JPS647444Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a linear tracking arm support device that is most suitable for supporting a linear tracking arm employed in playback devices such as audio record players and video disk players.

In recent years, there has been a tendency for linear tracking arms to be adopted in playback devices such as record players and disk players in order to improve their playback performance. This linear tracking arm has a support that can reciprocate in the axial direction attached to a linear guide shaft.The pick-up arm is supported by this support, and by driving the support, the pick-up arm is moved linearly in parallel. It is meant to be moved. By the way, the type of guide shaft mentioned above is generally one in which two parallel guide shafts are used as a set, but this has drawbacks such as a complicated structure and an increase in size. For this reason, very recently a single cylindrical guide shaft has been adopted, into which a slider is inserted, so that the slider can freely slide in the axial direction of the guide shaft and rotate around the guide shaft. A linear tracking arm has been proposed which is configured to be movable and in which the support body is attached to the slider so as to be horizontally rotatable. It is true that this type has the effect of simplifying the structure of the linear tracking arm and eliminating wobbling of the support or pick-up arm, but on the other hand, the outer circumferential surface of the guide shaft and the inner circumferential surface of the slider are The entire load of the pick-up arm, support body, and slider is applied to this point by sliding contact at one place (the upper end of the guide shaft), and the frictional force when the slider slides becomes large, causing the slider to slide. Load is placed on the drive source. Further, at this time, sliding noise is generated, which has an unfavorable acoustic effect on the pickup arm.

The present invention was devised to correct the above-mentioned defects, and it is possible to reduce the frictional force between the guide shaft and the slider with an extremely simple structure. This reduces the load on the drive source and suppresses the generation of sliding noise.

An embodiment in which the present invention is applied to a linear tracking arm of a record player will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention, and a guide shaft 1 shown in FIG. 1 is a cylindrical guide shaft provided horizontally on one side of a record player. It is. As shown in FIG. 1, a linear tracking arm 20 is attached to the guide shaft 1 and is slidable in the axial direction of the guide shaft 1. A linear tracking arm 2 is attached to one end of the guide shaft 1.
A drive device 21 is provided for reciprocating the linear tracking arm 20 and the pulley 22 of the drive device 21 along the guide shaft 1. There is. The drive device 21 includes two motors 24 and 25 and a speed reducer 26, and the linear tracking arm 20 is driven at low speed by the rotation of the motor 24 during play, and by the rotation of the motor 25 during lead-in, return, etc. It is configured to be driven at high speed.

In addition, 27 in FIG. 1 is a frequency generator attached to the rotating shaft of the motor 24.
The rotational speed of the frequency generator 27 can be detected by a magnetic head 28 provided close to the outer periphery of the frequency generator 27. The same applies to the motor 25, whose rotational speed can be detected by a frequency generator 29 and a magnetic head 30.

The linear tracking arm 20 is attached to the guide shaft 1 by inserting its cylindrical slider 2 into the guide shaft 1, as shown in FIGS. 2 to 4. A groove 33 extending along the axial direction of the guide shaft 1 is provided on the outer peripheral surface of the guide shaft 1 on the side opposite to the turntable (not shown). As shown in FIGS. 2 and 4, the groove 33 has a U-shaped cross section, and its center is at the same height as the center of the guide shaft 1. A screw hole 34 communicating with the inside of the groove 33 is provided at one side of the longitudinal center of the slider 2 at a right angle to the groove 33. A screw 35 is screwed together. The tip of the screw 35 protrudes into the groove 33, and a ball bearing 36 as a rotor is attached thereto by fitting and fixing its inner ring. That is, the ball bearing 36 is rotatable around an axis perpendicular to the axis of the slider 2.
The outer ring of the ball bearing 36 has a diameter slightly smaller than the width of the groove 33, and is capable of rolling on a lower horizontal surface 55 of the groove 33. In this case, the depth of the groove 33 may be such that the ball bearing 36 is completely accommodated inside the groove 33, and there is no need to make it a particularly deep groove.

