JPS6125205Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a concentric two-axis variable resistor, and more particularly to a concentric two-axis variable resistor with a small depth in which resistance elements are arranged concentrically on a substrate.

Variable resistors are used in radios and other electronic equipment to adjust the volume, sound quality, balance, contrast, etc. independently from the front of the panel. Various methods have already been devised in which a plurality of variable resistors are stacked in the depth direction and fixed to each other, and each variable resistor is operated independently using an outer shaft and an inner shaft arranged concentrically.

From the viewpoint of miniaturization and resource saving of recent electronic devices,
There is a strong demand to reduce not only the space in front of the installation but also the space in the depth direction. Conventionally, various ideas have been announced in which two or more resistance elements are arranged concentrically on the same board for the purpose of providing a variable resistor with a small depth. The elements are adjusted at the same time, and there are currently almost no ideas for adjusting them separately using two concentric axes. The reason for this is that a complicated mechanism is required to increase the rotation-stopping strength of the inner shaft to a level that can withstand practical use, resulting in an increase in manufacturing costs.

In view of these problems, the present invention was devised for the purpose of providing a concentric two-axis variable resistor that has a small depth, a simple structure with an inner shaft rotation prevention strength, and a strength that can withstand practical use. I will explain it together.

Figure 1 shows an example of a conventional concentric two-axis variable resistor. As shown in the figure, the outer shaft 4, which is stacked and fixed one after the other and is rotatably fitted into a bearing 3 fixed to the front stage variable resistor 1, is a slider receiver equipped with a slider 6 that slides against the resistor 5. It rotates together with the table 7, and an appropriately adjusted output is taken out from the terminal 9 via the collector 8. Both ends of the resistor 5 are connected to external terminals (not shown) by a known method. The inner shaft 10 rotatably fitted into the outer shaft 4 reaches the inside of the rear-stage variable resistor 2, and the slider 12 provided on the slider holder 11 fixed to the inner shaft 10 moves into the resistor 13. According to the rotation of the inner shaft 10, an appropriately adjusted output can be taken out from the terminal 15 via the collector 14. Both ends of the resistor 13 are connected to external terminals (not shown) by a known method. At both ends of the rotation range of the outer shaft 4 and inner shaft 10, projections 16 and 17 provided on parts of the slider pedestals 7 and 11 fixed to the respective shafts are connected to stoppers 18 provided on the case of the pre-stage resistor 1, respectively. It also comes into contact with a stopper 19 provided on the case of the rear-stage resistor 2, and has a structure that can sufficiently withstand the torque applied to the outer shaft 4 and the inner shaft 10.

It can be easily understood from the above description and drawings that in the conventional structure, two variable resistors are stacked one on top of the other, so it is difficult to make the depth L particularly small. Therefore, the present invention has been devised to solve the above-mentioned drawbacks.

2 to 15 are drawings relating to embodiments of the present invention. FIG. 2A is a front view, FIG. 2B is a side view, FIG. 3 is a side sectional view, and FIG. 4 is an exploded perspective view showing the main components. In addition, in FIG. 3, the left direction will be described as the front, and the right direction will be described as the rear.

Reference numeral 20 denotes a substrate made of an insulator, and on the front side thereof, as shown in FIG. 2 resistor 24, a second conductor 25,
From one end of the conductors 22, 25 and from both ends of the resistors 23, 24, the respective terminal portions 2 are connected as appropriate.
6 is provided with a conductive path by a known method, each terminal 28 is fixed to the terminal hole 27 bored in each terminal portion 26 by a known method, and the round hole 21 and the round hole 21 are formed on the outer periphery of the resistor board. Guide grooves 29 are provided concentrically at four locations.

Reference numeral 30 denotes a round cap-shaped metal case with four mounting legs 31 extending from the periphery of the opening as shown in FIG.
extends parallel to the axis, and in the center of the top plate 32, a bearing part 34 having an outer shaft fitting hole 33 is integrally formed outward, and a stopper claw 3 is formed near the periphery of the top plate 32.
5 protrudes inward.

As shown in FIG. 3, the board 20 has the guide groove 29 guide the mounting foot 31 of the metal case 30, and the conductors 22, 25 and the resistors 23, 2.
It is assembled in close contact with the open end 36 of the metal case 30 with the end 4 facing inward.

