Abstract: A high-pressure sodium arc discharge lamp having a novel arc tube support member which provides a secure mechanical and electrical connection and does not require welding between the support member and the arc tube lead wire or feedthrough. The support member may be adapted for mounting a single arc tube or two arc tubes within the outer envelope. The feedthrough of each arc tube is inserted into an aperture in the support member such that a secure interference fit is achieved. The interference fit is similar to the fastening of a threadless nut. In a preferred embodiment, the support member has a first planar surface having one or more apertures therein and two second planar surfaces substantially perpendicular to the first planar surface; each second planar surface has a protruding leg by which the support member may be mounted on the internal lamp frame.

Abstract: An electric lamp assembly includes a sealed lamp envelope, a lamp capsule located within the lamp envelope, a cylindrical, light-transmissive shroud surrounding the lamp capsule, and a mounting arrangement for supporting the lamp capsule and the shroud within the lamp envelope. The mounting arrangement includes one or two supports rods parallel to the axis of the shroud and first and second clips for retaining the shroud and the lamp capsule. The clips prevent both axial and lateral movement of the shroud. The clips are attached to the support rods, typically by welding. In a preferred embodiment, a single clip at each end of the shroud retains both the shroud and the lamp capsule, and requires only a single weld to the support rod.

Abstract: A metal halide arc lamp assembly has a configuration which provides improved containment performance in the event that the arc tube bursts. The lamp assembly includes a metal halide arc tube, a cylindrical quartz shroud surrounding the arc tube and a sealed outer envelope enclosing the shroud and the arc tube. The arc tube has press seals with a generally I-shaped cross section. The maximum dimension of the press seals perependicular to the arc tube axis is not substantially greater than the maximum dimension of the bulb portion of the arc tube. The spacing between the outside surface of the bulb portion and the inside surface of the shroud is not greater than about three millimeters.

Abstract: A lamp assembly includes a lamp capsule, a reflector, an electrical connector and a lens. The lamp capsule includes a lamp envelope having a base portion, and the reflector includes an opening for receiving the base portion of the lamp envelope. The reflector is fabricated of a resilient material such as a high temperature thermoplastic or thermosetting plastic. The base portion of the lamp capsule and the reflector include lamp interlocking elements which mechanically lock the lamp capsule in the reflector. The lamp interlocking elements preferably position the center of light output of the lamp capsule at the focal point of the reflector. The connector and a neck portion of the reflector include connector interlocking elements which mechanically lock the connector to the reflector. The lens and the outer rim of the reflector include integral lens interconnecting elements which mechanically lock and position the lens on the reflector.

Abstract: A commercially feasible triple-enveloped metal-halide arc-discharge lamp having a hermetically sealed light-transmissive enclosure surrounding the arc tube and a hermetically sealed light-transmissive outer envelope. There is a vacuum within the enclosure and outside the arc tube. There is a gaseous fill within the outer envelope and outside the enclosure. Preferably, metal frame parts within the outer envelope are electrically isolated from the electrical circuit of the lamp in order to minimize sodium loss from the arc tube and providing superior luminous maintenance. The vacuum enclosure about the arc tube eliminates convective heat loss and redistributes reflected heat back to the arc tube such that arc tube operation is hotter and more nearly isothermal. As a result, lamp performance characteristics are comparable or improved with respect to double-enveloped prior art counterparts. Color temperature is substantially reduced.

Abstract: By controlling the temperature of a glass reservoir tube attached to a closed vapor cell, the vapor pressure inside the cell can be accurately controlled. The apparatus for controlling the reservoir temperature includes an electric heater, a temperature sensor, heat straps to distribute and remove heat from the reservoir, and a clamp to hold the apparatus in close thermal contact with the exterior of the reservoir. An external control circuit energizes the reservoir heater as required. In the preferred embodiment the vapor cell functions as an optical filter when filled with a heated metallic vapor such as cesium. The reservoir tube functions as the cold spot of the cell and contains a small pool of the metal in liquid form.This invention was made with Government support under N66001-86-R-0050 awarded by the Department of the Navy. The Government has certain rights in this invention.

