JPH0477961B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pick-up arm lifting/lowering braking device for a record player.

Conventional Structure and its Problems Conventionally, a pick-up arm elevating braking device for a record player is mainly composed of a braking cam 1 and a resin cam receiver 2, as shown in FIGS. 1 to 3. The brake cam 1 includes a lateral cam portion 3 having an inclined surface 3a and a flat portion 3b continuous thereto, and a hollow shaft 4, and an insertion hole 5 is formed in the top plate of the hollow shaft 4. On the other hand, the cam receiver 2 includes an inner cylindrical portion 6 and an outer cylindrical portion 7 located radially outward therefrom, and a mounting flange 8 extending radially outward from the outer cylindrical portion 7 is formed.
The cam receiver 2 is mounted by fixing the mounting flange 8 to the player body 9. A storage space for a hollow shaft is formed between the inner cylindrical part 6 and the outer cylindrical part 7 of the cam receiver 2, and the braking cam 1 is placed in this space.
The hollow shaft 4 is inserted, and the grease 10 is interposed between the hollow shaft 4 and the inner cylindrical portion 6. After the brake cam 1 and the cam receiver 2 are fitted together in this manner, the stop shaft 11 is inserted into the lock hole 12 formed in the inner cylindrical portion 6 and locked, so that the brake cam 1 is fitted into the cam receiver 2. Prevent it from slipping upwards. In addition, in the figure, 1
3 is a tension spring connected to the brake cam 1, 14 is a pick-up arm, and 15 is a pick-up arm 1.
A lift arm 16 is a lift rod that extends downward from the lift arm 15 and comes into contact with the cam portion 3.

In the above configuration, the brake cam 1 is rotated in the direction of arrow A, and the lift rod 16
The pick-up arm 14 is temporarily brought to the raised position by rising along the line a. When the restraining force on the brake cam 1 is released in this state, the brake cam 1 slowly rotates in the direction B while being subjected to the large viscous resistance of the grease 10 due to the action of the tension spring 13. As a result, the lift rod 16 slowly slides down the inclined surface 3a from the flat surface 3b of the cam portion 3, and the pick-up arm 14 descends quietly.

However, in the conventional lifting braking device, when inserting the hollow shaft 4 of the brake cam 1 into the storage space of the hollow shaft formed between the inner cylindrical part 6 and the outer cylindrical part 7 of the cam receiver 2 for assembly, There was a problem in that not only the grease 10 was pushed up along with the air through the small gap 17 between the hollow shaft 4 and the outer cylindrical portion 7 and was washed away to the outside, but also that a large force was required to insert the hollow shaft 4. In order to solve this problem, it is possible to make the gap 17 larger, but in this case, the gap
In the worst case scenario, if foreign matter from the outside enters through the brake cam 17, a serious problem will occur in which the brake cam 1 will become unable to rotate. In addition, not only is a separate stop shaft 11 required to prevent the brake cam 1 from coming off upward, but also a complicated shape is required on the inner cylindrical portion 6 of the cam receiver 2 in order to insert and lock the stop shaft 11. Locking hole 1
2, and the mold for the cam receiver 2 becomes complicated.

OBJECTS OF THE INVENTION An object of the present invention is to provide a pick-up arm lifting/lowering braking device that has a simple configuration, is easy to assemble, and does not leak grease.

Structure of the Invention The pick-up arm lifting/lowering braking device of the present invention has the following features:
In order to achieve the above object, the brake cam is equipped with a brake cam and a cam receiver that rotatably supports the brake cam, and the brake cam has a hollow shaft and an air vent hole that communicates the storage space of the hollow shaft with the outside. It has a face plate and a cam part for raising and lowering the pick-up arm by rotation of the braking cam provided on the upper face plate, and the cam receiver provides a storage space for the hollow shaft and the hollow shaft. The shaft has a bottomed cylindrical part into which the shaft is fitted via grease, and a mounting flange that extends radially outward from the bottomed cylindrical part and is attached to the player body, and a pawl provided on the mounting flange is connected to the brake cam. The brake cam is characterized in that it engages with the top plate of the brake cam to prevent it from coming off upward.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 4 and 5.

