Abstract: A mercury vapor discharge lamp having an envelope of light-transmitting vitreous material containing an inert starting gas and a quantity of elemental mercury at least partially convertible to soluble mercury. Enclosed within the lamp is an amount of chemical agent suitable for electrochemically reducing a substantial portion of the soluble mercury to elemental mercury when the lamp is pulverized as a result of disposal. Preferably, the chemical agent is an element (i.e., copper or iron) which has an electrode potential for oxidation reactions higher than mercury. In a preferred embodiment, the chemical agent is sealed within an enclosure (e.g., glass) which is rupturable upon pulverization of the lamp. The sealed enclosure is disposed within the envelope or external to the envelope, such as within a cavity defined by a lamp base member. In another embodiment, the chemical agent is mixed with the basing cement used to secure the lamp bases to the envelope.

Abstract: A mercury vapor discharge lamp (e.g., a fluorescent lamp) having an envelope containing an inert starting gas and a quantity of elemental mercury at least partially convertible to soluble mercury. Enclosed within the lamp is an amount of chemical agent suitable for chemically combining a substantial portion of the soluble mercury as a sparingly soluble salt when the lamp is pulverized as a result of disposal. In one embodiment, the chemical agent is potassium periodate which is sealed within a enclosure which is rupturable upon pulverization of the lamp. The sealed enclosure may be disposed within the envelope or external to the envelope, such as within a cavity defined by a lamp base. In another embodiment, the chemical agent is mixed with the basing cement used to secure one or more of the the lamp bases to the envelope.

Abstract: An electric discharge lamp has an arc tube within an outer gas filled glass envelope, and a thermal switching means is located within the outer envelope. The thermal switching means has a bimetal strip and a spring-like member each affixed to at least one of the electrical conductors, and upon application of heat the bimetal strip and spring-like member are flexed to short-circuit the electrical conductors and remove any DC potential between the main electrode and the starting electrode minimizing electrolysis.

Abstract: A circular fluorescent lamp assembly having the entire ballasting circuit, along with a thermal protector, contained within the assembly's lamp holder. The thermal protector serves the dual function of preventing permanent damage to the assembly's ballast means and for extending lamp starting switch means operating life under normal end of lamp life cycling conditions. The thermal protector is responsive to the coil temperature of the ballast means and is electrically coupled in series with the ballast means, starting switch, capacitor and the lamp. One example of the thermal protector is a bimetal bottle switch.

Abstract: An improved electric lamp including an envelope of high silica glass material having a press sealed end wherein there is embedded a thin molybdenum foil which in turn forms part of the lamp's lead-in wire assembly. Crack formation in the area of the interface between the foil's external longitudinal surfaces and the compressed glass material is substantially prevented by providing the longitudinal sides of the foil with rough surfaces to assure substantial adhesion between the glass material and foil when the press sealed end is subjected to elevated temperatures (e.g., during pressing and/or subsequent lamp operation). These rough surfaces are provided by exposing the longitudinal sides of the foil to a sandblasting operation.

Abstract: A circuit breaker for a rapid-start fluorescent lamp includes a pair of electrical conductors sealed into a glass bottle, a bimetal switch within the bottle having one end affixed and the other end contacting the pair of electrical conductors and a meltable by-pass element shunting the pair of electrical conductors and formed of a material having a relatively high cold resistivity and a low temperature coefficient of resistance.

Abstract: A method of operating a high intensity discharge lamp having a pair of electrodes hermetically sealed within an arc tube, the method comprising frequency modulation of a carrier waveform in the kilohertz range to provide a variable frequency AC output, and applying the AC output across the electrodes of the lamp to thereby operate the lamp in a manner which minimizes or avoids acoustic resonance effects within the arc tube. The circuit includes an inverter having a first input provided by a DC power source and a drive input coupled to a square wave carrier generator which is frequency modulated by a ramp generator. The resulting variable frequency AC output of the inverter is then coupled across the lamp electrodes.

Abstract: A tungsten-halogen lamp capsule is disposed within a curved reflector, the lead-in support wires for the capsule protruding through the rear portion of the reflector. After a front lens is sealed to the reflector, the lamp is energized and the beam pattern is adjusted by moving the support wires relative to the reflector. When the desired pattern is obtained, the wires are secured to the reflector.

Abstract: An incandescent projection lamp which includes a reflector located within the lamp's envelope at an established distance from a biplanar filament structure. The lamp provides bidirectional light output with the reflector having an opening therein for defining the light output in one of the directions.

Abstract: A tungsten-halogen lamp for use in motor vehicle headlights comprises a tubular sealed glass capsule containing two coiled tungsten filaments, parallel to each other and disposed substantially orthogonally to the axis of the capsule. The two filaments are offset laterally from each other and one of the filaments is a coiled coil, in order to reduce the lateral traverse of both filaments.

Abstract: A disposable, manually operable flashlamp assembly which uses a percussively-ignitable flashlamp. The assembly includes a housing with a tapered end and a tubular light-transmitting end in which is positioned the flashlamp's envelope. The tapered end cocks a spring during insertion of the housing within an orificed base member after which the spring aligns with a recess in the housing. The spring enters the recess to strike a portion of the flashlamp's projecting primer tube, causing the flashlamp to fire.

Abstract: An electrical heating element for ovens, furnaces and other infrared light applications comprises an elongate tubular envelope of thermally translucent refractory material such as pure alumina enclosing an elongate coiled refractory metal conductor which is capable of carrying a linear power loading of at least one hundred watts per inch. Refractory spacers along the coiled conductor and envelope hold the conductor spaced from the envelope and coaxial therewith so that the conductor attains heat in excess of the temperature limit of the envelope.

Abstract: An overhead projection system which includes a planar lens assembly having two concentrically-oriented condensing lenses. The outer lens has a greater focal length than the inner lens to receive light reflected from the system's reflector while the inner condensing lens receives direct lighting from the system's light source. Accordingly, the inner lens images the light source at the projection lens of the system and the outer lens images the virtual image of the light source.

Abstract: A circuit for switching storage capacitors in a high voltage xenon flash tube circuit includes at least one storage capacitor with parallel low and high resistance paths in series with the capacitor, switching means selecting one of the two paths and a time delay device triggering discharge of the tube at a predetermined interval, the discharge time constant of said one capacitor being a substantial portion of the triggering interval. The time delay device enables operation of the switching means a substantial time after triggering discharge.