Abstract: Thermal protection material coating of an aggregate of mineral fibers, in particular carbon or silicon, is provided with at least one coat of a silicon-based material covering at least the area exposable to the flaking or crumbling sources of the thermal protection device. The coating is especially applicable to thermal protection structures.

Abstract: In a turbofan engine, particularly of the type in which the front end of the fan frame (26) is separate from the air inlet (24), the seal between the said two structures is provided by an elastic sleeve (32) fixed to the air inlet and fitted onto the front part of the fan frame. The diameter of the part of the sleeve before it is mounted onto the frame (26) is smaller than the external diameter of the front part of the latter. The sleeve (32) has an internal fitting preventing any relative circumferential displacement between the two ends thereof. An inflatable member (46) can be placed about that part of the sleeve which is fitted into the frame.

Abstract: The present invention relates to a system for determining the roll angle (.phi.), as well as the position with respect to an axis (OX), of a moving body (2), said system (1) having an optical detector (3). According to the invention, said system (1) includes:three optical elements (8, 9, 10) mounted on said moving body (2) and capable of generating light flashes (7), two of said elements (8, 9) being mounted so as to be diametrically opposed and the third element (10) being arranged so as to be perpendicular to these two elements; anda computer (4) determining the position and roll angle of the moving body (2) from the position of said optical elements in a picture.

Abstract: The invention relates to a composite material combining a magnesium alloy containing zirconium with a carbon reinforcement, as well as to its production process.According to the invention, such a composite material is prepared by the infiltration of a reinforcement formed from graphite or carbon fibres by a liquid magnesium alloy containing 0.3 to 1% by weight zirconium at a temperature of 650.degree. to 850.degree. C.Under these conditions, on said fibres is formed a zirconium carbide layer containing magnesium in solid solution and e.g. complying with the formula ZrC.sub.x Mg.sub.y with 0.3<x<1 and 0.02<y<0.12, which leads to the wetting of the fibres by the melted magnesium and to a good adhesion between the fibres and the matrix, without any deterioration to the mechanical characteristics of the fibres.

Abstract: The present invention concerns a clean room featuring a closed enclosure having at least two opposite walls, a first of said walls being provided with blower means adapted to blow into said room a gaseous fluid, in particular air, having a specified controlled particle concentration, and a second wall being provided with evacuation means adapted to evacuate the gaseous fluid blown into said room. In accordance with the invention, said first wall is divided into at least two blower sectors, the blower means of each of said blower sectors blowing a gaseous fluid that has a uniform particle concentration different from the particle concentration of the other blower sector.

Abstract: An electronic device (1) includes a set of boards (2) carrying electronic components (3). The boards are mounted so as to be separated from and parallel to one another. The electronic device (1) is capable of withstanding shocks in a defined direction approximately orthogonal to the planes of the boards (2). The electronic device (1) also includes a protective body (5) made of an elastomeric substance encapsulating the set of boards (2). The elastomeric substance fills the spaces between the boards (2) and forms at least one front shield (6), in the direction of the shocks (E) for the set of boards (2).

Abstract: The invention relates to a heat-insulating structural carbon material and the process for producing thereof. This heat-insulating structural material is prepared from a suspension of discrete carbon fibers in a viscoplastic liquid such as polyglycol, glycerine and petroleum oils, by molding a preform and orienting discrete filaments, followed by baking the preform and depositing pyrolytic carbon in the porous structure thereof. This heat-insulating material comprises a coke matrix, discrete carbon filaments, the coke matrix as a porous film-like structure of coke residue on said filaments, and pyrolytic carbon.

Abstract: A device intended to be associated, on the one hand, with a viewfinder, on the eyepiece side thereof, and, on the other hand, with a calculating mechanism, to form a system making it possible to determine at every instant that portion of a field sighted by the eye of an observer through the viewfinder. The device is arranged on the image side of the eyepiece of the viewfinder and includes a splitter element associated with a thick optical plate whose parallel faces are orthogonal to the optical axis of the finder.

Abstract: A device for the unlockable connection between two objects such as a satellite and a spacecraft incorporating a rotary key connection. The unlocking connection is made by the rotation of a ring carrying the key. This rotation is induced by the axial displacement of a rod carrying the ring and controlled by a spring. This spring is released by an initiating system, such as a pyrotechnic or similar system.

Abstract: A system for extending or retracting two rotationally interconnected members and locking or releasing the members in the extended position. The system includes a locking cam (4) on a shaft (5) combined with the first member (2) and connected to a drive (9). The cam is engageable with a bearing surface (8) on the second member. The drive (9) is preferably a power drive rotating the two members about their pivot axis and includes a motor (9A) with a rotational axis (17) parallel to the rotational axes (10, 11) of the cam and the shaft, the rotational axis coinciding with the pivot axis of the two members; a transmission (18) linking the motor to the shaft; and a radial linkage (19) rotating with the motor and capable of rotating the second member about the pivot axis.

Abstract: The invention relates especially to an exhaust piping for a catalytic gas exhaust system including a gas manifold and a catalyzer, said piping (4) being situated between said manifold and said catalyzer and provided with a composite tube (8) which consists of an internal tube and of an external tube defining between them a substantially annular space.Advantageously, said composite tube (8) is housed inside said exhaust piping (4), the external tube coming substantially into contact with said piping, and said internal tube (10) and external tube (11) exhibit thin walls (10A, 11A), the thickness of which is less than 0.3 millimeter.

