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: 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: 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: 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 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.

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 metallic coating on a part made from a ceramic composite is obtained from a powder obtained by mixing two powders: namely,a base powder A comprising 2 to 5% of a reactive element Ti or Zr, at least one melting element B or Si in proportions ensuring a liquidus temperature between 1000.degree. C. and 1300.degree. C. and additional metallic elements including at least 50% Ni or Ni+Co;a powder B in a weight ratio of 5 to 30%, the elements of which are chosen to impart to the part particularly desired surface properties such as anti-wear, anti-oxidation and/or anti-corrosion, and to ensure a liquidus temperature of powder B greater than that of powder A.

Abstract: A fluid supply system including a casing having at least one duct extending through it for the passage of fluid and a recess in the casing around the duct or ducts, a cover covering the recess and held against a bearing surface on the casing surrounding the recess, the cover carrying a continuation of the or each duct, and a vent in either the casing or the cover communicating the recess with the environment outside the casing, is provided with a leak tell-tale device for indicating passage of fluid along a path, such as the vent, which, in the event of a leakage of fluid from a duct into the recess, would be followed by the leaked fluid.

Abstract: A separator for an annular gas turbine engine combustion chamber is disclosed having a plurality of separator segments arranged in a generally annular configuration to form an annular separator extending from an upstream end wall of a combustion chamber into the combustion chamber so as to separate first and second combustion zones within the combustion chamber. Each of the separator segments has a hollow interior defined by a front wall, an outer wall, an inner wall which has at least a portion tapering or converging towards the outer wall in a direction extending away from the front wall, and first and second sides. The sides define an array of holes communicating with the hollow interior, the positioning of the array of holes on a first sides being different from that of the array of holes on the second sides such that the axes of the holes are out of alignment with each other.

Abstract: A fuel distribution system for a gas-turbine engine is disclosed which ensures homogenous fuel supply to all fuel injectors in order to avoid local fuel oversupplies that might cause local overheating of the turbine blades. The fuel system compensates for the deleterious load factors experienced by the aircraft and the gas turbine engine that affect the fuel distribution to the fuel injectors. The system supplies fuel to a plurality of fuel injectors arranged in an annular array so as to inject fuel into an annular combustion chamber of the gas turbine engine. The system has a closed loop, generally annular fuel connector line and a plurality of fuel distributors connected in parallel to the fuel connector line so that fuel passes into a central chamber of each of the distributors. Each fuel distributor has end chambers on opposite ends of the central chamber in which are movably located pistons whose positions within the end chambers open or close a fuel outlet in communication with each of the end chambers.

Abstract: A rotary valve assembly is disclosed in which a rotary valve member is located within a casing having one or more fluid inlets and a plurality of fluid outlets. The rotary valve member has a fluid conduit which extends in a generally radial direction and which communicates with the fluid inlet. Fluid orifices communicate with the fluid conduit and exit through opposite sides of the rotary valve member to thereby minimize, or eliminate altogether, axial forces acting on the rotary valve member. Fluid outlet passages communicate with the two fluid orifices during at least part of the rotation of the rotary valve member to direct the pressurized fluid to the valve outlets. The rotary valve may include a pair of rotary valve members drivingly connected to each other such that they rotate synchronously. The connection may include gear teeth formed on the adjacent peripheries of the rotary valve members such that rotation of one of the valve members causes rotation of the other.

Abstract: A hollow blade for a turbomachine includes a unitary body having a multiplicity of transverse cavities in at least the aerofoil shaped portion of the blade, and plugs disposed within the cavities for restoring the surface continuity of the intrados and extrados faces of the aerofoil shaped portion, the plugs being rigidly secured to the unitary body, such as by welding.

Abstract: An afterburner for a turbofan engine is disclosed having a plurality of connecting arms connecting the inner wall to the outer wall wherein each of the connecting arms defines an air chamber, an inlet communicating with the main air bypass passageway and a plurality of outlets communicating with the afterburner chamber. The plurality of connecting arms are distributed generally radially about the longitudinal axis of the engine and serve to distribute a portion of the bypass air into the afterburner chamber. The bypass air is further distributed into the afterburner chamber through a plurality of flame holders extending radially inwardly from the outer wall towards the longitudinal axis. Each of the flame holders also defines an air chamber, an inlet communicating with the main air bypass passageway and a plurality of air outlets. The flame holders may also be distributed in a radial array about the longitudinal axis and are interposed between adjacent connecting arms.

