JPH07269595A - Clutch device and paper feeding device therewith - Google Patents

Abstract

PURPOSE:To reduce noise, a click, generated when a lever is returned to collide with the outer periphery of a cam. CONSTITUTION:Releasing a locked lever 27 from a cam 25 by means of an electromagnet 26 rotates the cam 25 and a partially toothed gear integrated with the cam 25 in the direction engaged with a gear 20 at a driving source side in accordance with the energization of a spring 28. The partially toothed gear 24 is then rotated, approximately one turn, by means of the gear 20 at the driving source side. When the partially toothed portion 24a of the partially toothed gear 24 arrives at the position opposing to the gear 20 at the driving source side, energization force is again stored in the spring 28 and the lever 27 is locked with the stepped portion of the cam 25 to stop the cam 25 and the partially toothed gear 24. The lever 27 waits for locking with the stepped portion of the one-turned cam. Thus the lever 27 is returned immediately after release from locking with the cam 25. The returned lever 27 collides with a buffer provided on the cam to reduce noise on collision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch device that rotates in a single rotation with a drive source and a paper feeding device in a printer or the like equipped with the clutch device.

[0002]

2. Description of the Related Art Conventionally, in this type of clutch device, the cam is engaged at a stop position with a lever or the like in an initial state, and the lever is temporarily disengaged from the cam by an electromagnet or the like. The cam is stopped again with the lever after one rotation.

A sheet feeding device equipped with this clutch device releases the lever from engagement with a cam based on a sheet feeding start signal, and rotates a sheet feeding roller based on the rotation of the cam to turn the sheet feeding roller on the sheet tray. Send out printing paper.

[0004]

In the above-mentioned conventional device, the lever is immediately returned after the lever is disengaged from the cam, and the cam waits for the cam to return to its original position after one rotation. Since the cam is made of a hard resin material, when the lever returns and collides with the outer circumference of the cam, a "click" noise is generated.

The present invention provides a clutch device that reduces this noise and a sheet feeding device including the clutch device.

[0006]

DISCLOSURE OF THE INVENTION A clutch device according to the present invention comprises a toothless gear capable of meshing with a gear connected to a drive source, a cam rotatable integrally with the toothless gear, and the toothless gear and cam. Is constantly urged in a direction in which the drive source side gear and the toothless portion of the toothless gear are in contact with the spring from a stop position in which the toothless portion of the cam is opposed to the cam, and the cam of the cam is in the stopped position. A lever that engages with the step portion and stops the cam against the rotational bias of the spring, a buffer body that is arranged at a position facing the lever that follows the step portion of the cam, and the lever And an operating means for temporarily releasing the engagement with the step portion of the cam.

Preferably, the shock absorber is fitted and fixed in a recess provided in the cam, and an outer surface facing the lever is formed as a continuous surface with an outer surface of the cam adjacent to the shock absorber.

Further, according to the present invention, in the paper feeding device, the second toothless gear which can mesh with the gear connected to the drive source, the paper feeding roller connected to the toothless gear, and the printing paper are stacked. And a biasing means for biasing the printing plate on the printing plate so that the printing paper on the printing plate approaches the paper feed roller, and the second tooth-chipped gear so as to be integrally rotatable. An actuating cam that moves the paper table in a direction in which the print paper is separated from the paper feed roller against the urging force of the urging means; and a second cam that is integrally rotatable with the second tooth-chipped gear. An arm that stops the second cam at a position where a toothless portion of the second toothless gear faces the gear on the drive source side, and the arm of the second cam is caused by the cam of the clutch device. It is configured to operate in the disengagement direction.

[0009]

In the clutch device having the above structure, when the lever is disengaged from the cam by the operating means, the cam and the tooth-missing gear integrated with the cam move to the gear on the drive source side in accordance with the bias of the spring. Rotate in the direction of engagement. Then, when the tooth-chipped gear makes one full rotation by the gear on the drive source side and the tooth-chipped portion of the tooth-chipped gear comes to a position facing the gear on the drive source side, the spring again stores the urging force and the lever. Engages the stepped portion of the cam to stop the cam and the toothless gear. The lever returns immediately after being released from the engagement with the cam in order to wait for the engagement with the step portion of the cam after one rotation. When the lever returns, it collides with the buffer provided on the cam, so that noise at the time of collision can be reduced.

