Pushbutton mounted in facia chassis element - has central stem with end piece surrounded by coil spring, and seal between chassis and stem

摘要

The basic pushbutton consists of a finger contact element (1) which has a suitable finger contact surface attached to a central column, which projects through a lower chassis element (2) and terminates in an end piece (7, 10). The two elements are spring loaded (3) and a seal (4) is mounted at the lower end of the spring (11, 12). A different concave shaped upper element (13) can be provided suitable for pushing by a pencil or pen. Several slightly different shapes are described for the upper and lower element, and a simple form using a buffer (18) element rather than a spring may be used.