JPS5819686Y2 - Tone arm device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of a lateral balancer in a tone arm device for a record player, and its purpose is to facilitate adjustment of the lateral balance.

Conventionally, as shown in Figure 1, a tone arm with an increased offset angle (usually J
It is called a type tone arm.

) has a large mass (・The center of gravity of the counterweight 1 is offset from the straight line connecting the stylus tip N and the fulcrum S, so the entire tone arm including the cart nozzle when the stylus pressure is zero is The position of the center of gravity C of is shifted above the fulcrum S as shown in the diagram.

In such a state, if the turntable board is horizontal, the force applied to the center of gravity C will be perpendicular to the turntable board, but if the turntable board is prone to tilt, the tone The force applied to the center of the entire arm,
Since a force is generated that tries to rotate the tone arm,
The forces applied to both walls of the record groove become unbalanced and the tracing ability deteriorates.

The first way to prevent this rotational force is to keep the turntable board horizontal, but as a means to proactively prevent this rotational force, as shown in Figure 2, the tone arm shaft 2 at the rear of the fulcrum S Even if a tone arm device is put into practical use, in which a lateral balancer 4 is attached to a balancer shaft 3 fixed on the opposite side of the center of gravity C, and the mounting position of the balancer 4 is adjusted to achieve lateral balance, it will be like this. To adjust the lateral balancer, move the counterweight 1 in the direction of the arm axis 2 to obtain zero balance, then move the balance weight 4 so that the tone arm 2 does not move even if you tilt the player board to the left or right. Fix it.

Therefore, it is necessary to fix the balance weight 3 at an arbitrary position on the balance shaft 3, and the means for this is usually a screw 5 screwed onto the side of the balance weight.
This is done by bringing the tip of the balance weight into contact with the balance shaft 3. However, the balance weight tends to move when tightening the screw 5 after adjusting the position, and the tightening requires great care. Also, if it was moved, the screws had to be loosened and adjusted again (this was extremely cumbersome and impractical).

This device has a dogleg-shaped leaf spring installed inside the balance weight, and uses the elastic force of the leaf spring to make fixing the balance weight extremely simple. I will explain in detail.

3 is a balance shaft passing through the center of the balance weight 4, and the balance weight 4 slides along the balance shaft 3.

A recess is formed in the upper part of the balance weight 4, and the push button 6 is loosely fitted into the recess.

8 is a stopper ring for regulating the vertical movement range of the push button 6.

Further, a hole 9 is formed at the center of the bottom of the recessed portion, and the hole 9
At some points, the balance shaft 3 is exposed within the recess.

7 is a leaf spring bent in a dogleg shape, the central bent part of the leaf spring 1 is on the exposed surface of the balance shaft 3, the center parts of both pieces of the leaf spring 70 are on the periphery of the hole 90, Leaf spring 7
The tips of both pieces abut against the bottom surface of the push-in button 6, respectively.

Therefore, in this state, the leaf spring 7 is interposed between the push-in button and the balance shaft 3, and its elasticity pushes them in opposite directions. 3 is suppressed (・ru.

When the push-in button 6 is pressed against the elastic force of the leaf spring 7, the ends of both sides of the leaf spring 70 are pressed downward, so that the central bent part of the leaf spring 7 is bent at the center of both parts. The balance weight 4 is pushed upward using the balance shaft 3 as a fulcrum, and is released from contact with the balance shaft 3.
It becomes possible to slide along the

When the balance weight 4 is moved to an appropriate position and the pressing force of the push-in button 6 is removed, the push-in button 6 is restored by the elasticity of the leaf spring γ, and the central bent part of the leaf spring 1 comes into contact with the balance shaft 3 again. The movement of the balance weight 4 is suppressed by contacting the balance weight 4.

Therefore, according to this invention, when the push button 6 is slid along the balance shaft 3 in a depressed state, and after the position is adjusted, the pushing force is removed, the push button 6 is automatically restrained and held in that position. The balance weight 4 can be adjusted extremely easily and accurately.

Furthermore, as mentioned above, this invention has an extremely simple structure that utilizes the elasticity of the dogleg-shaped leaf spring 7, so it is less likely to break down, has sufficient durability, and has practical advantages such as being able to keep cost amplifiers to a minimum. It also has excellent effects.

[Brief explanation of the drawing]

1 and 2 are top views of the tone arm device, FIG. 3 is a partial perspective view of a conventional tone arm device, FIG. 4 is a perspective view of essential parts of the tone arm device of this invention, and FIGS. 6
The figures are a cross-sectional view and a vertical cross-sectional view of the main part of this invention, respectively. 4 is a lateral balance weight, 6 is a push button, 9
1 is a hole, and 1 is a dogleg leaf spring.

Claims (1)

[Scope of utility model registration request] A recess is formed in the upper part of the lateral balance weight 4 in the tone arm device, and the button 6 is pushed into the recess.
At the same time, a hole 9 is made in the bottom of the recessed part to expose the balance shaft 3 passing through the center of the balance weight 4, and the central bent part abuts the exposed part, and the central part of both pieces A tone arm device characterized in that a dogleg-shaped leaf spring 1 is provided around the periphery of the hole 90 and abuts on the bottom of the push-in button 6, which is the end of both pieces.