JPH06187601A - Tone arm - Google Patents

Abstract

PURPOSE:To provide a tone arm which has no room for causing the looseness at the supprting point of the arm, can prevent the deterioration of the sound quality, and can be easily adjusted while realizing simplification of the structure and reduction of the number of parts. CONSTITUTION:An arm tube 2 and a weight support member 3 are set on the front and back sides of a support shaft 1, respectively. These tube 2 and member 3 are connected to each other with a connector member 5, and a counter weight 4 is slidably provided on the member 3. In regard to the supprting form of the tube 2 and the member 3 relative to the shaft 1, the apexes of the conical recess parts 10 and 9 of the shaft 1 are hit by the tips of pins 15 and 18. So that the tube 2 and the member 3 can be supported by the shaft 1 at a single point in an oscillatable way secured in all directions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tone arm provided in a record player for reproducing an analog disc such as an LP record.

[0002]

2. Description of the Related Art As is well known, a tone arm in a record player supports a base portion of an arm pipe to which a cartridge is attached at a tip end portion thereof so as to be rotatable in horizontal and vertical directions, and has a predetermined needle for the cartridge. Most commonly, a counterweight for applying pressure is provided so as to be slidable in the front-rear direction from the support point of the arm pipe to the base end side.

[0003]

By the way, in the conventional tone arm, in order to smoothly rotate the arm pipe, as a supporting structure thereof, various types such as one using a bearing and one using a knife edge are used. However, in those conventional supporting structures, it is inevitable that some play will occur at the supporting points, which adversely affects the reproduced sound quality. In addition, the conventional tone arms are not always easy to handle because they have a complicated structure, a large number of parts, and require delicate adjustment.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tone arm which eliminates any rattling that adversely affects sound quality, and has a simple structure and which can be easily adjusted. is there.

[0005]

SUMMARY OF THE INVENTION The present invention is a tone arm provided in a record player for reproducing an analog disc, in which a base is fixed to a player board and a supporting shaft is provided upright. An arm pipe supported by the support shaft and arranged on the front side of the support shaft and having a cartridge attached to the tip end thereof, and a front side of the arm pipe supported by the support shaft and arranged on the rear side of the support shaft and The weight support member is connected to the base end portion via a connecting member, and the counter weight is slidably attached to the weight support member in the front-rear direction. A protruding pin is provided, and the tip of the pin is abutted against the apex of a conical recess formed on the front side of the support shaft, and the weight support is provided. A pin projecting forward is provided on the front side of the member, and the tip of the pin is abutted against the apex of a conical recess formed on the rear side of the support shaft, whereby these arms are provided. It is characterized in that the pipe and the weight support member are respectively supported at one point so as to be swingable in all directions with respect to the support shaft.

[0006]

In the tone arm according to the present invention, the arm pipe and the weight support member are provided separately, and the arm pipe and the weight support member are swingable in all directions by pins, respectively, at one point with respect to the spindle. To support. Therefore, there is no room for rattling at those supporting points. Further, the base end of the arm pipe and the front of the weight support member are connected by a connecting member, and the counter weight is used for balancing with the support point as a fulcrum.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall side view of the tone arm of this embodiment, FIG. 2 is a plan view of a main part thereof, and FIG. 3 is a side sectional view of the main part. In the figure, reference numeral 1 is a support shaft, 2 is an arm pipe, 3 Is a weight support member, 4 is a counterweight, and 5 is a connecting member.

As shown in FIG. 3, the support shaft 1 has its base end (lower end) penetrating the player board 6 and nuts screwed on the bottom surface side and the front surface side of the player board 6, respectively. The player board 6 is sandwiched between the player board 6 and the arm base 8 and is fixedly installed on the player board 6. Two conical recesses 9 are formed on the rear side (right side in each drawing) of the upper end of the support shaft 1 and on the front side (the same left side) at a position lower than that. 10 are provided at intervals in the vertical direction and at positions facing each other with the axis of the support shaft 1 interposed therebetween in plan view. The positions of the apexes of the conical recesses 9 and 10 are both set to coincide with the position of the axis of the support shaft 1.

The arm pipe 2 is a tapered pipe member having a head shell 11 for integrally mounting a cartridge (not shown) formed integrally with the arm pipe 2 and a support portion 12 mounted at the base end portion. At the axial center position of the base end of the arm pipe 2, a rod 1 having a screw formed on the distal end side is formed.
3 is provided so as to project rearward, the rod 13 thereof penetrates the support portion 12 and the nut 14 is screwed to the tip end thereof, so that the arm pipe 2 is pulled toward the support portion 12 and Is a tightly integrated one. A pin 15 is provided at the tip of the rod 13, and the tip of the pin 15 is abutted against the apex of the recess 10 of the support shaft 1 in a point contact state so that the arm pipe 2 supports the apex of the recess 10. The point P1 is supported by the support shaft 1 so as to be swingable in all directions.

