Abstract: A deterministic bus control (as shown in FIG. 2) comprises a conventional CAN integrated circuit bus controller, a transmit request buffer for storing transmit requests and a deterministic scheduler which detects the status of the bus and controls the release of stored transmit requests to the controller in accordance with a deterministic protocol (e.g. the ARINC 629 system protocol).

Abstract: A fuel injector comprising a valve needle, engagable with the seating to control fuel flow through a fuel outlet, the valve needle having a thrust surface oriented such that the application of fuel under pressure thereto applies a force to the valve needle urging the valve needle away from the seating. The fuel injector also comprises a valve member for controlling fuel pressure within a control chamber and a piston member slidable within a bore and defining, with the bore, the control chamber. The piston member is exposed to fuel pressure within the control chamber and is arranged to transmit a force applied by the fuel pressure to the valve needle. The piston member has an effective surface area exposed to the fuel pressure which is greater than that of the thrust surface so as to urge the valve needle towards the seating.

Abstract: A filter arrangement is described in which fuel flows through a filter member in a radially outward direction. A sleeve surrounds the filter element and defines, with the filter member, an air collection chamber. One or more small openings are provided in the sleeve whereby air is permitted to escape from the air collection chamber at a controlled rate.

Abstract: A vehicle door locking system including a latch mechanism (11) having an operative condition and a release condition, external and internal manually operable controls (14, 16) for releasing the latch mechanism, and controllable coupling means (15, 17) for determining whether or not the internal and/or external controls (16, 14) are linked to the latch mechanism (11); the system includes a control arrangement (21) responsive to locking input signals for determining the relationship between the controls (15, 17) and the latch mechanism (11).

Abstract: A fuel injector comprising a valve needle which is slidable within a bore, a surface associated with the valve needle defining, in part, a control chamber which communicates, through a restriction, with a supply passage. The fuel injector also includes an injection control valve controlling communication between the control chamber and a low pressure reservoir, and a drain valve controlling communication between the supply passage and the low pressure reservoir. The injection control valve and the drain valve include respective armatures moveable under the influence of a common electromagnetic actuator.

Abstract: A fuel injector comprising a valve needle biased by a spring into engagement with a seating, a surface associated with the valve needle being exposed to fuel pressure within a control chamber and restricted communication structure providing a restricted flow path between a supply passage and the control chamber. The fuel injector further comprises a drain valve controlling communication between the supply passage and a low pressure reservoir and an injection control valve controlling communication between the control chamber and the low pressure reservoir, the drain valve and the injection control valve being moveable under the control of a single electromagnetic actuator including an armature common to both valves.

Abstract: A pump injector comprising a pumping chamber, a valve needle controlling communication between the pumping chamber and one or more outlet openings, and a spill valve controlling communication between the pumping chamber and a low pressure fuel reservoir, in use. The pump injector also comprises an inlet non-return valve arranged to permit fuel to flow from the fuel reservoir to the pumping chamber, in use, but substantially preventing fuel flow in the reverse direction. Alternatively, the pump injector may comprise an abutment piston engageable with the valve needle which defines, in part, a control chamber for fuel, and a control valve controlling communication between the pumping chamber and the control chamber.

Abstract: A fuel injector includes a first needle, and a second needle slidable within a passage formed in the first needle. The needles are engageable with respective seatings to control fuel delivery through respective groups of outlet openings. A load transmitter is provided whereby movement of the first needle can be transmitted to the second needle. An alternative injector includes a second needle provided with formations defining an integral resilient biasing arrangement.

Abstract: A fuel system comprising a fuel pump having a pump outlet which communicates with a fuel volume, the volume communicating with the inlets of a plurality of fuel injectors. The fuel flow paths between the pump outlet and the inlet of each injector form substantially equal restrictions to the flow of fuel.

Abstract: A seal comprises a support member having an outer periphery of substantially circular form, and a resilient seal member mounted upon the support member, the seal member, when occupying a relaxed condition, having an outer periphery of generally circular form and a diameter greater than that of the support member, the seal member and support member being eccentric to one another when the seal member occupies the relaxed condition, the seal member being compressible towards a compressed condition in which the seal member and the support member are of substantially equal diameter and are substantially coaxial.

Abstract: A fuel injector comprises an outer valve needle, an inner valve needle slidable within a bore formed in the outer valve needle, an inner end of the inner valve needle being located within the bore, the inner end of the inner valve needle being provided with a recess whereby the application of fuel under pressure to the bore deforms the inner valve needle to form a substantially fluid tight seal between the inner and outer valve needles. The inner and outer needles may be exposed to the fuel pressure within a common control chamber, a single actuator arrangement being used to control movement of both needles.

