Variable capacitor for use in a keyboard

DETAILED DESCRIPTION The foregoing and other objects and advantages of the present invention are accomplished in an illustrated embodiment comprising a variable capacitor for use with a key on a keyboard or control panel.
The capacitor has a stationary capacitor plate formed of thin, conductive, sheet material on an insulative substrate such as a printed circuit board and having a substantially planar, upper capacitor face.
A movable member formed from a single piece of thin conductive sheet material includes a capacitor plate having a substantially planar and continuous or uninterrupted capacitor face in overlying, spaced apart relation with the upper face of the stationary capacitor plate.
The movable capacitor plate is struck from the body of a short length of strip of conductive sheet material and is formed with a pair of free side edges and an outer free edge transverse thereto.
A portion opposite the outer free edge projects laterally outwardly of opposite sides and is integral with a pair of supporting, spring-like deflectable legs which are disposed on opposite sides and which slope downwardly to join an integral base mounted on the insulative substrate.
The integral spring-like legs provide support for the movable plate for controlled movement toward and away from the fixed capacitor plate.
A separate washer-like element is mounted above the movable plate for resiliently biasing the movable plate toward the stationary plate.
The spring-like element is mounted on the lower end of a plunger supported for movement toward and away from the substrate and adapted to be biased toward the capacitor plate upon depression of a key or a keyboard or control panel.
The plunger is biased away from the plate to provide a minimum capacity until the key is manually depressed.