Control keyboard with extended key stroke and exchangeable key top - has spring or bellows between key-top and hinged actuator to damp excess key pressure

摘要

The keyboard consists of conducting elements which are deformed under touch pressure and make a connection between two conductors on the surface of a substrate. The key pressure is transmitted to the deformable conductor via an actuator connected by a flexible hinge to the key switch shell. A spring (54) is inserted between the operators pushbutton (50) and the actuator (30) which compresses the deforming conductor (10). The pushbutton, spring and actuator may be a one piece moulding or three separate pieces. The keyswitch shell (32) has slides which correspond to complementary shapes in the button and are perpendicular to the plane of the substrate. The shell and button also have corresponding stops (37,55) which limit the key stroke. Different coloured key tops can be easily used on the same keyboard and the spring element allows extended key travel and damps the risk ofdamagedue to accidental over pressure. The spring may be replaced by an elastic bellows.