JPH0237569Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an ink sheet winding mechanism.

Conventionally, an ink sheet winding mechanism has a mechanism for slipping a peripheral speed difference due to a difference in the winding diameter in order to keep the peripheral speed of the ink sheet to be wound constant. The problem with this mechanism is that slipping occurs between the members and winding at a constant circumferential speed causes various damage due to object friction such as seizure and poor rotation of the shaft.

Therefore, an object of the present invention is to eliminate the damage caused by the above-mentioned reasons and to provide a smooth and stable ink sheet winding mechanism.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a schematic diagram of an ink sheet winding mechanism. In a thermal transfer type recording device, printing is performed by pressing a head 2 against a platen 1. At this time, the ink sheet 3 must be constantly fed out by a pinch roller 4 and a capstan 5 to prevent printing misalignment. . The sent-out ink sheet is wound up on the winding drum 6, but as the diameter of the ink sheet increases, the winding circumferential speed increases, and it is impossible to wind the ink sheet at a constant circumferential speed. Therefore, it is necessary to provide a mechanism for uniformly winding the ink sheet by slipping the peripheral speed difference due to the difference in the winding diameter of the ink sheet.

FIG. 2 shows an embodiment of the slip mechanism described above.

A shaft 9 is passed through a housing 8 fixed to a substrate 7, and a pulley 10 for transmitting power from a motor is fixed at the right end in the figure. The slip ring 11 is the spring 1
2 is constantly pressed against the flange 13, and the shaft 9
Rotation is fixed by a pin 14 press-fitted into the shaft. The flange 13 is provided with a bearing member 15 for receiving the load of the core for winding up the ink sheet, and is fixed to the shaft by a screw 16. The needle roller 17 is the ink sheet core 12
It is press-fitted into the flange 13 to stop the rotation.

Next, the operation of the above-described configuration will be explained.

The number of rotations transmitted from the pulley 10 to the shaft 9 is constant, and the radius of rotation is also constant. However, as described in FIG. 1, the diameter of the ink sheet wound around the ink sheet core 18 gradually increases, and the winding circumferential speed also increases accordingly.
The ink sheet must be wound at a constant peripheral speed by slipping the circumferential speed difference in the winding diameter at the contact surface between the ink sheet 3 and the slip ring 11 and reducing the number of rotations for winding the ink sheet. Here, when starting to wind the ink sheet with the ink sheet core 18, the ink sheet that is constantly fed out from the pinch roller and capstan described above must be wound with a certain amount of tension so that the ink sheet does not slacken. It includes a flange 13 and a slip ring 1.
Winding the friction force on the contact surface of 1 with the tension mentioned above,
In addition, the slip ring 11 is pressed so that it can be wound at a constant circumferential speed. It is necessary to select the spring 12. The frictional force is also determined by the contact surface between the flange 13 and the slip ring 11, and the material and surface roughness of the slip ring and the contact area matter. When implementing this invention,
It was necessary to perform several tests to determine these items, and here we used Aspest Pakelite as the material for the slip ring.

The characteristics of each member will be described in more detail.

The flange 13 is provided with a bearing member 15 that receives both the radial load due to the weight of the ink sheet wound around the ink sheet core 18 and the thrust load generated by the pressure of the spring 7. The bearing member 15 is a cylindrical member having a collar portion 15a at one end, and bears the shaft 9 on the inner surface of the cylinder.
The thrust load applied to the flange 13 is received at point a. Slip ring 11 and flange 1
3 and the bearing member 15 are pressed by a spring 12 and are fixed to the shaft 9 by a screw 16. The screw is threaded in the direction opposite to the rotation transmitted from the pulley 10 to the shaft 9, so that the screw 16 will not loosen as the shaft 9 rotates.
The ink sheet core 18 has two grooves cut into it, and two needle rollers 1 press-fitted into the flange 13.
At 6, the flange 13 and the ink sheet core 18 are stopped so as to rotate together after the ink sheet core 18 is attached. The flange 13 is provided with a cylindrical convex portion 13a to prevent friction powder coming out from the contact surface between the flange and the slip ring 11 from directly entering the shaft and bearing members and causing rotational defects. The shaft hole of the slip ring 11 is supported on the outer surface of the cylindrical convex portion 13a, and the cylindrical convex portion 13a
The cylindrical portion of the bearing member 15 is inserted into a,
This allows rotation of the slip ring around the axis 9. In order to reduce torque fluctuations, it is necessary to make the overall length of the spring 12 as long as possible and also to increase the width, so a recess is provided in the slip ring 11 and the shaft 9. Also,
The shaft 9 and the slip ring 11 are fixed by a pin 14 so that they always rotate in the same direction.

As explained above, the present invention is an improvement of the slip mechanism that winds the ink sheet at a constant circumferential speed regardless of the winding diameter, and provides the following effects.

(1) The cylindrical convex part provided on the flange makes it difficult for friction powder from the contact area to enter the bearing and shaft, preventing seizure and poor rotation of the bearing.

(2) Since recesses are provided in the slip ring and the shaft, and the distance between them is lengthened, spring swivel is improved and torque fluctuations can be reduced.

(3) Since the bearing member is shaped to receive thrust and radial loads, the entire slip mechanism has a simple structure, making it easy and economical to manufacture.

The present invention can be applied not only to the winding of ink sheets but also to the winding of a wide variety of belt-shaped objects.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an ink sheet winding mechanism;
FIG. 2 is a sectional view of the slip mechanism. 1... Platen, 2... Head, 3... Ink sheet, 4... Pinch roller, 5... Capstan, 6... Winding drum, 7... Board, 8... Housing, 9... Shaft, 10 ...Pulley, 11...
Slip ring, 12... Spring, 13... Flange, 14... Pin, 15... Bearing member, 16...
Screw, 17... Needle roller, 18... Ink sheet core.

Claims (1)

[Scope of utility model registration request] In a mechanism that winds an ink sheet at a constant circumferential speed regardless of the winding diameter, there is a housing that is fixed to the board with a screw and contains a bearing that supports the entire winding section, a recess that stops the compression spring, and a pin that fixes the rotation of the slip ring. A slip ring having a shaft formed with a through hole, a friction surface on one side, and a shaft hole approximately in the center; In order to prevent the slip ring from entering the shaft, there is a flange having a cylindrical convex portion approximately in the center that bears the shaft hole of the slip ring, a spring that constantly presses the slip ring against the flange, and a spring that presses the slip ring against the flange at one end. A cylindrical bearing member having a flange portion for receiving a thrust load applied to the flange and inserted into the cylindrical convex portion to receive the shaft, and a rotating direction of the shaft for fixing the bearing member to the shaft. An ink sheet winding mechanism characterized by comprising a set screw in a tightening direction.