JPS6341657Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive device for a linear tracking arm that moves along the radial direction of a record.

In a record player that automatically lowers the needle to a predetermined position on the record and plays,
In order to accurately lower the needle to a predetermined position, it is necessary to control the position of stopping the movement of the tone arm with high precision. However, in the conventional linear tracking arm device using a worm-based deceleration mechanism,
As shown in FIG. 4, there was a backlash between the teeth of the worm and the teeth of the drive gear, so even if the worm was stopped, the drive gear moved and the tone arm stopped at an accurate position. Furthermore, as is well known, in order to correct tracking errors in linear tracking arms, the tone arm position is corrected by rotating the arm motor, but there is a drawback that accurate correction cannot be made due to the above-mentioned backlash. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a linear tracking arm drive device that eliminates the drawbacks of the prior art described above.

Therefore, in order to improve the positional accuracy of the drive mechanism, the present invention uses a compressible spring to press the worm against the drive gear to remove the bump between the worm and the drive gear, thereby improving the positional accuracy of the tone arm. be.

Embodiments of the present invention will be described below with reference to FIGS. 1, 2, 3, and 5. Reference numeral 1 denotes an arm drive motor, which is attached to the board 2. 3 is a worm shaft, one end of which is inserted into a movable bearing 4, and a movable spring 5 and a spring receiver 6 formed on the base plate 2.
A worm 11 is inserted and fixed in the center, and the other end is supported on a fixed bearing 9.
The pulley 12 is fixed to the outside of the fixed bearing 9 so as not to play in the axial direction. A belt 13 is attached between the arm drive motor 1 and the pulley 12. Reference numeral 14 denotes a drive gear, which is connected to the drive gear 14 by a fixing screw 15, with a drive system 17 wound around three small rollers 16 around its outer periphery. Reference numeral 18 denotes a rail, and 19 a plate rail, each of which is fixed to a substrate and supports the slide bail 20 so as to be movable in the axial direction. A fixing pin 21 is fixed to the drive system 17 and connected to a hole in the slide base 20. Reference numeral 22 denotes a tone arm, which is equipped with a cartridge 24 provided with a needle 23, and is supported on a shaft so as to be rotatable vertically and horizontally relative to the slide base 20.

Next, the operation will be explained. When the arm motor 1 rotates, the belt 13, pulley 12 and worm 11
The slide base 20 is moved via the drive gear 14 and the drive system 17. Next, when stopping the movement of the tone arm 22, it is sufficient to stop the arm motor 1. At this time, the worm 11 is pressed against the drive gear 14 by the compressible spring 5 to maintain the backlash between the worm 11 and the drive gear 14. Therefore (see Figure 5), it does not occur. Furthermore, since the reduction ratio between the worm 11 and the drive gear 14 can be made sufficiently large, when the worm 11 stops, the movement of the tone arm 22 immediately stops. Furthermore, even if the worm 11 has poor dimensional accuracy, tooth profile, or eccentricity of the drive gear 12, the compressible spring 5 will deflect, thereby absorbing the problem.

As described above, according to the present invention, since the bump between the worm and the drive gear can be almost completely eliminated, the rotation control of the arm motor can be reliably transmitted to the tone arm, and the tone arm position can be accurately controlled. Furthermore, its structure requires only the use of a movable bearing and a compressible spring, and dimensional accuracy of the worm and drive gear is not required, so performance can be improved at very low cost.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the linear tracking arm drive device according to the present invention, FIG. 2 is a front side view of FIG. 1, and FIG. FIG. 4 is a diagram showing the meshing of the conventional worm and the drive gear, and FIG. 5 is an enlarged view of section D in FIG. 1, showing the meshing of the worm and the driving gear. 1: Arm motor, 4: Compressible spring,
5: Movable bearing, 11: Worm, 14: Drive gear.

Claims (1)

[Scope of utility model registration request] A linear tracking arm drive characterized in that a worm rotated by an arm drive motor is biased toward a drive gear by a pressurized spring and a movable bearing attached to a U-shaped notch provided in a base plate to prevent backlash. Device.