Abstract: A backup trip circuit is provided for an electronically controlled recloser or circuit breaker which requires a constant voltage direct current supply for its normal tripping circuit. Whenever the normal DC supply voltage drops below the minimum level, a capacitor is coupled to and charged by, the distribution line current. Then, whenever the line current exceeds a selected magnitude for a selected period of time, the capacitor is discharged through the trip coil of the breaker to open this distribution line.

Abstract: A fuse assembly for a miniature plug-in fuse is provided with a pair of parallel spaced-apart conductive legs, each having plug-in members at one end. A fuse link of generally constant cross sectional area, integrally formed with the conductive legs, extends therebetween to form a fuse assembly of substantially planar construction. The fuse link is provided with one or more transverse offsets, each forming a weak spot.

Abstract: A current limiting fuse includes a fusible strip having semi-circular apertures formed therein, centrally disposed between the longitudinal edges of the strip. The diametric edges of the apertures lie transverse to the longitudinal edges of the fusible strip. The curved edges of the apertures are disposed in opposing relationship. Electrical weak spots which are less conductive than the remaining areas of the strip are defined between the semi-circular apertures and the longitudinal edges of the fusible strip. Semi-circular cut-outs may be included along the longitudinal edges of the fusible strip adjacent the centrally disposed semi-circular apertures to define the electrical weak spots between the cut-outs and centrally disposed apertures.

Abstract: A lighting unit comprising a lamp and a reflector provides high intensity, high efficiency, even illumination over an area of particular shape and size and has a cut-off angle which enables a person to approach close to the lighting unit without seeing the lamp or its reflection. The reflector comprises at least two spaced apart curved reflector surfaces which join each other along an edge line in a plane behind and spaced from the lamp. Points on the curve line of each reflector surface are spaced progressively farther away from the lamp than the edge line. Some points on the curve are located on the side of the plane remote from the lamp. The lighting unit, which may employ reflector surfaces in addition to those above mentioned, may be employed in systems wherein it projects light upwardly for downward reflection from a ceiling or projects light downwardly directly onto a work surface.

Abstract: A compact load break switch having at least one vacuum interrupter connected between two terminals carried by respective insulating bushings through a current exchange assembly. The vacuum interrupter is disposed within one of the insulating bushings, and a current exchange insulating housing having portions which extend telescopically into both insulating bushings, provides adequate creepage distance through air from the vacuum interrupter and the current exchange assembly to a grounded housing for the load break switch. Also, a current transformer is disposed about the insulating housing to provide remote indication of the flow of fault current through the current exchange assembly.

Abstract: The invention relates to a method and apparatus for checking the internal pressure of a filled lamp bulb. According to the invention, a filled bulb to be checked is inserted into a gas tight chamber; the chamber is then sealed and pressurized. The lamp envelope is broken by means in the chamber. Chamber pressure is measured before and after breaking the envelope.

Abstract: A vertical axis floor treating machine and support attachment are disclosed. The machine includes a housing to which the attachment is clamped. The attachment includes a frame having a slide thereon. The frame and slide define an aperture for receipt of the housing. Clamps secure the attachment to the housing.

Abstract: The invention relates to vacuum fluorescent devices having a grid element positioned between the filament and fluorescent anodes of the device. An insulating material on a portion of the grid is effective to reduce grid current and to enable achievement of greater brightness of fluorescence from the fluorescent anodes.

Abstract: An automatic voltage regulating transformer is provided which incorporates a potential transformer electrically disposed across its series windings, and a set of sensing windings disposed across its shunt windings to provide a voltage sensing network which is responsive to the flow of current both into and out of the transformer. The output of the potential transformer is connected in series with the sensing windings to provide a control voltage which is representative of the voltage across the shunt windings and series windings taken together. In the case of a normal voltage regulating transformer, this control voltage is proportional to the voltage across the output terminals. In the case of an inverted regulating transformer, the output voltage of the voltage sensing network is proportional to the voltage across the input terminals.

