Key switch unit for computer keyboards

摘要

A key switch unit including a key holder frame having a plurality of key holders respectively mounted on the rubber cones of a conductive rubber pad above a membrane circuit, one L-shaped key switch and a plurality of elongated key switches and a plurality of square key switches respectively mounted on the key holders and depressed to trigger the membrane circuit to produce a respective electric signal, wherein each key holder has an inside annular flange, a plurality of symmetrical longitudinal grooves on the inside, and a female guide means on the outside; each key switch has a stepped plunger inserted into one key holder, the stepped plunger having longitudinal ribs slidably inserted into the longitudinal grooves of the respective key holder, at least one bottom hook hooked on the inside annular flange of the respective key holder at the bottom, and a step around the periphery, the step being stopped against the inside annular flange of the respective key holder to limit the down stroke of the respective key switch, the L-shaped key switches and the elongated key switches each having at least one one male guide means guided by the female guide means upon down stroke of the respective key switch.