JPH05201565A - Paper feed device - Google Patents

Abstract

PURPOSE:To enable a paper feed roller to be smoothly rotated by hand so as to easily remove a sheet during disposal of a jam or the like, by forming a cut-out in the outer peripheral part of an output gear so that the paper feed roller is made to be free when a clutch is disengaged. CONSTITUTION:In a condition such that a motor 1 is driven so as to continuously rotate an input part 3, an actuator 11 is driven so that a clutch 10 falls in a power transmission condition, and accordingly, the output gear 5 is rotated, resulting in the rotation of a driven gear 9 meshed with the output gear 5 together with a paper feed roller 7. When the clutch 10 falls in a power cut-off condition, a cut-out 4 in the output gear 5 is arranged opposing the driven gear 9 which is therefore made to be free together with the paper feed roller 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device for feeding paper sheets such as printing paper fed to an image forming device and originals fed to an image reading device one by one.

[0002]

2. Description of the Related Art Generally, a paper feed roller is driven at regular intervals to intermittently feed paper sheets. The structure will be described below with reference to FIGS. Reference numeral 1 denotes a motor that continuously rotates when the power is turned on. The rotation of the motor 1 is transmitted from the motor gear 2 to the input gear 22 via the idler gear 21. A paper feed roller 7 is in contact with the stacked paper sheets 6, and an output shaft 23 is fixedly connected to one end of a shaft 8 of the paper feed roller 7. The input gear 22 is rotatably fitted to the shaft 8.

Further, an on / off spring clutch 24 is provided for transmitting the rotation of the input gear 22 to the output shaft 23 in a unit of one rotation by the operation of the armature 12 of the electromagnet 11. That is, a spring 27 is wound around a boss 25 formed on the input gear 22 and a boss 26 formed on the output shaft 23 in a tensioned state, and one end of the spring 27 is attached to the tip 16 of the armature 12. A hook 28 to be abutted is formed.

Therefore, when the motor 1 is continuously rotated, the rotation is transmitted to the input gear 22. When the power of the on / off spring clutch 24 is cut off, the hook 28 of the spring 27 is locked to the tip 16 of the armature 12, so that the spring 27 does not rotate even if it receives frictional force from the boss 25 of the input gear 22, and the input gear 22 does not rotate. 22 runs idle. Here, when a voltage of one pulse is applied to the electromagnet 11, the armature 12 is attracted and the hook 28 is released, so that one end of the spring 27 is rotated by the frictional force from the boss 25. As a result, the winding diameter of the spring 27 is reduced and the bosses 25 and 26 are pressed, and the rotation of the input gear 22 is transmitted to the output shaft 23. As a result, the paper feed roller 7 rotates, but by the time the input gear 22 completes one revolution, the energization of the electromagnet 11 is cut off and the armature 12 returns to the hook 28 by the urging force of the spring (not shown). Since the contact is made, the spring 27 is stopped. As a result, the input gear 22 idles, but the output shaft 23 stops due to the frictional resistance with the spring 27 and the load on the paper feed roller 7.

[0005]

The conventional structure shown in FIGS. 5 and 6 acts between the bosses 25 and 26 and the spring 27 even when the on / off spring clutch 24 is kept in the power-off state. Since the frictional resistance acts on the paper feed roller 7, the paper feed roller 7 is not completely free. As a result, it is laborious to manually rotate the paper feed roller 7 during jam processing or the like. Although not shown, there is a sheet feeding device that sequentially feeds the stacked paper sheets one by one by rotating the sheet feeding roller having a semicircular cross section once. Since the disk-shaped flanges are arranged on both sides of the paper feed roller in order to press the paper of the next layer and below when the paper of the upper layer is fed, the clutch between the paper feed roller and the motor. Even if the paper is turned off, it takes some labor to rotate the paper feed roller by hand.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided an input section driven by a motor, a circular driven gear fixed to one end of a sheet feeding roller which comes into contact with a sheet to be conveyed, and the driven gear. An output gear meshed with the clutch, a clutch for transmitting the rotation of the input section to the output gear in a unit of one rotation by the operation of the actuator, and a predetermined gap with respect to the outer periphery of the driven gear when the power of the clutch is cut off. And a notch formed in a part of the outer circumference of the output gear.

[0007]

With the motor being driven to continuously rotate the input portion, the actuator is operated to put the clutch in the power transmission state to rotate the output gear once, and the driven gear meshed with the output gear is fed. It makes one rotation with the roller, but when the clutch is kept in the power-off state,
The cutout part of the output gear can be made to face the driven gear, and this driven gear can be freely set together with the paper feed roller. This allows the paper feed roller to be lightly rotated by hand to easily remove the paper when jamming etc. Can be removed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The parts having the same structure as the parts described in FIGS. 5 and 6 will be described using the same reference numerals. A motor gear 2 is directly connected to the motor 1, and an input gear 3 as an input portion meshed with the motor gear 2 and an output gear 5 having a cutout portion 4 formed in a part of its outer periphery are provided coaxially. There is. A driven gear 9 meshed with the output gear 5 is fixedly connected to one end of a shaft 8 of a paper feed roller 7 that contacts the paper sheet 6.