36 is an outer shaft formed by molding synthetic resin, and as shown in FIGS. 3 and 7, the metal case 30
A pipe shaft 37 that rotatably fits into the outer shaft fitting hole 33 of the bearing portion 34 and projects forward rotates against the inner wall of the metal case 30 within the space formed by the metal case 30 and the resistance board 20. It is integrally provided in the center of an annular pedestal 38 that freely slides on it, and an inner shaft fitting part 39 with a slightly smaller diameter is provided on the inner diameter part of the pipe shaft 37. A circular arc-shaped stop groove 40 is drilled concentrically on one front surface at a position to appropriately accommodate the stop claw 35, and on the rear surface opposite to the pedestal 38, a stepped circular first recess 41 is formed. Second recess 42
is provided in the first recess 41, and a caulking projection 4 is provided in the first recess 41.
3, an outer shaft slider 44 (FIG. 10) made of an elastic metal plate that is in sliding contact with the second resistor 24 and second conductor 25 on the substrate 20 is fixed by caulking.
By appropriately rotating the slider 6, the slider rotates and a desired resistance value is obtained from the corresponding terminal 28.

Reference numeral 45 denotes a back plate made of synthetic resin, which is located in close contact with the rear surface of the resistor board 20 as shown in FIG. , with a through hole 4 in the center.
6, a circular stopper recess 47 is formed in the rear surface, and stop protrusions 48 are provided at appropriate locations in this recess 47.

Reference numeral 49 denotes a metal mounting plate, which covers the rear surface of the back plate 45, and is bent and swaged through the mounting holes 50, which are drilled at the corresponding positions of the mounting legs 31 of the metal case 30. There is. A shaft support hole 51 is bored in the center of the back plate 45, and snap-in side plates 52 are provided on two opposing sides of the mounting plate 49 using a known method to provide reinforcement and attachment to a printed wiring board.
is provided.

Reference numeral 53 denotes a metal inner shaft, which is housed inside the pipe shaft 37 of the outer shaft 36 sequentially from the front as shown in FIGS. 3 and 13, with its front end projecting from the outer shaft 36 and its central portion The inner shaft fitting part 39
A large diameter portion 54 that rotatably fits into the main body, a medium diameter portion 55 having a non-circular cross section, and a flat portion 56 at the rear end that passes through the round hole of the substrate 20 and the through hole 46 of the back plate 45.
It consists of a small diameter portion 57 having a small diameter and a protrusion 58 having an even smaller diameter.
9, the inner shaft 53 and the outer shaft 36 are rotatably held concentrically and separately.

Reference numeral 59 denotes a slider pedestal made of synthetic resin, and as shown in FIGS.
The first conductor 2 on the substrate 20 is rotatably accommodated in the space created by the recess 42 and is mounted on the rear surface of the disc-shaped base 61.
2 and the first resistor 23, an inner shaft slider 60 (see FIG. 11) made of an elastic metal plate is fixed.
A cylindrical portion 62 rotatably accommodated within the inner diameter of the pipe shaft 37 is provided at the center of the front surface of the disc-shaped base portion 61. A medium-diameter portion 55 having a non-circular cross section of the inner shaft 53 engages with the hole 63, and a circular hole 64, which is communicated with the non-circular hole 63 and penetrates through the center of the base portion 61, is engaged with the inner shaft 53. By penetrating the small diameter portion 57, the inner shaft 53 and the slider pedestal rotate together. Therefore, when the inner shaft 53 is rotated appropriately, the inner shaft slider rotates and the desired resistance value is achieved. , corresponding terminal 2
8 can be obtained from...

Reference numeral 65 denotes a stopper plate made of a metal plate, which is rotatably accommodated in the space created by the stopper recess 47 of the back plate 45, and includes a circular plate 67 having a square hole 66 in the center.
The stopper plate 65 comes into contact with a stop protrusion 48 provided in the stopper recess 47 on a part of the periphery of the stopper plate 65.
A stopper 68 is provided protrudingly to restrict the rotation range of the inner shaft 53, and a flat portion 56 of the inner shaft 53 is provided in the square hole 66.
The inner shaft 53 is fixedly engaged with the inner shaft 53 by a known method (for example, caulking) so as to rotate together with the inner shaft 53. Therefore, the inner shaft rotates by a predetermined angle when the stopper 68 comes into contact with the stop protrusion 48 at both ends of its rotation range, and since the stopper plate is made of metal, it has the rotation-stopping strength (approximately 3 kg) that is practically required. −cm or more).

