JPH048717Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a moving coil type pick-up cartridge.

According to Utility Model Publication No. 53-172, a moving coil type pick-up cartridge that allows needle exchange is disclosed. That is, in this cartridge, a pair of front and rear magnets are arranged in the needle exchange block so that their different polarity faces face each other to form a magnetic gap, and an armature supported through a damper is placed in the magnetic gap. At the same time, the cantilever, which is integrally connected to the armature, is made to protrude from a through hole formed in the front magnet. According to this, it is possible to change the needle as easily as with a moving magnet type, but in that case,
As is clear from the above structure, the magnet itself has to be replaced, and the replacement needle ends up being expensive. Also, because a pair of magnets are installed in the narrow space of the needle exchange block,
The structure becomes complicated and it is not preferable in terms of assembly workability.

Therefore, the purpose of this invention is to create a moving coil type pick-up in which a magnetic gear is directly constructed using a magnet without intervening a magnetic core such as a yoke on the cartridge body side, and a needle assembly including an armature can be attached to and detached from the gear. Our goal is to provide cartridges.

Hereinafter, embodiments of this invention will be described with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, this moving coil type pick-up cartridge 1 includes, for example, a plate-shaped permanent magnet 2 curved in the shape of a quarter arc.
and a plate-shaped induction magnetic body 3 which is arranged in parallel with the permanent magnet 2 at a predetermined interval and is also curved in the shape of a quarter arc. The permanent magnet 2 is magnetized in the longitudinal direction of the cartridge, so that a uniform magnetic gap 4 is formed between the permanent magnet 2 and the induction magnetic body 3. In this invention, the permanent magnet 2 and the induction magnetic body 3 are fixed to the main body A side of the cartridge 1, as will be described later. Moreover, both the permanent magnet 2 and the induction magnetic body 3 are made of a flat plate shape. On the other hand, a cantilever 6 having a needle tip 5 at its tip has its base end fixed to a support 7 made of synthetic resin or the like.
Attached are two coil armatures 8, 8 oriented in the 45-45 direction, for example, so as to correspond to the two sound groove modulating walls of the record. In this embodiment, the coil armature 8 consists of a coil wound around a magnetic rod embedded in the support 7 in a V-shape. Furthermore, a suspension wire 9 extends from the center of the back surface of the support body 7, and a mounting rod 1 is attached to the rear end of the suspension wire 9.
0 are integrally connected. This mounting rod 10 is inserted into a through hole 12 formed in the knob 11 and fixed with a needle fixing screw 13. In this case, a damper 14 is provided between the knob 11 and the support body 7. is arranged, and the suspension wire 9 passes through the hole 15 in the axial direction of the damper 14. The damper 14 and the suspension wire 9 work together to support the entire vibration system including the cantilever 6 and give it a damping effect, so that the vibrations picked up by the needle tip 5 are , are transmitted to the coil armatures 8, 8 via the support 7. Needle assembly B consisting of these configurations includes cartridge main body A.
When the coil armature 8, 8 is attached to the cartridge main body A, the coil armature 8, 8 is properly placed in the magnetic gap 4 formed by the permanent magnet 2 and the induced magnetic material 3. It is becoming more and more common. In addition, in the figure, 16 is a coil lead wire.

FIG. 3 shows a more specific structure of this cartridge 1. That is, the cartridge main body A has a casing 17 whose lower surface is open, and a permanent magnet 2 and an inductive magnetic body 3 are fixed to the front lower surface of the casing 17 so as to face each other in the front and rear with their curved concave portions facing downward. has been done. Further, a socket 18 for receiving the needle assembly B is formed on the rear lower surface of the casing 17. Furthermore, in connection with this, four L-shaped terminal pins 19 and 20 (only two are shown for convenience in FIG. 3) are buried.
One end 19a, 2 of these terminal pins
0a protrudes from the rear wall of the casing 17 by a predetermined length, and the other end portions 19b, 20b
protrudes from the lower surface side of the casing 17 by a predetermined length. On the other hand, referring also to FIG. 4, the knob 11 of the needle assembly B has a pair of left and right side walls 2 formed to sandwich both sides of the casing 17.
1, 21, a raised portion 22 formed longitudinally in the central portion, and a socket 18 of the casing 17.
It is provided with a columnar projection 23 formed upward from the raised portion 22 so as to fit into the bottom lid 24. The through hole 12 into which the above-mentioned mounting rod 10 is inserted is formed within the raised portion 22.
Further, on both sides of the raised portion 22 of the knob 11, four terminal chips 25 are provided that fit with the ends 19b and 20b of the terminal pins described above, and the coil lead wire 16 is attached to the lower end of these terminal chips. It is connected.

