Abstract: A melting furnace or cupola utilizing electric arc heaters to provide an arc-heated air stream to melt loose metal chips as well as larger pieces of metal scrap. In one embodiment, the arc-heated gas stream and metal chips are directed into a melting segment with the melted chips and gas stream passing therefrom into the furnace through a tuyere. In another embodiment an electric arc heater serves as a tuyere for the furnace with the metal chips being fed into the arc-heated stream at the outlet of the arc heater. The chips and arc-heated air stream immediately enter the furnace wherein melting of the metal chips occurs. With either embodiment, recycling of the gases in the furnace and metal chip preheat can be provided.

Abstract: A fluid pressure device for detecting two or more fluid pressure levels from a varied range of fluid pressure includes a housing having a cylindrical bore and a pressure inlet in communication therewith. A piston member is reciprocably movable within the cylindrical bore. A piston rod extends from the piston member and projects outward of the housing where a switch-operating arrangement is secured. The switch-operating arrangement includes an interlocking arm and a number of blocking elements corresponding to the number of switch devices to be operated. Guide slots formed in the interlocking arm allow adjustment of the position of the blocking elements, thus affecting a change in the operating points of the switch devices. Surrounding the piston rod within the housing is a multiple-spring arrangement which opposes the movement of the piston and which exhibits a nonlinear spring coefficient.

Abstract: A dry-type transformer cast into casting resin, includes windings, a main leakage canal, at least one of the windings being subdivided into coaxial winding parts spaced apart from each other defining an additional axial cooling canal therebetween, separate inner and outer casting resin bodies each having end faces and being cast around a respective one of the winding parts, reinforcements formed on diametrically opposite outer surface regions of the outer casting resin body for receiving axially extended connecting conductors for electrically wiring the winding parts, line terminals and tap terminals disposed on respective reinforcements, and elastic blocks common to all of the windings and winding parts between which the winding parts of a respective winding are clamped and metallically interconnected in front of the end faces of the casting resin bodies.

Abstract: A combination keyboard including a first set of switches closed by depressing discrete keys (b 21) and a second set of switches closed by depressing selected areas (69) of a flexible overlay (49) is disclosed. The first set of switches includes a printed wire board (pwb) (23) having switch terminals (31) on one surface. Overlying the switch terminals are switch closing elements, which may take the form of caged metal domes (29). Overlying the closing elements are the discrete keys (21). The second set of switches also includes a pwb (41) having switch terminals (51) on one surface and overlying switch closing elements, which may also take the form of caged metal domes (59). The flexible overlay (49) is positioned atop the switch closing elements. Further, the pwb and flexible overlay include aligned apertures (57, 71) through which the discrete keys (21) pass. Thus, both the discrete keys (21) and the flexible overlay (49) lie in substantially the same actuation plane.

Abstract: In a diaphragm apparatus, such as a switch having a diaphragm to be driven by a pressure difference between two spaces, an iron disk is fixed to the center of the diaphragm and a ring-shaped permanent magnet is fixed to an inside wall of a case to magnetically attract the iron disk. This provides hysteresis in the force-motion characteristic of the diaphragm to reduce hunting.

Abstract: An induction device comprises a winding support with a base having connection points. The upper side of the base carries a centering member having an exterior surface that defines either a cylindrical or conical surface co-axial with the cylindrical central portion of a core. A winding is provided about the central portion of the core. The core has a non-circumferentially or rotationally symmetrical upper flange. A ferromagnetic adjusting core in a form of a cap is arranged over the core that carries the coil, the portion of the cap facing the base having internally a shape a radial dimensions corresponding to the cylindrical or conical surface of the centering member. The cap encloses the centering member with a close fit, so that the adjusting core is rotatable about the axis of the core that carries a winding. The portion of the adjusting core adjacent to the upper flange portion of the core that carries a winding is also non-circumferentially (i.e., rotationally) symmetrical.

Abstract: An induction heating coil having fluoroplastic coated polyimide tape wrapped windings for providing a bonded, solid monolithic structure. The induction heating coil includes a cooling fin of predetermined length extending in interleaved relationship between a plurality of consecutive turns of current-carrying coil windings. A plurality of fluoroplastic coated polyimide sheets are fused to the coil body between the coil body and a fluoroplastic face sheet forming the outer wear surface of the induction heater coil, thereby providing a non-stick surface for release of hot melt adhesives.

Abstract: An operator is provided for a molded-case circuit breaker of the type in a motor controller where the circuit breaker is removably mounted on a pan brace which is held in place by a pan latch. The operator mounts on the breaker for opening and closing the breaker and for providing three interlocks. One interlock prevents withdrawal or insertion of the breaker with the operator handle in the "on" position. A second interlock prohibits closing or opening the control door except when the handle is off and a third interlock locks the operator handle in "off" position.

Abstract: A composite water-cooled electrode for electric arc steel furnaces comprises a tubular graphite body held in compression by means of tension stressed internal water supply pipe located between a metal header at one end and a hollow metal nipple at the other end of the electrode.

Abstract: The current transformer for instruments for measuring electric currents includes a magnetic core that has two cores and an inductive current divider with three parallel current paths. The current dividers form, together with cores, two current transformer stages whose magnetic fluxes mutually cancel one another. In a current transformer for AC currents having a DC component, the ratio of the ohmic resistances of the individual current paths is in direct relation to their transformation ratio.

