JPH0451390Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a push button switch used in electronic equipment such as consumer electrical equipment, information equipment, OA equipment, and industrial equipment.

[Prior Art] As shown in FIGS. 4 and 5, a conventional push-button switch has an inverted cup-shaped contact rubber made of silicone rubber or the like whose upper part is convex to form a head 14. A surface key 15 made of non-compressible hollow resin is fitted into the head 14. A contact point 12 exists at the center of the inner surface of the elastic contact rubber 11.

[Problems to be solved by the invention] Since the surface key 15 is non-compressible, when it is fitted to the elastic contact rubber head 14, the contact rubber head 1
4 is compressed, a margin is required as an escape for this compressed portion.

However, if this clearance is too large, the fit between the surface key 15 and the contact rubber head will be too loose, and conversely, if the clearance is too small, the fit will be too tight. requires precision and is difficult to manufacture.

[Means for solving the problem] Therefore, the present invention is designed to ensure that the surface key and the contact rubber head can be reliably fitted even if the dimensional tolerance of the clearance of the fitting member is increased. For this purpose, the contact between the fitting parts of the two was changed from the entire surface contact to a line contact using ribs, etc., and vertical ribs were installed on either the inner surface of the hollow surface key or the outer surface of the contact rubber head. A plurality of these were provided at appropriate intervals.

By doing this, a space is formed between the vertical ribs, so that the compressed portion of the elastic contact rubber head when mating can escape into the space, and the presence of the vertical ribs also ensures that both Mating is achieved.

[Embodiment] The upper surface of the elastic contact rubber 1 made of inverted cup-shaped silicone rubber is convex and constitutes a head 4, and the side surface 4a of the head 4 has a vertical rib-shaped protrusion 3.
are provided at appropriate intervals. A hollow cap-shaped surface key 5 made of resin is fitted into the head 4.

A contact 2 is fixed to the center of the inner surface of the contact rubber 1 and faces the electrode of the printed circuit board below.

A second alternative embodiment is shown in FIG.

In this case, the structure is similar to that of the first embodiment shown in FIGS. 1 and 2, but the vertical rib-like structure provided on the side surface of the contact rubber head 4 in the first embodiment is In this second embodiment, a rib-shaped projection 7 is formed vertically on the inner wall 6a of the front key 6. As shown in FIG. 8 is the head of the contact rubber.

[Effects of the invention] Since the present invention is configured as described above,
When the surface keys 5, 6 are fitted to the heads 4, 8 of the contact rubber, the rib-shaped protrusions 3, 7 are compressed between them, but spaces A, B are formed between each rib. As a result, the compressed portion expands laterally and escapes into the spaces A and B, which serve as gaps, so that fitting is performed smoothly and without strain. The elasticity of the contact rubber head and the protrusion allow the two to fit together more reliably than in the prior art, making it difficult for them to come apart.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of the first embodiment of the present invention. FIG. 3 is a cross-sectional view of a second embodiment of the present invention. Fourth
The figure is a vertical cross-sectional view of a conventional model. FIG. 5 is a cross-sectional view of a conventional one. 1... Contact rubber, 2... Contact, 3, 7... Projection, 4, 8... Head, 5, 6... Surface key.

Claims (1)

[Scope of utility model registration request] In a push button switch in which a hollow surface key is fitted to the head of an inverted cup-shaped silicone elastic contact rubber, at least one contact surface of the head side surface 4a of the contact rubber and the inner wall surface 6a of the surface key that are in contact with each other. A push button switch characterized in that a plurality of vertical ribs 3 and 7 are formed on the top.