Abstract: The sighting device comprises first means for displaying at least one displacement mark parallel to the central vertical spider-line, means for altering the position of said displacement mark, means for measuring the target moving time which has elapsed between one initial moment at which the target seen in the range finder is superimposed with a reference mark, and a subsequent moment at which said target seen in the range finder held in immobilized position reaches said displacement mark; and second means for displaying at least one cross velocity adjusted mark, parallel to said central vertical spider-line, and whose position is determined first as a function of the projectile flight time, which is itself determined from the firing distance, and second, as a function of the target moving time, measured for a given displacement mark.

Abstract: The present invention relates to abradable rings for turbines, wherein they are constituted by an abradable refractory material and are formed by at least one open ring maintained clamped against a fixed metallic structure with the aid of at least one spring, and to refractory materials which may be used for making said rings.

Abstract: The invention relates to a process for preparing a body of a rocket propulsion unit comprising a rubber wall forming a chamber which contains a propergol and an outer wall forming reinforcement, characterized in that the following steps are carried out:the rubber chamber is coated with an adhesive agent,the whole is baked at a temperature higher than about 100.degree. C.,the propergol is introduced into the chamber,the outer wall is made by depositing impregnated fibers around the chamber and polymerization at a temperature lower than about 100.degree. C.

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.

Abstract: The carrier of the image to be analyzed is fixed on a transparent cradle shaped as a portion of cylinder; a light beam is sent back perpendicularly to the cradle by a mirror pivoting about an axis which blends with the axis of the cradle and which is moved with respect to said cradle in order to light up, successively, and line by line, the image elements of the image to be analyzed; the light beam after traversing the image carrier is sent back on to an optico-electrical device by means of an elliptical mirror, so as to return, without introducing any aberrations, the light issued from the different image elements of one line.

Abstract: A missile drive is provided comprising a single combustion chamber shared by a first, acceleration stage and a second, ramjet cruising stage, said chamber housing the solid propellant to be consumed during acceleration. At least one air inlet is opened at the end of the acceleration stage to allow an air flow to be introduced into the combustion chamber. Moreover, at least one additional exhaust outlet forming an additional nozzle is provided in the back of the combustion chamber and means are provided to seal off said additional exhaust outlet or outlets throughout the initial acceleration stage, such that said additional exhaust outlet or outlets contribute, together with the converging-diverging nozzle, to ejecting the exhaust gas during the ramjet cruising stage.

Abstract: The structure is formed by superposed layers of fibrous reinforcing material, which layers are bound together by threads implanted through the layers by being pushed by a pressurized fluid into a tubular needle which is actuated with back and forth movements during which it penetrates through the superposed layers and is pulled out therefrom, leaving in a portion of binding thread, the next portion of binding thread being positioned after a relative displacement of the needle with respect to the structure along the surface thereof.

Abstract: A device for reducing the vibrations of a rotating machine equipped with an active magnetic suspension comprises at least two vibration detectors located on the machine frame for detecting disturbances applied to the frame, and at least an additional selection feedback loop with narrow band and high gain whose central frequency is synchronized with a reference frequency and which receives signals delivered by the vibration detectors. The additional selective feedback loop comprises means for integrating the signals delivered by the vibration detectors and filtering means for eliminating the transient signals whose frequency is not linked to the reference frequency.

Abstract: The present invention relates to a process for manufacturing an axi-symmetrical three-dimensional structure formed by superposed layers of fibrous material bonded together, said process comprising the following steps of:--bringing onto a rotary mandrel having the section of the structure to be manufactured, a tape of fibrous material whose width is several times less than the length of a generatrix of said structure:--winding the tape over the mandrel to form superposed layers, each layer being formed by successive turns of the tape of fibrous material, and--during winding, successively bonding the layers together by needling, said needling being effected at the place where the tape is superposed on the mandrel or on the previously formed layer. The invention also relates to an apparatus for carrying out said process.

Abstract: The truss-like beam is formed by the regular repetition along the axis of the beam, of polyhedral elementary cells, each one having two parallel and identical end faces, shaped as regular polygons with n sides which constitute the faces shared with the adjacent cells, and 2n triangular lateral faces formed by joining each apex of an end face to the two closest apices of the opposite end face; the edges of the elementary cell are materialized by elements which are permanently subjected to a pulling force, whereas rigid bars in buckled state join each apex of the elementary cell to its center.

Abstract: The invention relates to a system for firing a propellent charge by pyrotechnic transmission, comprising mechanical means of actuating a hammer, a primer cooperating with said hammer, and a propellent charge connected to the primer by pyrotechnical means and situated inside a firing tube.The hammer and the primer are positioned excentrically with respect to the axis of the firing tube, and mechanical means, which cooperate with other mechanical means for actuating the hammer, are provided to break the pyrotechnic chain during storage and to cause the pyrotechnic chain to come in alignment when the hammer moves under the effect of the said mechanical means for actuating the hammer.

