JPS633361B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tone arm drive device for a record player.

Generally, tone arm drive devices reduce the rotational speed of a motor using a gear train to raise and lower the tone arm, or use the rotational force of a turntable to raise and lower the tone arm. however,
A tone arm drive device having such a structure has a problem in that since a motor or a turntable is used as a drive source, the mechanism for raising and lowering rotational movement is complicated and difficult to assemble.

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

FIG. 1 shows an embodiment of the tone arm driving device of the present invention. In the figure, 1 is a tone arm, a pick-up cartridge 2 is attached to its tip, and a balance weight 3 is attached to its rear end. ing. The tone arm 1 has a mounting portion 4 attached to a rotating frame at the rear of the central portion thereof, and the mounting portion 4 is rotatably supported on a horizontal shaft 6 with respect to the rotating frame 5. The rotating frame 5 has a vertical shaft 7 provided thereon and is rotatably supported by a bearing 9 provided on a panel 8. Therefore, the tone arm 1 is able to move up and down in the direction of the arrow shown in the figure about the horizontal axis 6, and can make a turning movement in the direction of the arrows E and I in the figure about the vertical axis 7. It is in. Reference numeral 10 denotes a lift arm for moving the tone arm 1 up and down, and a lift shaft 11 supported by a bearing 14 attached to the panel 8 is connected to this lift arm. Reference numeral 12 denotes a rotating plate for rotating the tone arm 1, which is attached to the vertical shaft 7 and connected to the connecting rod 15.
have. Reference numeral 13 denotes a drive device main body that is associated with the lift shaft 11 and the connecting rod 15 to cause the tone arm 1 to move up and down and rotate. The cutout portions 17 are connected to the rotating plate 12 by facing each other. Further, the rotating plate 12 has a cutout portion 18 at a predetermined angle,
A stopper pin 19 is positioned within the cutout 18 to regulate the amount of rotation of the rotating plate 12.

As shown in FIG. 2, the driving device main body 13 includes a container 20 made of a non-magnetic material having concentric first and second ring recesses 20a and 20b, and a container 20 made of a non-magnetic material.
0 and the second ring recess 20 of the container 20.
a ring-shaped driven member 26 that is enclosed in the interior of the container 20 and is magnetically coupled to the electromagnet 23; A ring-shaped driving member 28 is provided. Here, the driven member 26 includes a first member 26a and a second member 26b that are magnetically coupled to the electromagnet 23.
These first and second members 26a,
26b is magnetized with a different polarity from the electromagnet 23. The driven member 26 is sealed in the second ring recess 20b of the container 20 together with a viscoelastic fluid 24 such as silicone oil,
The inside of the second ring recess 20b is sealed by a ring-shaped lid 25. Further, the movable rod 27 is a hollow shaft 2 formed integrally with the lid body 25.
9 so that it can rotate and slide, and one end thereof is connected to the lift shaft 11.
is in contact with the bottom edge of. In addition, the electromagnet 23
is a laminate core 2 made by laminating multiple thin magnetic plates.
Coils 22a and 22b are wound around 1 and fixed to the hollow shaft 29, and the starting and ending ends of the coils are connected to the lid 2.
5, respectively. The electromagnet 23 is configured so that different magnetic poles are generated at the ends of the core when voltages of different polarities are applied to the coils 22a and 22b. The driving member 28 also has first and second members 28a and 28b that are magnetized to have different magnetic poles with respect to the driven member 26.
and are stopped in a balanced position due to their magnetic relationship. Further, the movable rod 27 has a feed screw 31b that is screwed into a feed screw 31a provided in the through-hole wall of the container 20, so that the rotational force of the movable rod 27 is converted into linear motion. There is. Further, a spring 33 is provided between the retaining ring 32 provided at the lower end of the lift shaft 11 and the lower end of the bearing 14, and the lift shaft 11 is always biased by the spring in the downward direction.

