JPH06104512B2 - Paper feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for feeding a sheet of paper to a device such as a printer.

[Conventional technology]

As a known technique of this type, for example, Japanese Utility Model Publication No. 58-54434 can be cited. FIG. 5 is a sectional view of an essential part showing a conventional sheet feeding device similar to this known technique. In the figure, 1 is a large number of stacked sheets, 2 is a tray for storing the sheets, 3 is a bottom plate rotatably supported by the tray 2 at the rear end, and 4 is rotatably supported by a fixed portion. The tip end portion of the lifted lever is rotated upward by a spring member (not shown), and the bottom plate 3 is rotated upward. Denoted at 5 is a delivery roller fixed to a roller shaft 6 which is rotatably supported by a fixed portion, and is rotated in the direction of arrow A by a drive motor.

Next, the operation will be described. The delivery roller 5 is rotated, and the push-up lever 4 whose front end portion has been rotated downward by the return rotation means (not shown) releases the return and is rotated upward. As a result, the bottom plate 3 is pushed upward and rotated, and the uppermost portion of the stacked sheets 1 is pressed against the feeding roller 5 and is fed one by one.

[Problems to be solved by the invention]

In the conventional sheet feeding device as described above, even if the contact pressure between the delivery roller 5 and the sheet 1 is set to be constant and the sheet 1 is delivered regardless of the amount of the sheet 1 stacked on the tray 2, a heavy load is generated. There is a problem in that the feeding cannot be completely prevented, a double feeding detecting device is required, and the double feeding paper must be reworked.

Further, if the sheet 1 stacked on the bottom plate 3 is erroneously delivered by the delivery roller 5 at a time when it is not yet delivered, there is a problem that there is no means for returning it to the tray.

The present invention has been made to solve such a problem, and it is an object of the present invention to obtain a sheet feeding device that prevents double feeding and that allows sheets erroneously fed by a feeding roller to be returned to a tray. Has an aim.

[Means for solving problems]

In the sheet feeding device according to the present invention, the sheet feeding roller is disposed on the feeding side of the feeding roller, and the separation roller supported at the tip of the support lever is detachably attached to the sheet feeding roller from below. In the feeding direction, and the separating roller is rotated in the direction for returning the sheet through the torque limiter. Further, a paper return lever is arranged on the sending side above the paper on the bottom plate, and when the bottom plate is rotated upward, the leading end bent downward is isolated above the separation roller, and the bottom plate rotates downward. In the moving state, the tip end portion is lowered toward the separation roller.

[Action]

According to the present invention, when the bottom plate is rotated upward and the uppermost sheet is fed by the feeding roller, the separating roller is in contact with the rotating feeding roller, and the separating roller is driven by the driving torque in the returning direction. The rotational force in the delivery direction due to is superior to the rotational force in the same direction. The uppermost sheet delivered by the delivery rollers enters between the paper feed roller and the separation roller and is delivered. In this case, when the second sheet is fed over the uppermost sheet, the upper one sheet is fed as it is by the sheet feeding roller, but the separation roller is released from the rotation by the feeding roller and is returned in the return direction. It is rotated and the lower one is not fed. The forward movement of the first sheet at a predetermined position causes the push-up lever to return and rotate, and the bottom plate to return and rotate downward,
At the same time, the lower rotation of the support lever separates the separation roller from the paper feed roller, and the lower rotation of the paper return lever causes its tip to press the second sheet of paper on the rotating separation roller. This paper is returned.

Also, even if there is an erroneous delivery other than the regular delivery of the uppermost sheet, the downward rotation of the push-up lever after the regular delivery, the return rotation due to the separating roller separating operation, and the tip of the sheet return lever By pressing the erroneously sent paper to the separation roller, the erroneously sent paper is returned to the tray.