As shown in FIGS. 2 and 3, ball bearings 3 and 4 are fitted on the outer periphery of both ends of the slider 2, and a first
A support body 5 is fitted and rotatably supported. That is, the first support body 5 is attached to be rotatable around the axis of the slider 2. The first support body 5 has a balance weight 6 extending horizontally on its outer periphery on the opposite side from the turntable of the record player (not shown), and the left and right sides of the balance weight 6 are shown in FIG. Yoke plates 7 and 8 are mounted perpendicularly to the guide shaft 1 in this way. Also, on the outer periphery of both ends of the slider 2,
Rings 9 and 10 are fitted to the outer sides of the ball bearings 3 and 4, and the rings 9 and 10 are fixed to the slider 2 by screws 11 inserted from the outer periphery to the slider 2 side. . and ring 9,1
0, one end portion of yoke plates 12, 13 perpendicular to the guide shaft 1 is fixed to the side surface on the side of the ball bearings 3, 4. The support plates 12 and 13 are parallel to each other with a predetermined gap between them and the support plates 7 and 8,
Magnets 14 and 15 are attached to the yoke plates 7 and 8 and flat coils 16 and 17 are attached to the yoke plates 12 and 13 on the opposite surfaces of the husband and husband. A vertical drive motor is constituted by the yoke plates 7 and 12, the magnet 14, and the coil 16.
13, a magnet 15, and a coil 17 constitute a vertical speed sensor, which allows the first support 5 to be rotated freely. In addition, at this time,
Since there is a gap equal to the thickness of the ball bearing 36 between the inner peripheral wall of the first support 5 and the outer peripheral wall of the slider 2, the head of the screw 35 is connected to the inner peripheral wall of the first support 5. We never run into each other. Moreover, the yoke plate 12,
The lower ends of the yoke plates 7 and 8 are connected by a connecting plate 18, and when the first support body 5 rotates clockwise in FIG. The rotation range of the support body 5 is restricted. Note that since the ball bearing 36 attached to the slider 2 is inserted into the groove 33, the slider 2 can be moved without any special rotation regulating means.
The yoke plates 12 and 13 do not rotate around the guide shaft 1.

On the turntable side of the first support body 5, a second
As shown in the drawings and FIG. 3, the printed circuit board 40 is mounted horizontally. Further, a pivot bearing portion 42 is provided at the upper and lower center of the first support body 5, as shown in FIG. The top and bottom of the first support 5 and the turntable side are covered with a second support 43 having a substantially U-shape, and the top and bottom of the second support 43 are covered with a second support 43 that protrudes toward the pivot bearing 42. A screw-in pivot 44 is attached. The tip of the pivot 44 is fitted into the pivot bearing 42, so that the second support 43 can smoothly rotate horizontally about the pivot 44. That is, the second support body 43 is attached so as to be rotatable around an axis perpendicular to the axis of the slider 2 . A yoke plate 46 is attached to the inner surface of the second support body 43 above the printed circuit board 40, as shown in FIG. 2, and is parallel to the printed circuit board 40 with a predetermined gap therebetween. As shown in FIG. 3, two flat coils 47 and 48 are attached to the opposing surfaces of the printed circuit board 40 and the yoke plate 46, as shown in FIG. 3, and a magnet 49 is attached to the yoke plate 46 side. . Further, a yoke plate 50 is provided on the lower side of the printed circuit board 40 in parallel thereto. and coil 48,
The magnet 49 and the yoke plates 46 and 50 constitute a horizontal drive motor, and the coil 47, the magnet 49 and the yoke plates 46 and 50 constitute a horizontal speed sensor, and the second support 43 can be moved freely in the horizontal direction. It is designed so that it can be rotated. Note that 51 in FIG. 3 is a Hall element provided between the coils 47 and 48, and is a Hall element provided between the coils 47 and 48.
The Hall element 51 is configured to detect the rotation angle. Further, a pick-up arm 52 is attached to the turntable side of the second support body 43, as shown in FIGS. 1 to 3, and extends horizontally toward the turntable side. A cartridge 53 provided at the tip of the pickup arm 52 traces the sound grooves on the record.

The linear tracking arm 20 is constructed as described above, and its center of gravity G is adjusted by the balance weight 6 so that it is located slightly closer to the groove 33 than the center of the guide shaft 1, as shown in FIG. ing. Therefore, the upper part of the outer peripheral surface of the guide shaft 1 and the upper part of the inner peripheral surface of the slider 2 are in contact with each other, and the groove 3 of the guide shaft 1 is in contact with the upper part of the inner peripheral surface of the slider 2.
The lower horizontal surface 55 of No. 3 and the ball bearing 36 are in contact with each other. And linear tracking arm 20
The weight of is distributed and supported by the two contact parts, and the frictional force at each contact part is reduced. In particular, the frictional force in the groove 33 is significantly reduced by the ball bearing 36, and the overall frictional force between the guide shaft 1 and the slider 2 is approximately half or less than that in the case of a conventional linear tracking arm.
Therefore, the load on the motors 24 and 25 of the drive device 21 that drives the linear tracking arm 20 is reduced, the linear tracking arm 20 can be driven with a small output, and the stability of the drive device is increased. In addition, due to the decrease in frictional force, the guide shaft 1
The generation of sliding noise between the slider 2 and the slider 2 is suppressed, and the playback performance of the record player is improved.

