JPS6146884B2 - - Google Patents

Description

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

A tone arm in a record player is electrically and mechanically integrated with a rotating mechanism such as a tone arm rotating shaft and a bearing that receives the rotating shaft. Therefore, replacing the cartridge is done by removing the plug-in head shell, cursor, etc. from the tone arm, but in such a structure, the part that connects to the tone arm is not strong, so harmful parts may be removed. It has the disadvantage of causing resonance. In addition, since the tone arm rotates horizontally and vertically, the lead wires installed in the tone arm and rotation shaft must be as thin and flexible as possible to reduce the mechanical resistance caused by the lead wires. be. However, if the lead wire is thin and soft, the electrical resistance will increase.
In particular, when using a cartridge with low internal impedance, it not only causes a negative effect on the output voltage, S/N, sound quality, etc., but also reduces the mechanical strength of the lead wire, causing accidents such as wire breakage. .

Furthermore, with integrated pickups in which the tone arm body and cartridge are integrated, the entire tone arm must be replaced when replacing the cartridge, but since the tone arm cannot be separated from the rotation mounting mechanism, it is difficult to replace the tone arm. has drawbacks that make it difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tone arm assembly which eliminates the above-mentioned drawbacks, allows for extremely easy replacement of the tone arm, and reduces mechanical resistance by increasing the degree of freedom of the lead wire when rotating the arm.

The present invention will be explained below using the drawings.

FIG. 1 shows an embodiment of the tone arm main body of the present invention, and is a side view including a partially cut section. In the figure, a cartridge 4 is attached to a fixing screw 18 at the tip of the arm 1, and the pickup output of the cartridge 4 is led out by a lead wire 8, passes through the inside of the arm 1, and is guided to the vicinity of the rotation center of the arm. A contact 7 serving as a connector is provided near the center of rotation and is connected to a lead wire 8 . An arm attachment screw 5 is provided at the center of rotation and is inserted through the arm so as to be slidable up and down. A stopper 6 is provided to prevent the screw 5 from coming off the arm 1. Reference numeral 3 denotes a weight, and by sliding it on a sliding groove 2 provided in the arm 1, the stylus pressure of the cartridge can be adjusted.

FIG. 2 is a diagram showing an embodiment of the tone arm mounting mechanism according to the present invention, in which a is a plan view and b is a side view. In the figure, a rotation shaft 14, which is the center of rotation of the tone arm in the horizontal direction, is rotatably attached to an arm stand 13 and fixed to a cabinet or the like via this stand 13. An outer holder 12 attached to the rotation shaft is provided above the rotation shaft, and this holder 12 is provided with a horizontal shaft 11 perpendicular to the rotation shaft 14 . Arm mounting base 9
is rotatably supported in a vertical direction about a shaft 11, and the tone arm is mounted on a plane substantially perpendicular to the rotation shaft 14. In order to fix the tone arm to the mounting base 9, an opening 17 is provided at the location where the mounting base 9 intersects the center line of the rotating shaft 14 to serve as a screw hole, and an electrical connector is provided on the mounting surface. A terminal 10 for physical connection is provided. The other end 15 of the terminal 10 is connected to a lead wire 16 wired inside the rotating shaft 14 .

FIG. 3 shows a partially cross-sectional side view of the tone arm 1 shown in FIG. 1 when it is attached to the attachment mechanism shown in FIG. 2. In FIG. 3, the same parts as those in FIGS. 1 and 2 are given the same reference numerals, and the arm stand 13 is omitted for simplicity. As shown in the figure, the mounting screw 5 of the arm 1 is inserted and fitted into the screw hole 17 of the arm mounting base 9, so that the arm 1 is fixed. At this time,
The contact 7 of the arm 1 is the connection terminal 1 on the mounting base 9
0, which electrically connects the lead wire 8 of the tone arm 1 and the lead wire 16 inside the rotating shaft 14 of the mounting mechanism, and these contacts 7 and the connection terminal 10 This means that they form a connector. As shown in FIG. 3, the arm mounting base 9 and the outer holder 12, which constitutes a part of the rotational bearing section, are respectively provided with recesses 9a and 12a facing each other, and the lead wire 16 in the rotational shaft 14 is is the mounting base 9 via the recesses 12a and 9a.
It is connected to the terminal 10 on the top.

