JPS582012Y2 - small variable resistor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a small variable resistor, and in particular, an object of the present invention is to provide a dust-proof variable resistor that is easy to assemble and has a simple structure.

In conventional small variable resistors of this type, the electrode patterns on the insulating substrate and the terminals were connected by soldering or tightening, which resulted in very poor assembly workability.

In particular, in the case of a small variable resistor with a case diameter of about 1Q mm, each component is minute, so the above-mentioned work is complicated and requires skill.

The present invention has been developed in view of the above points, and the details of the present invention will be explained below with reference to an embodiment shown in FIGS. 1 to 8.

In the figure, 1 is an approximately cylindrical case with a bottom made of insulating synthetic resin, 2 and 2 are grooves on the circumferential surface of the case 1, 4 is an annular pedestal provided on the bottom surface 3 of the case, and 5 is a bottomed cylindrical case. The bottomed concave portion 6 formed by the pedestal 4 is a protrusion extending from the inner wall of the circumferential surface of the case 1 toward the pedestal 4, and has a first function as a stopper for the rotating body 15 and a positioning function for the cover 25, which will be described later. It has a protrusion 6a and a second protrusion 6b that connects the first protrusion 6a and the pedestal 4 and positions the terminal 7 and the insulating substrate 10, which will be described later.

7.7 is a terminal made of a highly conductive metal plate, each having a connecting portion 7a and a terminal portion 7b hanging down from the connecting portion 7a (see FIG. 2).

The terminal 7 has its connecting portion 7a connected to the bottom surface 3 of the case 1.
The terminal portion 7b is led out from the through hole 8 (see FIG. 3) of the bottom surface portion 3.

In order to position the terminal part 7b, a recess 9 having the same shape and thickness as the connecting part 7a is formed in the bottom part 3 (see FIG. 3), and the connecting part 7a is formed in the recess 9. In the state stored in the case 1, the upper surface of the connecting part 7a is located on the same plane as the bottom part 3 of the case 1, and the end surface of the connecting part 7a is located between the inner wall of the circumferential surface of the case 1 and the second The protrusions 6b are respectively placed in contact with the protrusions 6b at the desired positions so as not to be rotatable.

Reference numeral 10 denotes a substantially disk-shaped insulating substrate, on the negative side (front side) of which an arc-shaped resistor 11 and electrode patterns 12 and 12 connected to both ends of the resistor 11 are formed, respectively. The electrode patterns 12 and 12 on the front side are respectively connected to the insulating substrate 10.
It is formed continuously through the end surface of the substrate 10 to the other surface side (back side) (see FIGS. 1 and 4).

Reference numeral 13 denotes a center hole of the insulating substrate 10, which is connected to the pedestal 4 of the case 1.
A notch 1 that is equal to the outer diameter of the
The width of the insulating substrate 10 is made equal to the width of the second protrusion 6b of the case 1, and the center hole 13 and the notch 14 are aligned with the base 4 and the second protrusion 6b, respectively. When placed on the bottom surface 3 of the case 1, the insulating substrate 10 is positioned unrotatably, and the electrode pattern 12° 12 on the back surface of the insulating substrate 10 and the connecting portion 7a of the terminals 7, 7,
7a are brought into contact with each other and are electrically connected.

Reference numeral 15 denotes a rotary body made of insulating synthetic resin, and a slider 17 is integrally embedded in a disc portion 16 of the rotating body.

Reference numerals 18 and 19 indicate stepped portions formed on the upper and lower sides of the disc portion 16, 20 indicates an operating shaft portion formed on the upper stepped portion 18, and 21
is a shaft formed on the lower step (see Figures 1 and 5).

The shaft portion 21 is inserted into the recess 5 formed by the pedestal 4 of the case 1 to position the rotating body 15, and the stepped portions 18 and 19 are connected to the insulating substrate 10, which will be described later. The rotating body 15 is positioned such that it cannot move up and down by abutting against the cover 25, respectively.

Numerals 23 and 24 are protrusions for a stopper that protrude from the disk portion 16 of the rotary body 15, and the elastic contact of the slider 7 is provided at a cutout portion of the disk portion 16 between the two business types 23 and 24. The arms 17a and 17b are vertically separated and protrude so that the contact portions of their tips are separated from each other.

The slider 17 has a substantially annular base (not shown) embedded in the disc part 16 and both types of business 23 and 24, and is made of a single sheet of highly conductive metal thin plate, which facilitates insert molding. In addition to this, it also serves as reinforcement for the two business types 23 and 24, which abut against the first protrusion 6a of the case 1 and function as a stopper.

(The buried structure of this slider is detailed in U.S. Pat. No. 53-109799, which was previously filed by the applicant of the present application, so please refer to this if necessary.

) 25 is a cover made of a highly conductive metal plate, which is attached to the case 1 so as to cover the open surface of the case 1 with the terminal 7, the insulating substrate 10, and the rotating body 15 placed thereon.

