Abstract: Starting and operating circuit for gaseous discharge lamps has device for quickly re-starting extinguished lamps while still hot. 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 a lamp, and a positive temperature coefficient resistor (PTCR) connected between the alternating current source and the oscillator circuit for reducing power to the oscillator circuit when the lamp is inoperative or absent.

Abstract: Luminaire assembly with readily detachable parts. Luminaire comprises top ballast housing, intermediate ballast and slipfitter mounting plate, and lower optical assembly with associated slipfitter housing attached to ballast housing and mounting plate by readily detachable clamp band. Optical assembly, which includes dome-shaped reflector and lamp mounting assembly, is suspended with associated slipfitter housing from lug on mounting plate when clamp band is detached.

Abstract: A jacketed discharge lamp which would release ultraviolet radiation in the event of fracture of the outer envelope is provided with a disabling fuse link which oxidizes in the event of breakage. The link consists of an alkaline earth metal film, suitably a barium film which may be deposited on a ceramic substrate for connection into the circuit. The outer envelope is evacuated or may contain an inert gas.

Abstract: In a high intensity metal halide discharge lamp utilizing thorium in conjunction with a transport cycle for electrode activation, a getter, preferably cadmium or zinc is added to the lamp fill for the purpose of reducing the concentration of free iodine during operation. By so doing, deposition of thorium on the electrode tip during operation is assured and performance and maintenance are improved. The quantity of getter may include a portion supplied as a corrective measure to scavenge excess iodine released during manufacture, and another portion providing a long-term buffering capacity for capturing iodine released during the lamp's life by reaction of the dose, particularly ScI.sub.3 and ThI.sub.4, with the SiO.sub.2 of the lamp envelope.

Abstract: Luminaire provides relatively uniform illumination in substantially rectangular pattern up and down the roadway adjacent the luminaire. The luminaire reflector is formed with a multiplicity of flat facets individually oriented to direct light to particular areas along the roadway surface.

Abstract: The present invention provides a dielectric paper frame structure suitable for use in a shell-type housing for supporting a small number of discrete electronic components in spaced-apart, non-contacting and electrically insulating relation from the walls of the housing. The frame structure comprises a thin elongated unitary piece of dielectric paper having two opposing major surfaces and two edges in contact with opposing walls of the housing. Along the edges of the frame structure there are provided substantially V-shaped slots which receive non-insulated leads of the electrical components such that the electrical components are located between the edges of the frame structure. The novel paper frame structure replaces a printed circuit board.

Abstract: Apparatus for maintaining coaxial alignment of luminaire support ring on a pole as it is raised or lowered on the pole. The aligning apparatus comprises a plurality of roller members secured around the support ring and resiliently urged against the pole surface to maintain the support ring in substantially centered position relative to the pole and to avoid shock to the luminaires by impact of the support ring on the pole.

Abstract: Wall mounted luminaire of hazardous duty type has mounting arm designed to protect luminaire parts from excessive pressure of explosive gases. The mounting arm is formed with an elongated wire passage of relatively small diameter wherein the gases are cooled and reduced in pressure before entering the luminaire housing.

Abstract: A high pressure alkali metal vapor lamp envelope of alumina ceramic has an externally projecting metal tube serving as an inlead and as a reservoir for excess sodium-mercury amalgam. The ability of the lamp to withstand heavy vibration without the occurrence of voltage rise and drop-out caused by expulsion of amalgam droplets from the reservoir is enhanced by flattening the end portion of the metal tube to a least dimension adequate to increase the capillary attraction to better than twice the force of gravity.

Abstract: A high pressure alkali metal vapor lamp envelope of alumina ceramic having wire inleads sealed into opposite ends and no external amalgam reservoir, has an internal amalgam retention compartment for reducing sensitivity to shock and vibration. The compartment is formed by a metal partition substantially coextensive with the end wall and spaced from it a distance within the range of capillary attraction for the amalgam used. A preferred construction uses for the partition an apertured niobium disc fitting snugly in the alumina arc tube.

Abstract: Transverse mounting of the arc tube within the lamp jacket is effected through a mount featuring a hinged attachment of the arc tube between divergent support rods which serve also as electrical connectors to the electrodes. During manufacture the hinges permit the arc tube to be folded in line with one support rod attached at the stem leading and the other trailing for passage through the neck, and then allow the arc tube to be transversely erected in the jacket after which the other rod is attached at the stem. Erection of the arc tube simultaneously causes leaf springs to engage the sides of the bulb and centralize the arc tube in its transverse attitude.

Abstract: An electrode for a miniature high pressure metal halide lamp having a volume not exceeding 1 cc and a discharge current not exceeding 1 ampere comprises a slender tungsten shank with a few secondary turns of mandrel-less coiled-coil overwind thereon and preferably a balled distal end. The shank diameter is chosen in the range of 5 to 15 mils and above the size where melt-back starts at the intended lamp current, and the overwind is made of primary wire not exceeding 3 mils originally wound on a primary mandrel of 3 to 7 mils subsequently removed. This assures a rapid glow-to-arc transition which provides good maintenance and also reduces ballast requirements.

Abstract: The coating on the inside of a metal halide lamp for promoting the formation of a liquid condensate film consists of particles of a refractory oxide in generally block-like or spherical or fiber-like shapes. Block-like or spherical particles should be laid down as monolayers with the distances between particles being of the order of the particle dimensions. Fiber-like particles may be also laid down as a monolayer or, alternatively, in a coating several diameters thick to form "fiber piles" having a free volume for holding liquid which is much greater than the volume of the fibers.

Abstract: Static inverter comprises a transformer and transistor for intermittent asymmetric energization of the transformer. The transformer includes three feedback windings which in response to saturation of a branch of the transformer core but before full core saturation discontinue regenerative feedback and then apply degenerative feedback. A fourth feedback winding in the transformer assures commutation and re-triggering of the transistor.

Abstract: Starting and operating circuit for gaseous discharge lamps has device for quickly re-starting extinguished lamps while still hot. 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 a lamp, the oscillator circuit comprising a transistor switch and an oscillator transformer connected to the step-up transformer for producing a high voltage, high frequency sine wave for starting and re-starting the discharge lamp. The operation of the oscillator circuit is improved by a turn-off circuit comprising series-connected diode and inductor connected to the transistor and the oscillator transformer.

Abstract: Luminaire has refractor with a hinged door to provide access to the enclosed lamp for re-lamping operations. A prismatic optical device is provided on the luminaire to indicate when the door is fully closed on the refractor.

Abstract: A high intensity discharge lamp comprises a two-electrode arc tube and an external starting probe supported from a base and preferably sealed within an outer envelope to which the base is attached. The base contains an electronic pulsing circuit comprising a capacitor connected in a charging circuit across the base terminals, a pulse transformer having its primary connected in series with a voltage sensitive switch across the capacitor, and a step-up secondary connected to the probe. After starting, the voltage across the capacitor drops below the breakdown level of the switch and pulsing stops.

Abstract: A jacketed metal halide discharge lamp combining a miniature arc tube containing sodium iodide and a standby filament within an outer envelope, is provided with a glass sleeve around the arc tube. The glass sleeve is preferably connected to a point of potential which is positive relative to the arc tube, suitably the anode when the arc is operated on d.c. The glass sleeve prevents sodium loss from the arc by trapping ultraviolet light and by shielding the arc from photoelectrons. The sleeve serves also to reduce color shift when the arc tube is switched over from "high" to "low", and to protect the outer bulb in the event of arc tube rupture.