Abstract: A locking member for insertion into a radial gap between radially inner and outer components 28,29 respectively which rotate together. The locking member is provided for preventing relative rotational movement between the components and exploits and centrifugal forces exerted on the ring due to the rotation of the components to ensure that frictional locking is maintained. The ring is shaped to form a plurality of "levers" 25 joined together the ring. Each lever 25 comprises two limbs 22,24 and has a fulcrum (b) which engages an inward facing circumferential surface of the outer component 29. The product of the mass of one of the limbs 22 of each lever 25 with its moment about the fulcrum is greater than the corresponding product for the other limb 24 so that the centrifugal forces on the limbs 22,24 cause each lever 25 to rock about its fulcrum (b) and thereby urge the limbs 24 into engagement with an outward facing circumferential surface of the inner component 28.

Abstract: The invention relates to intakes for turbopropeller gas turbine engines of the tractor type. A tractor turbopropeller gas turbine engine comprises a gas generator, an upstream propeller and a downstream propeller. The propellers are positioned upstream of the gas generator, and the propellers are driven via shaft means and gear means. An intake means supplies air to the gas generator, the intake means comprises an intake opening and an intake duct. The intake opening is positioned axially between the propellers, and a portion of the intake duct extends axially through the downstream propeller. This arrangement reduces the length of the shaft and the turbopropeller gas turbine engine, and reduces the weight accordingly. The intake opening is arranged to provide improved protection against ingestion of large foreign objects, such as birds, into the intake duct and gas generator.

Abstract: A circumferential array of aerofoil blades (11) comprising an aerofoil portion and a root portion is mounted on the periphery of a disc (14), sealed in place under vacuum and subsequently hot isostatically pressed to achieve diffusion bonding across the interface between the array (11) and the disc (14). Each of the root portion of the array (11) and the disc (14) is provided with axially extending flanges (12, 13, 15 and 16) at its axial ends. The flanges (12, 13, 15 and 16) are so dimensioned that when the array (11) is mounted on the disc (14) the flanges (12, 13, 15 and 16) engage each other in close fitting relationships in such a way that the array (11) and the disc (14) have an enclosed annular chamber radially spacing them apart. Annular chambers (18, 19) are provided at the interfaces of the confronting flanges (12, 13, 15 and 16), and the regions of the interfaces between the chambers (18) and the free axial ends of the flanges (12, 13, 15 and 16) are sealed by vacuum brazing.

Abstract: A common mechanism enables both throat area change in either a fan duct or an exhaust gas duct and flow deflection at the nozzle of the duct.

Abstract: The invention relates to fluid outlet ducts particularly cooling air outlet ducts of a gas turbine engine. A fluid outlet duct for a gas turbine engine is divided across its width into a plurality of second plenum chambers, each of the second plenum chambers has an associated exit nozzle located in the casing of the gas turbine engine for discharging cooling air. The cooling air from a heat exchanger is supplied through a first plenum chamber to each of the second plenum chambers. Each of the second plenum chambers has a valve to vary the flow of cooling into the second plenum chambers so that the total flow area of the fluid outlet duct may be varied to obtain relatively high exit velocities for the cooling air to give good thrust recovery.

Abstract: A gas turbine engine disc having integral, radially extending aerofoil blades and an integral shroud interconnecting the radially outer extents of the blades is described. In the manufacture thereof continuous fibres are wound around an annular array of inserts provided in a dividable disc. The inserts define the spaces between adjacent blades on the disc. A mixture of chopped carbon fibre and an epoxy resin matrix material is then injected into the central portion of the die interior. Any part of the wound fibres which has not been impregnated by the chopped fibre/resin matrix material is subsequently impregnated by a matrix material whereupon the die is opened to release the thus produced bladed disc.

Abstract: One problem associated with aircraft using variable cycle engines is how to provide an air intake which is sufficiently large to be able to supply air to both the first and second compressors of the engine during the parallel flow mode and sufficiently small to minimize aerodynamic drag when the engines are operated in the tandem flow mode during supersonic forward flight. This invention overcomes this problem by providing an air intake which combines a blocker door covering a second portion of the duct which communicates with the second compressor and a means of varying the inlet area of the duct such that the area is maximized when the engines are required to operate in the parallel flow mode and minimized during series flow operation.

Abstract: A geared turbofan gas turbine engine has a fan rotor carrying a plurality of fan blades driven by a gas generator via a gear assembly. A fan casing which has an exterior surface is positioned coaxially with and encloses the fan rotor.A lubricant supply is provided to lubricate and cool the gear assembly and a heat exchanger is provided to cool the lubricant.An air scoop forms a first duct which supplies air to the heat exchanger to cool the lubricant. A second duct defined partially by the air scoop downstream of the heat exchanger and an annular chamber formed coaxially supplies air warmed in the fan casing by the heat exchanger to the exterior surface of the fan casing for deicing or anti-icing purposes.The air scoop and heat exchanger can be positioned on the fan casing, the gas generator casing or a pylon. A valve in the air scoop controls the flow of warmed air to the second duct.

Abstract: One problem associated with aircraft using variable cycle engines is how to provide an air intake which is sufficiently large to be able to supply air to both the first and second compressors of the engine during the parallel flow mode and sufficiently small to minimize aerodynamic drag when the engines are operated in the tandom flow mode during supersonic forward flight. This invention overcomes this problem by providing an air intake which combines a blocker door covering a second portion of the duct which communicates with the second compressor and a means of varying the inlet area of the duct such that the area is maximize when the engines are required to operate in the parallel flow mode and minimized during series flow operation.

