JPH0219252Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cover opening/closing mechanism for a printing device.

Conventional cover opening/closing mechanisms are shown in Figures 1 and 2.
There is a structure shown in FIG. 3 and FIG. In this structure, the two holes 5 and 16 of the U-shaped pointer 4
Since the diameters of the holes are the same, there were cases where the shaft 2 came into contact with the hole 5 below the pointer 4. This contact force is maximum when the cover 8 is most open, that is, when the stopper 15 collides with the upper surface of the pointer 4 via the spring 11 and washer 17. This means that when the opening angle of the cover 8 is small, the shaft 2
can be freely positioned relative to the holes 5 and 16 of the pointer 4, but when the cover 8 is in the most open state, the stopper 15 of the shaft 2 is in pressure contact with the pointer 4 via the spring 11 and washer 17.
The shaft 2 is restrained by the pointer 4 and cannot move freely. In this case, when the shaft 2 and the holes 5, 16 of the pointer 4 come into contact, abrasion occurs between the shaft 2 and the holes 5, 16, resulting in phenomena such as a decrease in the shaft diameter and an increase in surface roughness. Since the shaft 2 is provided with a system in which frictional force is applied by the brake 6, when the shaft 2 comes into contact with the hole 5 below the pointer 4, the brake 6 applies the friction force to the shaft 2.
Because of its rough surface, it wears out in a short period of time. Therefore, since the braking force decreases due to the reduction in the diameter of the shaft 2 and the wear of the brake 6, the braking force from the brake 6 no longer acts on the shaft 2 near the maximum opening angle of the cover 8, and the stopper 15 and pointer 4 Since the impact force at the time of the collision increases, the upper surface of the pointer 4 is deformed as shown in FIG. 3.

Further, when the pointer 4 is deformed, the pointer 4 makes partial contact with the brake 6, which imparts a rotational moment to the brake 6, causing a portion of the brake 6 to wear abnormally.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and extend the life of the cover opening/closing mechanism of this type of printing device.

In this invention, the diameter of the pointer hole is devised so that the pointer does not come into contact with the part of the shaft where the brake operates, and the shape of the hole in the pointer is devised so that the brake does not receive the rotational moment due to the pressing force of the pointer. be.

An embodiment of the present invention will be described with reference to the drawings. 4, 5, and 6, the cover 8 is attached to the base 7, which is the housing of the device, by a hinge 9.
It is fixed so that it can be opened and closed through. The U-shaped pointer 4 fixed to a part of the cover 8 has holes 5,
Two numbers 16 are provided at the top and bottom. The shaft 2, which is rotatably held around a hinge 10 fixed to a base 7, is connected to a spring 1 and holes 5, 1 of a pointer 4.
6. Brake 6 held by pointer 4, spring 11
A nut 12 is fixed to the other end of the hinge 10. The spring 1 is a compression spring designed to generate a cover opening moment that balances the rotational moment of the cover 8 due to its own weight. The brake 6 presses the outer circumference of the shaft 2,
This is for applying frictional force to the shaft 2. The spring 11 is a buffer material for reducing the opening speed of the cover 8 near the maximum opening angle of the cover 8.

The structure around the pointer 4 will be explained with reference to FIGS. 5 and 6. The centers of the holes 5 and 16 of the pointer 4 coincide with the center of the shaft 2, and a cylindrical collar 18 is provided on the edge of the hole 16 on the pointer 4 side, and the upper hole 16
The diameter of the hole 5 is smaller than that of the lower hole 5. In this structure, the position of the shaft 2 is restricted by the hole 16 above the pointer 4, so the hole 5 below and the shaft 2 do not come into contact. Also, the upper hole 1
6 and the shaft 2 are normally in contact with a light force, and the force is strong only when the top surface of the pointer 4 contacts the nut 12 which is a stopper via the spring 11 and washer 17 near the maximum opening angle of the cover 8. Pressed down by force. When pressed, the shaft 2 will wear out, but since it is not a sliding part of the brake 6, it will not affect the brake 6 in any way. On the other hand, when the pointer 4 collides with the nut 12, it deforms downward. In this case, the collar 18 applies a pressing force only to the vicinity of the shaft 2 of the brake 6, so that no large rotational moment is generated. Therefore, the brake 6 is less likely to wear out due to rotational moment.

The upper hole 16 and the lower hole 5 of the pointer 4 in FIG. 6 do not have to be perfect circles. For example, a long hole
Oval or square holes are also acceptable.

The collar 18 of the pointer 4 in FIG. 6 does not have to be integral with the pointer 4. For example, a similar effect can be expected by attaching a washer 19 with a flange as shown in FIG.

According to the present invention, the diameter of the hole above the pointer is made smaller than the diameter of the hole below, and a flange is provided on the edge of the hole on the brake side, so the lower hole and the shaft do not interfere, and the brake is not affected. Since the rotation moment generated by the cover is reduced, the shaft and brake are less likely to wear out, the life of the cover opening/closing mechanism can be extended, and the cover opening/closing force can be kept stable for a long time.

[Brief explanation of drawings]

Figure 1 is a side view showing a conventional cover opening/closing mechanism.
Figure 2 is an enlarged sectional view of the main part of Figure 1, and Figure 3 is an enlarged cross-sectional view of the main part of Figure 1.
4 is a side view showing an embodiment of the opening/closing mechanism of the present invention, FIG. 5 is an enlarged sectional view of the main part of FIG. 4, FIG. 6 is a side view of FIG. 5, and FIG. 5 is a side view of FIG. 5 showing an application example of the present invention. 1, 11: Spring, 2: Shaft, 4: Pointer, 5: Lower hole, 6: Brake, 7: Base,
8: cover, 9, 10: hinge, 12: nut,
15: Stopper, 16: Upper hole, 17: Washer, 18: Collar, 19: Washer with flange, 2
0: Retention ring.

Claims (1)

[Scope of utility model registration request] A cover with one end rotatably held in the housing and the other end openable and closable, a U-shaped pointer fixed to a part of the cover, a shaft that passes through two holes provided above and below the pointer, and a shaft. One end is rotatably held in the housing, both ends of the shaft have projections perpendicular to the shaft axis, a compression coil spring is placed below the pointer, and the shaft is positioned inside the coil spring. , in a printing device in which a brake mechanism for applying a frictional force to the shaft is disposed inside the pointer, a cylindrical protrusion is provided at the edge of the pointer hole on the brake mechanism side; The cover opening/closing mechanism is characterized in that the diameter of the upper hole is smaller than the diameter of the lower hole.