Abstract: Sectors of tubes are adhesively fixed around a prefabricated propellant, the sectors being juxtaposed edge to edge to constitute a cylindrical tube, and a winding is formed around the tube at least in circumferential direction. The front and rear walls which are equipped with a seating and a tuyere, can be joined to the tubular structure formed by the tube sectors, by adhesive means on the inside of that structure, or as a variant, by means of a helical winding formed simultaneously on the wall and on the tubular structure.

Abstract: A method for producing a laminated composite structure is provided, the structure including a tubular reinforcement braid, of which the wall is folded over to form corrugations of wrinkles which constitute layers of fibrous material superposed in axial direction, each layer extending from the inside surface to the outside surface of the structure.

Abstract: A valve which works without friction is provided which includes a movable obturating member and an annular seat. The annular seat is secured to a base by means of a support. The obturating member, preferably a ball, is set in a support which is fixed in the central opening of a substantially flat circular flexible membrane. The circular membrane is secured in a prestressed condition, in a plane parallel to the plane of the annular seat with the obturating ball member coaxial to the seat, by welding the contour of the membrane to the base. The membrane is mechanically isotropic so as to be radially rigid in the plane thereof and deformable in the direction perpendicular to its plane. Deformation of the circular membrane in directions perpendicular to its plane cause the obturating ball member to move into and away from the annular seat to interrupt and allow fluid flow therethrough.

Abstract: The transducer has a primary winding wound around a first cylindrical support which delimits a passage where a core is axially movable, a first secondary winding wound around the primary winding and a second secondary winding wound on a second cylindrical support which surrounds completely the first secondary winding. The first secondary winding is formed in two portions: a regularly wound portion and a stepped portion which are phase connected, and the second secondary winding is formed in two similar portions which are antiphase connected. The output signals of the secondary windings are combined to obtain a differential signal representative of the ratio between the sum and the difference of said signals. The secondary windings are designated so that the ratio cannot reach the value +1 or -1 unless one secondary winding is cut-off, thus conferring to the transducer the capacity of being self-monitored.

Abstract: A ball valve comprising a valve body defining inlet and outlet sections, and a ball with a calibrated through-port. The valve further comprises a stem to rotate the ball between open and closed positions, a seal to insure a fluid tight closure of the valve when the ball is in the closed position, and a mechanism for retracting the seal. This seal retracting mechanism is selectively coupled to the stem, and the mechanism eliminates all contact, when the valve is in the open position, (i) between the ball and the seal, and (ii) between the stem and the seal retracting mechanism.

Abstract: Bearing for rotary shaft, of the type comprising at least one bearing element with a friction surface contacting with one external surface of the shaft. The bearing element comprises a bearing block on which is defined the friction surface and a support housing having an opening for receiving the block. The block and the housing are separated over the whole periphery of the opening by a gap, and joined together resiliently through the gap. The block and housing together define a closed cavity filled with a substantially incompressible fluid.