Abstract: A discrete type starter for HID lamps uses a ferrite core pulse transformer whose secondary is connected in series with the lamp across a ballast output winding. The primary is formed by mounting one or more sidacs and a resistor astride the core loop and interconnecting them by cladding on the board to make two or three turns around the core. The primary is connected across a capacitor which is connected in series with an impedance across the ballast output winding.

Abstract: A polycarbonate orientable refractor for a luminaire comprises a mounting ring which has a collar portion fitting a neck portion of the refractor with matching diameters. A diametric interference is provided between a groove in one part and a mating ridge in the other part to an extent allowing a snap fit. Shallow interfering ribs and valleys in the mating surfaces controllably lock the parts together while allowing angular indexing for orienting the light distribution pattern of the refractor.

Abstract: In a luminaire comprising an upper housing assembly for a light source and a lower plastic refractor closing the underside and having a rim adapted to mate with that of the assembly, C-shaped latches are disposed around the periphery of said refractor for clamping the rims together when pivoted into position astride both rims. Circumferentially extending bail wires attach the latches to the underside of the refractor rim and allow them to be pivoted into clamping position while preventing them from dropping off when disengaged. The bail wires pass through holes molded in the plastic of the refractor rim.

Abstract: A nonflame-propagating joint between the flared rim of a tempered glass globe and a globe support ring is effected by means of a gasket of a suitable moldable material, preferably solder, cast between the faying surfaces. The gasket may be cast in place by pouring molten solder between the globe and the preheated globe ring. Alternately a precast gasket may be assembled in placed between globe and globe ring, and recast by induction heating of the assembly.

Abstract: A tempered glass globe for a hazardous location luminaire comprises a bowl portion and a flaring rim portion with the walls substantially uniform in thickness in both portions. The rim portion makes an angle of taper with the vertical in the range of 15.degree. to 45.degree. and defines a section of a conical surface for making a nonflame-propagating joint with a mating conical surface in a globe ring. The outside of the flared rim may be ground for sealing directly to an accurately machined metal surface.

Abstract: An electrical receptacle of the twist lock type adapted to receive a photoelectric controller can be assembled into a luminaire without requiring the luminaire housing to be turned over and can be oriented in the field without use of tools. The receptacle is retained in an aperture through the housing by a snap ring having tabs on the inside edge which engage ledges in the body portion of the receptacle. The snap ring has leaf springs which hold the receptacle resiliently down against the housing. By lifting up the receptacle, keying pins and recesses in the receptacle and housing are disengaged and the receptacle may be turned to a different orientation.

Abstract: A multifunction connector block for use in a luminaire to interconnect circuit components and facilitate assembly and subsequent changeouts. A plurality of similar interconnecting strips are disposed in spaced side-by-side relationship in insulating material. The strips have terminations on one side accommodating a disconnect plug for the line supply and the lamp, and on the other side accepting individual terminal connectors from ballast components. Intermediate terminations are accessible through the top of the block to a plug-in starting aid.

Abstract: This invention relates to a circuit for shifting a control signal from governance by one variable function to governance by another. It is more particularly concerned with a phase-controlled ballast wherein such a circuit shifts the control from a function of lamp current to a function of line voltage for better overall performance and economy.

Abstract: A bifluxer type transformer for use in a static inverter utilizes an E-E or shell-type core. Such configuration is particularly suitable for ballasting hid lamps because it minimizes stray flux which causes eddy current losses in the luminaire metal enclosure. A pair of apertures are provided in the yoke area, one above and the other below the central leg, around which the main winding is wound. Control windings are looped through the apertures and provide feedback from the output to the input of a power transistor as a result of linkage by transverse flux.

Abstract: High voltages are removed from a safety socket when an HID lamp is unscrewed from it. The socket comprises an actuator which is engaged by the lamp base and operates a switch. When the lamp is unscrewed the switch opens the primary supply to a high voltage pulse generating circuit which is disabled thereby.