Abstract: A fuel injector comprising a valve needle slidable within a bore formed in a nozzle body, the valve needle including an axially extending fuel supply passage which communicates with at least one outlet opening provided in the valve needle, the end of the supply passage adjacent the at least one outlet opening being closed by a plug. The plug has an inner end region which is arranged to be located, in use, adjacent the, or at least one of the, outlet openings, and shaped to modify the flow characteristics of the fuel flow upstream of at least one of the outlet openings.

Abstract: A fluid flow system for supplying fuel to an engine, the system including a fluid flow valve having a valve element movable alternatively to a first operative position in which a relatively low fluid flow rate is permitted through the valve, for achieving a normal gradual shut-off of fuel supply, and a second operative position in which a relatively high fluid flow rate is permitted through the valve, for achieving a rapid emergency shut-off of fuel supply. Also disclosed is a fluid flow valve for use in the system. The invention has application in aircraft gas turbine engines.

Abstract: A terminal clamp for a battery terminal post including first and second relatively movable jaws defining between them a passage for receiving a battery terminal post, and a screw-operated clamping arrangement for closing the first and second jaws about the terminal post, in use, to grip the post against the action of a resilient restoring force urging the jaws apart, the screw-operated clamping arrangement including first and second components in screw-threaded arrangement with one another, the first component being held against rotation relative to the jaws, the second component having a frusto-conical cam surface cooperable with corresponding part frusto-conical cam surfaces of the jaws, whereby rotation of the second component relative to the first component and the jaws causes rotational and axial movement of the frusto-conical cam surface of the second component relative to the part frusto-conical surfaces of the jaws either to close the jaws or to release the jaws.

Abstract: A fuel injector comprises a valve needle slidable within a bore and engageable with a seating to control the supply of fuel to an outlet opening, an end surface of the valve needle being exposed to the fuel pressure within a control chamber defined, in part, by a piston member moveable under the influence of a piezoelectric actuator. The control chamber may be supplied with fuel under pressure, in use, through a restricted flow path. The piston member may have an effective area exposed to the pressure within the control chamber which is greater than that of the needle.

Abstract: A connector is disclosed which is intended for use with an injector. The connector comprises a projection defining an inlet passage sealed, in use, within a bore provided in the injector. The inlet passage communicates with at least one outlet passage. The connector further comprises at least one tooth received within a recess provided in the injector to secure the connector to the injector. The recess is conveniently defined by a body and nut forming part of the injector.

Abstract: A pressure regulator for use with a low pressure fuel pump comprises a pressure relief valve connected between the inlet and outlet of the pump to permit fuel flow from the outlet to the inlet upon the pressure difference therebetween exceeding a predetermined level, and an accumulator independent of the pressure relief valve communicating with the outlet of the pump.

Abstract: A variable speed rotary electric machine comprises a stator having windings and a rotor having windings mounted within the stator for rotation about an axis; a cooling fluid inlet into a first end region of the rotor; at least one first fluid duct having an inlet orifice in the first end region of the rotor and an outlet orifice arranged to discharge fluid onto a first region of the stator windings; and at least one second fluid duct having an inlet orifice in an opposite end region of the rotor and an outlet orifice arranged to discharge fluid onto a second region of the stator windings. A flow path extends through the rotor from the first end region to the opposite end region, the rotor windings being in the flow path. The machine also comprises at least one third fluid duct having an inlet orifice in said opposite end region of the rotor and an outlet orifice.

Abstract: An injector includes a nozzle body having a bore and defining a seating, and a fuel flow path along which fuel flows, in use, towards the seating. A needle is slidable through a range of movement within the bore, and engagable with the seating to control fuel flow to an outlet aperture. The needle includes a thrust surface against which fuel at high pressure acts, in use, to lift the needle from its seating. The bore and needle together define a restriction to the flow of fuel along the fuel flow path towards the seating. The restriction is located upstream of the thrust surface, and the restriction is arranged to restrict the rate of flow of fuel towards the seating throughout the range of movement of the needle. In a preferred embodiment, the restriction is arranged such that the rate of fuel flow towards the seating through the restriction varies as the needle separates from the seating.

Abstract: An advance arrangement comprises an advance piston slidable within a bore, the advance piston cooperating, in use, with a cam arrangement of a fuel pump to adjust the timing of fuel delivery by the pump, a servo-piston slidable in a bore provided in the advance piston, a light load piston moveable relative to the advance piston against the action of a light load control spring, a servo control spring engaged between the light load piston and the servo-piston, a light load control valve operable to control the application of fuel to the light load piston to adjust timing under light load conditions, and an independent temperature control valve operable to control the application of fuel to the light load piston depending upon the engine temperature to permit adjustment of the timing of fuel delivery to compensate for cold conditions.