JPS6237442B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tone arm lifting device for a record player, and an object thereof is to provide a tone arm lifting device that does not leak oil.

Generally, a tone arm lifting device has a lift shaft connected to a lift arm for raising and lowering the tone arm supported by a bearing, and the lift shaft is moved up and down in response to the action of a cam plate serving as a drive source. The tone arm is configured to move up and down, and in order to smoothly move the tone arm up and down, a viscoelastic fluid such as silicone oil is placed between the friction surfaces of the bearing and the lift shaft. It was designed to provide sufficient braking force. However, in the above configuration, since the lift shaft must be supported so that it can move appropriately, there is a moderate clearance between the lift shaft and the bearing, and this clearance causes the problem of oil leakage. It was hot.

The present invention eliminates these drawbacks, and will be described below with reference to drawings of embodiments of the present invention.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is a tone arm, a part of which is provided with a mounting portion 2. As shown in FIG. The tone arm 1 has a mounting portion 2 supported by a horizontal shaft 3, and a heavy shaft 5 connected to a pedestal portion 4 that supports the horizontal shaft 3 is supported by a bearing 6, so that it can freely move up and down. And it is configured to be able to freely rotate. A turning plate 7 for turning the tone arm 1 is connected to the heavy shaft 5, and the bearing 6 is attached to a panel 8. Reference numeral 9 denotes a lift arm for raising and lowering the tone arm 1, and includes a lift shaft 10. 11 is the lift shaft 1 for raising and lowering the tone arm 1 with the lift arm 9;
This is an electromagnet as a driving source for moving the 0 up and down. The electromagnet 11 is provided with a ring-shaped recess 14 in a synthetic resin bobbin 13 having a slide hole 12 through which the lift shaft 10 is inserted.
The coil 15 is wound around the coil 15. The lift shaft 10 is a driven member formed in a ring shape surrounding the electromagnet 11 and magnetically coupled to the electromagnet 11 so as to be driven by the magnetic force generated in response to the current flowing through the coil 15. 16, and a driving member 17 which is fixed to the lift shaft 10 so as to be surrounded by the driven member 16 and is magnetically coupled to the driven member 16, so that the driving member 17 is moved up and down by power transmission. It's summery. Here, the electromagnet 11 is disposed within a first ring recess 19a of a container 19 made of a non-magnetic material and having concentric first and second ring recesses 19a and 19b; 19
is fixed to the panel 8 by inserting a threaded shaft portion 19c provided therein into the panel 8 and tightening it with a nut 20. The driven member 16 is a first member 1 magnetically coupled to the electromagnet 11.
6a and a second member 16b that is magnetically coupled to the drive member 17, and these first and second members 16a and 16b are connected together by a ring-shaped connecting body 16c made of a non-magnetic material. has been made into The driven member 16 is sealed in a second ring recess 19b of the container 19 together with a viscoelastic fluid 21 such as silicone oil, and a ring-shaped lid 22
The second ring recess 19b is sealed by the second ring recess 19b. The lift shaft 10 also includes a slide hole 12 of the bobbin 13 for the electromagnet 11 and a slide hole 23 of the threaded shaft portion 19c of the container 19.
It is supported on a shaft so that it can slide at
A part of it is connected to the lift arm 9.
Therefore, in the tone arm lifting device, when a single-pole voltage is applied to the electromagnet 11, the first member 16a of the driven member 16 is generated by the electromagnet 11, is attracted in the direction of the magnetic force, and moves upward. and the second member 1 together with this first member 16a.
6b also moves in the same direction. Then, the driving member 17 follows the movement of the second member 16b.
shifts to the upward direction, the lift shaft 10 rises, and the tone arm 1 is lifted in the direction of arrow C in the figure by the lift arm 9 coupled to the lift shaft 10. On the other hand, in this state, when a voltage of the other pole is applied to the electromagnet 11, the driven member 1
The second member 16a of No. 6 is repelled by the magnetic force generated by the electromagnet 11 and moves in the downward direction, and the second member 16b also moves in the same direction together with this first member 16a. And the second member 16b
The driving member 17 moves in the downward direction to move the lift shaft 10 downward, and the tone arm 1 is lowered in the direction of arrow N in the figure by the lift arm 9 connected to the lift shaft 10. do. In such a process of raising and lowering the tone arm 1, the electromagnet 11 that drives the lift shaft 10 is magnetically coupled to the drive member 17 provided on the lift shaft 10 by the driven member 16 disposed in the viscoelastic fluid 21. Therefore, a braking force corresponding to the resistance force that the driven member 16 receives in the viscoelastic fluid 21 acts on the lift shaft 10, and the tone arm 1 moves slowly from the initial stage of the vertical movement. This allows for stable vertical movement. Incidentally, in order to magnetically couple the electromagnet 11 and the driving member 17 with the driven member 16,
It is desirable that at least one of the driving member 17 and the driven member 16 be made of a permanent magnet.