Further, since the shock absorber is fitted and fixed in the concave portion of the cam and is formed on a continuous surface with the outer surface of the cam, noise when the lever moves from the shock absorber to the outer surface of the cam can be eliminated.

In the paper feeding device, when the lever of the clutch device is released as described above, the arm is driven by the rotation of the cam. As a result, the arm is disengaged from the second cam, and the second cam and the second toothless gear integrated with the cam are driven by the urging force of the urging means for urging the paper tray. It rotates in the direction that meshes with the gear of. The gear on the drive source side rotates the paper feed roller together with the toothless gear, and the paper base approaches the paper feed roller by following the rotation of the operating cam by the urging force of the urging means. When the printing paper on the paper tray is sent out by the rotation of the paper feed roller, the paper tray again starts to separate from the paper feed roller against the biasing means. When the paper feed roller makes almost one rotation, the toothless portion of the second toothless gear faces the gear on the drive source side, and the arm engages with the second cam and stops.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

The paper table 1 on which the printing paper P is loaded is supported by a pivot shaft 30 so that its base end can be rotated up and down, and its tip end is directed toward the paper feed roller 2 by a biasing means such as a coil spring 3. Is being biased upwards. The paper feed roller 2 is fixed to the support shaft 8, and the operation cam 4 that comes into contact with a driven roller 21 provided on one side of the paper tray 1 so as to project upward is also fixed to the support shaft 8.
The paper feed roller 2 and the operation cam 4 can rotate integrally.

Conveying roller pairs 5a and 5b are provided on the downstream side of the paper feeding roller 2 in the paper feeding direction, and the printing paper P fed by the feeding roller 2 is supplied to the conveying roller pairs 5a and 5b for printing on the downstream side. Print on the device. The rotational force of the drive source, for example, the motor 6 is transmitted to the pair of conveying rollers 5a and 5b and the support shaft 8 via the transmission gear mechanisms 11 to 20.

The support shaft 8 is provided with a second clutch device 9 which selectively receives the rotational force from the transmission gear mechanisms 11-20. The second clutch device 9 includes a paper feed roller 2 on the support shaft 8.
And the second partly tooth-missing gear 9a and the second cam 31 which are provided so as to integrally rotate coaxially with the operating cam 4.
And an arm 23 that engages with and disengages from the second cam 31, and a biasing means 3 that biases in the rotational direction within a predetermined angle range via the actuating cam 4.

The tooth-chipped gear 9a has a toothless portion in the circumferential direction,
It has a toothless portion 10. One gear 20 in the transmission gear mechanisms 11 to 20 meshes with the tooth portion of the tooth-chipped gear 9a or faces the tooth-chipped portion 10. The second cam 31 is
It has a step portion 31b protruding in the radial direction. Arm 23
Is urged by the spring 22 in the direction of coming into contact with the cam 31, and in the state of being engaged with the stepped portion 31b of the cam, the tooth-chipped gear 9a.
The positional relationship between the cam 31 and the tooth-missing gear 9a is determined such that the tooth-missing portion 10 of the gear faces the gear 20. Further, in this state, the paper feed roller 2 is positioned so that the semicircular chordal portion thereof faces the paper tray 1, and the operation cam 4
Is located at a position where the paper tray 1 is pushed down so as to be most distant from the paper feed roller 2. In this state, the spring 3 urges the second cam 31 through the actuating cam 4 to rotate in the direction R in which the step portion 31b engages with the arm 23.
The toothless gear 9a, the second cam 31, and the actuating cam 4 are stopped by the arm 23 engaging with the step portion 31b.

The arm 23 is driven by the rotation of the cam 25. The cam 25 is fixed to the shaft 32 and is rotated by one gear 20 in the transmission gear mechanisms 11-20. Note that other gears in the transmission gear mechanisms 11 to 20 may be used, and a drive source different from the motor 6 may be used.

