Plunger-actuated, lost motion switch with tactile feedback

Claim 1

An electrical switch of the class suitable for use in keyboards or the like comprising: a dielectric switch housing defined by a hollow integral body having first and second pairs of opposed interior walls formed therein and further having an external aperture in communication with the hollow portion of said integral body; a dielectric base surface supporting said switch housing; a dielectric plunger defined by a shaft disposed for reciprocal motion within said external aperture and an actuator arm formed integrally with one end of said shaft and disposed within the hollow portion to have its opposed ends adjacent said first pair of opposed interior walls; terminal means disposed on each of said second pair of opposed interior walls proximate said base surface; biasing means for urging said plunger toward a rest position distal from said base surface; electrically conductive annular means, dimensioned and disposed to freely encircle the ends of said actuator arm and to frictionally bear against said second pair of opposed interior walls, for defining a conductive path between said terminal means, whereby the conductive path is effected when said actuator arm is caused to travel against said biasing means from its rest position to a lowermost position proximate said terminal means and the conductive path continues effected until said actuator arm has traversed an initial distance from its lowermost position toward its rest position through a lost motion relation between said plunger and said annular means; and threshold means disposed on each of said second pair of opposed interior walls for interferring with the travel of said annular means to provide a force threshold for the passage of said actuator arm between its rest position and its lowermost position.