In a tone arm drive device configured like this,
When the switch 34 shown in FIG. 4 is closed and a voltage of one polarity is applied to the electromagnet 23, the driven member 26 rotates in the direction of the arrow H in the figure due to the magnetic relationship between the electromagnet 23 and the driven member 26. The driving member 28 is rotated in the direction of arrow H in the figure to follow the movement of the driven member 26, and the power of the electromagnet 23 is transmitted to the movable rod 27 via the driven member 26 and the driving member 26. is transmitted as rotational force. Then, when the movable rod 27 rotates in the direction of arrow H in the figure, the feed screw 31a,
31b converts the rotational motion of the movable rod 27 into linear motion, so that the movable rod 27 is raised in the direction of the arrow H in the figure. When the movable rod 27 moves straight a predetermined distance, the threaded relationship between the feed screws 31a and 31b is released. Therefore, the tone arm 1 is lifted from the position of the armrest (not shown) in the direction of the arrow C because the lift shaft 11 is raised by the linear movement of the movable rod 27 in the direction of the arrow H in the drawing. . Even if the tone arm 1 reaches the raised position of the armrest due to the upward movement of the tone arm 1, the electromagnet 23 is not de-energized, so the movable rod 27 continues to rotate in the direction of arrow H in the figure. When the tone arm 1 reaches the record playing start position by the moving plate 16, this is detected, the switch 34 is opened and the switch 35 is closed, so that the energization of the electromagnet 23 is switched to the opposite polarity. Then, the electromagnet 23 and the driven member 26 are rotated in the direction of the arrow G in the figure, and the driving member 28 is rotated in the direction of the arrow G in the figure so as to follow the driven member 26, and the power of the electromagnet 23 is The rotational force is transmitted to the movable rod 27 via the driven member 26 and the driving member 28. On the other hand, since the tone arm 1 detects that it has come to the record playing start position and the feed screws 31a and 31b are synchronously screwed together, the rotational force of the movable rod 27 in the direction of the arrow G in the figure is generated. is converted into a linear motion, causing the movable rod 27 to move straight in the direction of the arrow shown in the figure, and the tone arm 1 descends in the direction of the arrow 2 shown in the figure and enters the playing state.

After entering the performance state, the switch 35 is opened, so that the electromagnet 23 is de-energized, and the positional relationship of the electromagnet 23, the driven member 26, and the driving member 28 remains in its original state. will be reinstated. The lead-in operation is thus completed.

On the other hand, when the tone arm 1 reaches the end position of playing the record, the switch 34 is opened, so that a voltage of one polarity is applied to the electromagnet 23. Then, the electromagnet 23 and the driven member 26
The driven member 26 is rotated in the direction of the arrow H in the figure in a magnetic relationship with the driven member 26, and the drive member 28 is rotated in the direction of the arrow H in the figure to follow the driven member 26, and the power of the electromagnet 23 is transferred to the direction of the arrow H in the figure. The movable rod 2 is connected to the movable rod 2 via the driven member 26 and the driving member 28.
7 as rotational force. When the movable rod 27 rotates in the direction of the arrow H in the figure, the rotational movement of the movable rod 27 is converted into a linear movement by the feed screws 31a and 31b, and is raised in the direction of the arrow H in the figure. When the movable rod 27 moves straight a predetermined distance, the threaded relationship between the feed screws 31a and 31b is released. Therefore, the lift shaft 11 is raised by the rectilinear movement of the movable rod 27 in the direction of the arrow H, so that the tone arm 1 is raised in the direction of the arrow C at the end position of the record playing. When the tone arm 1 rises to the end position of record playing, this is detected, the switch 34 is opened and the switch 35 is closed, so that the energization of the electromagnet 23 is switched to the opposite polarity. Then, since the magnetic relationship between the electromagnet 23 and the driven member 26 is also reversed, the driven member 26 is rotated in the direction of arrow H in the figure, and the driving member 28 is rotated to follow the driven member 26.
is rotated in the direction of arrow T in the figure, and the power of the electromagnet 23 is transmitted to the driven member 26 and the driving member 28.
The rotational force is transmitted to the movable rod 27 via the rotary force. The rotational force of the movable rod 27 in the direction of arrow T in the figure is applied to the rotating plate 1 through the rotating plate 16.
2, the tone arm 1 is rotated in the direction of the arrow RO in the figure and returned to the raised position of the armrest. When the tone arm 1 reaches the raised position of the armrest, this is detected and the feed screws 31a and 31b are screwed together, so that the rotational force of the movable rod 27 in the direction of the arrow G in the figure is converted into a linear motion. Then, the movable rod 27 is moved straight in the direction of the arrow shown in the figure, and the tone arm 1 is lowered in the direction of the arrow D and returned to the armrest position. When the tone arm 1 returns to the armrest, the switch 35 is de-energized, and the electromagnet 23 and the driven member 2
6. The positional relationship of each of the drive members 28 is returned to its original state. In this way, the return operation is completed.

