Abstract: A plurality of titanium sheets are assembled into a stack. At least one of the sheets is provided with a stop off material on one of its surfaces to prevent diffusion bonding at predetermined positions. The edges of the sheets are welded together and a pipe is welded to the stack to interconnect with the stop off material to form a sealed assembly. The assembly is heated and externally pressurized to diffusion bond the sheets together. The integral structure so formed is heated and opposite ends of the integral structure are twisted relatively to contour the integral structure to a predetermined shape. The integral structure is internally pressurized to break the adhesive bonds. The integral structure is heated and internally pressurized to superplastically form one sheet to produce an article, e.g. a fan blade.

Abstract: A vectorable nozzle for directing the thrust produced by an aircraft mounted lift fan includes three relatively rotatable nozzle sections. A first of the nozzle sections is part toroidal in form, and is mounted for rotation at the downstream end of the fan casing about an axis tangential to the casing periphery. The second and third sections define corresponding scarf nozzle sections which are mounted for rotation about respective axes perpendicular to the exit flow plane of the respective upstream nozzle section.

Abstract: An electrical connector has a pair of mating halves comprising a plug and a receptacle mounted on the respective ends of cables to be joined. The plug and receptacle each have a peripheral surface or shell and removable insulated inserts mounted therein through which electrical contacts extend. Spring fingers mounted on thee peripheral surfaces of the plug and receptacle retain the inserts and make electrical contact between the plug and receptacle. Bands hold the cables against the inserts to relieve the strain on the electrical contacts. Environmental seals are provided to prevent the ingress of contaminants into the connector. A releasable locking ring secures the plug and receptacle together.

Abstract: A pitch change mechanism for a plurality of fan blades (12) comprises adjustment device (60) to rotate the blades (12) about their longitudinal axes. A gear box (34) provides rotary power to drive the adjustment device (60) in response to a control signal. The gear box (34) is mounted in the fan shaft (30) and rotates therewith. An input shaft (33) to the gear box (34) is mechanically connected to a turbine shaft (32) so that the input shaft (33) rotates with the turbine shaft (32). The difference between the speeds of the fan shaft (30) and the turbine shaft (32) is used to drive an output shaft (39) of the gear box (34). The rotary power of the output shaft (34) drives the pitch adjustment device (60) via a plurality of gears (50).

Abstract: The stress wave activity produced during a first generation of a piece of handwriting in an enrollment procedure is put into a store and the stress wave activities produced for subsequent generations of the piece of handwriting in the enrollment procedure are used sequentially to produce a weighted average of the stored stress wave activity and the stress wave activity of the subsequent generation of the piece of handwriting and replaces the stored stress wave activity; the weighted average includes a weighted average of amplitudes and times of events. For subsequent generations of the piece of the handwriting are resequenced in order of increasing difference from the respective stored stress wave activity. The subsequent generations of the piece of handwriting are again used to sequentially produce weighted averages and replace the stored stress wave activity.

Abstract: A gas turbine engine combustion chamber has primary and secondary combustion zones. An annular secondary fuel and air mixing duct surrounds the primary combustion zone. The annular secondary fuel and air mixing duct is defined at its radially outer extremity by an annular wall. The annular wall is at least partially formed by an annular manifold. The annular manifold has a number of radially inwardly extending fuel injectors which inject fuel into the secondary fuel and air mixing duct. The annular fuel manifold is mechanically isolated from the remaining portion of the annular wall by an annular gap. The annular fuel manifold is supported from the combustor casing by a fuel supply pipe which is secured to the combustor casing and the annular fuel manifold.

Abstract: A variable area exit for a gas turbine engine discharge nozzle having a generally rectangular outlet includes a pair of rotatable flaps which extend between opposing sidewalls of the nozzle. Each of the flaps are provided with a profiled cam track which cooperates with a cam roller mounted on an axially moveable shroud ring. The shroud ring is coaxially disposed about the nozzle axis so that translation of the shroud causes the flaps to rotate and the nozzle exit area to alter.

Abstract: A gas turbine engine 10 is suspended via a casing 15 from a pylon 12 by a front mount 20 and a rear mount 40. The front mount 20 comprises a bracket 22, having a plurality of pins 26,28 and 30 integral therewith, which is bolted to the underside 11 of the pylon 12. The first pin 26 engages an annular flange 16 around the casing 15 to support the engine 10 in a vertical plane. Any vertical loads act peripherally of the casing 15 through the annular flange 16 to minimise the distortion of the casing 15. The second pin 28 engages with the casing 15 directly to prevent axial and lateral movement of the engine 10 relative to the pylon 12. The third pin 30 is provided as a failsafe. In normal operation the third pin 30 carries no load, however if the first pin 26 should break the third pin 30 then supports the engine 10 in a vertical plane. Any vertical loads then act peripherally of the engine casing 15 through an annular flange 18.

Abstract: A ducted fan gas turbine engine is provided with a plurality of sensors which detect the presence of liquid water in air exhausted from the high pressure compressor of the engine into its combustion system. In the event that liquid water is detected, the fuel flow to the combustion system is increased to cause the high pressure compressor to rotate faster and thereby vaporize the liquid water. Such liquid water can be present in the air exhausted from the high pressure compressor when the engine is operating in very heavy rain and can adversely affect normal engine operation.