Abstract: A reinforcing fiber of the non-oxide ceramic type or of carbon to be used in the manufacture of a composite material with a glass, glass-ceramic or ceramic matrix, which composite exhibits good oxidative stability, is treated using a process comprising the steps consisting of: if necessary, oxidizing the fiber superficially or depositing thereon a layer of the same composition but including oxygen; placing the fiber in a chemical vapor deposition vessel; carrying out a pre-treatment at a temperature of 850.degree. to 1250.degree. C., in the presence of hydrogen, at a pressure of 50 to 300 mbar; injecting a mixture of neutral carrier gas and ammonia; stopping the injection and adjusting the pressure to a value of 1 to 10 mbar; injecting AlCl.sub.3 in a neutral diluting gas; producing on the fiber a deposit of AlN by simultaneously injecting a mixture of AlCl.sub.3 and a neutral carrier gas, and a mixture of NH.sub.

Abstract: The present invention concerns a plasma torch with an approximately axi-symmetrical structure including a tubular bare torch portion having a single upstream electrode or a pair of coaxial upstream and downstream electrodes. The electrodes are tubular and cooled by a suitable cooling circuit. A field coil moves the arc foot. An injection mechanism injects a plasma gas downstream of the upstream electrode or between the upstream electrode and the downstream electrode. A starter mechanism ensures starting of the torch. An external structure integral with the bare torch at its proximal extremity includes fluid and electric linkings with the outside of the torch. The bare torch includes a bearer structure formed of three coaxial casings overlapping, at least partially, and integral with the external structure.

Abstract: DC arc plasma torch, in particular intended for obtaining a chemical substance from a plasma-generating gas (P) which includes said substance.According to the invention:the electrode (2A) is in communication with the chamber (3) for injecting the plasma-generating gas via a tubular piece (2B) through which the arc (10) passes and which constitutes the reaction chamber in which said plasma-generating gas (P) gives rise to the plasma (13) under the action of the electric arc (10); andmeans (7, 8) are provided which make it possible to form a fluid barrier (14) between the electrode (2A) and the plasma (13).

Abstract: An inner piston (10) is housed inside a petalled pin (9) and a releasing piston (13) in the form of a sleeve placed outside the said petalled pin form the sliding pieces that maintain the connection between a satellite base and a rocket platform, via a slotted nut (6) and connecting pieces (5).A pyrotechnical initiator (27) is provided in a shock absorber (25) at the base of the releasing device, and a detonating line (29) is placed above the base of the releasing piston.

Abstract: In order to localize in space a focal point of a laser beam (14) of a machining machine with respect to a work table (18) thereof, the table is fixed an equipment (22) comprising a square target (20) and impact detectors such as illumination or light sensors. In a first plane (YOZ) perpendicular to the target plane localization takes place of the impact points of the beam with the edges of the target perpendicular to the first plane, by placing an estimated focal point (PFE) at a given distance d above and below the target. Thus, determination takes place of a first calculated value (PFC1) of the focal point. This operation is repeated at least once in the plane (YOZ) and then the same operations are performed in another plane (XOZ) in order to obtain a precise and reproducible space localization of the focal point.

Abstract: System for deriving an information, warning or alarm signal on board an aircraft in the event of an anomaly during take-off.According to the invention, the system comprises:means (4) for calculating the position D.sub.stop on the runway where the aircraft must stop if the pilot decides to interrupt the take-off procedure immediately, that is to say representative of the stopping distance of the aircraft during the acceleration phase of the latter at take-off; means (5) for comparing D.sub.stop to the length of runway L available so as to determine whether an interruption of the take-off is still possible.

Abstract: The present invention relates to a method and a machine for producing a reinforcement in the form of a block for a composite component formed by said reinforcement embedded in a cured matrix.According to the invention, said block (B) is made up by continuously forming a succession of superposed sheets, and the machine, comprising a stand provided with a subframe and with uprights for mounting at least one frame which can move along said uprights, capable of receiving a thread laying-down tool which can move in a plane transverse to said uprights, is noteworthy in that it comprises an additional frame (6) which can move along said uprights (4) and is provided with pegs (9) for hooking on said straight portions of thread (F).

Abstract: The invention relates to a process for obtaining refractory antioxidative coatings on carbon-based materials and articles operating in an oxidizing environment at temperatures of up to 2000.degree. C. under thermal cycling and high-speed gas stream conditions. The process comprises the heat-treatment of the surface to be protected in silicon vapors and is characterized in that prior to said silicon vapor treatment, the surface to be protected is covered with a layer of the composition consisting of HfB.sub.2 +C powdery filler and a carboxymethyl cellulose-based binder, followed by drying under normal conditions till it is completely dry. The process is intended for oxidation protection of structural elements and articles in metallurgy, aircraft, and other industries.

Abstract: An unlockable connecting device between two objects is provided. The device includes a connecting member for connecting the objects when the device is in a connected state, and an elastic system for applying to the connecting member a tensile stress for breaking the connecting member when the device is in a separation state. The tensile stress is caused by expansion of the elastic system as a result of elastic resiliency of the elastic system.