Abstract: Starting and operating circuit for gaseous discharge lamps having device for quickly restarting extinguished lamps while still hot includes means for reducing power supply voltage overshoot upon turn-on of the system. Circuit comprises a source of alternating current, an inductive regulator ballast having its input connected to the alternating current source, and a gaseous discharge lamp connected to the output of the ballast, a sine wave oscillator circuit having its input connected to the current supply and having its output connected to a transformer connected in series between the ballast and the lamp for stepping up and applying voltage to the lamp, a rectifier connected between the alternating current source and the oscillator circuit, the overshoot reducing means comprising a resistor connected between the rectifier and the oscillator circuit and a controlled switch for selectively connecting and disconnecting the resistor in the circuit.

Abstract: A birdshield for closing off the back end of a luminaire having a slipfitter accommodating a range of pipe sizes, is formed from a substantially flat piece of moderately stiff and resilient material cut to a pattern fitting into the rear of the luminaire. A hole through the piece accommodates the smallest size of pipe and a lune-shaped knock-out may be torn out for larger sizes. Bent-out tabs on each side engage the upturned end wall of the slipfitter yoke to hold the birdshield captive.

Abstract: A luminaire having a slipfitter mounting for adjustably clamping a pipe support. The slipfitter comprises a yoke member which engages the underside of the pipe, and a transverse pivot rib forming part of the upper housing which engages the topside of the pipe. The yoke is pressed against the pipe by two pairs of bolts, one to the front and the other to the rear of the pivot rib, and these bolts are adjusted for leveling and clamping. Bosses with cored holes are cast in the housing to accommodate the bolts which are of thread-forming type.

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: A trunnion degree marker and reset stop for a luminaire indicating the angle of aim and providing a positive stop to facilitate resetting after service. It comprises a flat plate having a trunnion bolt hole, an arcuate slot around it with angle markings, and a screw extending therethrough for locking the plate to the trunnion bracket independently of the trunnion bolt. The plate has a foot protruding at an angle and turned toward the housing for engaging a shoulder stop cast as an integral part of the housing.

Abstract: A vitreous arc tube is provided with constricted cylindrical neck portions intermediate the bulb portion proper and the pinched seals. The constricted necks may be formed as an incident in the blowing of the bulb out of quartz tubing. When the seal portions are pressed by the pinching jaws about the foliated inleads, the necks are maintained in substantially their original configuration and merely shrunk slightly about the inleads extending through them. An internal configuration is achieved which is substantially a surface of revolution and fin-effect is avoided.

Abstract: A retaining means for a lamp within a luminaire provides structural support and positive positioning. It comprises a resilient wire formed to a four-sided parallelogram shape with four outboard reverting projections between segments. One pair of diametrically opposed projections encircle bolts which hold the retainer transversely to the lamp axis at the rim of the socket compartment. Another pair of projections are unrestrained and provide extra flexibility in accommodating to variations in lamp diameters.

Abstract: A high pressure metal (sodium) vapor lamp comprises an outer vitreous envelope and an inner ceramic arc tube supported within it. The arc tube contains vaporizable metal in excess of the quantity vaporized in operation and the heat balance determines a cold spot whereat excess metal collects. The temperature of the cold spot determines the metal vapor pressure and the voltage drop across the lamp which must lie between specified limits. A thermal link is provided to a metal member such as the exhaust tube the heat loss from which influences significantly the temperature of the cold spot. In completed lamps measuring too low in voltage, such thermal link may be partly severed without breaking open the outer envelope in order to raise the voltage. One convenient way utilizes an auxiliary wire which is cut by aiming a laser beam at it.

Abstract: Composite coating on aluminum article comprising base layer formed from alkali metal silicate compound and outer layer formed of a dispersion of colloidal silica and a silicone resin is tightly adherent to the aluminum surface, provides protection from corrosion and is abrasion resistant. Improved aluminum reflectors are made by suitably brightening the surface to provide a highly specular reflective surface, applying a base coating of a silicate solution on the thus treated surface, heating the thus applied base coating to remove the chemically bound water therefrom, rinsing the base coating to remove alkali metal ions therefrom, applying an outer coating of the colloidal-silica-silicone resin composition, and drying the latter coating.

Abstract: A heavy-duty luminaire comprises a housing assembly of plastics having good resistance to weathering or corrosion but capable of withstanding only low structural stress. The heavy electrical components are supported with a ballast compartment on a removable ballast tray which is attached to a main bracket. The main bracket receives its support directly from metal mounting means independently of the housing. The structural load on the plastic housing is limited substantially to its own weight plus that of a lightweight reflector assembly.