Magnetic key touch control

Abstract

The "touch" or "feel" of a key in a keyboard is controlled by a system of permanent magnets. A first magnet is attached to one end of a key lever and the key lever is pivoted intermediate its ends. A bias spring is provided to normally bias the key lever against a stop. A second magnet is disposed adjacent the path of movement of the first magnet whereby the force required to depress the key lever is dependent upon the spring constant and the interaction of the fields of the magnets. The magnets are positioned such that, as the lever is depressed there is a repelling force between the magnets. Thus, the force required to depress the key is the sum of the spring bias force and the repelling force between the magnets as the first magnet is moved from the home position to a position opposite the second magnet, but is the difference between the spring bias force and the repelling force between the magnets as the key is further depressed.

Dependencies are inferred from the claim text.