Abstract: This invention is concerned with a circuit arrangement for reducing the residual voltage on partially disconnected loads, such as control coils of electromagnetic switchgear having long control lines, by connecting an auxiliary load in parallel to the load. According to the invention, a constant-current sink is connected in parallel to the load as an additional load, which is dependent on a control circuit that the circuit closes when the applied voltage is below a predetermined value and breaks when it exceeds a predetermined value.

Abstract: A puffer-type compressed-gas circuit-interrupter is provided having a tubular stationary and at least two movable contacts which draw at least two arcs within at least two regions in the interrupter. The two regions are connected by a series of insulating flow guides, tubular contacts, and an insulating nozzle to a single fluid motor which during contact opening, after a predetermined portion of the opening travel of the interrupter, provides a blast of puffer gas extinguishing the arcs.

Abstract: A ground fault accessory for a molded case circuit breaker is provided by converting a shunt trip accessory to automatically trip the breaker when a ground fault occurs. A printed circuit mounted in the housing with the shunt trip eliminates the need for a separate ground fault relay. The ground fault relay and the shunt trip are made available in the same accessory requiring no additional mounting of equipment or external wiring while conserving space which is scarce in load centers and other locations where both ground fault and shunt trip are desired.

Abstract: The invention discloses a rotary gas compressor for liquids which includes an impeller housing, an impeller rotatably mounted in the housing, a housing cover, a control disc arranged between the housing and the cover, and a suction intake and pressure outlet provided on the housing cover. Within the housing cover suction and pressure chambers are defined by a separating web arranged between the cover and the control disc. Into the suction chamber opens the suction intake provided on the housing cover; a suction slot provided in the control disc then provides communication with the impeller. The pressure outlet connection communicates with the pressure chamber, and a pressure slot provided in the control disc then also communicates with the impeller. One or more additional pressure aperatures are arranged in the control disc adjacent to the pressure slot, and resilient valve tongues cover all of the additional pressure apertures, except for one aperture to which a pressure relief pipe is connected.

Abstract: An electrodynamically opening contact system including a fixed and a movable contact element. The movable contact is biased by a prestressed spring arrangement which is pivotally mounted at one end while at its other end slidably engages the movable contact element such that an overcenter or toggle action is effected.

Abstract: The cooling arrangement for a machine provided with hollow fins has in the end regions of the stator housing ports for the internal air and below the stator housing, closed at one end by an end plate, in the region of the respective ports, a motor-driven internal fan which is laterally covered by an air deflection surface between it and the pierced inner bearing bracket. Between the inner shaft end and the motor attached to the end plate, a rotation sensor coupled with the shaft end is arranged and it is used for air conduction as well. In the fan shell a motor-driven external fan is arranged and its motor may be attached on the outer side of the end plate.

Abstract: An initiator for a contactless switch comprises a support section (3) and an adjacent, conical-shaped control section (5), which has a sensor surface (11) and is free to move into several positions with respect to the front side of the support section. In one position, the sensor surface is turned away from the support section and in other positions it is parallel to the lateral surfaces of the support section. The control section is equipped with a prism-shaped recess in which is fitted a fastening element (4). The fastening element can be rotated about a longitudinal axis (6) that is perpendicular to the front side of the support section, and the control section can be rotated with respect to the fastening element about a central axis (7) which extends in the direction of a diagonal across the lateral face of the control section.

Abstract: For an internal combustion engine, such as a motor vehicle engine, operating on the principle of "flywheel utilization" an electromagnetic unit can be used both as a starter motor and as a generator. In addition, this unit is easily adaptable to the given flywheel dimensions and it involves as low a cost as possible for the controlling semiconductor components and for the exciter power. The invention proposes, among other things: (a) a stator with several independent sector stators arranged at tangential distance from each other, with pairs of toothed sector stator elements arranged at an axial distance a one behind the other and each having a radially projecting pole shank connected together by a flux return yoke; (b) a rotor with two rows of teeth mutually offset "tooth on gap" on the circumference of the clutch flywheel; and (c) use of MOS transistors for the electrical commutating of motor operation, the inverse diodes of which are utilized as rectifier elements in generator operation.

Abstract: A vacuum circuit breaker (1) having two switching tubes (5) which are electrically connected in series and aligned coaxially. By means of an offset drive unit (toggle lever system 26) two motions that are contrary to one another are produced for the drive tappets (15) of the breaker tubes (5), from the common drive motion of a rod (11). The contact pressure springs (32) of the two switching tubes (5) are directly or indirectly connected to a common stationary support (35) which can be unfastened and moved to a new position. Simultaneous contacting or separation of the breaker elements of the two breaker tubes produced by the common drive is ensured by loosening the bearing block, after releasing the connection with the common drive mechanism, and fastening it again after the force differential has been automatically compensated for. The invention is suitable for vacuum circuit breakers in the medium-voltage range, such as those used to supply power to railroads.

Abstract: An improved gasket sealing motor leads which extend from the interior of an electric motor enclosure. The gasket is provided with one or more resilient, conical bushings whose diameters extend through a wide range of lead diameters. By severing the bushings at an appropriate point, round apertures are formed through which the leads can be pulled and sealed. The flat portion of the gasket which surrounds the bushings is secured to the motor enclosure in a conventional manner.

