Abstract: A rubber spring is disposed on a base on which are mounted fixed electrodes. The rubber spring includes first and second cup sections. The first cup section is in the form of an inverted cup, whose top portion is smaller in diameter than the bottom portion thereof, and is adapted to be bent by a force applied thereto from above and to produce a resilient restoring force corresponding to the size of such deflection. The second cup section, which is located inside the first cup section, has a U-shaped longitudinal section and is adapted to be bent by a force applied thereto from above and to produce a resilient restoring force corresponding to such deflection. Thin-walled portions are formed at the bent portions of the first and second cup sections. A center projection protrudes upward from the center of the second cup section. The top face of the center projection is situated below the upper surface of the support seat.

Abstract: A keyboard switch is provided with an insulating substrate, a first electrode laid on the insulating substrate, a second electrode formed of a conical coil spring and facing the first electrode, a dielectric disposed on the first electrode, a button positioned on the top portion of the second electrode, and a rubber cap disposed between the button and second electrode, for giving snap feeling to an operator when the button is depressed and the capacitance of the switch exceeds a given value. The capacitance varies with the change in the facing area which changes substantially in proportion to the depth of depression of the button. The switch is capacitive-coupled for a switching operation and the snap feeling is given to the operator when the capacitance exceeds the given value.