Abstract: A method and a ballast circuit are disclosed for operating a metal halide lamp particularly suited for horizontal applications that provides signals capable of being varied so as to control the power applied to the metal halide lamp while still providing a uniform arc. The ballast circuit has a filter which passes a selected band of frequencies for the operating signals of the metal halide lamp.

Abstract: An arc gas controller-insert is used with molded case circuit breaker covers to direct the flow of arc gases that occur during intense overcurrent circuit interruption. The gas controller-insert provides access to the line and load terminal lugs for connection with and disconnection from an associated electrical power distribution system while controlling the egress of the arc gases.

Abstract: Molded plastic bus covers are attached to the ends of a pair of molded case circuit breakers to isolate the circuit breakers from an electrical enclosure as well as to isolate between the circuit breakers themselves when connected within the enclosure in a double-branch configuration. Molded plastic lug covers are attached to the opposite ends of a molded case circuit breaker when the circuit breaker lugs are connected to power distribution cables to electrically isolate the power cables and the circuit breaker lugs.

Abstract: A molded case circuit breaker utilizes a thermally responsive trip unit for providing long and short-time overcurrent protection and a magnetically responsive trip unit for instantaneous or short-circuit protection. An electrically and thermally insulative lever interfaces between the thermal element and the circuit breaker trip response bar to linearize the movement of the thermal trip element in response to circuit current.

Abstract: An all glass reflector having a front reflecting surface and terminating in the rear in a cavity into which a lamp is cemented transmits substantially less light out of the rear when at least the inside or the outside of the cavity and the reflecting surface are coated with an optical interference coating. The coating is applied by a low pressure chemical vapor deposition process.

Abstract: An improved tapped-inductor boost converter for operating a gas discharge lamp is disclosed. The converter includes a pair of input terminals connected to a power source supplying an input voltage, a pair of output terminals for providing an output voltage greater than or equal to the input voltage to the lamp, or other load, a tapped-inductor having first and second windings, an active switch for controlling current flow through the first winding for variably controlling the output voltage, a passive switch for controlling current flow through the second winding, and a first capacitor. The converter further includes an arrangement for varying the clamping voltage at the active switch in response to variations in the output voltage and also includes a clamping capacitor for transferring energy stored in the leakage inductance of the tapped-inductor to the load for improved efficiency.

Abstract: The secondary latch of a molded case circuit breaker latching arrangement is formed from a latching pin assembly with a solid metal latching sphere rotatably mounted at one end thereof. The latching sphere contacts the operating mechanism latching plate to provide a low-friction latching force to the circuit breaker operating mechanism. The latching sphere contacts the latching plate and is continuously lubricated by means of a lubrication reservoir integrally-formed within the latch pin assembly.

Abstract: This vehicle headlamp comprises a housing adapted to be fixed to the body of a vehicle and having a light-transmissive portion through which upper and lower beams are directed. Within the housing is a discharge-type lamp serving as the light source for both these beams and an arrangement for mounting this lamp in a fixed location with respect to the housing. Also located within the housing is a reflector that is mounted on the housing in such a manner as to permit relative movement between the reflector on one hand and the housing and the lamp on the other hand. An actuating arrangement causes movement of the reflector between two spaced-apart positions while the lamp remains fixed relative to the housing. The reflector in one of said positions causes light from the lamp to be reflected from the reflector as the upper beam, and the reflector in its other position causes light from the lamp to be reflected from the reflector as said lower beam.

Abstract: This electrodeless high intensity discharge lamp comprises a light-transmissive arc tube having spaced wall portions of dielectric material and a first gaseous fill within the arc tube. An excitation coil about the arc tube is energizable with RF current effective to develop a toroidal arc discharge in the first gaseous fill upon a dielectric breakdown of the fill. A starting container is joined to the arc tube and has an end wall constituted by one of arc-tube wall portions. A second gaseous fill within the starting container has a dielectric strength lower than that of the first gaseous fill. For initiating toroidal arc discharge, we provide an arrangement for producing a dielectric breakdown of the gaseous fill within the starting container that develops into an electric discharge that changes the potential at end wall in such a manner as to cause a dielectric breakdown of first gaseous fill.

Abstract: The open and closed conditions of the contacts within industrial-rated circuit breakers is externally ascertained by means of an auxiliary switch-contact position verifier accessory. A viewing aperture in the circuit breaker accessory cover provides visual access to a color-coded shutter that forms part of the auxiliary switch accessory and operates off the circuit breaker crossbar assembly. In the event that the circuit breaker contacts remain closed when the circuit breaker operating handle is moved to the OFF position, the colored indicia verifies the actual condition of the circuit breaker contacts.

Abstract: Optical interference coatings useful on lamps for transmitting visible light radiation at about 90% average from 400-770 nm and for reflecting infrared radiation comprise three spectrally adjacent multiperiod stacks of alternating high and low index of refraction layers. Compared to conventional filters, these filters have a greater tolerance to layer thickness variations incurred during manufacture with little or no color shift when viewed at non-normal angles.