On the other hand, the weight support member 3 is swingably supported in all directions in the recess 9 provided on the rear side of the upper end of the support shaft 1. As shown in FIG. 2, the weight support member 3 has a U-shaped block body 16 in a plan view, and a front end portion screwed into the central portion of the rear wall surface of the block body 16 to extend rearward. It is composed of a rod 17 provided and the rod 1
A counterweight 4 is mounted on the slide member 7 so as to be slidable in the front-rear direction. Then, inside the block body 16,
A pin 18 located on the extension line of the rod 17 is provided so as to project forward, and the tip of the pin 18 is brought into contact with the apex of the recess 9, whereby the weight support member 3 makes the apex of the recess 9 support point P2. Is supported by a support shaft in a swingable state in all directions.

The counterweight 4 has a main weight 20 in which a through hole through which the rod 17 penetrates is formed in an upper portion thereof, and a front end of the main weight 20 is projected and retracted into the through hole by turning a knob. 17, a screw 21 for fixing to the main weight 20, a sub-weight 22 slidably provided in the hollow portion provided in the main weight 20 in the front-rear direction, and a knob screwed to the central portion of the sub-weight 22. Sub weight 2 by turning
Screw 23 for sliding 2 back and forth in minute increments
And a spring 24 which is incorporated in the hollow portion and biases the sub-weight 22 forward. The adjustment of the zero balance and the stylus pressure by the counterweight 4 is performed by first sliding the entire counterweight 4 with respect to the rod 17 in the front-rear direction with the screw 21 loosened, and thereafter. The fine adjustment is performed by sliding the sub-weight 22 back and forth with respect to the main weight 20 by a small amount with the screws 23.

Further, the support portion 12 forming the base end portion of the arm pipe 2 is provided with two connecting portions 30 projecting upward, and the weight support portion 3 is also provided.
Two connecting parts 31 are provided so as to project upward also on the front part of the block body 16 of, and the connecting parts 30 and 31 of both of them are
It is arranged at a position in front of the support shaft 1 at a predetermined interval so as to face each other,
The upper ends of the connecting portions 30 and 31 are connected by the connecting member 5. That is, the front wall surface of the upper end portion of the connecting portion 30 provided on the arm pipe 2 and the rear wall surface of the upper end portion of the connecting portion 31 provided on the weight support member 3 have conical shapes. The recesses 32 and 33 are provided at opposite positions. On the other hand, the connecting member 5 has a plan view H as shown in FIG.
It has a mold shape, and pins 34 and 35 facing the rear side and the front side are respectively screwed to the front portion and the rear portion thereof. Then, the connecting member 5 is attached to the upper ends of the connecting portions 30 and 31, and the tips of the pins 34 and 35 are abutted against the apexes of the recesses 32 and 33, so that the connecting member 5 causes both connecting members 30 and The upper end portions of 31 are connected to each other in such a manner that they are sandwiched from the front and rear. As a result, the front portion and the rear portion of the connecting member 5 have the respective pins 34, 35.
Recesses 32, 3 whose tips are abutted via
The apex of 3 is set as the support points P3 and P4, and the support points P3 and P4 are supported in a state in which they can swing relative to the connecting portions 30 and 31.

In this case, as shown in FIG. 3, the support point P1 of the arm pipe 2 (the apex of the recess 10) and the support point P3 on the front side of the connecting member 5 (the apex of the recess 32) are connected to each other. The connecting virtual line and the connecting virtual line connecting the support point P2 of the weight support member 3 (the apex of the recess 9) and the support point P4 on the rear side of the connecting member 5 (the apex of the recess 33) are parallel to each other in a side view. It is better to set so that

In the tone arm having the above construction, when in the zero balance state, as shown by the arrow in FIG. 3, the arm pipe 2 is lowered at the tip side about the support point P1 due to its own weight and the own weight of the cartridge. Direction, and thus the connecting portion 30 tries to fall forward. Further, the weight support member 3 is supported by its own weight and the counterweight 4 by its own weight.
Trying to rotate in the direction in which the rear end side goes down around 2
Therefore, the connecting portion 31 tends to fall rearward. However, since the upper ends of the connecting portions 30 and 31 are connected by the connecting member 5, the vertices of the recesses 32 and 33 of the connecting portions 30 and 31 are the pins 3 respectively.
They are pressed against the tips of 4, 35 with an even force, and at the same time, their reaction force is applied to the recess 1 by the pin 15.
In addition to being added to the top of 0, the pin 18 adds to the top of the recess 9. If the counterweight 4 is slid slightly forward from such a zero balance state, the zero balance is broken and the tip side of the arm pipe 2 is lowered, and a desired stylus pressure is applied to the cartridge.