The shaft 32 is provided with a clutch device 33 which selectively receives the rotational force from the gear 20. The clutch device 33 includes a toothless gear 24 provided on a shaft 32 so as to rotate integrally with the cam 25 coaxially, a cam 25 that also drives the arm 23, and a lever that engages and disengages with the cam 25. 27, a spring 28 for urging the toothless gear 24 and the cam 25 in the rotational direction within a predetermined angle range, and an operating means for operating the lever 27, such as an electromagnet 26. The toothless gear 24 has a toothless portion in the circumferential direction, a toothless portion 24a. The gear 20 meshes with the tooth portion of the toothless gear 24 or faces the toothless portion 24a. The cam 25 has a step portion 25b protruding in the radial direction. Lever 27 is spring 3
4 is urged in the direction of coming into contact with the cam 25, and in the state of being engaged with the stepped portion 25b of the cam, the toothless portion 24 of the toothless gear 24 is
The cam 25 and the tooth-chipped gear 2 so that a faces the gear 20.
The positional relationship of 4 is decided. In this state, the spring 28
Is the direction Q in which the step portion 25b engages the cam 25 with the lever 27.
However, the tooth-chipped gear 24 and the cam 25 are stopped by the lever 27 engaging the step portion 25b.

The cam 25 has a lever 27 that follows the step 25b.
A buffer 35 is provided at a position opposed to. That is, step 25
A concave portion 25c that is convex in the radial direction is formed on the outer peripheral portion of the cam 25 that is adjacent to b in the direction opposite to the rotational direction Q, and a cushioning body, for example, rubber 35 is press-fitted and fixed in place. The outer periphery of 35 is formed as a continuous surface. The shock absorber 35 is in a position where the lever 27 collides when the lever 27 is temporarily released from the engagement with the cam 25 by the electromagnet 26 and then returned by the spring 34. The distance from the stepped portion 25b to the buffer 35 is determined by the rotation speed of the cam 25 and the suction time of the lever 27 by the electromagnet 26.

When the motor 6 rotates, the conveying roller pair 5
The a and 5b rotate in the direction of sending the printing paper toward the printing apparatus. In the initial state shown in FIG. 1, the cam 25 rotatable integrally with the tooth-chipped gear 24 is held stationary by the lever 27, and the second cam 31 is also held stationary by the arm 23. The toothless portion 24a of 24 and the toothless gear 9
The toothless portion 10 of a faces the gear 20, and the rotational force of the motor 6 is not transmitted.

When a paper feed start signal is input, a current is supplied to the electromagnet 26 for a predetermined time, the lever 27 is attracted and the engagement of the cam 25 with the step 25b is released. Since the spring 28 urges the cam 25 to rotate, when the attraction of the lever 27 by the electromagnet 26 is cut off, the lever 27 returns to the buffer 35 of the cam 25 by the urging force of the spring 34. At this time, the collision noise is reduced by the action of the buffer body. Since the outer peripheral surfaces of the buffer 35 and the cam 25 are formed as continuous surfaces, the lever 27 will slide on the cam as the cam 25 rotates thereafter, and no collision noise will be produced.

Further, when the lever 27 is released from the engagement with the step portion 25b of the cam, the toothless gear 24, which is urged to rotate in the Q direction by the urging force of the spring 28, is the gear 2.
The toothless gear 24 meshes with the zero gear and is rotated by the gear 20. As a result, the cam 25 pushes the arm 23 in the direction S in which the arm 23 is disengaged from the step 31b of the second cam 31.

At this time, the urging means 31 for urging the paper tray 1 upward is provided with the second cam 31 via the actuating cam 4.
Since the tooth-chipped gear 9a is urged to rotate in the direction of arrow R, the tooth-chipped gear 9a meshes with the gear 20 and is rotated by the gear 20. As a result, the operating cam 4 continues to rotate in the direction of arrow R, and the upper surface of the printing paper P on the paper tray 1 contacts the paper feed roller 2 that rotates integrally with the operating cam 4.

The paper feed roller 2 rotates in accordance with the rotation of the tooth-chipped gear 9a, and only one printing paper P is picked up by the circular arc outer peripheral surface of the paper feed roller 9a, and the conveying roller pair 5a,
Send to 5b. After that, the operation cam 4 pushes the driven roller 21 to rotate the paper tray 1 downward, and the contact state between the paper feed roller 2 and the printing paper P is released.

