Abstract: Current limiters, preferably PTC resistors, are used for limiting short-circuit current when connected in series to capacitors and converter valves. Protective devices operating with these PTC resistors are able to work reversibly and respond without arcing. They have a low inductance and can be used in space-saving designs. Protective circuits with such PTC resistors have a low loss, are shake-proof, and can be integrated into an existing cooling circuit. They respond autonomously and enable a flexible application. The PTC resistors preferably are constructed in a meander shape of porous metal foam or a metal braid or fabric and have electrical contact bridges between their resistor tracks. At least 2 resistor tracks that are electrically connected in parallel are arranged at a small distance on top of each other in such a way that partial currents (I1, I2) flow in opposite directions through resistor branches in superposed track areas formed in this manner.

Abstract: A guide blade for steam turbines, having in the blade interior a cavity (18) to which a vacuum is applied, is provided with an opening (3) for drawing off fluid in the region of the trailing blade edge (4). This opening is provided with a porous cover (7). The cover is dimensioned in such a way that, during operation, all its capillaries are filled with the fluid to be drawn off. It is anchored in the guide blade by a mechanical fastening element (20).The mechanical fastening element (20) is a spring-loaded quick-acting lock and comprises a bush (21) which fixes the cover in the blade opening (3) and projects with its cylindrical part (24) into the blade cavity (18), and a pin (25) which is axially displaceable in the interior of the bush, is equipped with spring means (26) and is provided at its end with a cap (28), which rests on the inner wall of the blade.

Abstract: In a process for applying a metallic adhesion layer for thermally sprayed ceramic thermal barrier coatings to metallic components, the surface which is to be coated being cleaned in a first process step, so that the metallic surface is free of grease and oxide, a binder is applied to the metallic surface of the base material in a second process step. Metallic adhesive powder is applied uniformly to the binder in a third process step and solder powder, which has a smaller particle size than the adhesive powder, is applied uniformly to the binder in a fourth process step. After drying the binder, a heat treatment is carried out for the purpose of soldering. The adhesion layers produced in this way are rough and provide a considerable positive lock for the ceramic thermal barrier coatings which are to be sprayed thereon.

Abstract: Process for shaping any desired metallic and/or ceramic component, in which a dry powder is filled loosely into a ceramic mold, which elastically/plastically yields or cracks and breaks under the influence of shrinkage stresses during sintering, and is sintered. Variants for the mold: thin, resilient shells made of Al.sub.2 O.sub.3, SiO.sub.2 or MgO; special glass which cracks in a network-like manner; a mold having predetermined breaking points, ceramic shell disintegrating into fragments; flexible green ceramic sheeting; green ceramic composition with shrinkage during sintering.

Abstract: A process for producing coarse, longitudinally oriented column crystals with improved temperature change resistance and ductility in the transverse direction in a workpiece of any cross-section from an oxide-dispersion-strengthened nickel-base superalloy, which exists in fine-grained form, by annealing in the temperature range between 1000.degree. and 1200.degree. C., cooling to room temperature and isothermally annealing for coarse grain in the range between 1230.degree. C. and 1280.degree. C.

Abstract: Process for shaping and improving the mechanical properties of blanks produced by powder metallurgy from an alloy with increased high-temperature strength by extrusion, and the deformation is successively performed in at least two temperature ranges different from one another or in two phases, in that the blank (2) is first reduced in its cross section at a temperature T.sub.1 and then is either agin reduced in at a lower temperature T.sub.2 or is deformed at a temperature T.sub.3 under counterpressure so that its cross section is further widened. T.sub.3 can be smaller than or equal to T.sub.1.

Abstract: Blading for a rotating thermal machine consists of an airfoil (1), a root (4) and a shroud plate (5) or a shroud, the tip (2) of the airfoil (1) having a spigot-type step (11) with a semi-circular groove (12) extending around the whole periphery of its generated surface. The shroud plate (5) or the shroud has a recess corresponding to the step (11) with a semi-circular groove (8) extending around the complete periphery. At least one piece of a firmly seated heat-resisting wire (10) is located in the circular duct formed by the grooves (8, 12) as the fastening element between the components (1, 5). The blading is manufactured by pushing and/or pulling the wire (10) sideways into the duct formed by the grooves (8, 12).

