Matrix push-button switch

Claim 1

A switch comprising an insulating substrate, a plurality of conductors on said substrate defining conductor pairs, means for making external connection with each of said conductors, an insulating body disposed above said substrate and forming the surface of said switch, said body having a plurality of recessed resilient depressible areas each of which is aligned with a different set of said conductor pairs, a plurality of individual conducting contact pieces each of which is mounted on the underside of a different one of said areas with the lower surface thereof spaced from said conductor pairs associated therewith when said area is in the nondepressed condition, a plurality of relatively rigid isolation means on said body integral with, disposed between and protruding above said depressible areas and separating same for isolating downward motions of each of said areas from the remaining areas, said means extending down towards said substrate beyond said lower surfaces of said contact pieces, whereby upon depressing any one of said depressible areas only the respective contact piece engages only the conductive pair associated therewith, thereby completing a circuit through said respective external connection means.