Abstract: A variable geometry exhaust nozzle for a turbojet engine is disclosed having an array of outer flaps and an array of inner flaps radially spaced apart and extending about a central axis of the exhaust duct structure. The array of outer flaps comprises a plurality of outer flaps each having an upstream end pivotally attached to the engine duct structure. The array of inner flaps comprises a plurality of upstream inner flaps, each having an upstream edge pivotally attached to the engine duct structure and a plurality of downstream inner flaps each having an upstream edge portion pivotally attached to a downstream edge portion of a corresponding upstream inner flap. A control annulus is movably attached to the engine structure so as to be movable axially along the central axis and is connected to an actuator which moves the control annulus between upstream and downstream limit positions along the central axis.

Abstract: A valve is disclosed having a valve piston slidably movable within a valve casing. The valve also includes a spring biasing the valve piston against a valve seat such that the valve is normally closed, but may be opened when the pressure acting on the valve piston exceeds the biasing force of the spring. In order to assure perfect sealing between the valve piston and the valve seat, the valve seat is formed on a member which is movably mounted in the valve casing by a generally annular elastic element. The elastic element connects the valve seat to the valve casing, as well as a shoulder extending from the valve casing into the valve chamber,d such that an axial clearance exist between the valve seat member and the shoulder, and a radial clearance exists between the valve seat member and the valve casing under all operating conditions of the valve. Such clearances enable the valve seat member to move axially and radially so as to assure perfect sealing between the valve seat and the valve piston.

Abstract: The process makes it possible to produce partitioned boxes by carrying out the fastening or fixture from the outside of said boxes.Use is made of two successive inclined laser beam shots or flashes (8A,8B), which intersect at the upper surface (1B) of the part (1) constituting the assembly head. The two laser welding axes (8A,8B) intersect two upper corners (2C) of the part (2) serving as the base of the T. The welding device is positioned outside the box, i.e. on the side of the upper surface (1B) of the head (1) of the T.Application to the manufacture of the arms of the outer duct of a turbojet engine.

Abstract: A method and apparatus for detecting a fouled fluid filter are disclosed in which the fluid pressure at the outlet of the fluid filter is corrected by a correction pressure to determine a corrected pressure drop. Such a corrected pressure drop has a mathematical function which passes through a maximum magnitude before the fluid flowing through the fluid filter reaches a maximum value. The corrected pressure drop is monitored during the operation of the fluid filter and when the corrected pressure drop reaches a predetermined threshold value, before the engine with which the fluid filter is associated reaches its maximum power, an alarm will be actuated.

Abstract: Turbojet engine compressor . . . Its rotor (43) includes a movable end portion (45), such as a monoblock vaned disk able to be removed and replaced by a block. High and low pressure shaft lines (54) are formed into several portions to enable these operations to take place without having to dismantle the entire engine.

Abstract: A thrust reverser for a turbojet engine is disclosed in which the thrust erser baffles have one or more deflectors to direct the cold gas flow over an inner surface of the baffles to ensure that the inner surface remains out of contact with the hot gas flow. The deflectors are movably mounted on the baffles such that, when the baffles are in their forward thrust positions, the deflectors are retracted so as to be generally flush with the inner surface of the baffle so as not to interfere with the forward thrust flow of gases. The deflectors may be automatically deployed to their extended positions when the baffles are moved to their reverse thrust positions.

Abstract: A variable camber vane for a turbomachine comprises leading and trailing edge parts, at least one of which is pivotable relative to the other, and a resilient joining part inserted into a space provided between the leading and trailing edge parts, the joining part being formed by a block of resilient material which is bonded to the leading and trailing edge parts and which ensures the continuity of the intrados and extrados faces of the vane to permit an even flow of fluid along the vane. The vane may also include means for enabling a cooling or heating fluid to flow in the leading and trailing edge parts, and a plurality of ducts in the resilient joining part establishing communication between the fluid flow means of the leading and trailing edge parts.

Abstract: A combination converging-diverging exhaust nozzle and thrust reverser for an aircraft turbojet engine is disclosed having a generally annular array of cold flaps extending from a downstream end of a cowling support structure and a generally annular, inner array of hot flaps, located radially inwardly of the cold flap array and extending downstream from an end of the hot gas exhaust duct. The annular array of hot gas flaps comprises two sets of hot flap arrays, an array of first hot flaps being pivotally attached to the downstream edge of the hot gas exhaust duct with the array of second hot flaps having upstream edges that are in contact with downstream edges of the array of first hot flaps. The positions of the arrays of the first and second hot flaps may be adjusted relative to a central longitudinal axis to form a converging-diverging nozzle with a variable cross-sectional area.

Abstract: A sectorized tubular structure able to resist implosion pressures, especially at the links between annular sectors. The tubular structure includes annular sectors interconnected by flat linking elements, each including at its ends at least one projection whose end enables the annular sectors to be supported. Thus, each linking element ensures the transmission of forces from one annular element to another. The unit is supported by fixing screws which are never in contact with the two annular sectors to be kept assembled.

Abstract: The system makes it possible to reduce the clearances existing between the rotor and stator of a turbine (40) of a turbo jet engine during the various operating phases of the latter whilst keeping the temperatures of the disks inside the limits of their mechanical behaviour. The disks (4) of the turbine (40) are ventilated via the sampling of high pressure air at a high temperature (2) and the stator via the sampling of low pressure air at a low temperature (3). The respective temperatures of these two samplings are homogenized by a heat exchanger (1). This exchanger is short-circuited by a branch circuit connection (5) on the low pressure circuit so as to keep as stable as possible the clearances inside the turbine (40) according to the various ranges of capacity of the turbo jet engine by means of a valve (6) controlled by the computer.Application for aircraft turbo jet engines.