Abstract: A detector for detecting the level of oil in an oil reservoir is disclosed having particular application for use in a lubricating system of a gas turbine engine in order to determine a malfunction of an oil-fuel heat exchanger. The device uses an electrically actuated level sensor within the oil reservoir connected to a first electrical circuit having an outlet junction at which is applied a voltage U.sub.1 which varies with the level of oil in the reservoir, and a second circuit having a second outlet junction at which is applied a voltage U.sub.2 which decreases as the oil level decreases, but which does not increase as the oil level increases. A comparison circuit connected to the outlet junctions of the first and second circuits compares the difference between the voltages U.sub.1 and U.sub.2 to a predetermined reference voltage U.sub.0 and, if the difference exceeds this reference voltage, provides an output signal to actuate a visual indicator.

Abstract: A generally annular combustion chamber for a gas turbine engine is disclosed having fuel injector assemblies, each with an oxidizer swirler, extending through an upstream end wall of the combustion chamber and control means connected to the control diaphragms of the oxidizer swirlers in order to move the control diaphragms between maximum and minimum flow positions. The upstream end wall of the combustion chamber defines complementary oxidizer intake orifices which have movable closure plates to selectively open or close the complementary oxidizer intake orifices. A mechanical linkage connects the closure plates to the control diaphragm of an adjacent air swirler such that, when the control diaphragms are in their maximum flow positions, the closure plates close the complementary oxidizer intake orifices, and when the control diaphragms are in their minimum flow positions, the closure plates are moved such that the complementary oxidizer intake orifices are fully open.

Abstract: A thrust reverser safety system for a turbofan engine is disclosed which is integrated into the hydraulic control system of the thrust reverser door so as to prevent the hydraulic actuator from permitting the thrust reverser door to be forced into its deployed, thrust reversing position. The hydraulic actuator defines a closing chamber which, when acted upon by pressurized hydraulic fluid, urges the thrust reverser door to its closed, forward thrust position. The safety system according to this invention provides a valve associated with the hydraulic control circuit and the closing chamber which prevents the hydraulic fluid from being forced out of the closing chamber. This positively prevents the thrust reverser door from moving to its deployed, thrust reversing position.

Abstract: An integral, one-piece afterburner structure for a turbojet engine is disclosed which is formed of composite material. The afterburner structure has an outer casing formed as a body of revolution about a central axis, an inner casing also formed as a body of revolution about the central axis, which casings are integrally joined by a plurality of connecting arms extending between the inner and outer casing. The connecting arms are also formed of a composite material and are integrally molded with both the inner and outer casings. The afterburner structure also has a plurality of secondary support arms formed of composite material which extend either from the outer, or the inner casing in a generally radial direction relative to the central axis. Integrally formed with the plurality of secondary support arms is at least one annular flameholder ring which extends around the central axis and is supported by the secondary support arms.

Abstract: A heat treatment installation for parts made of a composite material having a ceramic matrix and including a treatment enclosure which is connected to a microwave generator by a waveguide and which includes a press for hot pressing a part to be treated in the enclosure and a gas source for introducing a protective gas into the enclosure.

Abstract: A variable geometry nozzle for a turbojet engine is disclosed wherein the adjustment of the cross-sectional area of the nozzle in a converging-diverging configuration is controlled by a single control system. The single control system varies the positions of both of the inner upstream and downstream flaps, as well as the outer flaps. A second control system operates simultaneously with the first control system to change the configuration of the nozzle to a converging-converging configuration. The inner, upstream flaps, which are pivotally connected to the downstream end of the turbojet exhaust duct, are controlled by an axially movable control ring which is connected to the controlled inner, upstream flaps via a link rod. The positions of the inner, downstream flaps, which have their upstream edges pivotally connected to a downstream edge of a corresponding upstream flap, are controlled by the movement of the upstream flap, as well as a connection with a cowling support via another link rod.