Abstract: The finishes of the present invention consist essentially of metal alloys having the general formula:T.sub.a Cr.sub.b Zr.sub.c B.sub.d M.sub.e M'.sub.f X.sub.g I.sub.h(I)in which a+b+c+d+e+f+g+h=100 atomic percent;T is Ni, Co, Ni--Co or any combination of at least one of Ni and Co with Fe, wherein 3<Fe<82 at. % and 3<a<85 at. %;M is one or more elements of the group consisting of Mn, Cu, V, Ti, Mo, Ru, Hf, Ta, W, Nb, Rh, wherein 0<e<12 at. %;M' is one or more rare earths, including Y, wherein 0<f<4 at. %;X is one or more metalloids of the group consisting of C, P, Ge and Si, wherein 0<g<17 at. %;I represents inevitable impurities, wherein h<1 at. %, and 5.ltoreq.b.ltoreq.25, 5.ltoreq.c.ltoreq.15, and 5.ltoreq.d.ltoreq.18.Powders obtained from these alloys that are deposited on substrates by thermal projection provide finishes having increased hardness in addition to high ductility and excellent resistance to corrosion.

Abstract: This invention relates to a sealing device ensuring lateral tightness of a weir gate with respect to the corresponding lock wall, of the type comprising a lip disposed over the whole length of each lateral face of the gate and a rounded rib extending the leading face of said gate, wherein the rounded rib projects transversely beyond the plane of the lock wall, so that its periphery, which takes a circular form, comes into abutment against the lateral face of a cylindrical chamber made in the lock wall. In this way, the displacements of the gate do not affect tightness.

Abstract: Low-head hydroelectric installation, in particular for a tidal power station, intended to operate under variable heads of water that can fall to values in the region of zero. When the head of water is lower than a defined value (Hd), lower than at least half the nominal head (Hn), the turbo-machine (1) is made to rotate at a speed (n1, n2, n2, . . . ) lower than the synchronous speed (ns) and bringing its efficiency near to the heart of the efficiency contours. For this purpose, a frequency converter (7) is inserted between the rotary electrical machine (3) and the network (4), the converter (7) being constructed for a power in all cases lower than at least half the nominal power (Pn).

Abstract: A hydrostatic bearing supplied with pressurized water positioned as a seal between the shaft of a pump-turbine and a suction bend adjacent the lower end of the shaft. The hydrostatic bearing replaces the conventional labyrinth joint usually located above the lower shaft bearing, and may additionally replace the lower bearing itself.

Abstract: A propeller runner having swivelling blades, each integral with a journal engaged in two bearings respectively in the outer portion and the inner portion of the runner, and equipped with lateral connecting rods for manipulation in rotation.The inner central portion of the hub of the runner includes a spider 29 each arm of which consists of a radial journal 31 prolonged by a threaded portion 32. Each blade journal 23 is engaged over a spider journal 31 with a bearing 26 and is held by a nut 33 screwed onto the portion 32 with the interposition of a thrust bearing 30. The spider 29 for a four-bladed runner preferably consists of a core 39 through which passes a shaft 40.The invention is applicable to propeller runners having swivelling blades for turbines.

Abstract: A method of tracking for telecommunications antennae.It consists in carrying out continuous measurements along each axis (X,Y) of displacement and in returning backwards by a measured amount before proceeding to change the axis.

Abstract: A tubular obturator for use with a hollow body e.g. a pipeline or cylindrical container, terminating in a cylindrical opening for closing the opening when it is desired to subject the body to a pressure test, comprises a cover, the diameter of which is slightly smaller than that of the opening of the body to be tested, and a cylindrical skirt extending from the cover and comprising a plurality of strips.

Abstract: Method of starting pumps, in particular a method of starting turbopumps functioning as pumps, the said pumps or turbopumps being of the type with a fixed distributor-diffuser, and in which the curve of variation of the power at working speed as a function of the flow of fluid passes through a minimum which is between the zero-flow point and the nominal-flow point.

Abstract: A mechanism for controlling two rotatable cut-off devices which are mounted in series in a shell for connection to one and the same pipe, comprises a jack in respect of each cut-off device, each jack being articulated to a lever fast with a journal of a respective one of the cut-off devices and to the shell in the zone thereof supporting the journals of the other cut-off device.The invention is particularly applicable to the valves for protecting a hydraulic machine in a high-fall hydraulic power station.

Abstract: A mechanism for a hydraulic pipe comprises two rotatable cut-off devices in series arranged inside two half-shells which are arranged symmetrically, relative to a mean transverse plane, and which are connected by being bolted together by their flanges. Each half-shell supports the journals of a cut-off device and an intermediate piece may be provided for supporting center gaskets.The mechanism is particularly applicable to the protection of turbines in a high-fall hydroelectric installation.