Abstract: In a lighting system in which each of a multiplicity of lighting fixtures has a receptable containing a multiplicity of electrical contacts, a switching cable assembly is provided. A pass-through power plug of the assembly has a housing, a stem connector projecting from the housing with a multiplicity of electrical contacts adapted to mate with complementary contacts in the fixture receptacle, a power-in receptacle mounted in the power plug housing and a power-out receptacle mounted in the housing, and electrical conductors electrically connected, mediately or immediately, to and between contacts of the power-in receptacle, contacts of the power-out receptacle and contacts of the stem connector, the stem connector and its complementary fixture receptacle constituting the means for mounting the plug on the system.

Abstract: In a lighting fixture louver assembly in which a plurality of louvers with side walls joined at their lower edges by a closed bottom, generally V-shaped in end elevation, are connected to side or end rails, an extension is provided of the lower portion of the louvers, projecting beyond a contiguous upper portion of the ends of the side walls, and cut wings are formed in the extension. The rails have a slot in a side wall extending upwardly from immediately adjacent the bottom edge of the wall and of a size to receive the extension. The extension projects through the slot, and the wings are bent outwardly laterally along a line substantially parallel to the long axis of the louver, a cut surface of each of the wings engaging the back surface of the side wall, whereby the closed bottom of the louver projects uninterruptedly through the side wall of the rail.

Abstract: In a recessed lighting fixture intended to be laid onto horizontal flanges of inverted T-shaped rails of a grid-type ceiling, the rails having a stem with a bulb defining shoulders below the upper edge of the stem, the fixture having a housing with metal end plates, a hook is formed integrally with one of the end plates. The hook extends across and embraces the bulb. The hook is either formed with a nose projecting in a direction toward the end plate and beneath a shoulder defined by the bulb, or a tab, integral with the end plate, is provided that has a free upper edge projecting from the end plate toward and beneath a shoulder facing the end plate.

Abstract: A lighting system is provided having a unique main runner structural configuration that enhances the adaptability of the system to a number of uses, including one-way, corridor and grid ceiling patterns. The main runner has an inverted U-shape design in cross section, the legs of the U-shape defining an open mouth channel. The legs also have a lip associated with them. The lower leg and lip portions or formation of the inverted shape hides the division line between various color combinations used in conjunction with the main runner from observers of the ceiling system, and also creates a recess for holding and supporting a number of accessories associated with the ceiling system. The lip of the main runner provides support for any associated ceiling panels. One embodiment of a lighting fixture compatible with the lighting system disclosed hereinafter has offset end pieces which permit continuous linear luminaire pattern installation.