Abstract: A molded case circuit breaker of the type containing an electronic trip unit and a combined actuator-accessory unit to articulate the circuit breaker operating mechanism employs an optimum cradle configuration within the circuit breaker operating mechanism. The operating cradle is fabricated from a steel composition that is optimized to promote improved hardness properties. The optimized cradle interacts with the circuit breaker latch assembly to substantially reduce the tripping force required to articulate the operating mechanism.

Abstract: Heat transfer means are disclosed to remove heat from a fused quartz arc tube being employed as the light source in an electric discharge lamp. The heat removal is carried out during lamp operation with a fused quartz protuberance that cooperates to remove heat being conducted through the arc tube walls. Various lamp embodiments are disclosed whereby such fused quartz protuberance is physically disposed adjacent the hot spot region of the arc tube in a xenon-metal halide lamp.

Abstract: A mount structure for a double ended type tungsten-halogen lamp is disclosed employing vibration damping elements to reduce the effects of mechanical shock and vibration. A thin layer of ceramic cement is interposed between the mount structure and lamp to improve the sealing arrangement related to a quartz lamp. A sealed beam headlamp unit employing the improved lamp mount construction is also disclosed.

Abstract: For mounting a lamp that comprises a glass envelope including a seal and a glass exhaust tube having a tip projecting from the seal, there is provided a base having a cavity for receiving the seal and the exhaust-tube tip. Within the cavity about the seal and the tip is a hard cement for fixedly positioning the envelope within the cavity. Surrounding the tip and located between the tip and the adjacent cement is a thin layer of soft material that can yield in response to forces developed thereon by thermal expansion and contraction of the cement, thereby protecting the tip from being cracked by these forces. The hard cement extends into contact with the glass seal about a substantial portion of the seal's exterior surface so that the hard cement is able to fixedly position the envelope relative to the base without interference from the softer material about the tip.

Abstract: A combination panelboard-switchboard housing accepts plug-on connection with a plurality of modular electric switch-circuit breaker enclosures. The modular enclosure accepts circuit breakers or electric switches which can be field-installed with minor alteration to the enclosure. The modular switch enclosure further accepts a wide range of ampere ratings within a standard enclosure size. A mechanical latch arrangement on the bottom of the modular enclosure prevents the modular enclosure from being removed from the panel-board-switchboard housing. Controlled temperatures are achieved within the housing by optimized circulating air flow.

Abstract: A molded case circuit interrupter of the type employing a thermal-magnetic trip unit to interrupt circuit current utilizes a flexible electrical braid conductor to connect between the thermal-magnetic trip unit and the movable contact arm. A helical spring arranged around the braid conductor at the welded connection with the movable contact arm provides long-term strain relief. A metal phosphate coating on the surface of the circuit breaker operating cradle and latch assembly eliminates polishing while insuring release of the cradle from the cradle-latch interface surfaces.

Abstract: Tungsten metal powder of controlled particle sizes is obtained in a fluid bed process by reducing particles of tungsten oxide having the formula WO.sub.X where x is from 2.5 to 3.0. The WO.sub.X powder particles are heated to and then maintained at a temperature between 650.degree. and 1000.degree. C. in a reducing atmosphere, which is maintained by passing a mixture of hydrogen gas, water and optionally nitrogen gas through a fluid bed of the tungsten oxide particles until substantially all of the powder solid is tungsten dioxide, WO.sub.2. The ratio of water partial pressure to hydrogen partial pressure in the feed gas is equal to or slightly higher than the equilibrium partial pressure ratio. The flow of water vapor is then discontinued, either gradually or instantaneously, while maintianing the flow of hydrogen gas to reduce the WO.sub.2 to tungsten metal. By maintaining the ratio of water partial pressure to hydrogen partial pressure above the equilibrium value until the original WO.sub.

Abstract: Since industrial-rated circuit breakers are often located remote from the associated protected electrical equipment it is often times necessary to monitor the operation of such electrical equipment by observing the condition of the circuit breaker contacts to ensure that such equipment remains operational. When a plurality of such circuit breakers are mounted within a common enclosure, an auxiliary device within each of the circuit breakers readily provides visual indication of the ON-OFF condition of the circuit breaker contacts. With such auxiliary devices, an actuator-reset lever is used to interface between the circuit breaker operating mechanism, the circuit breaker trip mechanism and the auxiliary device to activate the auxiliary device when the circuit breaker contacts are open and closed and to reset the trip mechanism when the circuit breaker contacts are opened.

Abstract: A weather-tight air conditioning disconnect switch has both plastic and metal enclosure components for low cost assembly. The exterior components include a metal case and cover whereas the interior non-electrical components are plastic-molded. One such molded plastic dead-front shields the electrical terminals within the enclosure and contains instruction and caution indicia integrally-formed on the exterior surface during the plastic molding forming process. ON - OFF indication of the switch is achieved by the orientation of the switch handle with the switch handle receiver.