Electric typewriter keyboard construction - has leaf springs distorted by keys into concave state to close contacts

摘要

The keyboard is for electric typewriters and similar machines, each key having a contact spring. The spring (7) is of the leaf type, with a central opening concentric to the key tappet (5), and convex-curved in the direction of the latter. Pressure on the key (6) distorts it into the concave state, in which its ends (7a) bear against the underside (4a) of the keyboard cover plate (4), closing the contact. There can be supporting beads (9) for the spring underneath it, and against which it bears in either the convex or concave states.