Abstract: Fuel flow is scheduled to a plurality of combustion stages by putting a plurality of engine fuel flow governors in parallel with each other and letting the governor which outputs the lowest fuel demand signal be the one which schedules the total fuel flow to the engine. Fuel flows to the plurality of combustion stages are then individually schedulled to achieve the lowest fuel flows consistent with predefined temperature limits for the corresponding stages of combustion.

Abstract: A cooling and sealing arrangement in a gas turbine engine comprises a seal assembly extending between nozzle guide vanes and combustion chamber discharge nozzles. The nozzle guide vanes have platforms having extensions which in one embodiment overlap the downstream ends of the discharge nozzles. Cooling air is supplied to the upstream edge portions of the platforms through holes in flanges on the discharge nozzles. The seal assembly defines a chamber adjacent the platform extensions which is supplied with cooling air through metering holes in the seal assembly which provides part of a boundary for a cooling air chamber, the boundary of the chamber having cooling air holes for metering cooling air into the chamber to cool the upstream portion of the nozzle guide vane outer platforms. Cooling air exits the chamber through holes in the platform extensions to film cool them.

Abstract: A workpiece holder for angularly reciprocatory friction welding apparatus includes clamp members for clamping the workpiece to a mounting table. The height and circumferential position of a drum is adjustable to facilitate blade attachment in manufacture of a blum. Means are also described for reinforcing the drum during blade attachment in order to absorb welding forces which might otherwise distort the drum surface.

Abstract: A plate-fin type of heat exchanger (100) facilitates exchange of heat between two or more process streams (101, 102). It comprises a matrix (M) of two different types of heat exchange plate elements (P1, P2) inter-digitated with each other. Adjacent plate elements are metallurgically bonded together for good thermal contact by an activated diffusion bonding process. The plate elements (P1, P2) are high-integrity diffusion bonded sandwich constructions comprising two outer sheets (201, 203--FIG. 4) and a superplastically expanded core sheet structure (202) between the two outer sheets. The sandwich construction provides flow passages (P) for the process streams. Adjacent plate elements (P1, P2) carry different process streams (102, 102).

Abstract: A gas turbine engine turbine is provided with an annular array of nozzle guide vanes which define a radially inner annular platform. The radially outer surface of the platform is configured so as to define a plurality of convex and concave portions. These portions are so arranged as to vary the static pressure of the gases which operationally flow across the vanes in such a manner that the static pressure in the field immediately downstream of the vanes is substantially circumferentially uniform.

Abstract: A plate-fin type of heat exchanger facilitates exchange of heat between two process streams such as high pressure methane and seawater and includes a matrix of heat exchange plate elements arranged side-by-side, flow passages for the seawater process stream being defined between adjacent plate elements. The plate elements are a high-integrity diffusion bonded sandwich construction comprising two outer sheets and a superplastically expanded core sheet structure between the two outer sheets. The sandwich construction provides flow passages for the methane process stream. Adjacent plate elements are held in position relative to each other by serrated bars or racks which engage the edges of the plate elements.

Abstract: Fan blades of a rotor stage do not have platforms and separate wall members are provided to bridge the space between adjacent blades with the wall members defining an inner wall of a flow annulus through the rotor; each wall member has a plurality of hooks which extend radially inwardly to engage correspondingly shaped hooks provided on the radially outer face of the disc and further hooks engage rings mounted on the rotor adjacent to the disc to lock the wall member in position and insure that the hooks on the wall member engage the hooks on the radially outer face of the disc.

Abstract: A fan rotor has separate wall members bridging the space between adjacent blades of the rotor to define an inner wall of a flow annulus through the rotor; each wall member is attached to the radially outer face of a disk and opposing side faces to which resilient seal strips are bonded; the seal strips have flange portions which are inclined radially inwardly along a curved edge to produce undulations to enhance the flexibility of the flange portion so that, in operation, as the fan rotor rotates about a central axis of the engine, the flange portions are deflected radially outwardly by centrifugal forces into sealing contact with the adjacent fan blade to seal the inner wall of the flow annulus.

Abstract: A fuel control system for a gas turbine aero engine comprises a first metering valve 22 which is controlled by a feed back loop 43 in flow series with a manually operated metering valve 34. A pressure drop regulator 31, 39 regulates the pressure drop across the series connected valves 22, 34. In this way response of the control system is directly influenced by movement of the manual valve 34 and the automatic valve 22 stabilizes the fuel flow rate in response to monitored operating parameters of the engine.

Abstract: A variable camber vane comprises a plurality of articulated spanwise segments which can be operated by a mechanism of pivoted links at one end. A plurality of such vanes may be arranged in a supporting frame to act a variable thrust deflector for the exhaust of a lift engine. In a VTOL or STOVL aircraft installation the vane array is mounted on the underside of the aircraft below a downwardly exhausting lift fan and the range of movement of the variable vane array is used to vector lift thrust between a mainly downward direction and a direction having a substantially rearward component.

Abstract: A combined reformer and shift reactor comprises a cylindrical reforming chamber arranged within and on the axis of a cylindrical vessel. An annular steam generator is arranged within, and coaxially with, the vessel. The steam generator is arranged around the reforming chamber. A plurality of shift reactors extend axially, with respect to the vessel, through the steam generator. Methane and steam are supplied via helically coiled pipe to the reforming chamber and air is supplied via helically coiled pipe. The methane and steam mixture and air flowing through the pipes are preheated by the reforming chamber product gases flowing in annular passage. The shift reactors convert carbon monoxide and water in the product gases to carbon dioxide and hydrogen and the heat produced is transferred to the water in the steam generator to produce steam.