JPS5819684Y2 - Dynamic balance type tone arm device - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a dynamic balance type tone arm device, and particularly to an improvement of a tone arm device that uses magnetism to adjust the stylus force of the tone arm device. .

Conventionally, a method of using magnetism to reduce the stylus pressure in a tone arm device is known. For example, as shown in FIG. There is a structure in which a magnet 4 is fixed at a position facing the above-mentioned magnet 3, and the stylus force of the tone arm is adjusted by moving the magnet 3 up and down. Since the repulsive force (or attractive force) changes significantly with a small movement of the magnet 3, the stylus force range of the high-sensitivity tone arm devices currently in use (approximately 0.
Fine adjustment between 5gr and 3gr is virtually impossible,
Furthermore, since records always have warpage, there is a drawback that the slight up-and-down movement of the tone arm can significantly change the stylus pressure during a performance, and I have never seen an example of this being used in a product.

Additionally, a device that uses electromagnetic force to increase the stylus force is also known, and this device can easily adjust the stylus force by changing the current, but there are special features such as the structure of the coil and other parts and the power supply circuit. Since it requires special means, the J product has the drawbacks of being expensive and not being able to be attached to any record player.

This invention was made to solve the above-mentioned drawbacks, and will be explained below with reference to the drawings.

In FIGS. 1 to 3, reference numeral 11 denotes a tone arm with a cartridge (not shown) attached to its front end, a balance weight 12 movably provided at its rear end, and a tone arm mounted on a holder 13 that can be moved up and down by a pivot 14. Possibly supported.

A ring-shaped magnet 15 is attached to the tone arm 11 and centered around one pivot 14 .

A U-shaped magnet 16 facing the ring-shaped magnet 15 is held by a holding member 17 in the holder 13, and can be moved in a direction perpendicular to the axis of the tone arm (in the direction of the arrow in FIG. 2).

The holding member 17 has a first pin 18 in a large diameter portion for guiding.
Since the magnet 16 is held vertically and fitted into a straight groove (not shown) provided in the cylindrical portion 13' of the holder 13, the magnet 16 can move in the direction of the arrow in FIG. 2 as described above.

In addition, a second pin 19 is attached to the small diameter portion of the holding member 11.
is implanted and is fitted into the bright line groove 21 of the rotating member 20.

Reference numeral 22 is a ring screw for preventing removal and is screwed into the cylinder body 13'.

A spring 23 is used to press the holding member 17, the rotating member 20, etc. against the ring screw 22.

Reference numeral 24 denotes an adjustment knob located outside the cylindrical body 13' provided at the tip of the rotating member 20, and the stylus pressure is indicated on the outer periphery.

26 is a rotating shaft that supports the holder 13 at its upper end and allows the tone arm to rotate in the horizontal direction.

21 is an armrest provided on the stand 28, 29
is an elevation mechanism.

Next, the operation will be explained.

As shown in FIG. 3, a magnet 16 provided in the holder
has a horizontal magnetic pole, and the magnetic pole of the magnet 15 provided on the tone arm 11 is fixed so that it rotates about 30 degrees when the tone arm 11 is held horizontally. stylus pressure is applied by the repulsive force of both magnets.

When applying stylus pressure, first rotate the knob 24 counterclockwise, and the rotating member 20 will rotate together, and since the pin 19 is engaged with the bright line groove 21, the holding member 11 will be attached to the cylindrical portion 13' of the holder. The magnet 16 is guided by the straight groove of the ring magnet 15 of the tone arm, and is retreated to a position where the tip of the narrow diameter portion of the holding member 16 abuts the innermost part of the hole of the rotating member 20.

At this position, the tone arm stylus pressure becomes zero.

Next, the balance weight 12 is moved to horizontally balance the tone arm.

Then, the knob 24 is rotated in the opposite clockwise direction, and the holding member 1γ and the magnet 16 are brought closer to the ring magnet 15 against the spring 23. Align it with the indication line provided on the outer periphery of 13'.

As described above, this invention involves moving the movable magnet 16 provided on the holder 13 toward and away from the magnet 15 provided on the tone arm, and in order to adjust the stylus pressure, the magnet 16 is moved within the range of one rotation of the knob. All you have to do is move it, and you can make fine adjustments to the stylus pressure very easily and reliably.

In addition, since the two magnetic poles are not directly facing each other, fine adjustments can be made easily and there is no need to worry about the stylus pressure changing significantly even if the tone arm moves up or down due to warping of the record, etc. effect can be obtained.

Note that the magnet is not limited to ring magnets and U-shaped magnets, but may be of any shape such as ring magnets, U-shaped magnets, bar magnets, etc., and the number of magnetic poles to be brought into contact and separated can be selected as necessary. .

[Brief explanation of the drawing]

Figures 1 to 3 are related to this invention. Figure 1 is a side view of the main parts of the tone arm mechanism, Figure 2 is a plan view with the roller section shown in Figure 1 removed, and Figure 3 is a side view of the main parts of the tone arm mechanism. It is a perspective view showing the positional relationship of a holding member and a magnet. FIG. 4 shows a plan view of a conventional tone arm. 11...Tone arm, 13...Holder, 15.
...Ring magnet, 16...U-shaped magnet, 1γ...Holding member, 20...Rotating member, 24...Knob.

Claims (2)

[Scope of utility model registration request] (1) A first ring-shaped magnet having a center in the same direction as the axis of the vertical rotation shaft is fixed to a tone arm held on a horizontal rotation holder so as to be able to rotate in the vertical direction, and Dynamic balance achieved by providing a moving mechanism having a second magnet and an adjustment knob, and adjusting the stylus pressure by moving the second magnet perpendicularly to the rotating surface of the first magnet by the moving mechanism. type tone arm device. (2) In paragraph (1) of the claims for utility model registration,
A holding member that holds a second magnet and moves linearly within the holder; a rotating member that engages with the holding member through a spiral groove and rotates to move the holding member; and a rotating member that rotates the rotating member. A dynamic balance type tone arm device having a movement mechanism consisting of an adjustment knob located externally from the holder.