With such a configuration, the tone arm 1 is connected to the rotation axis 1.
Since the arm mounting base 9 is rotatable around the horizontal axis 11, the tone arm 1 can be rotated in the vertical direction around the horizontal axis. Further, as described above, since the recesses 9a and 12a are provided in the mounting base 9 and the outer holder 12 so as to face each other, and the lead wires 16 are positioned in the recesses, the lead wires 16 can be easily moved when the tone arm 1 is rotated. The degree of freedom increases.

In order to determine the mounting direction and mounting position of the tone arm 1 on the mounting base 9, the structure of the mounting base 9 is shown in a plan view in FIG. 4a and in a side view in FIG. 4b, for example. That is, sloped portions 19 directed outward are formed on two sides of the mounting base 9 parallel to the axial direction of the arm 1. As shown in the schematic cross-sectional view in FIG. The mounting direction and mounting position of the screw 5 and the screw hole 17 are determined regardless of the mounting error. Therefore, the inclined portion 19 of the mounting base 9
serves as a guide when attaching the arm.

As described above, according to the present invention, the tone arm main body can be attached to and detached from the arm mounting mechanism using only the mounting screws, and can be electrically separated and connected using the connectors 10 and 7, so that the arm main body can be replaced. This is very easy, and since the lead wire 8 can be a thick wire, the electrical resistance of the lead wire can be reduced. Further, by providing recesses facing each other in the arm mounting base and the rotating shaft bearing, and positioning the lead wire 16 in the recesses, the degree of freedom of the lead wire 16 when rotating the tone arm is increased, and therefore The mechanical resistance of the wire 16 can be reduced and problems such as wire breakage do not occur. Furthermore, the cartridge can be replaced while the arm body is separated from the attachment mechanism. Further, since the cartridge, tone arm, and weight are replaced as one unit, it is possible to always select tone arms and weights for various cartridges according to the characteristics such as mass and compliance of the cartridge. Furthermore, since the bearing portion can be shared by any tone arm, if the bearing portion is manufactured with high precision, a highly sensitive tone arm assembly can always be provided.

[Brief explanation of the drawing]

FIG. 1 is a side view including a partial cross section of the tone arm according to the present invention, FIG. 2 is a diagram showing the arm mounting mechanism section according to the present invention, a is a plan view, b is a side view, and FIG. FIG. 4 is a side view including a partial cross section of an embodiment of the invention, and FIG. 4 is a diagram showing an example of an arm mounting base, in which a is a plan view, b is a side view, and FIG. 5 is a diagram showing the relationship between the arm mounting base and the arm. It is a schematic front sectional view shown. Explanation of symbols of main parts, 1...Tone arm,
4... Cartridge, 5... Mounting screw, 7... Contact, 8, 16... Lead wire, 9... Arm mounting base, 10... Connection terminal, 11... Horizontal axis, 14
... Rotating shaft, 17 ... Screw hole, 19 ... Inclined part.

Claims (1)

[Claims] 1. A tone arm having a weight at its rear end, capable of supporting a cartridge at its distal end, and having a mounting section at an intermediate section; An arm mounting base that is coupled to determine the mounting direction and position of the arm portion, a rotation bearing that supports the arm mounting base so as to be rotatable in horizontal and vertical directions, and fixed to the mounting portion and the arm mounting base. What is claimed is: 1. A tone arm assembly comprising a fixing means for fixing the tone arm assembly, wherein the arm mounting base and the rotary bearing section are provided with mutually opposing recesses, and a lead wire is positioned in the recess.