Patent ID: 6133539
Filing Date: 2000-10-17
Classification: H01H

Abstract:
A key switch comprising:a key cap having a plunger extending downwardly from a center thereof and at least two hooks extending downwardly therefrom about the plunger;a support device including at least two protrusions outwardly extending from edges of a bottom surface thereof, and at least two depressions formed on outer sides thereof for slidably receiving the at least two hooks of the key cap on outer sides of the support device;a support board having at least two positioning portions for engaging the at least two protrusions of the support device;a membrane circuit having an electrical contact;a rubber board positioned between the support board and the membrane circuit, the rubber board having a rubber spring for receiving the plunger of the key cap and for contacting the electrical contact of the membrane circuit in response to a downward movement of the key cap; anda base supporting the membrane circuit, the rubber board and the support board;the at least two protrusions of the support device being downwardly slidable in the at least two positioning portions of the support board when an external force is exerted on the key cap, and the support device being upwardly displaceable to engage the at least two protrusions with the at least two positioning portions when the force is released.