An index spring clutch 10 which is a clutch for transmitting the rotation of the input gear 3 to the output gear 5 in a unit of one rotation by the operation of the armature 12 of the electromagnet 11 is provided. That is, the spring 15 is wound around the boss 13 formed on the input gear 3 and the boss 14 formed on the output gear 5 in a tensioned state, and one end of the spring 15 has the armature 1
A hook 17 abutting on the tip 16 of the second gear 2 is formed, and a hook 19 locked on a locking recess 18 formed on the output gear 5 is formed on the other end. Reference numeral 20 is a support shaft that rotatably holds the input gear 3 and the output gear 5.

Next, FIG. 4 shows a state in which the paper feed roller 7 is mounted on a printer. In FIG. 4, the power transmission structure from the motor 1 to the paper feed roller 7 is omitted. Reference numeral 30 denotes a main body of the printer. A paper discharge receiver 31 is formed on an upper surface of the main body 30, and a paper feed cassette 32 is detachably attached to a side surface of the main body 30. The paper feed cassette 32 has a pressing plate 34 which is urged upward by a spring 33 and which can be raised and lowered. The paper sheet 6 is stacked on the upper surface of the pressing plate 34, and the uppermost paper sheet 6 is fed. It is pressed against the paper roller 7. An image forming unit 36 is provided in the paper sheet conveyance path 35 extending from the paper feed roller 7 to the paper ejection receiver 31.
A transport roller 37 and a paper discharge roller 38 located at the entrance of the paper discharge receiver 31 are provided.

In such a structure, the paper feed cassette 3
The paper sheet 6 in 2 is sent out to the paper sheet conveyance path 35 by the paper feed roller 7, printed by the image forming unit 36 in the process of being conveyed by the conveyance roller 37, and ejected to the paper ejection receiver 31 by the paper ejection roller 38. To be done.

Power transmission to the paper feed roller 7 will be described with reference to FIG. Now, when the motor 1 is continuously rotated, the rotation is transmitted to the input gear 3. When the power of the index spring clutch 10 is cut off, the hook 17 of the spring 15 is attached to the tip 16 of the armature 12.
Since the spring 15 is locked to the input gear 3, the spring 15 does not rotate even when frictional force is applied from the boss 13 of the input gear 3, and the input gear 3 idles. Here, when a voltage of 1 pulse is applied to the electromagnet 11, the armature 12 is attracted and the hook 17 is released, so that one end of the spring 15 is rotated by the frictional force from the boss 13. Hook 1 at the other end of spring 15
9 is locked in the locking recess 18 of the output gear 5,
The rotation of the input gear 3 is transmitted to the output gear 5. As a result, the paper feed roller 7 rotates, but by the end of one rotation of the input gear 3, the electromagnet 11 is de-energized and the armature 12 returns to the hook 17 by the urging force of a spring (not shown). Since the contact is made, the spring 15 is stopped. As a result, the input gear 3 idles, but the output gear 5 is stopped because it is locked by the hook 19 of the spring 15.

FIG. 3A shows a state in which the index spring clutch 10 transmits the rotation of the input gear 3 to the output gear 5, but when the index spring clutch 10 is maintained in the power cut-off state. , Fig. 3
As shown in (b), the cutout portion 4 of the output gear 5 is maintained in a state of facing the driven gear 9 with a predetermined gap therebetween. Therefore, the driven gear 9 can be freely set together with the paper feed roller 7, and thus the paper feed roller 7 can be lightly rotated by hand to easily remove the paper sheet at the time of jam processing or the like.

[0014]

According to the present invention, an input section driven by a motor, a circular driven gear fixed to one end of a sheet feeding roller which comes into contact with a sheet to be conveyed, and an output meshed with the driven gear. A gear, and a clutch that transmits the rotation of the input unit to the output gear in a unit of one rotation by the operation of an actuator,
When the power of the clutch is cut off, the motor is constructed by a notch formed in a part of the outer periphery of the output gear, which is positioned at a position opposed to the outer periphery of the driven gear with a predetermined gap therebetween. While the input part is continuously rotating to drive the actuator, the actuator is operated to move the clutch to the power transmission state to rotate the output gear once, and the driven gear meshed with the output gear rotates once together with the paper feed roller. However, when the clutch is maintained in the power cut-off state, the cutout portion of the output gear can be opposed to the driven gear so that the driven gear can be freed together with the paper feed roller. This has the effect that the paper feed roller can be lightly rotated by hand to easily remove the paper sheet.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a main part of an index spring clutch.

FIG. 3 is a front view showing a power transmission operation from an output gear to a driven gear.

FIG. 4 is a front view showing the internal structure of the printer.

FIG. 5 is an exploded perspective view showing a conventional example.

FIG. 6 is an exploded perspective view showing a main part of an on-off spring clutch.

[Explanation of symbols]

 1 Motor 3 Input Section 4 Notch Section 5 Output Gear 6 Paper Sheet 7 Paper Feed Roller 9 Driven Gear 10 Clutch 11 Actuator

Claims (1)

[Claims] 1. An input unit driven by a motor, a circular driven gear fixed to one end of a paper feed roller that comes into contact with a sheet to be conveyed, and an output gear meshed with the driven gear.
A clutch that transmits the rotation of the input section to the output gear in a unit of one rotation by the operation of an actuator, and a clutch that is opposed to the outer periphery of the driven gear at a predetermined interval when the power of the clutch is cut off. And a cutout portion formed in a part of the outer periphery of the output gear.