In the configuration described above, the needle assembly B includes four
The ends 19b and 20b of the terminal pin are fitted into the two terminal chips 25, and the columnar protrusion 2
3 into the socket 18, and by sandwiching both sides of the casing 17 with the side walls 21, it can be detachably attached to the cartridge body A. Along with this, the two coil armatures 8, 8 oriented in the 45-45 direction are connected to the permanent magnet 2.
and is inserted into the center of a magnetic gap 4 formed by an inductive magnetic material 3. In this state, the mechanical vibrations picked up from the sound groove of the record by the stylus tip 5 are transmitted to the coil armatures 8, 8 via the support 7, as described above, and an induced voltage is generated. This induced voltage is transmitted to the coil lead wire 16 and terminal pins 19 and 20.

As is clear from the description of the embodiments described above, according to this invention, by arranging the magnet and the induction magnetic material facing each other on the side of the cartridge body, there is no intervening magnetic core such as a yoke between them. An extremely high-density magnetic gap with low magnetic flux leakage is formed in the coil armature, which further increases the power generation efficiency of the coil armature.
Since a magnetic core such as a yoke is not required as in the conventional case, the cartridge can be made smaller and lighter, and the structure can be simplified. In this case, since each coil armature is placed in the same magnetic gap, the mechanical vibrations from the left and right sound groove modulation walls engraved on the record are enhanced in a well-balanced manner and without distortion in each channel. can be reproduced faithfully. Further, in this invention, since the coil armature can be inserted into the magnetic gap from below, the needle assembly, that is, the replacement needle and the magnet can be configured separately. Therefore, replacement needles for moving coil type cartridges can be provided at low cost. Furthermore, since both the permanent magnet and the induced magnetic material are made of flat plate members curved with a predetermined curvature, the thickness of the entire cartridge in the height direction can be made even thinner. can be realized.

[Brief explanation of the drawing]

Fig. 1 is a perspective view schematically showing the main parts of the cartridge according to this invention, Fig. 2 is a longitudinal sectional view thereof, Fig. 3 is a longitudinal sectional view showing the attachment/detachment structure between the cartridge body and the needle assembly, and Fig. 4. 3 is a sectional view taken along the - line in FIG. 3. FIG. In the figure, 1 is a cartridge, 2 is a permanent magnet, 3 is an inductive magnetic material, 4 is a magnetic gap, 5 is a needle tip, 6 is a cantilever, 7 is a support body, 8 is a coil armature, 11 is a knob, and 14 is a Damper, 16 is a coil lead wire, 17 is a casing, 18 is a socket, 19, 20 are terminal pins, 19a, 20
a is one end of the terminal pin, 19b, 20
b is the other end of the terminal pin, 21 is the side wall,
22 is a raised portion, 23 is a columnar projection, 25 is a terminal tip, A is a cartridge body, and B is a needle assembly.

Claims (1)

[Claims for Utility Model Registration] Comprising a cartridge body and a needle assembly replaceably attached to the cartridge body, the needle assembly has V-shaped grooves corresponding to the two sound groove modulation walls of the record. In a moving coil type pick-up cartridge, in which a pair of coil armatures formed by winding coils around oriented magnetic rods are supported so that they can vibrate together with a cantilever via a damper, both of the cartridge bodies have a predetermined shape. One magnetic gap is provided, which has a flat plate shape with a curvature, and is made of a permanent magnet and an induced magnetic material, the end surfaces of which are arranged facing each other with a predetermined interval in the axial direction of the cantilever. . A moving coil type pick-up cartridge, wherein each of the coil armatures is inserted into the same magnetic gap from below when the needle assembly is attached to the cartridge main body.