Abstract: A hollow plunger is slidable vertically in a housing that has an open upper end, but its upward travel is limited to a predetermined elevated position, in which the lower end of the plunger body is spaced above the housing's bottom wall that holds a pair of opposed spring contact strips that extend below it to form terminals and that also converge upwardly inside the plunger and have upper ends urged toward engagement with each other. Loosely disposed inside the plunger is a shuttle provided with a cross member extending between the contact strips. The inside of the plunger is formed for supporting the shuttle while the plunger is held in its elevated position by a coil spring encircling the contact strips with the shuttle cross member spreading the upper ends of the contacts apart. After the plunger has been depressed a predetermined distance, it starts to move the shuttle downwardly with it.

Abstract: A keyswitch includes a tubular plunger with a body slidable vertically in an open-top housing that has a bottom wall supporting the lower end of a coil spring extending up around a pair of opposed upright spring contact strips, the lower ends of which extend through the bottom wall. The inside of the plunger is provided with a cross member that normally separates the upper ends of the contact strips, but permits them to engage each other when the plunger is pushed down. The contact strips are substantially identical. Each has at least two parallel slits extending downwardly from its upper end to form a plurality of narrow contact fingers beside a wider contact finger that is wide enough to be engaged by the narrow contact fingers of the opposing contact strip.