| 摘要 |
<p>PUSHBUTTON SWITCH ASSEMBLY A pushbutton switch assembly, for a keyboard, comprises a plurality of switch units each having at least a pair of superposed switch contacts, one of which is movable by an actuator to make or break contact. Each actuator is a hingedly mounted cantilever having a pushbutton at its free end. When the pushbutton is depressed an intermediate part of the cantilever actuates the movable switch contact. The cantilever is dimensioned so that the operating force needed at the pushbutton is only a fraction of that required to operate the switch contact directly. Also the pushbutton travel is correspondingly longer. Accordingly the assembly may use a relatively stiff, small travel type of switch unit, for example a snap-action spring plate or flexible membrane, yet provide at the pushbutton the "soft" action and long travel preferred by so many users. In order that this can be achieved without sacrificing the compactness desirable in a keyboard array, the distal end of one cantilever actuator is arranged to extend across the hinge axis of the next adjacent actuator.</p> |
