Keyboard switch assembly with multiple isolated electrical engagement regions

A switch assembly comprising:

• a substrate having a conductive circuit pattern on a surface thereof, the circuit pattern defining switch contacts at switch contact regions of the substrate;
• a generally planar, non-conductive spacer disposed adjacent the surface of the substrate in fixed, nonmoving relationship thereto, the spacer having apertures therethrough at locations opposite the switch contact regions of the substrate to provide communication through the spacer to the switch contacts;
• a generally planar layer of resilient, multiple conductive contact material having a resiliency in the plane thereof providing all of the return bias force tending to maintain the contacts at each switch region in an open condition and disposed adjacent the spacer on a side thereof opposite the substrate, the planar layer of multiple conductive contact material electrically engaging each of the switch contacts of each contact region at a large number of separate and isolated electrical engagement regions when forced through an aperture of the separator into engagement with the switch contacts of a switch contact region, the resiliency of the multiple conductive contact material providing an only source of positional bias tending to oppose engagement of the multiple conductive contact material with the switch contacts of a switch contact region;
• a protective layer of flexible material disposed adjacent the multiple conductive contact material on a side thereof opposite the spacer, the protective layer having a conductive surface adjacent the multiple contact conductive material to provide bridging contact between the conductors thereof when the conductors are forced into engagement with the switch contacts of a switch contact region;
• and
• an actuator disposed in opposed relationship to each spacer aperture to force the multiple conductive contact material through an aperture of the spacer and being adapted for operation in conjunction with the multiple conductive contact material to close the switch contacts of a switch contact region in response to operator actuation.

A switch assembly comprising:

• a substrate having a conductive circuit pattern on a surface thereof, the circuit pattern defining switch contacts at switch contact regions of the subtrate;
• a generally planar, non-conductive spacer disposed adjacent the surface of the substrate in fixed, nonmoving relationship thereto, the spacer having apertures therethrough at locations opposite the switch contact regions of the substrate to provide communication through the spacer to the switch contacts;
• a generally planar layer of resilient, multiple conductive contact material having a resiliency in the plane thereof providing all of the return bias force tending to maintain the contacts at each switch region in an open condition and disposed adjacent the spacer on a side thereof opposite the substrate, the planar layer of multiple conductive contact material electrically engaging each of the switch contacts of each switch contact region at a large number of separate and isolated electrical engagement regions when forced through an aperture of the separator into engagement with the switch contacts of a switch contact region, the resiliency of the multiple conductive contact material providing an only source of positional bias tending to oppose engagement of the multiple conductive contact material with the switch contacts of a switch contact region;
• a protective layer of flexible material disposed adjacent the multiple conductive contact material on a side thereof opposite the spacer, the protective layer having a plurality of deformable protrusions extending away from the spacer, each protrusion being disposed opposite a different aperture of the spacer and having a force distance hysteresis effect when forced into engagement with the multiple conductive contact material, each protrusion having an electrically conductive surface on a side thereof adjacent the multiple conductive contact material to provide switch closure bridging contact between switch contacts at a region through the multiple conductive contact material when forced into engagement therewith;
• and
• an actuator disposed in opposed relationship to each spacer aperture to force the multiple conductive contact material through an aperture of the spacer and being adapted for operation in conjunction with the multiple conductive contact material to close the switch contacts of a switch contact region in response to operator actuation.

A switch assembly comprising:

• a planar substrate having a conductive circuit pattern printed on a surface thereof, the circuit pattern defining a plurality of switch contacts for a plurality of switches;
• a dielectric spacer disposed adjacent the surface and having an aperture therethrough opposite each contact defined by the circuit pattern;
• a planar layer of uniaxially conducting material disposed to extend parallel to the surface and adjacent to each switch contact and compressing a resilient dielectric material and a plurality of parallel spaced conductors extending through the dielectric material perpendicular to the surface;
• means defining a conductive surface opposite each plurality of switch contacts for each switch defined by the circuit pattern, each conductive surface providing a switch closure when forced toward the substrate surface to squeeze the planar layer of uniaxially conducting material between the conductive surface and a switch contact defined by the circuit pattern in opposed relationship thereto to provide switch closure circuit conduction between the plurality of switch contacts for a switch and the conductive surface.