Abstract: A metal halide arc discharge lamp includes an arc tube and a light-transmissive shroud mounted within a lamp envelope. The arc tube and the shroud are mechanically supported within the lamp envelope by resilient spring members. Since the support structure for the arc tube and the shroud is mechanically and electrically isolated from the lamp stem, leakage current between the support structure and the electrical inleads is eliminated, thereby reducing sodium loss from the arc tube and extending the operating life of the lamp. The spring-mounted construction enables the lamp to withstand mechanical shock and vibration.

Abstract: A metal halide arc discharge lamp includes an arc tube and a light-transmissive shroud mounted within a lamp envelope. The arc tube and the shroud are mechanically attached to a frame. The frame is mechanically supported within the lamp envelope by resilient spring members. Since the frame is mechanically and electrically isolated from the lamp stem, leakage current between the frame and the electrical inleads is eliminated, thereby reducing sodium loss from the arc tube and extending the operating life of the lamp. The spring-mounted construction enables the lamp to withstand mechanical shock and vibration.

Abstract: An electric lamp assembly includes a sealed outer envelope, an arc discharge tube mounted within the outer envelope, a safety filament connected in series with the arc discharge tube for extinguishing the arc tube within a predetermined time after the outer envelope is broken, and an electrically-insulating sleeve disposed around the safety filament. The insulating sleeve suppresses emission of electrons from the safety filament and thereby prevents a reduction in frame potential which would increase sodium loss from the arc tube. The insulating sleeve includes openings which permit air to reach the safety filament when the outer envelope is broken. A mounting arrangement includes a pair of mounting tabs which provide electrical connections for the safety filament and which approximately centers the safety filament in the insulating sleeve.

Abstract: An electric lamp includes an arc tube assembly mounted in a lamp envelope including a reflector, a lens and a base for connection to an electrical source. The arc tube assembly includes an arc tube having a longitudinal axis aligned with the optical axis of the reflector, a light-transmissive shroud disposed around the arc tube, first and second clips attached to opposite ends of the arc tube, a connection member attached to the first and second clips such that the shroud is retained between the first and second clips in a fixed position relative to the arc tube, and upper and lower electrode supports for mechanically supporting the arc tube in the lamp envelope entirely from the base region and for coupling electrical energy to the arc tube. A support ring is positioned in a heel region of the lamp envelope and is attached to the connection member. The support ring cushions the arc tube assembly when the lamp is subjected to mechanical shock.

Abstract: A pulsed light source includes a sealed, ultraviolet-transmissive lamp tube defining a discharge region containing a rare gas or a mixture of rare gases, anode and cathode electrodes sealed into the lamp tube at opposite ends, leads for connecting the electrodes to a pulsed source of electrical energy and a phosphor material located on a surface external to the discharge region. The lamp tube contains mercury in sufficient quantity to cover the cathode electrode when the lamp tube is oriented with the cathode electrode at the bottom. The cathode electrode is protected by the mercury from sputtering that results from ion bombardment. The mercury emits pulsed ultraviolet radiation which stimulates emission of visible light by the phosphor material. Lamp tube pressure is below 200 torr. The light source is operable over a range of pulse widths and duty cycles. The color of light emission is determined by the phosphor.

Abstract: The present invention provides a tungsten-based duplex composite member, e.g., wire or rod, which combines the emissive, nonsag, or other desirable qualities of an inner tungsten-based core material with a different combination of properties, for example, resistance to attack, by the presence of a different tungsten-based material as an outer sheath or shell surrounding the core material.In one embodiment of the present invention, an electrode is formed from a duplex composite member, composed of a thoriated tungsten core (W-ThO.sub.2) and a thin rhenium (Re) shell.Other embodiments of duplex composite members are provided by thoriated tungsten discharge electrodes in which it is desirable to have two different concentrations of thoria (ThO.sub.2) in the element, a first concentration in the core of the duplex composite member and a second concentration in the shell or surface of the member.

