Abstract: The invention relates to an automatically opening tapping thimble made from a refractory material for casting crucibles which are used in aluminothermic reactions. This thimble consists entirely or partially of air-permeable graphite or metal whose melting point lies between 2100 and 3727.degree. C.

Abstract: Disclosed is a method for the aluminothermal production of molten steel for the aluminothermal welding of workpieces, wherein the aluminothermal reaction is carried out in a crucible made of porous or hollow spherical .alpha.-Al.sub.2 O.sub.3 with a density of 0.8-3.0 g/cm.sup.3 and a bulk density of 0.3-1.8 g/cm.sup.3.

Abstract: A method for the preparation of alloys of the SE.sub.2 Fe.sub.17-x TM.sub.xN.sub.y type where SE stands for a rare earth metal, including Y or a mixture of these metals, while TM stands for Co, Ni, Cu, Zr, Ga, Hf, Ta, Nb, Ti, Si, A1, V, Mo, Cr, Zn or Sn or a mixture of these metals, x=0 to 10, y=>0 to 5 is described. The preparation involves calciothermal reduction of a finely divided, homogeneous mixture of the alloying components, subsequent diffusion of the components, followed by nitriding and separating the calcium oxide and excess calcium formed. The method is characterized by:a) Preparation of an alloy of the SE.sub.2 Fe.sub.17-x TM.sub.x bya1) Adjusting the exothermic reaction of the calciothermal reduction by the oxide content of the reaction mixture, so that T.sub.M >TR .gtoreq.0.9 T.sub.M where T.sub.M is the melting temperature of the intermetallic phase, and T.sub.

Abstract: A method for producing single-phase intermetallic phases, which melt incongruently within a temperature range of 900.degree. to 2,000.degree. K., with a homogeneity range of .ltoreq.10 atom % at room temperature by co-reduction is described. The exothermic reaction of the calciothermal reduction is adjusted by altering the oxide content of the reaction mixture, the composition of which corresponds to the desired single-phase alloy, in such a way that the temperature condition T.sub.m >T.sub.R .gtoreq.0.9 T.sub.m (in .degree. K.) is fulfilled, T.sub.m being the melting temperature of the intermetallic phase and T.sub.R the reaction temperature. The components of the reaction mixture, with the exception of calcium, have an average particle size of .ltoreq.75 .mu.m. The reaction product at the end of the exothermic reaction is tempered at a temperature which is at least 0.7 times the melting temperature T.sub.m of the desired, single-phase alloy, measured in .degree. K.

Abstract: For preparing a chromium metal powder lacking in oxygen and having an average particle size not greater than 20 .mu.m, a mixture of chromium oxide and calcium oxide, in a molar ratio of 1:0.5 to 1:2, is calcined initially at temperatures of 650.degree. to 1,200.degree. C. with access of oxygen up to a weight increase of 1 to 6 g per mole of chromium oxide, the calcined product is comminuted to a particle size not greater than 100 .mu.m and the product so obtained is reduced calciothermally. The calcium oxide can be replaced wholly or partially by calcium carbonate.

Abstract: In a hydraulic driving device for an electric pressurized-gas switch, the piston-cylinder systems are responsive to pressure from a hydropneumatic pressure accumulator. The driving device is equipped with a hydraulic pump which feeds several pressure accumulators and is controlled by pressure monitors, and with a gas monitoring device for the pressure monitors. For solving the problem of carrying out indirect gas monitoring while feeding several pressure accumulators by one hydraulic pump instead of direct gas monitoring, there is provided at least one threshold switch for measuring the feed pressure of the hydraulic pump as part of the gas monitoring device. By feeding the pressure accumulators which takes place sequentially in time and is controlled on the one hand by the gas monitoring device and by the pressure monitors on the other hand, it is possible to establish a correlation specific as to the pressure accumulator of the gas loss signal delivered by the threshold switch.

Abstract: For protecting service personnel during maintenance work on a metal-encapsulated, compressed-gas-insulated high-voltage switching installation, a protective device is provided which is used if gas spaces with voltage-carrying conductor parts are bounded by unilaterally exposed bulkhead bushing insulators. Sensors of the protective device are arranged at the gas spaces and their signals are fed via an evaluating unit to a tripping unit for opening feed switches to cut off the voltage to the conductor elements in the gas spaces as well as for blocking the reclosing of these feed switches.

Abstract: A process is disclosed for the preparation of alloy powders, which can be sintered and which are based on titanium, by the calciothermal reduction of the oxides of the metals forming the alloys in the presence of neutral additives. This can be accomplished by mixing TiO.sub.2 with oxides of the other components of the alloy, admixing an alkaline earth oxide or carbonate with the metal oxides, calcining the mixture. After cooling, the mixture is crushed and calcium is added. Thereafter, green compacts are formed which are heated and leached to remove the calcium oxide. The powder obtained is of uniform structure composition, is free of segrations of oxides nitrides carbides and/or hydrides and has high bulk and tap densities and can be molded by isostatic hot molding.

Abstract: This invention relates to a vacuum rotatable tubular furnace for metallothermal reactions comprising an outer housing adapted to be evacuated and having one end thereof a closable filler cap, and a vacuum-tight passage for a shaft on the other end, rotatable tube means in said outer housing, said tube means being open on an end thereof facing said filler cap, and having a shaft connected to the other end of said tube and extending through said housing, a cylindrical reaction chamber mounted in said rotatable tube means symmetrically to the longitudinal axis of the latter, and being detachably connected thereto, said reaction chamber being narrowed on a filling end thereof to a tube having a small lumen and being closed at the other end thereof, a cylindrical evaporation chamber mounted in the area of the filling end of the reaction chamber and being adapted to contain metal effecting a metallothermal reaction, said evaporation chamber having an opening on an end thereof facing said filler cap, heating means o

Abstract: A shock absorber for the absorption of vibrations acting horizontally between foundation and base of an apparatus includes two shock absorbing components which are connected to each other through a pendulum. The free ends of the pendulum are linked in wobble-like fashion to respective ones of the shock absorbing components and at least one friction surface is disposed between the shock absorbing components for absorbing the vibrations and translating the same into heat.