The arm pipe 2 is horizontally rotated about the apex (support point P1) of the recess 10 which coincides with the axis of the support shaft 1, and the arm pipe 2 is horizontally rotated. Following the rotation of the arm pipe 2, the weight support member 3 connected to the arm pipe 2 by the connection member 5 also has the apex (support point P2) of the recess 9 that also matches the axis of the support shaft 1. As a center of rotation, the arm pipe 2 rotates in the same direction as the rotation direction. Further, the arm pipe 2 is also rotated in the vertical direction with the support point P1 as the center of rotation. With the vertical rotation of the arm pipe 2, the connecting portion 30 is rotated with the support point P1 as the center of rotation. Is displaced vertically,
Following this, the connecting portion 31 rotates about the support point P2 as the center of rotation and is displaced in the vertical direction. Therefore, the weight support member 3 is displaced about the support point P2 of its rear end side in the vertical direction. To rotate.

Since the horizontal and vertical rotations of the arm pipe 2 and the weight support member 3 are restricted within the range of the apex angle of the recesses 9 and 10, the recesses 9 and 10 are prevented.
The apex angle of 10 must naturally be set in consideration of the horizontal and vertical rotation ranges of the arm pipe 2 and the weight support member 3. Also, the arm pipe 2
When is rotated in the vertical direction, the connecting member 5 inclines from the horizontal state, and the front and rear portions thereof swing vertically relative to the connecting portions 30 and 31, The apex angles of the recesses 32 and 33 provided in the connecting portions 30 and 31 also need to be set so as not to restrain such swinging.

Further, in the conventional general tone arm, the counterweight is directly attached to the base end portion of the arm pipe, and therefore, the support point of the counterweight is common with the support point of the arm pipe. In the above tone arm, the arm pipe 2 and the weight supporting member 3 are separated from each other and are connected by the connecting member 5, and they are respectively connected to different supporting points P1,
Since it is supported by P2 and the supporting point P2 of the weight supporting member 3 is set above the supporting point P1 of the arm pipe 2, the weight of the counterweight 4 can be reduced by the principle of the lever. ing.

As described above, in the tone arm of this embodiment, the support points P1 and P2 are supported at one point by abutting the tips of the pins 15 and 18 on the apexes of the recesses 10 and 9, respectively. Since all the supporting points P3 and P4 are the same, there is no room for backlash at any of the supporting points P1 to P4, and therefore it is possible to prevent the reproduced sound quality from being adversely affected. is there. Further, since the support point of the form of supporting at one point by the pin alone allows both horizontal and vertical swings, for example, a plurality of bearings for horizontal rotation and vertical rotation may be used. , Or, compared with the conventional general tone arm that uses a combination of a bearing and a knife edge, the structure has been greatly simplified and the number of component parts has been reduced. There is also an advantage that it is easy to handle because it requires less amount.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and it is needless to say that the shape, size, etc. of each part can be appropriately modified in design. Is.

[0020]

As described above, the tone arm of the present invention supports the arm pipe and the weight support member respectively on the support shaft, and also supports the arm pipe and the weight support member on the support shaft. In each case, since the tip of the pin is abutted against the apex of the conical recess so that it can be swung in all directions at one point, there is room for rattling at those support points. Therefore, it is possible to eliminate the adverse effect on the reproduction sound quality, and the structure is greatly simplified and the number of components is reduced compared to the conventional general tone arm, which is advantageous in terms of cost and adjustment. It has an excellent effect that it is easy to handle because it requires few parts.

[Brief description of drawings]

FIG. 1 is a side view of a tone arm that is an embodiment of the present invention.

FIG. 2 is a plan view of a main part of the tone arm.

FIG. 3 is a side sectional view of a main part of the tone arm.

[Explanation of symbols]

 1 spindle 2 arm pipe 3 weight support member 4 counterweight 5 connecting member 6 player board 9 recess 10 recess 15 pin 18 pin.

Claims (1)

[Claims] 1. A tone arm provided in a record player for reproducing analog discs, comprising a support shaft having a base portion fixed to a player board and erected, and a support shaft having a base end portion supported by the support shaft. An arm pipe that is arranged on the front side of the
A weight support member whose front side is supported by the support shaft and is arranged on the rear side of the support shaft and which is connected to the base end of the arm pipe via a connecting member, and is freely slidable in the front-back direction on the weight support member. A counterweight attached to the arm pipe, and a rearward projecting pin is provided at the base end of the arm pipe, and the tip of the pin is a cone formed at the front side of the support shaft. A cone that is abutted against the apex of a concave portion, and has a forwardly projecting pin on the front side of the weight support member, the tip of the pin being formed on the rear side of the spindle. By being abutted against the apex of a groove-shaped recess, the arm pipe and the weight support member are respectively supported at one point so as to be swingable in all directions with respect to the support shaft. .