Abstract: A glass electric lamp bulb, and an electric lamp, such as, for example, a tungsten halogen lamp, which includes such a lamp bulb, is provided. The inner surface of the lamp bulb includes a light-diffusing coating containing silica particles and a soluble silicate binder such as potassium silicate.

Abstract: A horticultural luminaire in which a lamp is contained within a first compartment and a ballast unit is contained in a second compartment. The ballast unit is in heat-conducting contact with the top of the unit and a plate member also covers the ballast unit to act as an additional heat sink. The top of the luminaire housing may be provided with bracket members to facilitate mounting of the luminaire on a structural I-beam.

Abstract: An electric lamp is provided including a sealed outer glass envelope having an arc tube therein supported from the stem of the outer glass envelope by a support frame. The support frame is attached to the stem by a stem clip to which the support frame is welded. An inert refractory fibrous material is disposed between the stem and the stem clip to provide resiliency and a friction fit therebetween.

Abstract: A quartz lamp envelope includes a press seal, at least one molybdenum foil feedthrough extending through the press seal to the lamp interior, and an external electrical lead connected to the molybdenum foil. The molybdenum foil has an oxidation-inhibiting material, such as chromium, aluminum and combinations thereof, embedded in a surface layer thereof by ion implantation. The electrical lead has an oxidation-inhibiting coating, such as silicon carbide, silicon nitride and combinations thereof, formed by plasma-enhanced chemical vapor deposition. Alternatively, the electrical lead can have an oxidation-inhibiting material embedded in a surface layer thereof by ion implantation.

Abstract: An arc discharge lamp which can be operated in any orientation without significant variation in performance includes an even number of electrodes at least equal to four, a discharge vessel including a spherical central portion and electrode mounting portions. The electrodes are mounted in the electrode mounting portions and have a substantially uniform three-dimensional distribution with respect to the central portion. The discharge lamp can be used in a lamp assembly including a switch apparatus for coupling electrical energy to a pair of the electrodes that is closest to a horizontal plane. An automatic switch apparatus includes orientation-sensitive switches, one having the same direction as each of the electrodes. The switches are interconnected such that electrical energy is coupled to a pair of electrodes in response to the orientation of the switch apparatus relative to a gravity field. The switch apparatus can be mounted in the base or within the lamp envelope of the lamp assembly.

Abstract: A lamp assembly includes a lamp capsule, a reflector, an electrical connector and a lens. The lamp capsule includes a lamp envelope having a base portion, and the reflector includes an opening for receiving the base portion of the lamp envelope. The reflector is fabricated of a resilient material such as a high temperature thermoplastic or thermosetting plastic. The base portion of the lamp capsule and the reflector include lamp introducing elements which mechanically lock the lamp capsule in the reflector. The lamp interlocking elements preferably position the center of light output of the lamp capsule at the focal point of the reflector. The connector and a neck portion of the reflector include connector interlocking elements which mechanically lock the connector to the reflector. The lens and the outer rim of the reflector include integral lens interlocking elements which mechanically lock and position the lens on the reflector.

Abstract: A lamp assembly includes a lamp capsule, a reflector, an electrical connector and a lens. The lamp capsule includes a lamp envelope having a base portion, and the reflector includes an opening for receiving the base portion of the lamp envelope. The reflector is fabricated of a resilient material such as a high temperature thermoplastic or thermosetting plastic. The base portion of the lamp capsule and the reflector include lamp interlocking elements which mechanically lock the lamp capsule in the reflector. The lamp interlocking elements preferably position the center of light output of the lamp capsule at the focal point of the reflector. The connector and a neck portion of the reflector include connector interlocking elements which mechanically lock the connector to the reflector. The lens and the outer rim of the reflector include integral lens interlocking elements which mechanically lock and position the lens on the reflector.