Abstract: A turbine engine stator has a metal casing surrounding an envelope carrying bearings for the pivots of pivoting blades. A control mechanism for setting the position of the blades includes a radial spindle to which are transmitted the thrust forces of the gases, the envelope being advantageously formed from angular sectors of axially juxtaposed flanges or rings and which are not loaded. Therefore, the bearings are not subject to wear giving rise to gas leaks and efficiency losses. Advantageously, the envelope is made from a composite material.

Abstract: A method of manufacturing an axisymmetric component made of a composite material having a metallic matrix is described in which at least one ceramic fiber and at least one wire of the metal which is to constitute the matrix are wound simultaneously side by side to form a number of layers on a suitably shaped mandrel and in such a manner as to ensure absence of contact between the fiber turns of each individual layer and between the fiber turns of adjacent layers, and the formed layers are subsequently subjected to hot isostatic compaction. The ceramic fiber may be of the silicon carbide type and the metal wire forming the matrix may be of titanium or titanium-alloy.

Abstract: The invention concerns a system for sealing the bearing of a machine, especially a turbomachine, in which a shaft is disposed inside a housing which includes a partition traversed by the shaft and separating an air chamber from an oil chamber, the housing including an axial boss on the side of the oil chamber, this system further including a device for generating a flow of air for pushing back the oil, which has penetrated into the space existing between the housing and the shaft, towards the oil chamber.

Abstract: A process for assembling at least two parts made from a composite material incorporating a ceramic or vitroceramic matrix reinforced by ceramic fibers. A continuous connection between these parts is achieved by approaching two of the parts along their respective edges to be assembled, forming a joint between the two parts by sewing with a tie or link of ceramic fibers from each of the parts to be assembled and heating the joints by a heating device employing a powerful and extremely localized heating until the two parts are welded together.

Abstract: A system for retaining and sealing vanes and composed of an flange provided with a throat on tabs which are interlaced in other tabs, also provided with throats of the vane feet. An elastic joint is engaged in the throats and a disk throat and keeps the elements of the flange and the vanes in an axial position.

Abstract: A seal arrangement located between a lubricated chamber and a pressurized chamber pressurized by a gas at a variable pressure. The seal arrangement includes a seal around a shaft extending into the lubricated and pressurized chambers through a wall separating the chambers. The seal slides along the shaft between a first and a second abutment position via a variable pressure exerting a force on an end face, i.e., a casing, of the seal. The casing, the shaft and seal define a clearance allowing air to pass from the pressurized chamber to the lubricated chamber. Springs urge the seal toward the first abutment position against the variable pressure and have a strength so that, when the variable pressure is under a predetermined value, the clearance is sealed. When the variable pressure is over a predetermined value, the seal slides to the second abutment position and the clearance is opened to allow the pressurized gas to flow from the pressurized chamber to the lubricated chamber.

Abstract: A method is disclosed for simultaneously molding separate portions of an article which may be subsequently assembled to form the complete separable article. Apparatus for carrying out the method includes separate mold portions which, when assembled, define a molding cavity in which each of the mold portions has an outwardly extending flange. The mold portions are fastened together such that the flanges are spaced apart a distance at least twice as great ad the thickness of the article to be molded. The mold portions extend along a longitudinal axis and each defines a molding surfaces which extends around the axis less than 360.degree.. When the mold portions are assembled, the molding surfaces extend completely around the longitudinal axis. The mold also includes silicone bead elements extending along the longitudinal axis in the space between the spaced apart flanges.

Abstract: A turbojet engine includes a combustion chamber located upstream of a turbine, the turbine having a rotor disk integrally bladed with vanes and including a channel blowing gas from a position outside a wall of the combustion chamber to a peripheral zone of the rotor disk adjacent to the vanes, a channel divided in front of a zone adjacent to the vanes into an internal channel and an external channel surrounding the internal channel, wherein the internal channel has a greater cross-section than the external channel and wherein the external channel converges upon approaching an outlet thereof so as to accelerate the gas flowing therethrough and prevent gas which passed through the internal channel from being dispersed.

Abstract: A variable cross-section nozzle for a jet engine is disclosed having main inner (hot) flaps defining an inner nozzle and main outer (cold) flaps defining an outer nozzle with adjacent main flaps interconnected by secondary flaps, such that actuators connected to two of the main flaps can vary the cross-sectional configuration of the exhaust nozzle outlet between a substantially circular configuration to one which is subsequentally or completely closed. The actuator is mechanically connected to the main inner and main outer flaps such that the nozzle configuration may be varied using a minimum number of actuators. A single outer nozzle may surround a pair of inner nozzles such as utilized on a dual jet engine aircraft.

Abstract: A fuel injection system for a gas turbine engine combustion chamber is disclosed having a sleeve defining a passageway extending along a longitudinal axis of a combustion zone, a first fuel injector orifice to inject fuel into the passageway, and second fuel injector holes arranged in a plurality of substantially linear arrays extending radially from the sleeve and angularly equidistantly spaced from each other, the second fuel injection holes located in a plane extending substantially perpendicular to the longitudinal axis of the combustion chamber such that the plane is located axially between an upstream end wall of the combustion chamber and the downstream end of the sleeve.