Computer keyboard with adjustable force keystroke feature using air pressure

摘要

A computer keyboard 10 having a plurality of keys 18 at desired locations being supported above a support plate 20 having a plurality of apertures 22 at the desired locations. A membrane keyswitch assembly 24 is mounted on the support plate 20 having keyswitches at each desired location. The keys have key plungers 28 that move up and down in the support plate apertures 22. An elastomeric dome sheet 46 is mounted over the membrane keyswitch assembly 24 with individual elastomeric dome return springs for biasing the keys 18 to their up position. An air chamber 52 is formed beneath the support plate 20 extending between the desired key locations. An air-impervious elastomeric membrane 60 is sandwiched between the air chamber 52 and the support plate 20 forming a flexible upper wall that receives and engages the key plungers 28. The membrane 60 has individual pedestal portions at the key locations for engaging the plungers 28. A manually adjustable air supply is connected to the air chamber 52 to adjust the air pressure and thereby adjust the force required to actuate a key.