Abstract: A switch assembly has an actuator assembly which is operable to actuate switches between first and second conditions. A pushbutton is movable from an initial position through an intermediate position to a fully actuated position to affect operation of the actuator assembly to actuate the switches from the first condition to the second condition. As the pushbutton moves to the fully actuated position, a holding coil is energized to hold the actuator assembly in the actuated condition to maintain the switches in the second condition upon a releasing of the pushbutton. A control circuit is activated by optical sensors to prevent energization of the holding coil until the pushbutton has been moved from the initial position to the fully actuated position. The control circuit maintains the holding coil energized until the pushbutton has been released for movement back to its initial position and then operated for a second time to its fully actuated position.

Abstract: An electronic light valve is disposed over a color fill lens formed in an opaque indicia plate and an infrared filter to be energized to a transmissive condition simultaneously with a low intensity light source to illuminate the legend either by ambient light reflecting from the lens or by the light source emitting prescribed energy wavelengths through the lens, whichever thereof having the greater intensity relative to the other. In a deenergized condition of the light source and light valve, the latter blocks ambient light from the legend to prevent viewing thereof.