Abstract: For compensating the geometrical defects of the annular armature of a radial position detector slaving an active radial magnetic bearing, a reference rotor having a small diameter is co-axially mounted within the rotor supporting the annular armature. The rotor supporting the annular armature and the reference rotor are both rotated in synchronism while a reference surface of the reference rotor is sensed by an additional radial position detector. A plurality of data representing the geometrical defects of the annular armature as a function of the angular position of the rotor are derived from the output of the additional radial position detector and stored in a memory to be applied to a compensation circuit linked with the radial position detector.

Abstract: The device for measuring the longitudinal tension in a strip leaving a rolling mill or stand comprises a measuring roll over which the strip bearingly runs, said roll consisting of at least one roll mounted on active radial magnetic bearings acting as load sensors and supplying a signal based upon the tensile stress in the strip bearing on said measuring roll, and means for measuring the current flowing in the windings of the magnetic bearings, as well as means for detecting the radial position of the rolls supported by said bearings and means for measuring the air gap of the magnetic bearings and keeping said air gap substantially constant.

Abstract: The present invention relates to a method for producing elastically deformable articles constituted of a textile substrate of carbon fibers which are elastically deformable with respect to an at rest shape, wherein a flexible structure of carbon fibers is used, a predetermined form being set for this textile by means of shaping tools, and said textile being retained in said at rest shape by forming around the said fibers a thin coating of rough laminar pyrolytic carbon deposited by chemical vapor infiltration at high temperature without bonding of the fibers one to another. The textile can be given a flat form by using holding plates. It is possible to start from a braided sleeve which is either compressed or stretched axially around a mandrel. It is also possible to use a woven tape which is wound in a conical pseudo-spiral for use as a cardiac valve.

Abstract: The present invention relates to a process and device for detecting the response of the heart to an electrical stimulation pulse, comprising: collecting, after the end of the stimulation pulse, a first signal v which represents the electrode potential in open circuit and of which the variation in time t, from an original instant t.sub.o is of substantially logarithmic form: ##EQU1## v.sub.o being the value of v at instant t.sub.o and k being a parameter connected in particular with the duration and amplitude of the stimulation pulse, converting the first signal v into a second signal of which the variation in time is substantially linear and, detecting in said second signal a non-linear component representing the signal produced by the provoked contraction of the heart.

Abstract: A method for the adhesive bonding of refractory parts wherein the refractory parts used are porous or capable of becoming porous by thermal treatment; a layer of thickness between 0.1. and 1 mm is interposed between the refractory parts, which layer is essentially formed of an adhesive which, after thermolysis, leaves a porous refractory residue, and fillers constituted by refractory particles of dimensions varying between 1 and 150 microns; the adhesive is thermolyzed so that a porous bond containing the said fillers is made between the porous refractory parts; then the assembly consisting of the refractory parts and the porous bond is densified by chemical vapor deposition of a refractory material.

Abstract: Electromagnetic bearing within a high temperature environment. The bearing comprises electromagnets, each one constituted by at least one coil made of conductors, and one armature in ferromagnetic material. Each coil is produced by weaving and comprises a warp constituted from at least one insulated conducting wire and a weft constituted from a strip of insulating material, the whole coil assembly being thereafter molded in a high temperature cement.

Abstract: The invention relates to an active magnetic suspension device of a rotor placed in a sealed enclosure. Each active radial bearing comprises a stator composed of electromagnetic windings associated with a magnetic yoke which has end pole pieces placed at a short distance from the annular armature mounted on the rotor, the electromagnetic windings being arranged outside the sealed enclosure. Each stator magnetic yoke of laminar material is extended at the level of the end pole pieces by a terminal portion of non-laminar material, of small thickness, which constitutes directly a portion of the wall of the sealed enclosure and is attached by welding to the non-magnetic sealed wall portions which are not situated facing the annular armature.

Abstract: There is disclose a round of ammunition for a recoilless weapon of the type having a launch tube which is open at both ends, comprising a projectile, a propulsive charge positioned behind the projectile, a countermass positioned behind the propulsive charge, and a linking means connecting the countermass to the projectile. The linking means is formed of a plurality of small rigid linking rods of low mass and high ballistic coefficient fixed to the peripheral region of the countermass and on retaining elements located on the rear end of the projectile. The retaining elements are designed to shear during the launching of the projectile when the tensile load exerted on the retaining elements by the linking rods exceeds a predetermined level.

Abstract: An articulated pipe line comprising rigid sections jointed together so as to allow a limited angular movement between adjacent sections, the axis of two successive articulations having different directions and a sealing device ensuring a tight separation between the outside and the inside of the pipe line at the level of the articulation. This device is particularly suitable for immersed pipe lines of large diameter.