Abstract: The pressure wave supercharger of the internal combustion engine has a diaphragm capsule (20) for controlling the supercharge air butterfly (14). The diaphragm (21) of the diaphragm capsule is, in operation, subjected on the butterfly side to the high pressure air in the high pressure air duct (2) and on the other side to the pressure at the protrusion 27 or in the compression pocket (5), via a control pressure line (26; 28). These pressures typical of the process vary with the speed of the cell rotor and control the setting of the supercharge air flap as a function of the speed and loading condition of the engine.

Abstract: The invention discloses an apparatus for adjusting or actuating an air throttle valve positioned in the intake manifold of an internal combustion engine which is supplied by air under pressure. The air throttle valve is held in a closed position by a spring when the engine is in the cold starting phase. Air is supplied to the engine through a by-pass valve when the air throttle valve is closed. The air throttle valve is opened against the force of the spring in response to a predetermined pressure or vacuum in the intake manifold at the end of the cold starting phase. The air throttle valve is held in an open position by an electro-magnetic structure which is effective when an ignition circuit of the vehicle is energized or by a detent structure which is effective when the engine or exhaust temperatures are at predetermined levels.

Abstract: An actuator for an air valve placed in the boost air duct of an IC engine and, more specially, of such an engine supercharged or boosted by a pressure wave supercharger, the air valve being in its closed position on starting up the IC engine from cold, at which time the engine takes in charge air by way of a breather valve, and at the end of the starting stage the valve in the boost air duct is moved into its open position and is kept open while the engine is running. After shutting down the engine, the valve in the intake pipe is automatically moved back into its closed position and the air valve is moved into its open position by the pressure of the air forced into the boost air duct and/or by vacuum against an air valve spring closing force.

Abstract: A positioning device for an air valve arranged in the charging air line of a diesel engine, particularly charged by means of a pressure wave-charging device. The air valve or flap is provided with a shutoff valve incorporated into the flow path between an impingement line branching-off from a pressure oil line of the diesel engine and an oil return flow line. The impingement line is connected with an impingement chamber for a positioning piston actuating the air valve or flap. The positioning piston is loaded by a continuously effective force and the shutoff valve is actuated, in order to impinge the positioning piston with oil, in the opening direction of the air valve or flap by a control piston loaded by the pressure in the air charging line against the force of a spring.

Abstract: A starting valve is disclosed having a starter choke valve and a poppet valve which is kept closed by the starter choke valve when the choke valve is in an open position. For mounting the starter choke valve there is provided a choke shaft and a bushing set screw which interact with a plurality of tapered bushes. The arrangement provides for an axial and a radial compression of the bushes to prevent foreign matter from fouling the movement of the choke. Also a compensation for the varying tolerances between the component parts is accomplished by providing a plurality of rubber-elastic components.

Abstract: A multi-flow gas-dynamic pressure-wave machine, the rotor of which comprises at least one intermediate tube which subdivides the cell zone into at least two flow channels. The cell walls of adjacent flow channels are circumferentially staggered by essentially one-half the circumferential interface between such cells to produce a reduction in noise due to the beat interference produced by the sound pressures occurring in the cells adjacent to one another in the radial direction. The rotor may be provided with a concertina-shaped or undulation-shaped intermediate tube whereby there occurs a more balanced distribution of stresses, requiring less accelerating power.

Abstract: A starting arrangement for a pressure-charged internal-combustion engine in which at the beginning of the starting phase combustion air is delivered to the engine by way of a bypass valve and a throttle valve in the charge-air line from the pressure-charging device is closed. Two mutually independent variables are used for controlling the opening of the throttle valve. At the end of the starting phase a command variable typical of the process e.g., charge air pressure is used to initiate an opening of the throttle valve and an engine-dependent operating variable e.g., engine lubricating oil pressure is then used to actually move the throttle valve to its open position, the throttle valve then remaining in the open position so long as the engine-dependent operating variable does not fall below a specified minimum value.

Abstract: A pressure exchanger cell ring comprising a rotor which, viewed in cross-section, possesses cell walls of at least double curvature, each of the cell walls being secured at its ends to the hub and shroud, respectively, of the rotor. Each cell wall is shaped to have protruding portions or lobes, each curving to either side of a radius extending through one of both attachment locations of the cell wall. The sector angle enclosed between the two radii extending from the center of the rotor through each attachment location of a cell wall does not exceed 4.degree., and the sector angle bounding the mean camber line of the cell wall does not exceed 7.degree..