Incidentally, in the above embodiment, the first member for coupling to the electromagnet and the second member for coupling to the driving member were used as the driven members, but these driven members 16 can be used in common as one as shown in FIG. It goes without saying that it can be done. Further, the driving member 17 includes a driven member 16
It may be biased by a spring 59 so as to maintain balance through magnetic coupling between the two. In addition, the above-mentioned elevating device is also shown in Fig. 3, Fig. 4,
It may be configured as shown in FIG. In other words, in the case shown in FIG.
3 is wound to constitute an electromagnet 104, and the above-mentioned container 1
A driven member 105 magnetically coupled to the electromagnet 104 is placed in the recess 101a of the viscoelastic fluid 10.
6 and includes a screw shaft portion 107.
08, and magnetically coupled to the driven member 105 to a cap-shaped wrist shaft 110 supported so as to be slidable along a guide shaft 109 provided at the other end of the container 101. A drive member 111 of a shape is attached. Here, the driven member 105 includes a first member 105a magnetically coupled to the electromagnet 104 and a driven member 111.
a second member 105b magnetically coupled to the second member 105b;
These first and second members 105a and 105b are connected by a non-magnetic connecting portion 105c.
Note that the lift arm 9 is coupled to the wrist shaft 110. In the case of FIG. 4, a spring 112 is added to the configuration of FIG. 3 so that a braking force is further applied to the movement of the driven member 105. In the case of FIG. 5, an electromagnet 124 is constructed by winding a coil 123 around a bobbin 122 provided in the axial direction of a bottomed cylindrical container 121 made of a non-magnetic material,
A driven member 125 magnetically coupled to the electromagnet 124 in the first recess 121a of the container 121
is enclosed together with a viscoelastic fluid 126 and sealed with a lid 127, while the second recess 12 of the container 121 is sealed with a lid 127.
A drive member 128 magnetically coupled to the driven member 125 is disposed in the drive member 1b, and a lift shaft 131 supported by a bearing plate 130 that closes the second recess 121b of the container 121 is attached to the drive member 28. A spring 132 is inserted through the lift shaft 131 and biased so as to balance the magnetic coupling between the driving member 128 and the driven member 125. And this is the above container 121
It is attached by a screw shaft portion 129 provided integrally with the.

In the above embodiment, an electromagnet was used as the drive source for the lift shaft, but if a chewing lever biased in one direction by a spring is used as the drive source, the sixth
As shown in Fig. 2, a movable shaft 226 that moves up and down in relation to the chewing lever 221 is provided with a drive member 22.
7 placed in the viscoelastic fluid 106
All you have to do is to connect them mechanically. Further, a cam plate may also be used as the driving source.

As described above, according to the present invention, power is transmitted between the drive source that drives the lift shaft and the drive member provided on the lift shaft through magnetic coupling of the driven member disposed within the viscoelastic fluid. None, and when the lift shaft is driven by the drive source, the driving member is driven via the driven member so that the power from the drive source can be taken out to the lift shaft. Braking force equivalent to the resistance force caused by elastic fluid can be applied without contact.
It is possible to provide an arm elevating device that is free from inconveniences such as oil leakage. In addition, power is transmitted to the lift shaft by applying power from the drive source to the drive member provided on the lift shaft via a driven member in the viscoelastic fluid, so that the tone arm can be moved from the initial state. The tone arm can be moved slowly up and down, and the tone arm can be driven stably.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one embodiment of the tone arm lifting device of the present invention, and FIGS. 2 to 6 are partial sectional views showing other embodiments of the tone arm lifting device of the present invention. . 1...Tone arm, 9...Lift arm, 1
0... Lift shaft, 11... Electromagnet, 16... Driven member, 18... Drive member, 19... Sealed container, 2
1... Fluid, 221... Queuing lever, 2
25...Spring.

Claims (1)

[Scope of Claims] 1. A lift shaft connected to a lift arm for moving the tone arm up and down, a driving member provided on this lift shaft, a driven member magnetically coupled to this driving member, and a driven member magnetically coupled to this driving member. A sealed container enclosing the driven member together with a viscoelastic fluid, and a drive source for driving the lift shaft magnetically coupled to the driven member in the sealed container, the lift shaft having the drive source. Power can be extracted from the drive source by magnetic coupling between the source and the driven member, and between the driven member and the drive member, and the driven member receives the viscoelastic fluid in the sealed container. A tone arm lifting device for a record player, characterized in that it is configured to apply a braking force corresponding to a resistance force. 2. The tone arm elevating device for a record player according to claim 1, characterized in that an electromagnet is used as a drive source for the lift shaft. 3. The tone arm elevating device for a record player according to claim 1, wherein a queuing lever biased in one direction by a spring is used as a drive source for the lift shaft.