Abstract: A disconnect switch is provided for a metal-clad, pressurized-gas insulated, high-voltage switchgear installation. The disconnect switch includes:first and second contact assemblies which have a common longitudinal axis and are switchable between an open position and a closed position. An isolating tube is positioned inside one of the first contact assemblies and is movable therein along the axis during a switching operation between an open position at which the contact element is completely within the said one contact assembly and a closed position at which the said contact element engages the other contact assembly. First and second resistors are positioned within the isolating tube and are movable along the axis inside the isolating tube during switching toward and from the other of the contact assemblies.

Abstract: An overload relay is provided which monitors current flow in a circuit and triggers an electromagnetic interrupter to open the circuit upon detection of an overcurrent condition. A train of pulses is generated and received by the electromagnetic interrupter for maintaining the circuit closed. The pulse train is terminated upon detection of an overcurrent condition.

Abstract: A method for the manufacture of plate-packs of coated metal laminas for electrical machinery and appliances in which the number of necessary manufacturing steps is reduced. After the laminas have been punched or stamped out, they are electrically upgraded by annealing and in the process are arranged at intervals with respect to one another and exposed to a reducing gaseous atmosphere. Then projections or depressions, known from punch-packing processes, which correspond to each other are punched into the laminas to connect them together. The laminas of a plate-pack are assembled into a unit by means of the interlocking projections and depressions prior to the annealing by an initial axial pressing step with an ensured axial minimum separation. After the annealing treatment, by means of a final axial pressing step, they are assembled into the final plate-pack form.

Abstract: An improved panel board construction is described, including an extruded insulative base pan which slidably engages at least one main-line bus bar and a neutral connector element and which has a plurality of electrical contact points. The base pan also prevents current flow through the base pan between any two of the contact points of the main-line bus bars. A protrusion extending from the base pan having a tortuously formed surface thereon prevents current flow through the base pan. The panel board is provided with interchangeable main-line lugs which may be used to directly contact the main-line bus bars or, alternatively, support a main-line circuit breaker between the lugs and the main-line bus bars. The base pan is symmetrically formed by an extrusion process so that it may be adaptable for use with a variety of panel board sizes simply by shearing the base pan to form the appropriate length.

Abstract: The invention relates to an ultrasonic converter with a plate type ceramic oscillator in which metal electrodes are fastened to the oscillator. At one end face of the ceramic oscillator an adaptation layer of plastic is present. The entire ultrasonic oscillator, except for the side of the adaptation layer facing the medium to be insonated, is provided with a foam covering, to reduce decay damping without a substantial loss in the transmission factor.

Abstract: For the desired pole-pair number combination p.sub.1 /p.sub.2 always those coils are omitted from the individual phases of the first pole-pair number p.sub.2, which form overlapping phase bands for the second pole-pair number in the coil side star; the remaining coils of each phase for 2p.sub.1 are distributed symmetrically along the periphery and in accordance with ##EQU1## over the base-speed winding connected in three-phase wye/three-phase wye configuration and the dead winding branches N.sub.1, connected in parallel or in series to it, for the first pole-pair number p.sub.1, whereby at least a large portion of the omitted coils is configured as additional dead branches for the second pole-pair number p.sub.2.

Abstract: In an encapsulated, compressed gas-insulated high-voltage switchgear there is arranged in the interior of the encapsulation a drive and breaker units actuated by it. The breaker units are carried by a flange plate which closes the encapsulation off so that is is pressureproof. The flange plate is connected with the drive on the side away from the interior. To secure the position of the breaker units and hence also the coupling between them and the respective drive independently of the compressive stress of the flange plate, a substantially flat support plate is provided which directly receives the breaker units and which, extending parallel with the flange plate, is connected therewith via at least three parallel spacers which are arranged in a triangle.

Abstract: An encapsulated medium-voltage electrical load switching apparatus has four, three-position rotary switches, supported by pairs of opposing insulated half-shells, two-over-two in parallel alignment within a gas-filled sealed shut shell housing.The housing front and back have dome-shaped protrusions to maintain the seal against fluctuations in gas pressure. Bushings in the floor and ceiling of the housing, aligned with the switch face plane, provide gastight connections between the switches and external cables, enclosed fuses and transformer terminals. Switch control is provided by drives mounted on a plate at the front of the housing exterior which operate actuator arms that extend in a gastight way through the housing front and manipulate selector shafts that connect to set the switches into closed-circuited, open-circuited and grounded positions.

Abstract: A front panel assembly for an electrical panelboard or the like. An interior trim panel is fastened within the enclosure proper, having holes through which circuit breakers may protrude and having upstanding edge flanges. A panelfront assembly includes a number of rotatable camming latches for engaging the edges of the flanges. The latches are secured in place with threaded screws extending through rabbets which are concealed by the door of the panelfront.

Abstract: A system for controlling current flow to the actuating coil of a contactor or the like. A solid state switch is provided for gating current flow to the coil, and operated by an oscillator stage. A time delay causes the oscillator to operate at a high duty cycle when power is initially applied, allowing a relatively high current to flow to the contactor coil to operate the contacts. Subsequently the control causes the oscillator to operate at a low duty cycle, wherein the solid state switch passes a significantly lower current flow to the coil to maintain the contacts in position.