Abstract: A current transformer for outdoor high-voltage installations which is insulated by pressurized gas includes a metallic top housing mounted to a hollow porcelain insulator. The top housing contains a primary conductor which is surrounded by coils of the secondary circuit. The secondary terminal leads are installed in a grounded lead-through tube which is disposed within the hollow porcelain insulator. In order to increase the dielectric strength of the current transformer, the space which is enclosed by the top housing and the porcelain insulator is divided into a high-pressure region and a low-pressure region, the former region including zones which are exposed to high voltages, in particular the interior of the top housing, and which are bounded throughout by metal and a mechanically strong insulating material, such as a casting region.

Abstract: An electric fence gate switch for controlling the flow of electricity across spaced electric fence wires in association with the opening and closing of an electric fence gate. The switch comprises first and second insulating members rigidly mounted to the gate post and fence post of an electric fence, a first leaf spring mounted to the first insulating member and connecting to one of the electric fence wires, and a second leaf spring mounted to the second insulating member and connecting to the other of the electric fence wires. The first and second leaf springs are in a position of aggressive contact urging each other into spring tension when the gate is in a closed position. The switch automatically closes as the gate is pivoted into a closed position without having to manually connect the first and second conducting means after the gate is moved to its closed position.

Abstract: A furnace for extracting gaseous components from material samples includes upper and lower electrodes mounted to press therebetween a crucible of electrically conductive material. An electric current is applied to the electrodes, thereby causing heating of the material sample contained in the crucible, with the result that gaseous components are extracted from the material sample. At least one of the upper and lower electrodes is rotated about a vertical axis, thereby causing surfaces of the crucible contacting respective surfaces of the upper and lower electrodes to rotate under friction against such respective surfaces, thereby improving electrical contact between the crucible and the electrodes.

Abstract: An interconnect is described as coupling the arms of a pair of double-throw switches, to ensure that, although both switches can be in simultaneous "OFF" conditions, only one, or the other, can be in an "ON" condition at any given instant of time.

Abstract: A current transformer characterized by a terminal bushing extending from a tank with a pair of spaced conductors extending through the bushing and into the tank and with the portions of the conductors in the tank being enclosed within tubular means. The assembly of the conductors, bushing, and tubular means being clamped together by resilient (spring) means for holding the conductors in tension and the bushing and tubular means in compression. The transformer also embodies two separate oil systems.

Abstract: A furnace for growing large single crystals from materials having high meng temperatures using the vertical solidification of melt method. The crucible containing the melt being encased in a muffle with vertically oriented heating rods arranged in a circular pattern around the outside of the muffle. The tops of the heating rods being electrically connected to a continuous graphite ring, and the bottoms of equal numbers of rods being electrically connected to two semi-circular sections of graphite. The power feeds for the heating rods being vertically brought into the furnace from the bottom for electrical connection to the semi-circular sections of graphite.

Abstract: An electrode for electric arc furnaces, comprising an upper, metallic, water-cooled section and a lower section of consumable material, such as graphite, is held in its given position by means of an electrode support arm 1,2. The connection elements for electric power and liquid coolant 12, 6, 25 are integrated in the electrode support arm and are designed as plug connections.

Abstract: The primary coil body (10) with its coil, the secondary coil body (11) with its coil and also the high voltage connector body (12) with a connector (13) therein are separate bodies put together by snap connections to provide a pre-assembled unit. A dual connector for the primary coil ends may also be provided as a separate part snap-connected to the primary coil body. The center leg of an E-shaped core part passes through the primary coil body, the latter having a cross extension on which a straight core member fits passing across the ends of the legs of the E part. After perfecting electrical contacts by soldering or welding, this unit is inserted into a single-use mold and is embedded in an insulating casting resin by injection molding. As a result of the snap-type fitting together of the coil bodies and the high voltage connector, as well as the low voltage connector body similarly fastened onto the primary coil body, it is possible to use a one-piece single-use mold for the injection molding operation.

Abstract: This invention relates to an electric-arc fired blast furnace system for the reduction of iron-bearing material utilizing electric-arc heated air containing a reducing gas or carbon-containing fuel allowing for a decrease in the amount of coke normally used in the reduction process. The excess reducing gases exiting the furnace are utilized as a source of power via a system consisting of turbines, compressors and a heat exchanger to drive the electrical generators which are used to provide electricity to the arc heaters. This arrangement forms an essentially closed loop furnace system for metal reduction. Injection of finely-divided coal into the arc-heated air to provide reductants is also employed.

Abstract: An apparatus for heating a workpiece at elevated temperatures both under vacuum and under superatmospheric pressures comprises a vacuum pressure vessel comprising a cylindrical pressure shell having an inner cylindrical sealing face near the upper edge thereof and a cover at one axial end and a bottom plug at the other axial end. Both are arranged to be placed within a reaction frame bearing thereupon. A furnace within the shell has an insulating hood for protecting the shell from the heated workspace. A vacuum manifold is mounted to the top edge of the cylindrical shell and is sealed thereto. The manifold has a cylindrical interior through which the cover passes and an inner cylindrical sealing face at the upper end thereof. Mechanically powered means are provided for raising and lowering the cover and placing it in a first or a second position.