JPS647588Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a grounding structure between an operating knob and a switch that is operated by pressing the operating knob, and particularly relates to a grounding structure between an operating knob of a cassette deck and a tact key switch. Regarding the optimal grounding structure between the two.

(Prior Art) Conventionally, the method of grounding the operation knob of the cassette deck and the tact key switch was as shown in FIG. In the figure, 11 is a printed wiring board, 12 is a tact key switch attached to the printed wiring board, and 13 is an operation knob, which is usually plated with metal.
In order to prevent conduction between the operating surface 14 and the tact key switch 12, the operating shaft portion 15 is masked before plating to form a non-conductive portion. However, conventional masking processing methods have the drawback of increasing costs.

(Purpose of the invention) The purpose of the invention is to eliminate the drawbacks of the conventional means described above, and to provide a grounding structure for an operating knob that has a simple structure, can be grounded accurately, and can reduce costs. .

(Structure of the invention) The grounding structure of the operating knob of the invention includes a grounding pin that protrudes from the printed wiring board to the rear side of the operating knob and is arranged so that the rear end is electrically connected to the grounding pattern, and the grounding pin is used as a guide. It is characterized by a conductive coil spring inserted between the printed wiring board and the back side of the operating knob, so that even if the operating knob is plated, it can always be accessed from the back side. It is designed to properly ground to the ground pattern of the printed wiring board via the coil spring and the ground pin.

As a result, there is no need to perform masking processing on the operation knob, the structure is simple, and the cost can be significantly reduced compared to conventional means that perform masking processing.

(Embodiment) An embodiment of the present invention will be described based on FIG. 2. In the figure, 1 is a printed wiring board, 2 is a tact key switch attached to the printed wiring board,
Reference numeral 3 designates an operation knob of the cassette deck, which causes the operation shaft 5 to press the tact key switch 2 by pressing the operation surface 4.
Reference numeral 6 denotes a ground pin protruding from the printed wiring board 1 toward the rear side of the operating knob 3;
The rear end 6a is electrically connected to the ground pattern 7 of the printed wiring board 1. Reference numeral 8 denotes a conductive coil spring inserted between the printed wiring board 1 and the back side 3a of the operation knob 3 using the ground pin 6 as a guide. In the embodiment, a wrapping pin is used as the ground pin 6, and the ground pin 6 projects at four locations around the tactile key switch 2, and a coil spring 8 is disposed at each of the four locations. coil spring 8
is made of phosphor bronze, and in the set state, the spring constant is 15 to 20 g with a deflection of 1 mm, and it is pressed against the back side of the knob.

With the above configuration, the operating knob 3 is grounded to the ground pattern 7 on the back side of the printed wiring board 1 via the coil spring 8 in contact with the back side 3a and the ground pin 6 in contact with the coil spring 8. Therefore, even if the entire surface of the operating knob 3 is plated, it is properly grounded, so there is no need to mask the operating shaft portion 5 of the operating knob 3.

By configuring as in the above-described embodiment, the cost was approximately 30% that of the conventional masking method, resulting in a significant cost reduction.

(Effect of the invention) According to the grounding structure of the operating knob of the present invention, the grounding pin protrudes from the printed wiring board to the back side of the operating knob and is arranged so that the rear end side is electrically connected to the grounding pattern, and the grounding pin is connected to the grounding pin. It is equipped with a conductive coil spring inserted between the printed wiring board and the back side of the operating knob as a guide, and the coil spring gives the operating knob an appropriate elastic force and the operating knob is It will always be grounded to the ground pattern of the printed wiring board via the coil spring and ground pin, and there is no problem even if the operating knob is plated all over.
Therefore, there is no need to mask part of the operating knob as in the conventional case, and costs can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a grounding means for an operating knob and a tactile switch in a conventional cassette deck, and FIG. 2 is a cross-sectional view showing an embodiment of the grounding structure for the operating knob according to the present invention. 1: Printed wiring board, 2: Tact key switch, 3: Operation knob, 4: Operation surface, 5: Operation shaft, 6: Earth pin, 6a: Rear end side, 7: Earth pattern, 8: Coil spring.

Claims (1)

[Scope of Claim for Utility Model Registration] A grounding structure between an operating knob of a cassette deck or the like and a switch operated by pressing the operating knob, which protrudes from the printed wiring board toward the rear of the operating knob and It is characterized by comprising an earth pin arranged so that its end side is electrically connected to the earth pattern, and a conductive coil spring inserted between the printed wiring board and the back side of the operation knob using the earth pin as a guide. Grounding structure of the operation knob.