JPH0432430A - Sheet separation pad installing structure for automatic sheet feeder - Google Patents

Abstract

PURPOSE:To prevent a sheet supply error in supplying a plural sports of sheets by fixing a plurality of separation pads of different friction coefficients to a pad base body, and rotating and oscillating the base body to select one pad and face it with a pick roller. CONSTITUTION:A rhomboid form pad base body 10 is installed at a pin 9 freely rotatably, and two separation pads 2a, 2b of different friction coefficients are fixed at symmetric positions of it. One end 11a of a coil spring 11 is caught at a pawl 15a of a ratchet 14 integrated with the base body 10, and the separation pad 2a is pressed to the circumferential surface of a pick roller 1 resiliently. In this condition, the pick roller 1 is removed, and a channel 16 for a sheet guide is pulled toward an operator against a spring 18. The base body 10 is then rotated clockwise, the engagement end 11a of the spring 11 is caught by a pawl 15b on the opposite side along the sprical circumferential surface of the ratchet 14, and the pick roller 1 is installed to let the channel 16 stand and press the other separation pad 2b to the roller 1. The pads can thus be changed easily corresponding to the sort of the sheet.

Description

Detailed Description of the Invention (Industrial Application Field) This invention relates to a paper separation mechanism for an automatic paper feeder for paper media inserted into printers, document reading devices, etc., which applies frictional driving force to the paper. The present invention relates to a separation pad mounting structure of a paper separation mechanism that separates paper by passing the paper between a pick roller that applies a friction load and a separation pad that applies a frictional load.

(Prior Art) FIG. 4 shows an example of the conventional structure of a paper separation mechanism of an automatic paper feeder that includes a pick roller 1 and a separation pad 2. The pick roller 1 is pivotally supported on a support shaft 3. It is pivoted to the tip of the arm 4 and comes into contact with the paper 6 stacked on the paper feed table 5. The contact force between the big roller 1 and the paper 6 is applied by a winding spring 7, and the big roller 1 is driven by a drive motor (not shown) via an intermediate gear 8 rotatably mounted on a support shaft 3 to move the big roller 1 in the direction indicated by the arrow in the figure. It is driven in the direction of A.

The separation pad 2 is fixed to a pad base 10 rotatably mounted around a pin 9 implanted in the arm 4.
The pad base 10 is biased clockwise in the figure by a winding spring 11 whose one end is locked to a pin 12 implanted in the frame, and presses the separation pad 2 against the circumferential surface of the big roller 1. The paper 6 stacked on the paper feed table 5 is fed out by the rotation of the big roller 1, and when it passes through the abutting part between the big roller 1 and the separation pad 2,
The frictional load applied by the separation pad 2 prevents the second and subsequent sheets from passing through, and only the topmost sheet is separated and sent out.

(Problem to be Solved by the Invention) The paper used in printers and document reading devices includes paper of various thicknesses ranging from thin paper to thick paper, as well as various paper sheets such as copy paper and envelopes made of multiple sheets of paper. Even if the same copying paper is used, the properties of the paper are slightly different between those using pressure-sensitive paper and those using carbon backing paper. 'For this reason, in conventional devices equipped with only one separation pad 2, if a separation pad with a large frictional load is used, paper separation performance improves, but thin paper cannot be fed or copy paper turns over. On the other hand, if the frictional load on the separation pad 7 is reduced to prevent the copy paper from turning over, the separation performance will be reduced and double feeding will be more likely to occur when feeding thick paper.

Therefore, in conventional devices, it is extremely difficult to obtain an automatic paper feeder that can reliably separate all types of paper with different properties, and there is a problem in that the types of paper that can be used are limited.

This invention was made with the purpose of providing a technical means for solving the above problems with a simple structure, and provides a paper separation mechanism with a simple structure that can easily change the frictional load characteristics of a separation pad. This is the issue.

(Means for Solving the Problems) In the present invention, a plurality of separation pads 2a and 2b having different friction characteristics are fixed to a pad base 10 that supports the separation pad, and the pad base 10 is rotatably or slidably mounted. However, by rotating or sliding the pad base 10, one of the plurality of separation pads 2a, 2b is selected and positioned at a position facing the big roller 1.

(Function) When using thin paper or copy paper as paper, the separation pad 2a with a small frictional load is placed opposite the big roller 1 to feed the paper.At this time, the load resistance acting on the paper 6 from the separation pad 2a is small. Therefore, it is possible to avoid the phenomenon of copy paper curling up and the occurrence of errors in feeding thin paper. On the other hand, when cardboard, an envelope, or the like is used as the paper 6, the separation pad 2b, which has a large frictional load, is opposed to the pick roller 1. In this case, a large load resistance is applied to the paper 6 from the separation pad 2b, improving paper separation performance and preventing double feed from occurring.

