₁ is connected to the conveying roller 3 and the sheet separating piece 4.
It is preferable that the paper sheet 1 is loaded so that it reaches just before the contact point B of the paper sheet 1, and it is also preferable that the other sheets 1 that have not yet been ejected are maintained in this state one after another even during the sheet feeding operation.

However, in the above-mentioned conventional automatic paper feeder, the friction coefficient μ ₂ of the sheet separating piece 4 is set to be large.
When loading the leading edge of the sheet 1 into the wedge-shaped gap A, if the leading edge of the sheet 1 hits the surface of the sheet separator 4 near the sheet insertion opening, the operator will be able to remove the sheet from the feeling of resistance. 1 may be mistaken as being loaded at a predetermined position within the wedge-shaped gap A. Also, during the paper feeding operation, other sheets 1 that are not ejected are sequentially moved between the conveying roller 3 and the sheet separating piece 4. There were cases where the robot was not moved in the direction of the contact point B with the contact point B. As a result, in the conventional automatic paper feeder, there was a risk that the paper sheet 1 would not be bitten between the conveyance roller 3 and the paper sheet separation piece 4, making it impossible to feed the paper sheet. This tendency was more pronounced as the inclination of the paper sheet mounting table 2 was closer to horizontal, and when the stiffness of the paper sheet 1 was large due to the thickness and low humidity of the paper sheet 1.

[Purpose of invention]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an automatic paper feeder that can stably feed paper sheets.

[Summary of the idea]

In order to achieve this objective, the present invention leaves the area near the contact point between the conveying roller and the sheet separating piece that performs the sheet separating action on the surface forming the wedge-shaped gap of the sheet separating piece, and then The friction coefficient of the surface is made smaller than the friction coefficient near the contact point and smaller than the friction coefficient between the sheets, thereby smoothly guiding the leading edge of the sheet deep into the wedge-shaped gap.

[Example of idea]

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 2 conceptually shows an automatic paper feeder according to the present invention. In this figure, the same elements as in FIG. 1 are indicated by the same reference numerals. Further, in FIG. 2, a spring 7 for pressing the free end of the sheet separating piece 4 against the conveying roller 3
The biasing means such as these are omitted.

The automatic paper feeder according to the present invention calculates the coefficient of friction μ 4 for the paper sheet 1 of the surface of the sheet separation piece 4 forming the wedge-shaped gap A, excluding the vicinity of the contact point B with the conveying roller 3, by the friction coefficient μ ₄ at the contact point B. It has a coefficient of friction μ ₂ smaller than the friction coefficient μ 2 with respect to the neighboring paper sheets 1. In the embodiment, the transport roller 3 is a sponge rubber roller, the paper sheet separation piece 4 is a rubber piece, and the contact point of the transport roller 3 on this paper sheet separation piece is A sheet 8 made of polyethylene or the like having a small coefficient of friction μ ₄ against the paper sheet 1 is pasted on the lower surface of the portion excluding the vicinity of B. In this way, in the embodiment, the friction coefficient μ ₁ between the paper sheet 1 and the conveyance roller 3, the friction coefficient μ ₂ between the contact point 4c of the paper sheet 1 and the paper sheet separation piece 4 with the conveyance roller 3, ,
The coefficient of friction μ ₃ between sheets of paper and the coefficient of friction μ ₄ between sheet 8 and sheet 1 are expressed as μ ₁ > μ ₂ > μ ₃ > μ ⁴ , respectively.
It is set so that

The operation of the above embodiment will be explained below. When paper sheets 1 whose tips are arranged in a step-like manner are inserted into the wedge-shaped gap A of this paper feeding device, the tips of the paper sheets 1 ₁ to 1 _o come into contact with the sheet 8; It is guided and loaded into position without being braked. In this way, among the sheets 1 ₁ to 1 _o loaded into the wedge-shaped gap A, as the conveying roller 3 rotates in the direction of the arrow, the lowest sheet 1 ₁ is ejected first. When paper leaf 1 ₁ is ejected in this way,
The sheets 1 ₂ to 1 _o that are waiting later are sequentially moved to the original positions of the sheets 1 ₁ to 1 _o-1 located below them. At this time, each of the sheets 1 ₃ to 1 _o has a coefficient of friction μ ₄ between the tip and the sheet 8 that is smaller than a coefficient of friction μ ₃ between the sheets, so that the step-like shape of the tip is not destroyed. Move to the back of wedge-shaped gap A.

In the above embodiment, a sheet 8 made of polyethylene or the like is pasted to the portion of the sheet separating plate 4 excluding the contact point 4c with the conveyance roller 3 to reduce the coefficient of friction in that portion. 8, a coating may be applied to that portion of the sheet separating piece 4, or the surface roughness of the sheet separating piece 4 may be changed.

[Effect of idea]

As described above, the automatic paper feeder according to the present invention can smoothly and reliably load paper sheets into a predetermined position in the wedge-shaped gap formed by the conveyance roller and the paper sheet separation piece, and During paper operation, as the paper sheets are discharged, the paper sheets waiting in the wedge-shaped gap are sequentially and smoothly moved toward the contact point between the conveyance roller and the paper sheet separation piece, so that the paper sheets are It is ensured that the paper sheet is bitten between the conveyance roller and the paper sheet separation piece, so that the paper sheet can be stably fed.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram showing a conventional automatic paper feeder.
FIG. 2 is a conceptual diagram showing an automatic paper feeder according to the present invention. DESCRIPTION OF SYMBOLS 1... Paper leaf, 2... Paper leaf mounting table, 3... Conveyance roller, 4... Paper leaf separation piece, 4a... Base, 4b...
...Tip, 4c...Near the contact point, 8...Seat, A
... Wedge-shaped gap, B... Contact point.

Claims (1)

[Scope of utility model registration request] A paper sheet loading table on which a plurality of sheets of paper are placed; a conveying roller positioned at the tip of the sheet loading table and conveying the sheet by rotating; and a wedge-shaped gap formed with the conveying roller. A plurality of sheets of paper are equipped with a paper sheet separating piece whose leading edge is pressed against a conveyance roller and grounded, and which is placed on the paper sheet mounting table and inserted into the wedge-shaped gap with the leading edge aligned in a stepwise manner. In an automatic paper feeder that separates and feeds leaves one by one using differences in friction coefficients, a portion of the upper air separation piece excluding the vicinity of the contact point with the conveyance roller on the surface forming the wedge-shaped gap. An automatic paper feeder characterized in that the coefficient of friction of the sheet is smaller than the coefficient of friction near the contact point and the coefficient of friction between the plurality of sheets.