JPH05132173A - Paper feed device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a paper feed error such as the feed of superposed sheets by keeping a play between a paper feed roller axis and a gear fitted thereto, causing the rotation of the sheet feed roller axis in an anti-sheet feed direction after the passage of the trailing end of a paper sheet fed through a pinch roller and then moving the pinch roller to a standby position. CONSTITUTION:When a paper feed roller axis 1 is caused to rotate in a paper feed direction, a pinch roller shaft 17 is caused to rotate in a sheet feed direction via gears 6 and 8, due to the rotation of a gear 4 fitted to the shaft 1. Also, a reversing roller shaft 12 is caused to rotate in an anti-paper feed direction via gears 15 and 16, due to the rotation of a gear 13. If two or more sheets as superposed are fed to a gap between a paper feed roller 5 and a reversing roller 10, frictional resistance between both rollers 5 and 10 is weakened to such a level as lower than frictional resistance between a reversing roller shaft 12 and a torque limiter 11. As a result, a trouble of feeding superposed sheets is eliminated via the rotation of the reversing roller 10. After a sheet passes the a pinch roller 7, the paper feed roller shaft 1 is caused to rotate in an anti-paper feed direction, and the pinch roller 7 is kept away at a standby position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for sequentially feeding sheets placed on a sheet placing plate by a pickup roller and a sheet feeding roller.

[0002]

2. Description of the Related Art For example, as shown in FIGS. 5 and 6, a conventional sheet feeding device of a copying machine is attached to a sheet feeding roller 5 attached to a sheet feeding roller shaft 1 and a sheet feeding roller shaft 17. And the reverse roller 10 attached to the reverse roller shaft 12
It was composed by and.

When the paper cassette on which the paper is placed is set in the main body of the copying machine, the paper is pushed upward by the push-up member 18.

Then, the paper feed roller shaft 1 is rotated in the paper feed direction based on the copy start signal. Also, the gears 3, 4, 5
Call-in roller 7 connected to paper feed roller shaft 1 by
Rotates in the paper feeding direction, and the feed roller lever 9 is rotated to the paper feeding position to feed the first sheet.

During the paper feeding operation, the paper feeding roller shaft 1 and the gear 1
Reverse rotation roller shaft 1 connected by 4, 15 and 16
2 rotates in the direction opposite to the paper feeding direction, but since the frictional resistance between the paper feeding roller 5 and the reverse rotation roller 10 is larger than the resistance between the reverse rotation roller 10 and the torque limiter 11, the paper feeding is performed. It goes around with the roller 5.

The paper feed roller shaft 7 and the gear 14 and the reverse rotation roller shaft 12 and the gear 16 are fixed without play.
Therefore, the first sheet fed by the call-in roller 7 was fed into the apparatus by the two rollers when it reached between the feed roller 5 and the reverse roller 10.

Further, when two or more sheets are overlapped and fed, the reverse rotation roller 10 reversely rotates due to the friction coefficient, so that the second and subsequent sheets are returned to the paper feed cassette side.

Since the call-in roller 7 is interlocked with the paper-feeding roller 5, the second sheet is fed in after the trailing edge of the first sheet has passed through the call-in roller 7 while being pressed against the sheet. Will cause double feed.

Therefore, in the conventional paper feeding device, the take-in roller 7 is used.
Was moved to the paper feed position and the standby position at preset timing.

Specifically, after the feeding of the first sheet, the rotation of the sheet feeding roller shaft 1 is stopped and the pull-in roller pull-up spring 20.
Therefore, the call-in roller lever 9 is rotated upward with the paper feed roller 5 as a fulcrum to move the call-in roller 7 to the standby position.

[0011]

However, in the above-mentioned conventional paper feeding apparatus, the reverse roller shaft, which is connected to the paper feeding roller shaft by the gear, is rotated in the paper feeding direction by the rotation of the take-in roller lever and the torque is generated. There is a drawback that the limiter locks the reverse rotation roller shaft and the reverse rotation lock rotates in the paper feeding direction, and when two or more sheets are fed, the sheets are double fed.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and includes a paper feed roller shaft to which a paper feed roller is attached, and the paper feed roller shaft and gears. A reverse rotation roller shaft connected via the torque limiter and the reverse rotation roller, and a pickup roller shaft connected via the gear and lever member to the pickup roller, As the paper feed roller shaft rotates in the paper feed direction, the reverse rotation roller rotates in a direction opposite to the paper feed direction, and the lever member rotates to press the intake roller against the paper. In a sheet feeding device that rotates in a sheet feeding direction to feed a sheet, a sheet to be fed is provided with a predetermined range of play between the sheet feeding roller shaft and a gear attached to the sheet feeding roller shaft. After the trailing edge passes through the above-mentioned call-in roller, the above-mentioned feeding The roller shaft and the paper feed direction without rotating the reverse roller rotates in the opposite direction, characterized in that moved to the standby position the drawing roller from the paper feeding position.