Note that the feed screws 31a, 3 are used to raise the tone arm 1 during lead-in and return operations.
1b was used to convert rotational motion to linear motion, and after a predetermined linear motion, the threaded relationship between the feed screws 31a and 31b was released, but in order to lower the tone arm 1, the feed screws 31a and 31b had to be screwed again. To do this, a plunger (not shown) is actuated by detecting that the tone arm 1 has been sent to the record playing start position or that the tone arm 1 has returned to the raised position of the armrest, and this plunger operates as described above. The movable rod 27 may be pulled slightly in the direction of the arrow shown in the figure. In this case, it is desirable that the movable rod 27 and the plunger be coupled with a slight play in the rotational direction and the thrust direction.

In the process of raising, lowering, and turning the tone arm 1, the electromagnet 23 that drives the movable rod 27 generates a magnetic force with the driven member 26 disposed in the viscoelastic fluid 24 with respect to the driving member 28 provided on the movable rod 27. Therefore, a braking force corresponding to the resistance force that the driven member 26 receives in the viscoelastic fluid 24 acts on the movable rod 27, and the tone arm 1
The movement starts to shift slowly from the beginning of the lifting, lowering, and turning movements, making it possible to perform stable lifting and lowering movements. In order to magnetically couple the electromagnet 23 and the driving member 28 with the driven member 26, the driving member 28 may be made of either a permanent magnet or a magnetic material, but the driven member 26 may be made of a permanent magnet. It is hoped that this will be done.

In the above embodiment, the rotational motion of the movable rod 27 is converted into linear motion by the feed screws 31a and 31b. However, if the drive device main body 13 is provided for linear motion, the feed screw 31a and 31b are normally placed in a positional relationship in which they do not screw together and are used to convert linear motion into rotational motion.

As described above, according to the present invention, the tone arm is provided so as to be freely rotatable about the vertical axis and freely movable up and down about the horizontal axis, and the tone arm can be freely moved up and down and rotated to drive the tone arm. A flexible drive device is provided separately from the tone arm, a rotating plate is provided on a movable rod constituting the main body of the drive device, and the rotating plate is related to a connecting rod provided eccentrically to the vertical axis. On the other hand, a lift shaft for raising and lowering the tone arm is provided so as to be coaxial with the movable rod, and the tone arm is turned up and down in accordance with the movement of the movable rod, so that the raising and lowering movement is controlled. The movement of the movable rod is transmitted to the lift shaft or the connecting rod, and the tone arm can be raised and lowered in response to the movement of the movable rod without using a lift cam. With a simple configuration, the tone arm can be stably driven without placing a large burden on the drive device.

[Brief explanation of the drawing]

FIG. 1 is a structural perspective view showing an embodiment of the tone arm driving device of the present invention, FIG. 2 is a cross-sectional view of the main part of the same device, FIG. 3 is an exploded perspective view of the main part of the same device, and FIG. It is an electrical circuit diagram of the same device. 1...Tone arm, 10...Lift arm,
11...Lift shaft, 12...Swivel plate, 13...Drive device main body, 15...Connection rod, 16...Swivel plate,
17... missing part, 27... movable rod, 33... spring.

Claims (1)

[Claims] 1. A tone arm is provided that is rotatable about a vertical axis and movable up and down about a horizontal axis, and a drive device that drives the tone arm is movable up and down and rotatable. is provided separately, a rotating plate having a substantially U-shaped recess is provided on the movable rod constituting the main body of the drive device, and a connecting rod provided eccentrically to the vertical axis is inserted into the recess of the rotating plate. On the other hand, a lift shaft is provided for raising and lowering the tone arm so as to be coaxial with the movable rod, and the tone arm is raised and lowered in accordance with the vertical movement of the movable rod, and the movable rod is rotated. A tone arm drive device characterized in that the tone arm is configured to rotate according to the operation.