JPS5819687Y2 - 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 of a record player, and its purpose is to facilitate adjustment of the lateral balance.

Conventionally, as shown in Figure 1, a tone arm (usually J
It is called a type tone arm.

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

In this condition, 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 tilted, the entire tone arm will be In addition to the force applied to the center of the record groove, a force that attempts to rotate the tone arm is generated, resulting in an unbalanced force being applied to both walls of the record groove, deteriorating the tracing ability.

The first way to prevent this rotational force is to keep the turntable full port horizontal, but as a means to actively prevent this rotational force, as shown in Figure 2, the tone arm shaft at the rear of the fulcrum S is A tone arm device has been 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 to 2, and the mounting position of the balancer 4 is adjusted to obtain lateral balance.

To adjust such a lateral balancer, move the counterweight 1 in the direction of the arm axis 2 to obtain zero balance, and then adjust the balance weight 4 so that the tone arm 2 does not flow even if you tilt the Blair board left or right. to be fixed.

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 was done by bringing the tip of the balance weight into contact with the balance shaft 3, but the balance weight tends to move when tightening the screw 5 after adjusting the position, and the tightening requires great care. If it is moved, the screws must be loosened and adjusted again, which is extremely cumbersome and impractical.

This invention makes it extremely easy to move and fix the balance weight by equipping the balance weight with a leaf spring that presses the balance shaft into contact and a knob shaft that releases the leaf spring from contact. 4th below
The embodiments shown in the drawings below will be described in more detail.

In the drawings from FIG. 3 onwards, the same numbers as in FIGS. 1 to 3 indicate the same parts.

Reference numeral 6 denotes a leaf spring provided on the bottom of the bottomed hole provided in the balance weight 4, and the leaf spring 6 comes into contact with the side surface of the balance shaft 3 that passes through approximately the center of the bottomed hole, and the balance shaft of the balance weight 4 is Movement along the axial direction of 3 is suppressed.

Reference numeral 7 denotes a knob shaft whose one end is exposed to the outside by passing through the side wall of the bottomed hole, and whose other end is brought into contact with the leaf spring 6.

In such a configuration, the plate spring 6 normally comes into pressure contact with the side surface of the balance shaft 3, so that the movement of the balance weight 4 is restrained by the frictional force between the two.

When the knob shaft 7 exposed on the side of the balance weight 4 is pressed, the other end of the knob shaft presses the leaf spring 6, and the contact with the balance shaft 3 is released, and the balance weight 4 is moved to the balance shaft. It becomes possible to slide along 3.

Therefore, according to this invention, after adjusting the position by moving the balance weight 4 while pressing the knob shaft 1, when the pressing force is removed, the movement can be automatically inhibited and the balance weight 4 can be held in a fixed position. 4 becomes extremely easy to adjust.

Furthermore, since this invention only requires the addition of the above-mentioned knob shaft 7 and leaf spring 6, the cost increase can be kept to a minimum and it has excellent practical 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 longitudinal cross-sectional view of a main part of the tone arm device of this invention, respectively. 4 is a lateral balance weight, 3 is a balance shaft, 6 is a leaf spring, and 7 is a knob shaft.

Claims (1)

[Scope of utility model registration request] In the tone arm device, a bottomed hole is bored in the lateral balance weight 4, and a plate spring is fixed in the bottomed hole and is to come into contact with and press the balance shaft 3 passing through the side wall of the bottomed hole. 6, and a knob shaft T whose one end is exposed through the side wall of the bottomed hole and whose other end presses the leaf spring 6 to release the contact between the leaf spring 6 and the balance shaft 3. A tone arm device.