[0013]

According to the paper feeding device of the present invention, the reverse roller can be prevented from rotating in the paper feeding direction when the feeding roller is moved to the standby position. Highly reliable paper feeding can be performed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a schematic structure of a sheet feeding device according to the present invention.

FIG. 2 is a schematic diagram showing the state of the paper feeding apparatus according to the present invention during paper feeding.

FIG. 3 is a schematic configuration diagram showing a standby state of the sheet feeding device according to the present invention.

FIG. 4 is an external perspective view of a copying machine equipped with the paper feeding device according to the present invention.

In the figure, 1 is a paper feed roller shaft,
A slip spring 2, a friction plate 3, a pickup roller lever 9, a gear 4, a sheet feed roller 5, and a pickup roller lever 9 are sequentially attached to the sheet feed roller shaft 1.

A gear 13 is attached to the end of the paper feed roller shaft 1 opposite to the intake roller lever 9.

Reference numeral 12 is a reverse rotation roller shaft, to which a gear 16, a torque limiter 11, and a reverse rotation roller 10 are sequentially mounted.

Gear 16 mounted on the reverse rotation roller shaft 12
Is the gear 13 attached to the paper feed lock shaft 1 and the gear 1
It is connected through 5.

Reference numeral 17 denotes a call-in roller shaft, one end of which is attached to the paper-feed roller shaft 1, a call-in roller lever 9, 9, a gear 8,
A call-in roller 7 is attached.

A gear 8 attached to the intake roller shaft 17
Is connected via a gear 6 to a gear 4 attached to the paper feed roller shaft 1.

The call-in roller 7 of the call-in roller lever 9
A pull-in roller pull-up spring 20 is provided between the side and the body frame.
Is stretched, and the intake roller pulling spring 20 urges the intake roller 7 toward the standby position away from the paper.

The gears 4, 8 and 16 are fixed to the shafts without any play, but only the gear 13 is attached to the paper feed roller shaft 1 so that a play within a predetermined range occurs. ..

As a specific mounting method, a pin hole is formed at the mounting position of the gear 13 of the paper feed roller shaft 1, and the parallel pin 14 is fitted into the pin hole so that both ends thereof protrude.

The parallel pin 1 is provided on one side surface of the gear 13.
A rectangular groove 13a is formed so that 4 can be accommodated. The groove 1
The width dimension of 3a is a dimension having a margin with respect to the dimension of the parallel pin 14, that is, an angle θ (about 3 ° to about 3 ° between which the feeding roller 7 pivots from the sheet feeding position to the standby position with the sheet feeding roller shaft 1 as a fulcrum.
The size is set so that the gear 13 does not rotate even if the paper feed roller shaft 1 rotates at 5 °.

Specifically, the groove 13 is provided at the feeding roller feeding position.
The parallel pin 14 is located on the diagonal line of a,
The parallel pin 14 is set so as to be positioned on the other diagonal line and stop when it is rotated by, for example, 3 ° to the standby position.

The sheet feeding device configured as described above is provided in each sheet feeding section. Next, the paper feeding operation will be described.

First, when a paper feed cassette on which a desired size of paper is placed is set in the main body, the paper placement plate 21 is raised by the push-up member 18 to a preset call-in position. Next, when the copy conditions are set and the copy start key is pressed, the paper feed roller shaft 1 rotates in the paper feed direction and the paper feed roller 5 rotates in the same direction based on the copy start signal.

At this time, the intake roller shaft 17 connected to the gear 4 mounted on the paper feed roller shaft 1 via the gears 6 and 8 also rotates in the paper feed direction, and the shaft 17 is accordingly rotated. The invocation roller 7 fixed to is also rotated in the same direction.

Further, the reverse rotation roller shaft 12 and the reverse rotation roller 10 which are connected to the paper feed roller shaft 1 via the gear 13, the gear 15, and the gear 16 are located below the paper to be fed. Rotate in the direction opposite to the paper feed direction.

However, in the state where there is no paper between the paper feed roller 5 and the reverse rotation roller 10, the reverse rotation of the paper feed roller 5 in the contact state is more than the frictional resistance between the reverse rotation roller shaft 12 and the torque limiter 11. Since the frictional resistance between the roller 10 and the roller 10 is larger, the reverse roller 10 rotates along with the sheet feeding roller 5 and rotates in the sheet feeding direction.