〔Example〕

1 and 2 are a partial cross-sectional side view and a perspective view showing an essential part of an embodiment of a sheet feeding device according to the present invention. A tray 2 is fixed to a frame 10 of the apparatus, a bottom plate 3 is supported in the tray 2 so as to be rotatable around a rear end side, and a large number of sheets 1 are stacked. Reference numeral 11 denotes a push-up lever, the tip side of which is rotated upward by a spring member (not shown) so that the bottom plate 3
Push the front end side upward and rotate. This push-up lever
Numeral 11 is adapted to be rotated back to the position shown in the drawing by a returning rotation means (not shown). A pair of feeding rollers 12 made of an elastic friction material such as a rubber material is used for the paper 1 on the bottom plate 3.
Is disposed on the upper side of the delivery side and is fixed to the roller shaft 13. The roller shaft 13 is rotatably supported on the frame body 10 side and is rotated by a drive source (not shown) such as an electric motor. Reference numeral 14 is a paper return lever rotatably supported at the rear end by a support shaft 15 supported on the frame body 10 side, and an intermediate protruding portion downward.
14b is in contact with the upper surface of the sheet 1 on the delivery side, and the leading end 14a is located above the front of the tray 2. The return lever 14 has a tip portion 14a exerted downward turning force by a spring member (not shown) and its own weight. The locus of the tip portion 14a caused by the rotation of the return lever 14 is indicated by E. A pair of paper feed rollers 17 made of an elastic friction material such as a rubber material is disposed on the delivery side of the delivery roller 12 and is fixed to the roller shaft 18. The roller shaft 18 is rotatably supported on the frame body 10 side,
It is rotated by a drive source (not shown) such as an electric motor. 19
Are a pair of separation rollers made of elastic friction material such as rubber material, which are located below the paper feed roller 17 and fixed to the roller shaft 20. The roller shaft 20 is rotated in the paper returning direction via a torque limiter (not shown) to a drive source such as an electric motor. Reference numeral 21 is a support lever that rotatably supports the roller shaft 20 at one end, and is rotatably supported by a support shaft 22 fixed to the frame body 10 side, and is C by a spring member (not shown).
Is rotated in the direction to bring the separation roller 19 into contact with the paper feed roller 17. Further, the support lever 21 is rotated in the direction opposite to the C direction against the spring force of the spring member by the operation of the rotation return means (not shown), and the separation roller 19 is separated from the paper feed roller 17.

The operation of the apparatus of the above-described embodiment is as follows. As shown in FIG. 1, a large number of sheets 1 are stacked on a horizontal bottom plate 3 in a tray 2. The feeding roller 12 is rotated in the A direction, and the paper feeding roller 17 is rotated in the B direction. The separation roller 19 rotated in the D direction is pressed against the paper feed roller 17, so that the rotational force in the F direction (see FIG. 3) is stronger and the separation roller 19 is rotated in the F direction by the slip due to the torque limiter. The return rotation restraint of the push-up lever 11 is released, and the push-up lever 11 is rotated upward to rotate the bottom plate 3 upward. As a result, as shown in FIG. 3, the upper surface of the sheet 1 pushes up the return roller 14 and rotates, and presses the delivery roller 12 under pressure so that the uppermost sheet is delivered and separated from the sheet feeding roller 17. It is sandwiched between the rollers 19, is fed in the direction of arrow G, and is passed between the upper and lower transport rollers (not shown) to be transported.

Here, when the lower sheet 1b is delivered while being overlapped with the uppermost sheet 1a, when the sheet reaches between the sheet feed roller 17 and the separation roller 19, the upper sheet 1a is rotated by the sheet feed roller 17 in the B direction. However, the separation roller 19 returns to the rotation in the direction of the arrow D by the interposition of the sheet 1b below the sheet 1a, and prevents the lower sheet 1b from being delivered.

