Push button-type switch

Claim 1

A push button-type switch comprising in combination: a rectangular casing including parallel side walls, parallel end walls, and a bottom wall, and opening at the top, said side, end and bottom walls defining a switching chamber therebetween, a key stem received within said switching chamber with a portion thereof extending upwardly through said open top of the casing for limited upward and downward movement, a return spring disposed externally of said casing about said extension of the key stem for normally urging the key stem in its uppermost position, a movable spring contact received within said switching chamber to be driven by said key stem and stationary contact means secured to said side walls to be engaged by said movable spring contact, said key stem including a bifurcated base portion with opposite legs at the lower end of the key stem disposed and received within opposite ends of said switching chamber and a cross bar extending between said legs in a spaced relationship to the underside of said base portion, and said movable spring contact comprises a substantially U-shaped leaf spring having a pair of legs connected at the upper ends and embracing said cross bar, said legs of the spring each having an outwardly warped contacting portion at the lower end adapted to engage said stationary contact means, whereby when said key stem is in its uppermost position a clearance is present between the underside of said base portion of the key stem and the top of said spring contact and when said key stem is in its lowermost position a clearance is present between the underside of said spring contact and said cross bar.