(under subclass 650) Subject matter wherein controlling or detecting means comprises means that react to the proximity of something that is capable of being sensed.
SEE OR SEARCH CLASS
200, Electricity: Circuit Makers and Breakers,
61.42+, for movable object controlled switches.
250, Radiant Energy,
221+, for optical or prephotocell systems controlled by article, person, or animal.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems,
509+, for proximity responsive external effects. 406, Conveyors: Fluid Current,
4+, 19+, and 31 for apparatus having an oscillator or other electron tube relay control means.