Abstract: A floor scrubbing apparatus including a combined solution and recovery tank is disclosed. The floor scrubber is of the type including a brush head, a squeegee and a vacuum system. A combined solution and recovery tank is operably connected to the vacuum system and the brush head. The tank is a one-piece, rigid integrally molded member having an inner wall and outer, spaced wall. The inner wall defines a recovery tank and the outer wall surrounding the inner wall defines therewith a solution tank. The one-piece member further defines an inlet opening, a solution drain opening, a recovery drain opening and a solution outlet tube.

Abstract: A rechargeable flashlight fits into and draws recharging power from an automotive type cigar lighter socket. A thermally controlled charging circuit within the flashlight adjusts the charging rate according to the ambient temperature. When the flashlight is withdrawn from the cigar lighter socket, it is illuminated; when it is replaced it is extinguished. Alternatively, the flashlight may be manually illuminated or extinguished outside the charging socket.

Abstract: A conductor support is provided for use with high voltage electrical devices having mounting walls with apertures formed therein through which electrical conductors pass. The conductor support is formed of first and second channel members sequentially inserted in the mounting wall aperture. The first channel member includes walls bendable toward and away from each other, corresponding to collapsed and expanded configurations of the first channel member, respectively. The first channel member is collapsed to take on a reduced cross sectional area, and is inserted through the aperture of the mounting wall. The first channel member includes retaining members, such as notches or grooves, for engaging the mounting wall. After insertion, the first channel member is expanded to bring the retaining members into engagement with the mounting wall.

Abstract: Compact bodies for use as contacts in vacuum current interrupters, plasma devices and the like are formed by a vacuum hot press fabrication of suitable powder material. The contacts which may be formed as a button or ring, are operable under high current arcing conditions. The powder material is mixed and placed between a pair of rams in a floating die cavity maintained in an inert atmosphere and is placed in a vacuum chamber. A vacuum is created without pressurizing the powder material. The powder material is heated to below its melting temperature for degassing. The die cavity preferably includes special outgassing ports. The rams are pressurized and the powder material reaches a sintering temperature and a vacuum of 3.times.10.sup.-6 torr. A uniform composition compact body essentially devoid of trapped gas and particularly suitable for use as a high current interrupting contact in an arcing environment results.

Abstract: A dual element, time delay fuse with greater blowing time accuracy and improved operating characteristics wherein any bridging of the circuit opening air gaps by molten alloy is effectively precluded during operation of the fuse, especially operation initiated by small protracted overloads. This is accomplished with a fuse element assembly comprising a series connection of a short circuit member, a central absorber member and a heater element member, the central absorber member held to the short circuit member and heater element member by masses of fusing alloy on each of its ends, which masses of fusing alloy are prevented from combining in fabrication and circuit opening operation by flow restricting apertures located near each end of the absorber member.

Abstract: An electrical capacitor having an improved dielectric system. The capacitor includes layers of metal foil and a dielectric sheet material which is impregnated with a liquid dielectric composition composed of a mixture of methyl diphenyl ethane and a lower alkyl diphenyl.

Abstract: A secondary valve arrester for protection of secondary electrical systems, comprises a housing having a lid and base portion, the latter of which includes a plurality of compartments each of which is dimensioned to receive a valve block and spark gap assembly or a varistor assembly; the number of said assemblies included in the arrester corresponding to the number of phases protected in the system. Each said assembly includes connecting electrodes of similar construction, each connecting electrode having two offset male terminals and one offset female terminal for connection to externally connected lead wires or other connecting electrodes. The housing lid includes first and second rib sets for extension into the base portion to retain the said assemblies in a tightly stacked condition in respective compartments.

Abstract: A power class fuse comprises an insulative canister having a female load break contact at a closed end of the canister and a male load break contact, coupled electrically to a fuse element. The male load break contact is inserted into the canister for engagement with the female load break contact to complete a circuit through the fuse element. An arc gas control device including a pair of spaced parallel plates each having apertures formed therethrough and filter material sandwiched between the plates, is mounted on the male load break contact. The arc gas control device forms a partition in the canister upon insertion of the male load break contact thereinto. Arc gas generated upon engagement of the male and female load break contacts passes through the control device into the canister interior surrounding the fuse element to reduce back pressure in the canister, while metallic particles and other contaminants which could produce flashovers within the canister, are trapped in the filter material.