Next, a second embodiment of the present invention will be explained based on FIG.

In this embodiment, the groove 33 is a deep groove so that the center of gravity G of the linear tracking arm 20 is located at the tip of the groove 33, and the ball bearing 36 is positioned in accordance with the position of the center of gravity G. In this case, the entire weight of the linear tracking arm 20 is applied to the ball bearing 36, and almost no sliding friction occurs between the outer peripheral surface of the guide shaft 1 and the inner peripheral surface of the slider 2. Therefore, the frictional force between the guide shaft 1 and the slider 2 is further reduced, and the load on the motors 24, 25 is further reduced. In the above case, the ball bearing 36 is moved to the center of gravity of the linear tracking arm 20, but the position of the ball bearing 36 and the depth of the groove 33 are the same as in the first embodiment, and the balance weight 6 is moved to the center of gravity of the linear tracking arm 20. The center of gravity G of the linear tracking arm 20 may be moved to the position of the ball bearing 36 by adjustment.

Next, a third embodiment of the present invention will be described based on FIG. 6.

In this embodiment, the center of gravity G of the linear tracking arm 20 is located near the outside of the groove 33 of the guide shaft 1. Therefore, the lower part of the outer circumferential surface of the guide shaft 1 and the lower part of the inner circumferential surface of the slider 2 come into contact, but since most of the weight of the linear tracking arm 20 is applied to the ball bearing 36, almost no frictional force is generated. do not have.

Although the embodiments of the present invention have been described above, the present invention is not only applicable to the linear tracking arm 20 of a record player, but also applicable to the linear tracking arm of other disc players. Further, although the ball bearing 36 is used as the rotor in the above embodiment, other rotors may be used. Furthermore, not only one rotor but two or more rotors may be provided along the groove 33.

As mentioned above, the present invention provides a groove along the axis of the guide shaft on the outer periphery, and a rotor that is rotatable around an axis perpendicular to the axis and is mounted inside the slider. The center of gravity of the first and second supports including the pick-up arm is located at or near the rotor by the weight balance of a balance weight that is inserted into the groove and balances the pick-up arm in the vertical direction. Since this is a linear tracking arm support device, all or part of the weight of the first and second supports including the pick-up arm is supported by the rotor with an extremely simple structure, and the outer periphery of the guide shaft is supported by the rotor. The sliding friction between the surface and the inner peripheral surface of the slider can be significantly reduced. Therefore, the output of the drive device for driving the slider can be small, and the stability of the drive device is increased. Further, the occurrence of sliding noise between the slider and the guide shaft is suppressed.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a linear tracking arm of a record player. Fig. 1 is an external perspective view of the linear tracking arm of the first embodiment, and Fig. 2 shows the main points of the same. 3 is a horizontal sectional view of the same as above, FIG. 4 is a partially enlarged vertical sectional view of FIG. 2, FIG. 5 is a vertical sectional view showing the main part of the second embodiment, and FIG. 6 FIG. 3 is a vertical cross-sectional view showing the main parts of the third embodiment. In the symbols used in the drawings, 1... guide shaft, 2... slider, 3, 4... ball bearing, 5... first support body, 20... linear tracking arm, 33... Groove, 35...Screw, 36
... Ball bearing, 42 ... Pivot bearing section, 43 ... Second support body, 44 ... Pivot,
It is.

Claims (1)

[Scope of utility model registration request] a guide shaft having a groove along the axis on its outer periphery;
a slider inserted into the outer periphery of the guide shaft so as to be slidable in the axial direction; a rotor inserted into the groove; a first support mounted on the outer periphery of the slider so as to be rotatable around the axis of the slider; The second slider is rotatably mounted around an axis perpendicular to the axis of the slider.
a support body, a pick-up arm attached to the second support body, and a balance weight that balances the pick-up arm in the vertical direction; . A linear tracking arm support device, characterized in that the center of gravity of the first and second supports including the pick-up arm acting on the slider is located at or near the rotor.