Simultaneously with the rotation operation of the above rollers, the take-in roller lever 9 is rotated to the paper feeding position with the paper feeding roller shaft 1 as a fulcrum, and the take-in roller 7 is moved to the uppermost position (one sheet It is pressed down on the paper of (eyes).

The take-in roller lever 9 is pressed against the friction plate 3 by the slip spring 2 and therefore rotates to the paper feeding position as the paper feeding roller shaft 1 rotates.
After the sheet is pressed against the first sheet, the resistance between the sheet feeding roller 7 and the sheet is increased, so that the sheet feeding roller lever 9 slips.

Therefore, the force with which the pickup roller 7 presses the paper is kept constant.

Next, when the first sheet is sent out by the intake roller 7 and reaches between the paper feed roller 5 and the reverse rotation roller 10, the reverse rotation roller 10 contacts the paper feed roller 5 by the pressing spring 19. Since the paper is rotated in the paper feeding direction, the paper is fed in the paper feeding direction as it is.

At this time, when two or more sheets are sent between the paper feed roller 5 and the reverse rotation roller 10 while being overlapped with each other, the frictional resistance between the reverse rotation roller 10 and the paper supply roller 5 is increased. Is weakened and the reverse rotation roller shaft 12 and torque limiter 1
Since the friction resistance between the paper feed roller shaft 1 and
By the rotational force transmitted from the gears 13, 15 and 16 through the gears 13, 15, 16 rotates in the direction opposite to the paper feeding direction.

Therefore, the second and subsequent sheets of paper are returned to the paper feed cassette side.

When the paper feed roller shaft 1 is rotated in the direction opposite to the paper feed direction after the first sheet of paper has passed through the take-in roller 7, the take-in roller lever 9 moves from the paper feed position to the standby position, for example. The drawing roller 7 is rotated by 3 ° and separated from the paper.

At this time, since there is play between the paper feed roller shaft 1 and the gear 13, the gear 13 does not rotate until the intake roller 7 reaches the standby position.

Therefore, since the torque limiter 11 does not lock the reverse rotation roller shaft 12, the reverse rotation roller 10 does not rotate in the paper feeding direction, and as a result, it is possible to prevent double feeding of paper.

[0044]

According to the paper feeding apparatus of the present invention, it is possible to prevent the reverse rotation roller from rotating in the paper feeding direction when the feeding roller is moved to the standby position. It is possible to perform highly reliable paper feeding.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a paper feeding device according to the present invention.

FIG. 2 is a schematic configuration diagram showing a state during paper feeding of the paper feeding device according to the present invention.

FIG. 3 is a schematic configuration diagram showing a standby state of the sheet feeding device according to the present invention.

FIG. 4 is an external perspective view of a copying machine including the paper feeding device according to the present invention.

FIG. 5 is a perspective view showing a schematic configuration of a conventional paper feeding device.

FIG. 6 is a cross-sectional view of a main part of a conventional paper feeding device.

[Explanation of symbols]

 1 Paper Feed Roller Shaft 5 Paper Feed Roller 7 Intake Roller 9 Lever Member 10 Reverse Rotation Roller 11 Torque Limiter 12 Reverse Rotation Roller Shaft 13 Gear 13a Groove 14 Pin 17 Incoming Roller Shaft

Claims (2)

[Claims] 1. A paper feed roller shaft to which a paper feed roller is attached, a reverse rotation roller shaft connected to the paper feed roller shaft via a gear and having a torque limiter and a reverse rotation roller attached thereto, and the paper feed roller. A feed roller shaft to which a feed roller is attached and which is connected to the shaft through a gear and a lever member, and the reversing roller is fed in the paper feeding direction in accordance with the rotation operation of the paper feeding roller shaft in the paper feeding direction. In the paper feeding device for rotating the lever member in the opposite direction to rotate the lever member to press the invocation roller against the paper and rotate in the paper feeding direction to feed the paper, A play in a predetermined range is provided between the feed roller shaft and a gear attached to the feed roller shaft, and the feed roller shaft is rotated to rotate the reverse rotation roller after the trailing end of the fed paper passes through the intake roller. Without rotating in the direction opposite to the paper feed direction. Sheet feeding apparatus characterized by moving to the standby position the drawing roller from the paper feeding position Te. 2. A range from the feed roller feed position to the standby position on a side surface of a gear to which a pin hole is bored in the feed roller shaft to fit a pin and which is attached to the feed roller shaft. 2. The sheet feeding device according to claim 1, wherein the groove is formed so that the pin has play.