Snap-in modular keypad apparatus

Claim 1

A keypad apparatus comprising: a planar frame member having a front surface and a back surface, and including a plurality of button accommodating apertures located on said planar member extending from the front surface to the back surface, and a plurality of mounting post members extending outwardly from said back surface thereof; a button assembly including a planar elastomeric member having a front surface and a back surface, and a plurality of elastomeric buttons dimensioned to be received by said button accommodating apertures and formed integrally with said elastomeric member extending outwardly from said front surface, said elastomeric member having a plurality of first apertures extending from the front surface to the back surface and being positioned thereon to receive said mounting post members such that each of said buttons extends through an associated button accommodating aperture of said frame, said button assembly being mounted to said frame such that said buttons are depressable, each button having a conductive bottom member located on the bottom thereof; a switch assembly including a thin planar member fabricated from Mylar having a front surface and a back surface, and a plurality of contact areas located on the front surface of the thin planar member, one contact area corresponding to each button, said contact area having an outer partial circular contact disrupted by an opening and electrically connected to at least four equally-spaced, inwardly disposed triangular sections, and an inner T-shaped contact surrounded by said outer contact, said T-shaped contact having an upper branch and a lower branch, said upper branch being positioned between said triangular sections and said lower branch extending through said opening, said inner T-shaped contact being electrically insulated from said outer partial circular contact, said thin planar member having a plurality of second apertures extending from the front surface to the back surface and being positioned to receive said mounting post members such that said contact areas oppose said corresponding buttons, said switch assembly being mounted on said button assembly such that said corresponding conductive bottom member electrically connects said outer contact to said T-shaped inner contact upon depression of an associated button; and a planar back plate member having a front surface and a back surface and including a plurality of third apertures positioned to receive said mounting post members, the front surface of said back plate being mounted on top of said switch assembly with said mounting post members extending through said third apertures, said mounting post members having their respective ends deformed to form a fixed, secured sandwich-like assembly, said back plate serving as a stop to enable an operator of a button to tactically feel said button operation.