Abstract: An electric luminaire is provided having an interior comprised of weather and corrosion resistant housing of non-metallic material, such as plastic. The housing defines an internal cavity, in which the electrical components of the luminaire reside, entirely sealed against intrusion of corrosive elements present in the atmosphere of the external environment. A rigid unitary metallic support structure, carried by a mounting hub adapted to be attached to an external support, extends from the mounting hub through the cavity and to the optical components at the lower end of the luminaire. The rigid support structure provides both primary and supplemental, or back-up, support for the electrical and optical components of the luminaire.

Abstract: Thread joints in explosion-proof electrical fixtures for hazardous areas must relieve the momentary pressure from an internal explosion without flame propagation to the exterior. Ordinary paint on the threads cannot be used due to variations in thickness which alter the flow characteristics and the cooling effects. The invention provides a dense, pinhole-free paint layer uniform in thickness within .+-.15% which can be achieved by electrodeposition. Such a coating facilitates assembly and inhibits deterioration of the clearance path through corrosion but has only a minor effect on the venting relief.

Abstract: Luminaire with high intensity gaseous discharge lamp for illuminating a work area such as an automobile assembly line. The lamp is arranged between a concave main reflector and an auxiliary reflector facing the central portion of the main reflector. The arrangement is such that it provides adequate light control to efficiently illuminate the work area while shielding the lamp from direct view of the worker and reducing shadows on the work area due to the worker being positioned between the work and the luminaire.

Abstract: Device for readily removable attachment of globe and protective guard to lighting fixture. Threaded collar of fixture support has elongated spring member with central mounting loop and opposite ends formed with yieldable detent portions for separately engaging and removably holding luminaire globe and protective guard mounted in the threaded support collar.

Abstract: Electrical socket device includes a threaded shell having inwardly projecting protuberances in the shell for cleaning the threaded base of the lamp when screwed into the socket. A resiliently mounted center contact arranged at the bottom of the socket has a central depression with a slot formed therein for cleaning the bottom contact of the lamp base.

Abstract: Dome-shaped reflector in indoor luminaire having a high intensity lamp and mounted at relatively low height has the lower portion of its reflecting surface formed to reflect light downwardly at an angle of not more than about 50% of the cut-off angle formed by the rim of the reflector relative to the lamp, so as to provide low glare at viewing angles of about 65.degree.-85.degree. from nadir. The cut-off angle is not more than 65.degree..