Further, when the leading edge of the above-mentioned sheet 1a reaches a predetermined conveyance position, a fourth detection signal from a detection unit (not shown)
As shown in the figure, the support lever 21 is rotated in the counter C direction,
The separation roller 19 is separated from the paper feed roller 17. At the same time, the push-up lever 4 is rotated back and the bottom plate 1 is brought into a horizontal position so that the sheet 1 is also in a horizontal state. Then, the return lever 14 also rotates downward, and the leading end 14a presses the double-fed sheet 1b downward, so that the sheet 1b is fed back by the separating roller 19 in the arrow H direction. When the leading edge of the sheet 1b is separated from the separation roller 19, the sheet 1b is urged by the trajectory E of the leading end portion 14b of the return lever 14.
Scrape back into the tray 2.

Further, the returned double-fed sheet 1b is pressed by the intermediate protrusion 14b of the return lever 14 and drops onto the sheet 1 stacked on the bottom plate 3.

Further, if the sheet 1 is erroneously delivered at a time when it is not delivered at the time when it is delivered due to the rotation of the delivery roller 12, it is detected by the detection means (not shown) on the conveyance side, and the support lever 21 is rotated in the counter C direction by this detection signal. The separation roller 19 is separated from the supply roller 18 and rotated in the D direction, and the misdelivered sheet 1 is returned to the tray 2 in the same manner as the returning operation in the case of the double feeding.

In the above-described embodiment, the return lever 14 is rotated in response to the lifting rotation of the stacking sheet 1 by the lifting lever 4, but it may be rotated by a solenoid or an electric motor. You may call it.

〔The invention's effect〕

As described above, according to the present invention, the paper delivered by the delivery roller by the upward rotation of the bottom plate of the tray is passed between the paper feed roller and the separation roller, the uppermost paper is delivered, and The paper is moved back by the rotation of the separating roller in the returning direction, and further, by the downward rotation of the push-up lever and the separation of the separating roller from the paper feed roller, the paper is rotated downward by the tip of the return lever. Since the double-fed paper is returned further and is inserted in the tray, double-feeding of the paper is prevented, erroneous paper feeding can be returned, and reliability is improved.

[Brief description of drawings]

1 and 2 are partially sectional side views and perspective views showing an essential part of an embodiment of a paper feeding device according to the present invention, and FIG. 3 is a part showing a paper feeding state of the device of FIG. Sectional side view, FIG. 4 is a partially sectional side view showing the returning state of the double-fed sheets from the state of FIG. 3, and FIG. 5 is a partially sectional side view showing the main part of a conventional sheet feeding device. Is. DESCRIPTION OF SYMBOLS 1 ... Paper, 2 ... Tray, 3 ... Bottom plate, 10 ... Frame, 11 ... Push up lever, 12 ... Sending roller, 14 ... Paper return lever, 14
a ... Tip, 17 ... Paper feed roller, 19 ... Separation roller, 21 ... Support lever. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A large number of sheets are stacked on a bottom plate whose front side is rotatably supported upward in a tray, and are fed and rotated by the push-up rotation of the bottom plate by a push-up lever. In a paper feeding device in which the above-mentioned paper is pressed against an upper feeding roller to feed and feed one sheet, a paper feeding roller disposed on the feeding side of the feeding roller and rotated in the feeding direction, It is arranged below the paper roller and is rotated in the returning direction via a torque limiter. When the paper roller is pressed directly against the paper feeding roller or pressed against only one sheet of paper, it is prevented from rotating in the returning direction. Separation roller that receives rotation in the feeding direction, a rotation supporting lever that presses the separation roller supported at one end against the paper feed roller at the time of feeding, and separates at the time of returning the multi-fed paper, and the bottom plate Placed on the upper front edge side of the upper paper The leading end, which is rotatably supported by the frame and bent downward, is separated above the separating roller when the paper is fed out, and when the double feed paper is returned, the push-up lever is rotated downwards. A sheet feeding device that is rotated downward, pushes and returns the multi-fed sheet onto the separating roller by the tip portion, and further includes a return lever that inserts the sheet into the tray.