In the above embodiment, a slider holder 59 made of synthetic resin is fitted to the inner shaft 53 made of metal so as to rotate with the slider holder 59. However, as another embodiment, as shown in FIG. 69, the base portion 70, the small diameter portion 71, and the protrusion portion 72 may be constructed in the same manner as in the above embodiment by using an insulated inner shaft that is integrally molded of synthetic resin. (Assembly diagram omitted) In addition, as a desirable configuration, the configuration shown in Figures 3 and 4 is
As shown in the figure, by interposing an elastic ring 70 between the outer circumference of the pedestal 38 of the outer shaft 36 and the inner wall of the metal case 30, the rotation of the outer shaft can be made smooth, and the rotation of the inner shaft 53 can be made smoother. By interposing the spring washer 71 between the end of the small diameter portion 57 and the mounting plate 49, the rotation of the inner shaft 53 is made smooth, and the inner shaft 5
If 3 is made of metal, the grounding effect can be further ensured, and as shown in FIG.
By providing an appropriate number of smooth small protrusions 73 on the cylindrical side surface where the pedestal 38 slides against the metal case 30, the rotation feel of the outer shaft can be improved.

Since the present invention is constructed and operates as described above, it is possible to provide a concentric two-shaft variable resistor with a small depth, a small number of parts, and a sufficiently large inner shaft rotation-stopping strength. As shown in
In the case where variable resistors each having a required function are arranged and mounted in parallel on a single mounting plate, for example, two small-depth single-axis variable resistors V ₁ and V ₄ (devised by the present applicant, application 55 -33382, etc.) and a 2-axis 2-set variable resistor can be installed within the same depth as the single-axis 1-set variable resistor V ₃ .
This has great practical effects, such as making it possible to downsize the set.

[Brief explanation of the drawing]

Figure 1 shows a conventional concentric two-axis variable resistor.
Figure A is a side view, Figure B is a plan view of the board, and Figures 2 to 15 relate to embodiments of the present invention.
FIG. 2A is a front view, FIG. The figure is a partially cutaway side view of the metal case, Figure 7A is a front view of the outer shaft, Figure 8B is a side sectional view thereof, Figure 8A is a cross-sectional side view of the back plate, and Figure 8B is its plan view. , FIG. 9A is a plan view of the slider pedestal, FIG. 9B is a side sectional view thereof, FIG. 10 is a plan view of the outer shaft slider, and FIG. Figure 12 is a plan view of the stopper plate, Figure 13
The figure is a side view of the inner shaft, Fig. 14 is a side view of the inner shaft used in another embodiment, and Fig. 15 A is a front view showing an example in which the inner shaft is mounted in parallel with other variable resistors on a single mounting plate. Figures 1 and 2 are side views thereof. 20... Substrate, 22... First conductor, 23... First resistor, 24... Second resistor, 25... Second conductor, 30... Metal case, 34... Bearing section, 36
... Outer shaft, 37... Pipe shaft, 38... Pedestal, 44... Outer shaft slider, 45... Back plate, 47...
...Stopper recess, 48...Stopper projection, 49...
...Mounting plate, 53...Inner shaft, 59...Slider holder,
60... Inner shaft slider, 65... Stopper plate, 72
……protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A base plate, a back plate, and a mounting plate are stacked in order on the edge of the opening of a metal case with a bottom, and a pipe with an outer shaft made of an insulating material is connected to a bearing part provided at the bottom of the metal case. The shaft is rotatably held, and an outer shaft slider is fixed to the pedestal of the outer shaft that rotates within the metal case,
An insulating slider pedestal is provided within the concave portion of the pedestal of the outer shaft, which penetrates the pipe shaft of the outer shaft and rotatably fits therein, and rotates with the inner shaft. A shaft slider is fixed, and two sets of conductors and resistors, on which the sliders of the inner and outer shafts slide in concentric circles on the board, are appropriately connected to terminals fixed to the board, and the inner shaft is Furthermore, a stopper plate made of a metal plate extends through the substrate and the back plate, and its end part rotates in contact with a stop protrusion in a stopper recess provided on the surface of the back plate, thereby regulating the rotation angle of the inner shaft. Concentric 2-axis variable resistor with fixed. (2) The concentric twin shafts according to claim 1 of the utility model registration claim, in which a protrusion provided at the end of the inner shaft is rotatably fitted into a shaft support hole provided at a corresponding position on the mounting plate. Variable resistor. (3) The concentric two-axis variable resistor according to claim 1 of the utility model registration, in which the slider pedestal and the inner shaft are integrally molded from synthetic resin.