JPS6210890B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer winding device for winding recording paper.

[Conventional technology]

The winding device of conventional printers was developed in Japanese Patent Application Laid-Open No.
As described in Japanese Patent Publication No. 20026 and Japanese Patent Publication No. 48-39757, the swinging motion of a lever that is in contact with one end of a constantly rotating cam is transferred to a feeder that is rotatably supported on the other end of the lever. It is a mechanism in which a pawl rotates a ratchet wheel that drives a take-up shaft (for winding up recording paper), and the center of rotation of the lever is located at a different position from the rotation axis of the ratchet wheel.

[Problem that the invention seeks to solve]

However, the conventional printer winding device has the following drawbacks.

Since the rotation center of the lever does not coincide with the axis of the ratchet wheel, the rotation locus drawn by the axis of the feed pawl that is pivotally supported by the lever deviates from the arc of the tip of the ratchet wheel. In particular, when the rotation center of the lever is located outside the point where the feed pawl is pivotally supported on the lever with respect to the center of the ratchet wheel as shown in the example, the amount of deviation described above is becomes very large. Therefore, the relative positional relationship between the feed pawl and the teeth of the ratchet wheel changes even during feeding. For this reason, (a) the maximum value that the ratchet wheel can send per one rotation of the cam is limited, and cannot be set too large. In addition, (b) it is necessary to increase the spring force of the spring that keeps the feed pawl always engaged with the ratchet wheel, resulting in large power loss and increased wear on the part where the feed pawl and ratchet wheel engage. Become.

disadvantages arise, and (c) The distance between the centers of the camshaft and pawl axle becomes large.

(d) It is necessary to provide a separate rotation shaft for the lever.

There are drawbacks such as:

The present invention is intended to solve these problems, and its objectives are: (a) a large recording paper feed amount per cam rotation; (b) low power loss and excellent durability; and (c) compact design. This is an opportunity to provide an inexpensive printer winding device.

[Means for solving problems]

The winding device of the present invention is a winding device of a printer for winding up recording paper, and includes a cam that constantly rotates in conjunction with the rotation of a rotating shaft of the printer that rotates continuously;
a drive lever that is rotatably supported on a take-up pawl axle so as to follow the cam and rotatably supports the take-up pawl at one end; and a take-up pawl that engages with the take-up pawl;
a spring means for engaging the take-up pawl with the take-up ratchet and biasing the take-up ratchet in a direction to rotate the take-up ratchet; and a reversal stop for preventing the take-up ratchet from reversing;
It is characterized by comprising a take-up shaft that winds up the recording paper by the rotational force of the take-up ratchet wheel.

[Effect]

According to the above configuration, the drive lever 23 has the same rotation center as the take-up pawl wheel 26, and the rotation locus drawn by the axis of the take-up pawl 24, which is supported by the drive lever 23, is the same as the take-up pawl wheel 26. It is concentric with the tip arc of No. 26. Therefore, the relative positional relationship between the winding claw 24 and the teeth 27 of the winding ratchet wheel at the feed angle does not change. Therefore, the efficiency of power transmission from the take-up pawl 24 to the take-up pawl wheel 26 is increased, and no wear occurs on the tip of the take-up pawl 24 and the teeth of the take-up pawl wheel during feeding.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, 16 is a constantly rotating motor that powers the printer, 17 is a motor shaft, and 18
is a motor pulley, 19 is a belt, 20 is a cam pulley, 23 is a drive lever, 24 is a winding pawl, 25
26 is a tension coil spring, 26 is a take-up ratchet wheel, 28 is a reverse stopper, 29 is a take-up shaft, 31 is a take-up frame, and 6 is a recording paper.

