Abstract: An optical coupler or photo adapter unit has an input port located on a first surface of a housing for receiving a parallel beam of light as may be derived from a microscope or beam splitter. The input port is associated with a first lens for converging the parallel beam. A first output port is located on a surface of the housing transverse to said first surface; and a second output, relatively coaxial with said first port, is located on a surface relatively parallel to the first surface. A second lens is located adjacent the second output port and is operative to diverge the light as transmitted through the second output port as received from said first port and lens.

Abstract: There is disclosed a rotary switch assembly comprising a lamp plate adapted to accommodate a plurality of switchable lamps. A power contact plate is positioned above said lamp plate and contains spring loaded contacts which coact with terminals associated with said lamp plate to enable energization of any selected one of said plurality of lamps.The two plates are positioned and held in alignment by means of a clamping ring into which both plates are located. The clamping ring assures proper detenting of the rotatable lamp accommodating plate to ascertain reliable switching and further assure that any bulb selected will have its optical axis properly aligned.

Abstract: There is disclosed a light assembly or similar apparatus which is adjustable by means of a ball and socket assembly incorporating an elastomeric "O" ring which abuts against the periphery of the ball when a ball accommodating sectionalized socket assembly is clamped together.