Abstract: A vibration mount having a body for coupling to an object to be supported by the vibration mount, a flexible member forming a foot on the body and together with the body, forming a chamber therein, a center member within the chamber and coupled to move in unison with the body, a valve having a first valve member coupled to move in unison with the central member and a second valve member coupled to move in unison with the flexible member, a connection for coupling air under pressure to the chamber through the valve member, and a vent for venting the chamber though the valve.

Abstract: Shakers and methods of testing suitable for various applications, including those presenting adverse test environments. The shakers have a permanent magnet assembly mounted in a sealed housing for vibration along a shaker axis. The permanent magnet assembly is double ended, and includes at least one shorting ring to hold down the inductance of the driving coils at higher frequencies. Fluid cooling (or heating) of both the shaker housing and the permanent magnet assembly allows placement of the shakers inside a temperature test chamber. The shakers may be coupled directly to the article to be tested, or coupled singularly or in a plurality to a test table to which an article to be tested is coupled. Various embodiments and methods of testing are disclosed.

Abstract: An optical switch for use as a modular keyboard switch designed to provide tactile and audible feedback to the keyboard operator. The switch includes an opaque housing in which a light emitting device and a light activated detector are mounted. A "U" shaped spring shutter rests within the housing between the emitter and detector and has an aperture through which light from the emitter may illuminate the detector. A spring loaded key stem moves longitudinally within the housing and is designed to penetrate the open end of the shutter. The key stem and shutter are shaped such that as the key stem is depressed the upwardly extending arms of the shutter are at first forced outward by projecting shoulders on the key stem and then snap back along upwardly sloping surfaces of the shoulder, thereby causing the shutter to spring upwards and block the optical path between the emitter and detector. The snap action of the shutter causes an audible "click" and also provides tactile feedback to the operator.