Abstract: An asymmetrical, one-piece, hollow metal structure, such as the trailing edge of an aircraft wing leading edge slat comprises two outer skins (16; 18) having different curvatures, interconnected by an edge (20) and moving progressively away from one another. The structure also comprises inner reinforcements defining pairs of cavities (26, 28) separated by a median bulkhead. Manufacture takes place by diffusion welding and superplastic moulding or forming, without opening the tools. In order to take account of the asymmetry, cutouts (40, 42) are made in the skin (18), which is elongated most during forming and the cut parts (44, 46) are joined to the other skin (16).

Abstract: In a pneumatic pressure-reducer, the control rod for the control valve is supported and guided by two spring washers whose radial stiffness is at least around 200 times greater than the axial stiffness. Each washer comprises internal and external annular regions connected by at least three inclined arms, separated by openings. Preferably, a restriction is formed between a region of the pressure-reducer situated downstream from the valve and a comparison chamber, the pressure of which acts on a comparison capsule connected to the rod.

Abstract: The conventional grating is substituted by one or more curved prisms in a concentric spectrometer of the type derived from the Offner mirror objective. The curved prisms are known as Fery prisms. The deviations from the concentric form are used as a corrective device. The spectral apparatus is especially suited as an imaging spectrometer having a detector array because the two-dimensional image can be formed in the direction of the spatial coordinate as well as the spectral coordinate without distortions and curvatures.

Abstract: The thermic protection device is obtained by winding refractory wires with plush loops and radial and reinforcement armament picots, also with refractory fibers, preferably twisted. The plush loops and the picots have a predetermined orientation and/or pitch with respect to the direction of the ablative flow in the hollow structure.Application for the embodiment of the ferrule of a ram jet engine chamber.

Abstract: The invention relates to a cylindrical elastomeric bearing with wide angular deflection comprising three cylindrical elements: a central element (1) and two lateral elements (2, 3) arranged either side of the central element (1). Each torsible cylindrical element is made up of a deformable elastomeric central part, relatively flexible angularly and relatively rigid radially, which is rigidly locked to an inner armature and to an outer armature; the outer armature (6) of the central element (1) and the inner armature (8, 11) of each lateral element (2, 3) are rigidly locked together so as to form a single part, the common armature (13).

Abstract: The method consists of separately embodying, by means of filamentary winding, the internal wall 11 of an annular caisson on a primary mandrel 9, of securing to this wall separately prefabricated stiffening elements 3, of juxtaposing to the primary mandrel an interpolated mandrel 17 inserted between the stiffening elements, of embodying above said interpolated mandrel the lateral walls and the external wall 12 of the caisson and of removing the single-piece assembly from the interpolated mandrel elements enclosed in the caisson.Application for the embodiment of load-bearing structures.

Abstract: A fastener is provided for pinning together an assembly of metal sheets or similar, comprising:a body defining a bearing face, intended to come into contact with the external face of one of said external metal sheets of said assembly,at least one elongate element intended to pass through facing holes formed in the metal sheets of said assembly and having an engagement nose. Said fastener is further provided with a mechanism comprising a first core able to rotate and slide inside said body and having a threaded portion with which a second threaded core cooperates, with which said elongate element is fast.

Abstract: The invention relates to a rotor head having interblade ties with resilient return in lag and with built-in damping, wherein each tie is connected, to each of the two rotor blades joined by it, by articulation means comprising a main ball retained on a member connecting a blade to the hub and centered on or in immediate proximity to the pitch change axis of the corresponding blade.A single main ball may be connected to the adjacent ends of two neighboring ties by a connection member having the shape of a V open towards the hub, or else each tie is connected to a connection member by a respective one of two main balls offset transversely in relation to the pitch change axis of the blade and/or radially along said axis.Application to the main and/or auxiliary rotors of helicopters.

Abstract: An ultrasonic testing device of the type comprising a fixed hub with at least one ultrasonic transducer as well as an annular rolling means mounted for rotation on said hub and surrounding said transducer, this latter being mounted on the hub through a support whose external face opposite said transducer defines with the inner face of said rolling means a rotational sliding slit, the coupling between said support and said rolling means being provided by an ultrasonic liquid present in said slit, wherein a spongy resilient element is provided imbibed with said coupling liquid, said element being housed in a recess in said hub and being applied resiliently against the inner face of said rolling means.