In FIGS. 4 and 5, 20 is a brake cam, and 21 is a resin cam receiver. Braking cam 20
is an inclined surface 22a and a flat portion 22 continuous thereto.
a lateral cam portion 22 having a diameter b; a hollow shaft 23;
A top plate 29 is provided with air holes 29a that communicate the storage space of the hollow shaft with the outside. on the other hand,
The cam receiver 21 includes a bottomed cylindrical portion 25 that is fitted onto the hollow shaft 23 of the brake cam 20 via grease 26 during assembly, and a bottomed cylindrical portion 25 that extends radially outward and is attached to the player body 28. A mounting flange 27 is provided. A locking pawl 24 is provided on the mounting flange 27 to prevent the brake cam 20 from coming off upward when it is inserted into the cam receiver 21. The brake cam 20 can rotate relative to the cam receiver 21 while being locked to the top plate 29 of the cam 20. The cylindrical portion 25 forms a hollow shaft storage space 30. Note that 31 in the figure is a tension spring.

In the above configuration, in order to attach the brake cam 20 to the cam receiver 21, the hollow shaft 20 of the brake cam 20 must be
can be inserted into the hollow shaft storage space 30 of the cam receiver 21. At this time, the air trapped in the hollow shaft storage space 30 is discharged to the outside through the air vent hole 29a, and does not become a resistance when the hollow shaft 23 is inserted. In addition, since the air hole 29a is located above the brake cam 20, when the air flows out from the air vent hole 29a, the grease 26 does not flow out along with it, and the excess grease 26 is always removed during assembly and insertion. A certain amount is stored in the hollow shaft storage space 30. In addition, a locking pawl 2 is used to prevent the brake cam 20 from coming off upward.
4, there is no need to use a separate stop shaft, and the structure of the cam receiver 21 can also be simplified. Note that the operating principle of the braking device according to this embodiment is the same as that of the conventional one, so the explanation thereof will be omitted here.

Effects of the Invention As described above, the pick-up arm elevating braking device of the present invention uses grease interposed between the outer circumferential surface of the hollow shaft of the brake cam and the inner circumferential surface of the cam receiving cylindrical portion that forms the hollow shaft storage space. An air vent hole is provided on the top plate located above the brake cam to communicate the hollow shaft storage space with the outside, and a locking pawl formed on the mounting flange of the cam receiver is locked to the top plate of the brake cam to close the brake cam. Since it is designed to prevent the grease from coming off, it has the advantage that there is no grease leakage and that the structure is simple and easy to assemble.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the main parts of a record player incorporating a conventional pick-up arm lifting device;
FIG. 2 is an exploded perspective view of a conventional pick-up arm lifting/lowering braking device, FIG. 3 is a sectional view of the same device when assembled, and FIG. 4 is an exploded perspective view of a pick-up arm lifting/lowering device according to an embodiment of the present invention. FIG. 5 is a sectional view of the device when assembled. 20...braking cam, 21...cam receiver, 22...
...Cam part, 23...Hollow shaft, 24...Latching claw, 2
5...Cylindrical portion, 26...Grease, 27...Mounting flange, 29...Top plate, 29a...Air vent hole, 30...Hollow shaft storage space.

Claims (1)

[Claims] 1. The brake cam is equipped with a brake cam and a cam receiver that rotatably supports the brake cam, and the brake cam has a hollow shaft, a top plate provided with an air vent hole that communicates the storage space of the hollow shaft with the outside, and a top plate that includes a hollow shaft. A cam portion is provided for raising and lowering the pick-up arm by rotation of the brake cam, and the cam receiver provides a hollow shaft storage space for storing the hollow shaft, and the hollow shaft is fitted through grease. a cylindrical portion with a bottom, and a mounting flange extending radially outward from the cylindrical portion with a bottom and attached to the player body, and a claw provided on the mounting flange prevents the brake cam from coming off upward A pick-up arm lifting/lowering braking device characterized in that the pick-up arm is engaged in the following manner.