26 is the center hole of the disc part 27 of the cover 1, 28 is the disc part 2
Notch 7, 29.29 is an intermediate terminal hanging from the disc part 27, 29a is a retaining part provided on the intermediate terminal 29 with the bottom surface of the case 1, and 29b is the bending elasticity of the tip of the intermediate terminal 29. Department.

Then, the cover 25 has the case 1 in the notch 28.
The first protruding part 6a of the case 1 is engaged with the operating shaft part 20 of the rotating body 15 in its center hole 26, and the rain intermediate terminals 29 and 29 are respectively engaged and positioned in the grooves 2, 2 of the case 1. By engaging the elastic engaging portion 29a of the intermediate terminal 29 with the bottom surface of the case 1 in a so-called snap-in fitting, the case 1 and the cover 25 can be reliably integrated with a simple operation. It is in full swing.

In the assembled state, the operating shaft 20 of the rotating body 15 protrudes a predetermined amount from the center hole 26 of the cover 1, and can be operated by hand or with a jig.

As is clear from the above description, during assembly, the case 1 includes the terminals 7, 7, the insulating substrate 10. By sequentially inserting and placing the rotating body 15 in the predetermined position and then attaching the cover 25 to the case 1 by snap-fitting, assembly is simple and does not require any means such as soldering, tightening, or welding. Furthermore, the contact between the terminal 7 and the electrode pattern 12 on the back surface of the insulating substrate 10 is also prevented by the cover 25 at the bottom surface 3. of the case 1. Due to the rotating body 15 being pushed to the side, both 7 and 12
is designed to ensure a reliable electrical connection.

□ Then, when the operation shaft section 20 is rotated, the slider 17 is rotated while being in elastic contact with the resistor 11 and the disk section 27.25 of the cover which also serves as a current collector, and the desired resistance value is obtained. In addition, rotation of the rotating body 15 beyond a predetermined amount is regulated by engagement between the protrusion 23 or 24 of the rotating body 15 and the first protrusion 6a of the case 1. There is.

For reference, the variable resistor of this embodiment is extremely small, with the case 1 having a diameter of 8 mm and the height of the case 1 being 2 mm.

As described above, according to the present invention, since the terminal 7 and the electrode pattern 12 on the back side of the insulating substrate 10 are pressed and brought into contact by the rotating body 15 held between the cover 25 and the case 1, Soldering the connection with the electrode pattern 12,
The assembly workability is extremely good since no means such as locking is required, and there is no need for means such as tightening or welding for fixing the terminal 7 to the case 1, so the workability is good in this respect as well.

Further, since the cover 25 also serves as a current collector, and the intermediate terminal 29 integrated with the cover 25 also serves as a piece for attachment to the case 1, the number of parts can be reduced.

In addition, by simply attaching the cover 25 to the case 1 with a snap-in fit, each component can be assembled without the need for means such as soldering, tightening, or welding. The assembly workability has been significantly improved, and the variable resistor can be easily and reliably assembled without requiring any skill as in the past. This has a remarkable practical effect in that it can provide a resistor.

[Brief explanation of drawings]

The drawings all relate to one embodiment of the present invention; Fig. 1 is an exploded perspective view of the whole, Fig. 2 is a perspective view of the terminal, Fig. 3 is a plan view of the case, and Fig. 4 is a back view of the insulating substrate. , Fig. 5 is a front view of the rotating body, Fig. 6 is a plan view of the case with terminals and an insulating board placed on it, Fig. 7 is a front view showing the assembled state, and Fig. 8 is the main part of the assembled state. FIG. 1...Case, 3...Bottom part, 7...
...Terminal, 7a...Connection part, 7b...
...Terminal section, 10...Insulating substrate, 11.Bend/resistor, 12...Electrode pattern, 15...
・Rotating body, 17...Slider, 25...
Cover, 29...Intermediate terminal, 29a...
・Engagement part.

Claims (1)

[Scope of utility model registration request] A case made of insulating synthetic resin, a metal terminal having a contact portion placed on the bottom surface of the case and having a terminal portion extending outside through the bottom surface portion, and a metal terminal on the contact portion of the terminal. an insulating substrate placed on the insulating substrate, an arc-shaped resistor formed on the front side of the insulating substrate, and an electrode pattern electrically connected to the end of the resistor and continuously formed to the back side of the insulating substrate. a metal cover covering the open surface of the case; a rotating body made of insulating synthetic resin rotatably held between the bottom of the case and the cover; and a resistor attached to the rotating body. a slider having a contact portion that makes elastic contact with the case and the cover, an intermediate terminal integrated with the cover, and a locking portion with the cover provided on the intermediate terminal, and a position regulating member between the case and the cover. A small variable resistor, characterized in that the electrode pattern on the back surface of the insulating substrate and the contact portion of the terminal are pressed and brought into contact by a rotating body.