Shin-etsu Polymer Co., Ltd.

Kenichi Miyajima

Masayuki Ito

Kazunobu Yokoyama

Satoru Kitazawa

Tadashi Hayashi

Hirohide Sato

A pushbutton switch member has a dome-shaped movable contact and an operation key facing and separated from a movable contact. Pushing the operation key toward the movable contact causes the movable contact to electrically connect at least two contacts on a substrate. The operation key is provided with: a key; a dome connected with an outer periphery of the key, and deformable by pushing of the key toward the substrate; and a foot connected with an outer periphery of the dome, and fixed on the substrate. The movable contact is provided with: an upper contact spaced apart from a site directly below the key, and which makes contact with a contact when the key is pushed in; and an outer fixing part disposed at the upper contact, or further outside thereof in the radial direction, and fixed outside of the key in the radial direction.

Pushbutton switch member

A pushbutton switch includes: a dome-shaped movable contact; and an operation key on a side of the movable contact. Pushing the operation key causes the movable contact to electrically connect at least two contacts. The operation key includes: a key body; a dome connected with an exterior of the key body and deformable by pushing the key body; a foot connected with an exterior of the dome; and a protrusion on top of the key body, protruding from the top, and deformable by compression. The movable contact includes: an upper contact in contact with a site below the key body and contacting the at least two contacts when the key body is pushed; and an outer fixing part at the upper contact in a radial direction and fixed outside of the key body of the operation key in the radial direction.

The push button switch covering assembly of the invention comprises a push button switch covering member made from a transparent rubbery material and a clicking member with a clicking diaphragm below the covering member which imparts the operator's finger tip with a sharp feeling of clicking when the key top of the covering member is depressed. Different from a conventional push button switch covering assembly of this type, in which the pushing load on the key top is transmitted to the top of the clicking diaphragm through a downward protrusion on the lower surface of the key top, the pushing load on the key top in this invention is transmitted to the clicking diaphragm by means of an upwardly raised part formed on the top of the upper surface of the upwardly convex clicking diaphragm so that the flat lower surface of the key top is fully available for forming a layer of indicia to indicate the particular function of the push button switch through the transparent key top without the disadvantage of wearing of the indicia as in the case where the indicia layer is formed on the upper surface of the key top.

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Shiojiri, Japan

Kenichi Miyajima