To explain the principle of operation, a motor pulley 19 is fixed via a motor shaft 11 to a motor 16 that continuously rotates at all times and serves as the power for the printer. A cam pulley 20 having a motor pulley 18 and an eccentric cam 21 of a winding device is a belt 19
The rotation of the motor 16 is transmitted to the cam pulley 20. Cam-pulley 20
As the eccentric cam 21 rotates, the eccentric cam 21 moves the L-shaped protrusion 22 provided on the drive lever 23 that is in contact with the eccentric cam 21 in the directions of arrows A and B. The drive lever 23 is rotatably supported by the take-up pawl axle 30. When the drive lever 23 rotates in the direction of the arrow A, the take-up pawl 24 rotatably supported by the drive lever 23 moves the take-up pawl wheel 2 in the direction of the arrow C.
It moves over the teeth of 6 and stores energy in the tension coil spring 25 that engages with the winding pawl 24. At this time, the winding pawl 24 is rotated by the teeth 27 of the winding pawl wheel 26.
Since the winding claw 26 is pressed against the winding coil spring 25 by the tension coil spring 25, the winding claw 26 also tries to rotate in the same direction as the winding claw 24, but one end is fixed to the winding frame 31 and the other end is connected to the teeth of the winding claw. Since the reversal stop 28 made of an elastic body is engaged with the reel 27, the take-up pawl 24 passes over the teeth 27 of the take-up pawl, and the take-up pawl 24
6 does not rotate. Back side 27- of the teeth 27 of the take-up ratchet wheel
By making the slope 1 small, the force exerted by the winding pawl 24 to rotate the winding ratchet wheel 26 in the direction of arrow E can be reduced.

The above is the operation when the eccentric cam 21 rotates from the minimum diameter to the maximum diameter.

Next, the operation when the eccentric cam 21 rotates by the minimum diameter rather than the maximum diameter will be described. The drive lever 23 is rotated in the direction of arrow D by a tension coil spring 25, and the take-up ratchet wheel 26 is rotated in the direction of arrow F by the take-up pawl 24 that engages with teeth 27 of the take-up ratchet wheel. . The rotation of the take-up ratchet wheel 26 is transmitted through meshing gears provided around the take-up ratchet wheel 26 and the winding shaft 29, and winds up the fed recording paper 6. The rotation angle of the drive lever 23 is set so that the amount of paper taken up by the take-up claw 24 is greater than the amount of paper fed from the printer's paper feeding unit (not shown), so that the drive lever 23 does not protrude. The portion 22 never comes into contact with the minimum diameter of the eccentric cam 21. The take-up pawl 24 is constantly pulled by a tension coil spring 25, and the teeth 27 of the take-up pawl wheel
Torque is applied to the take-up shaft 29 that meshes with the take-up pawl 26 through the roller, and tension is applied to the recording paper 6, so that the winding does not become thick.

When the tension of the recording paper 6 becomes large and the value obtained by converting the tension into the torque around the take-up pawl axle 30 becomes larger than the value obtained by converting the tension of the tension coil spring 25 into the torque around the take-up pawl axle 30, , after the eccentric cam 21 rotates once, the eccentric cam 2
1 rotates once, the eccentric cam 21 only contacts the protrusion 22 of the drive lever 23, and the drive lever 23 does not rotate, so the take-up ratchet wheel 26 does not rotate in the direction of arrow F in the figure. Therefore, according to this mechanism, a tension greater than the set torque is not applied to the recording paper.

〔Effect of the invention〕

The present invention has the following effects by adopting a configuration in which the rotation center of the drive lever is the axis of the take-up ratchet wheel.

(a) The feed amount of the take-up ratchet wheel per rotation of the eccentric cam can be set to a large value, and the maximum value of the paper feed speed can be increased.

(b) Since the relative position of the take-up pawl and take-up ratchet does not change during feeding, the tension coil spring force can be set to the minimum necessary value, reducing wear on each rotating and sliding part and reducing power loss. I can do that.

(c) The distance between the shafts of the eccentric cam and the take-up ratchet wheel can be reduced, so the device can be made smaller.

(d) Since there is no need to provide a separate drive lever shaft,
We can supply inexpensive equipment.

[Brief explanation of the drawing]

FIG. 1 is a side view of a winding device showing an embodiment of the present invention. 16...Motor, 18...Motor pulley, 1
9...Belt, 20...Cam pulley, 21...
Eccentric cam, 22...Protrusion, 23...Drive lever, 24...Take-up claw, 25...Tension coil spring,
27...Take-up ratchet tooth, 28...Reverse stopper, 29
9... Take-up shaft, 30... Take-up pawl axle.

Claims (1)

[Claims] 1. In a printer's winding device for winding recording paper, there is a cam that constantly rotates in conjunction with the rotation of the printer's rotating shaft, which rotates continuously, and a shaft supported on the winding pawl axle so as to be able to rotate freely to follow the cam. a drive lever rotatably supporting a take-up claw at one end; a take-up ratchet wheel that engages with the take-up claw; and a drive lever that engages the take-up claw with the take-up ratchet wheel, and It is characterized by comprising a spring means for biasing in the direction of rotation, a reversal stopper for preventing the winding ratchet from reversing, and a winding shaft that winds the recording paper by the rotational force of the winding ratchet. A winding device for