KEYTOP FOR PUSH-BUTTON SWITCHES, AND METHOD OF MANUFACTURING SAME
Inventors: Jiro Inagaki, Tokyo; Atsushi Hari,
Kanagawa; Nobuyuki Yagi, Tokyo;
Yasutoshi Kaku, Kanagawa; Takasbi
Shinoki, Tokyo, all of Japan
Assignee: Teikoku Tsushin Kogyo Co., Ltd.,
Kanagawa, Japan
Appl. No.: 138,260
Filed: Oct 20,1993
Int. Cl.« H01H 3/12
U.S. CI 200/341; 200/517;
200/520; 200/302.2; 200/345; 200/5 A;
200/308; 264/257
Field of Search 200/341-345,
200/520, 517, 302.2, 5 A, 308; 264/257, 274;
425/127
References Cited
U.S. PATENT DOCUMENTS
3,594,262 7/1971 Magidson 264/257 X
4,059,737 11/1977 Gergaur 200/302.2 X
4,201,612 5/1980 Figge et al 264/257 X
4,216,184 8/1980 Thomas 264/257 X
4,237,351 12/1980 Boulanger et al 200/5 A
4,500,218 2/1985 Nishikawa 200/308 X
4,595,551 6/1986 Maurer 264/257 X
4,814,561 3/1989 Kawasaki 200/517
4,839,474 6/1989 Hayes-Pankhurst et al 200/5 A
4,925,615 5/1990 Willis et al 264/257
4,980,522 12/1990 Murakami et al 200/302.2 X
5,011,728 4/1991 Imae et al 200/302.2 X
5,057,059 12/1991 Green , 264/257 X
5,185,118 2/1993 Siano 264/257
5,340,956 8/1994 Chen 200/341
FOREIGN PATENT DOCUMENTS
483898 5/1992 European Pat. Off. .
Primary Examiner—Ernest G. Cusick
Attorney, Agent, or Firm—Wenderoth, Lind & Ponack
[57] ABSTRACT
A push-button switch keytop includes a flexible resin film deformed in such a manner that the resin film bulges upwardly to form a curved portion that is filled with a molding resin while the resin film is being deformed. The molding resin is allowed to harden to form a keytop body, whereby the top side of the keytop body consisting of the molding resin is integrated with the resin film in a state in which the top side of the keytop body is covered by the resin film. The keytop is manufactured by clamping a resin film between upper and lower molds, charging a molten resin from a pin gate provided on the lower mold into a cavity provided in the lower mold, thereby deforming and urging the resin film upward by pressure and heat produced by the molten resin and causing the resin film to adhere to the inner surface of the upper mold, filling the cavities of the upper and lower molds with the molten resin and separating the upper and lower molds after the resin hardens. An adhesive layer may be provided directly or indirectly via another printed layer on the underside of the resin film on that portion thereof where the keytop is located.
6 Claims, S Drawing Sheets