(Embodiment) FIGS. 1 and 2 are diagrams showing a first embodiment of the present invention, in which a big roller 1, a support shaft 3, an arm 4, a paper table 5, a coil spring 7, and an intermediate gear 8 are arranged in a fourth embodiment. This is the same as the conventional one shown in the figure. The pad base 10 has a pin 9 similar to that in FIG.
Although it is rotatably attached to the
Two separation pads 2a and 2b are fixed at symmetrical positions.

One of the separation pads 2b is softer than the other 2a and has a greater coefficient of friction against the paper than the other 2a.

14 is a ratchet wheel that is substantially integrated with the pad base 10, and the coiled spring 1
One end 11a of the separation pad 2a is hooked on a pawl 15a of a ratchet wheel, and the pad base 10 is biased clockwise in the drawing to press the separation pad 2a against the circumferential surface of the pick roller 1. The channel 16 that guides the leading edge of the paper sheets 6 stacked on the paper feed table 5 is swingably attached to the lower part of the channel 16 with a pin 17, and resists the force of the spring 18 that makes it stand up in a fixed position. on the front side (
(paper feed tray side). Further, the big roller 1 is mounted so that it can be easily removed by moving the roller shaft 19 in its axial direction (perpendicular to the plane of the paper) and pulling out the shaft ends from the arm 4 alternately.

In the above structure, when the big roller 1 is removed and the pad base lO is rotated clockwise with the channel 16 tilted to the right (see FIG. 2), the engagement end 11 of the winding spring 11
a moves along the spiral circumferential surface of the ratchet wheel 14 and is hooked on the claw 15b on the opposite side. The retaining end 11a of the winding spring is the claw 1
5b, the channel 16 is erected with the pad base 10 slightly turned counterclockwise in the figure, and the bin roller 1 is attached, thereby switching the separation pad in contact with the big roller 1 from 2a to 2b. By such a separation pad switching operation, the frictional load applied to the fed paper 6 is changed from a high frictional load to a low frictional load or from a low frictional load to a high frictional load. A separation pad 2b with a large frictional load resistance and a separation pad 2a with a small resistance are selected according to the properties of the paper 6.
You can use them properly.

FIG. 3 shows a second embodiment of the invention. The bin roller 1 usually has one roller shaft 1 as shown in the figure.
9 has a structure in which a plurality of roller elements 21 are fixed at intervals. The pad base 10 has a cross-sectional shape similar to that of the conventional pad base shown in FIG. 4, and is elongated in a direction parallel to the roller shaft 19. Two types of separation pads 2a and 2b having different frictional load characteristics are alternately attached to the top surface of the pad base 10 in accordance with the arrangement interval of the roller elements 21 of the big roller, and the pad base 10 is attached to the roller shaft 19.
The separation pad facing each roller element can be converted from a low friction load to a high friction load or from a high friction load to a low friction load by moving the separation pad in a direction parallel to the It is now possible to do so. In this second embodiment as well, by moving the pad base 10 left and right in a direction parallel to the roller shaft 19, the frictional load resistance of the separation pad pressed against the bin roller 1 can be changed, and the paper By changing the frictional load force according to the properties, it is possible to prevent both paper curling phenomenon in copy paper and double feeding when thick paper is used.

(Effects of the Invention) According to the paper separation mechanism of the present invention described above, the frictional load characteristics of the separation pad can be changed according to the paper used, so when feeding thin paper or copy paper, the frictional load A separation pad with a small frictional load is used to prevent the inability to feed one sheet of paper or the phenomenon of copying paper being turned over, and when cardboard or envelopes are used as paper, a separation pad with a large frictional load is placed opposite the bin roller. The large frictional load applied by the separation pad makes it possible to separate the second and subsequent sheets of paper and prevent double feeding of the sheets.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams showing a first embodiment of the present invention, with Figure 1 being a side view of the main parts of the automatic paper feeder, and Figure 2 schematically showing the state when converting the separation pad. FIG. FIG. 3 is a perspective view showing a second embodiment of the invention. FIG. 4 is a side view showing the main parts of a conventional automatic paper feeder. In the figure, 1: Bick roller 2a, 2b: Separation pad 6: Paper 10: Pasodo base 11: Winding blade Figure 3 Figure 4

Claims (1)

[Claims] The paper is passed between a pick roller (1) that rotates in the paper feeding direction and a separation pad made of a high-friction body that is pressed by the pick roller to separate the first paper and the second paper attached to it.
A pad base (10) that supports a separation pad in a paper separation mechanism of an automatic paper feeder that separates subsequent sheets of paper.
A plurality of separation pads (2a) and (2b) having different frictional load characteristics with respect to the paper (6) are attached to the pad base (
10) is rotatably or slidably mounted, and one separation pad selected by the rotation or sliding faces the pick roller (1).