The partly tooth-missing gear 9a rotates almost once, and the partly tooth-missing part 1
When 0 again faces the gear 20, the arm 23 is engaged with the step portion 31b of the cam 31 by the urging force of the spring 22. At this time, the actuating cam 4 is rotated by the biasing force of the biasing means 3 again in the direction of the arrow R to the position where it is biased.
The stepped portion 31b of the cam 31 is pressed against the arm 23 by the urging force of. As a result, the feed roller 2, the tooth-chipped gear 9a, the second cam 31, and the operation cam 4 are stopped in a state where the rotation transmission from the gear 20 is cut off.

Similarly, the tooth-chipped gear 24 also makes almost one rotation, and when the tooth-chipped portion 24a again faces the gear 20,
The lever 27 is urged by the spring 34 so that the step portion 25b of the cam 25
Engage with. At this time, the cam 25 is rotated by the urging force of the spring 28 again in the direction of the arrow Q to a position where it is urged.
The step portion 25b of the cam 25 is pressed against the lever 27 by the urging force of the spring 28. Thereby, the toothless gear 24 and the cam 25
Stops with the rotation transmission from the gear 20 being cut off.

In the above embodiment, the second cam 3
A buffer may also be provided in a portion of the vehicle body 1 that collides when the arm 23 returns. Alternatively, the cam 25 and the toothless gear 24 may be omitted, and the arm 23 may be directly operated by an operating means such as an electromagnet like the lever 27.

[0028]

As described above, the clutch device of the present invention is
A toothless gear capable of meshing with a gear connected to a drive source,
A cam that is rotatable integrally with the tooth-chipped gear, a spring that biases the tooth-chipped gear and the cam in the rotational direction from a stop position where the gear on the drive source side and the tooth-chipped portion of the tooth-chipped gear face each other; Following the stepped portion of the cam, a lever that is constantly urged in the direction of contact with the cam and that engages with the stepped portion of the cam at the stop position to stop the cam against the rotational urging by the spring. Since the cushioning body is provided at a position facing the lever, and the operating means for temporarily releasing the lever from the engagement with the stepped portion of the cam, it is possible to prevent the cam from returning when the lever returns. It is possible to reduce the occurrence of "clicking" noise when colliding with the outer periphery, and it is possible to provide a paper feeding device that exhibits the same effect.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a schematic plan view.

FIG. 3 is a partial operation state diagram of FIG. 1.

FIG. 4 is a partial side view of FIG.

[Explanation of symbols]

 1 Paper Stand 2 Paper Feed Roller 6 Drive Source 9a Second Partial Gear 23 Arm 31 Second Cam 33 Clutch Device 24 Partial Gear 25 Cam 26 Operating Means (Electromagnet) 27 Lever 28 Spring

Claims (3)

[Claims] 1. A toothless gear capable of meshing with a gear connected to a drive source, a cam rotatable integrally with the toothless gear, the toothless gear and the cam, the gear on the drive source side and the toothless tooth. A spring that urges the toothless portion of the gear in the direction of rotation from the opposing stop position and a spring that is constantly urged in the direction of contact with the cam, and engages with the stepped portion of the cam at the stop position to rotate by the spring. A lever that stops the cam against an urging force, a cushioning member that is disposed at a position facing the lever that follows the stepped portion of the cam, and the lever that is temporarily engaged with the stepped portion of the cam. A clutch device, comprising: 2. The buffer body according to claim 1, wherein the buffer body is fitted and fixed in a recess provided in the cam,
A clutch device, wherein an outer surface facing the lever is formed as a continuous surface with an outer surface of the cam adjacent to the cushioning body. 3. The second partly tooth-missing gear capable of meshing with the gear connected to the drive source, the paper feed roller connected to the partly tooth-missing gear, and the paper tray on which printing paper is stacked according to claim 1. An urging means for urging the paper base so that the printing paper on the paper base approaches toward the paper feed roller; and the urging means provided integrally rotatably with the second toothless gear. An operating cam that moves the paper table in a direction in which the printing paper is separated from the paper feed roller against the biasing force of the means; a second cam that is integrally rotatable with the second tooth-chipped gear; An arm that stops the second cam at a position where a toothless portion of the toothless gear of the second gear faces the gear on the drive source side, and the arm of the second cam with respect to the second cam is provided by a cam of the clutch device. A paper feeding device characterized by being operated in the engagement / disengagement direction.