Abstract: A radiation probe includes an optionally cooled tube 10 with a window 22 at one end, and can be traversed across a gas turbine engine combustion chamber 20 by drive means 26. A radiation detector 28 simultaneously measures radiation intensity at a plurality of wavelengths, at each of a succession of positions during the traverse. From this data, local values of radiation levels, grey and non grey absorption coefficients, local temperature and local gas composition and soot concentration are calculated, using a recurrence formula which relates intensities at neighboring positions.

Abstract: Known porous laminates of the kind wherein ambient atmosphere each side of the laminate is connected via holes and passageways, the latter lying within the laminate thickness in planes parallel with the faying faces, suffer from airflow energy loss which arises from the changes in direction undergone by the airflow while in transit from one side of the laminate to the other side thereof. The invention provides extra holes on the high pressure side of the laminate, over those points in the passages wherein the greatest change in direction of flow occurs, so as to re-energize the airflow which has reached those points via the relevant holes of the known arrangement.

Abstract: An apparatus for winding a filament onto a former includes one or more filament supply bobbins mounted on an annular carrier for rotation about a first axis for receiving a plurality of windings of the filament, and a translation device for moving the former relative to the carrier along a path which passes through the carrier thereby enabling the filament to be wrapped around the former. A guide member guides the filament from a respective bobbin to the former, the guide member defining a radially outward facing cylindrical surface. The apparatus reduces bending of the filament as it is wound onto the former.

Abstract: A rigid, non-metallic laminate suitable as a fire barrier, made by impregnating a layer of non-metallic fibers other than glass fibers with a resin, coating glass fibers with a refractory aluminum silicate to form a sheath, superimposing a layer of the thus alumina silicate coated glass fibers on the resin impregnated layer of non-metallic fibers and then subjecting the resulting laminate simultaneously to heat and pressure to squeeze resin from the non-metallic fibers into the interstices of the alumina silicate coated glass fibers and to cure the resin binder. A rigid multi-layer laminate in a common resin binder useful as a fire resistant panel or duct for a gas turbine engine results.

Abstract: A cooled vane suitable for a gas turbine engine is provided with an internal chamber which is fed with cooling air from the radially inner and outer ends of the vane. Cooling air supplied to the radially inner end of the vane is at a higher pressure than that supplied to the radially outer end. In order to ensure effective cooling of the vane a chordwise extending baffle is provided within the chamber to divide the chamber into radially inner and outer portions. The baffle is so configured as to permit a limited flow of cooling air from the radially inner chamber to the radially outer chamber. This facilitates effective cooling of the aerofoil of the vane in the region of the baffle.

Abstract: A power turbine suitable for a gas turbine engine which a blade of one array of turbine blades has a fan propulsion blade attached to its radially outer extent. A drum member is further provided which carries at least one further annular array of turbine blades and is coaxially interposed between the arrays of turbine blades and fan propulsion blades to rotate with the same in operation. Aperatures are defined through the drum member to accommodate the attachment structure provided between the turbine blade and the fan propulsion blades such that relative radial movement is permitted between the turbine blade and the drum.

Abstract: Monitor signals are produced which are qualitative or quantitative measures of the shape, size or position of a light spot on an optical head relative to fibre-optic receptors in the optical head. One pair or two pairs of receptors may be used. Production of the monitor signals involves modulating the incident light forming the light spot at a predetermined frequency, delaying the light signals in one or more of the fibre-optic receptors relative to the light signals in one or more of the other receptors by, say half a wavelength of the predetermined frequency, combining the outputs of the fibre-optic receptors to produce a compound light signal, producing an equivalent compound electrical signal by means of a photodiode, and processing the compound electrical signal in electronic processors to extract one or more of its components to act as the monitor signals.

Abstract: The present invention is particularly concerned with the supply of fuel to fuel servos of gas turbine engines. A check valve (62) is positioned in a return pipe (40, 24, 22, 26) from a fuel spill valve (12) to the upstream low pressure side of a high pressure pump (10). An aperture (32) in a piston (30) of the check valve (62) produces a predetermined pressure drop across the check valve (62) when the flow of excess fuel reaches a predetermined value. A fuel servo shut off valve (64) is positioned in a pipe (42, 58) connecting a fuel flow regulator (14) to a fuel servo (80). A piston (46) of the fuel servo shut off valve (64) initially closes a chamber (56) to prevent fuel being supplied to the fuel servo (80), from the fuel flow regulator (14). The piston (46) of the fuel servo shut off valve (64) is moved against a spring (48) when the predetermined pressure drop is formed across the check valve (62) to allow fuel to be supplied from the fuel flow regulator (14) to the fuel servo (80) via chamber (56).

Abstract: Known methods of controlling inertia welding and friction welding processes fail to control metal upset, and so require post machining of the welded components. The invention pre-determines the ideal rates of relative rotation, force applied and metal upset rates for a given material to be welded, enters those rates in a microprocessor memory and then connects the microprocessor to the apparatus on which the weld is to be effected. The microprocessor monitors the actual rates, compares them with the ideal rates and, should differences occur, generates signals from those differences with which to adjust operation of the apparatus.

Abstract: A brush seal operationally located between a rotatable shaft and static structure comprises a number of stages. The seal stage adjacent a region of low fluid pressure and its adjacent stage are spaced apart by an apertured ring. The apertures in the ring being so dimensioned as to vent pressurized fluid from the chamber and thereby reduce the magnitude of the pressure differential across the seal stage adjacent the region of low fluid pressure.

Abstract: A load transference structure between a core engine and power turbine comprises a plurality of circumferentially spaced apart radially extending spoke members, each of which is attached at its radially inner extent to first and second axially spaced apart support panels. Each of the spoke members is provided with a circumferentially extending portion positioned adjacent the panels which are adapted to cooperate with a circumferentially adjacent spoke member in such a manner that radial but not circumferential load transfer is permitted to take place between them. The load transfer structure permits load transfer to take place between the core engine casing and the power turbine.