Abstract: A valve arrangement comprises a piezo electric member arranged to control fuel flow through an orifice, the piezo electric member being operable to flex away from the orifice to allow an increased rate of fuel flow therethrough. The piezo electric member is also engageable with a valve member of a pressure relieving valve to control lifting of the valve member from a seating.

Abstract: An electronically controlled brake booster for a vehicle brake system including a housing having a vacuum chamber and a servo chamber separated from the vacuum chamber by a movable wall. The brake booster further includes a control valve operable by an electromagnet. The control valve is coupled to the wall for common relative movement with respect to the housing. The electromagnet is connectable to a control unit generating a drive signal to operate the electromagnet. A braking pressure generation unit is connected to the movable wall for generating a braking pressure for a brake of the vehicle in dependance on the position of the movable wall. The drive signal is generated in the control unit in dependance on a control parameter, the parameter being adjusted in dependance on a dead time of the braking pressure between supplying the electromagnet with the signal and a rising of the braking pressure in response thereto.

Abstract: A fuel supply system for supplying fuel to the cylinders of an associated engine is disclosed. The system comprises a fuel pump for supplying high pressure fuel to a delivery line, a plurality of injectors connected to the delivery line and means operable to deliver fuel through the injectors to respective cylinders of an associated engine, and a control valve connected to the delivery line and operable to control the pressure of fuel within the delivery line.

Abstract: An electrical generator provides an output at a main stator winding which is excited by a main rotor winding. The main rotor winding is connected via a rectifier to a main exciter rotor winding which is excited by a main exciter field winding. A control circuit controls excitation of the main exciter field winding so as to stabilise the generator output voltage. The control circuit includes a detector for detecting excessive generator output voltage and a transistor switch for connecting a resistor in the current recirculation path of the main exciter field winding so as to prevent transient over-voltages caused by sudden load reductions.

Abstract: A wear sensing system for the brake linings of a vehicle. Since the sensors are mounted within the brake mechanism, the reduction in the disc thickness must be taken into account to supply an accurate reading. A non-volatile memory stores the position of the brake before replacement and is compared to the position after replacement. However, the latter reading is established only after a predetermined number of brake applications to take up any starting clearances.

Abstract: A fuel control system for a gas turbine engine having a plurality of burner manifolds, comprising a spill valve for spilling excess fuel from a high pressure fuel supply line and a plurality of control arrangements, each of which is arranged to control fuel flow rate to a respective one of the manifolds and comprises a metering valve and a regulator for regulating the pressure drop across the metering valve, the spill valve having a cylinder containing a piston which is movable to close the spill valve and each of the regulators having a valve for connecting the cylinder of the spill valve to high pressure fuel when the pressure drop across the metering valve is less than a predetermined value.

Abstract: A fuel filter element includes an outer casing within which is located an annular filter medium which surrounds an inner tube. The filter medium is supported by upper and lower annular support plates. The upper support plate is provided with apertures to allow fuel flow and the lower support plate has a series of apertures which are located adjacent the outer peripheral edge of the plate.

Abstract: An optical displacement sensor is used to measure the rotary displacement between two shafts which rotate together. By connecting the shafts together by means of a torsion bar, the sensor may be used to measure transmitted torque. The sensor comprises first and second coaxial discs mounted on the shafts and having slots formed therein. A light source directs light through the slots onto an array of photodetectors and a data processor determines the displacement or torque from the positions on the array of images of the slot edges.

Abstract: A fuel injector for use in conjunction with a common rail supply system comprises a nozzle within which a valve element is slidable. The valve element includes a thrust surface to which fuel is supplied from a source of fuel at high pressure through a supply passage. The pressure controller in the form of a restrictor is located in the supplied passage so that, in use, during injection the fuel pressure applied to the thrust surface falls to a level lower than that prior to injection.

Abstract: An injector is described which comprises a valve element engageable with a seating, the valve element being resiliently biased into engagement with the seating. The valve element includes a thrust surface arranged, in use, to have high pressure fuel applied thereto to lift the valve element from the seating. A stop in the form of a second valve member is arranged to restrict movement of the valve element away from the seating, the second valve member being arranged to have high pressure fluid applied thereto and being movable under the influence of the valve element against the action of the high pressure fluid, in use.

Abstract: The present invention relates to a radial piston pump, and more particularly to a radial piston pump suitable for delivering liquid at a high pressure and at a volumetric output rate which can be controlled independently of the speed of rotation of the pump drive shaft. A radial piston pump(1) is provided which comprises a multiplicity of radially extending cylinders(14) each of which is provided with a radially moveable pumping plunger(15) to define, within the cylinder, a pumping chamber(16) which may be increased in volume by a movement of its associated plunger(15) in one direction to receive a liquid to be pumped and may be reduced in volume by movement of its associated plunger(15) in the opposite direction to deliver a liquid at high pressure to an output line. The pump(1) also comprises means for selectively disabling one or more of the pumping chambers(16) so that the or each disabled pumping chamber delivers no pumped fluid to the output line.

Abstract: A piston pump for the delivery of hydraulic fluid, in particular for ABS braking systems, comprises a pump housing 10 with an inlet 12 and an outlet 14 for the hydraulic fluid. A piston 16 is guided in the pump housing 10 without a sliding sleeve and supplies hydraulic fluid from the inlet 12 to the outlet 14 of the housing 10. A valve assembly 20 together with the piston 16 and a return spring 34 for the piston is joined as an asseembly capable of being handled independently and arranged directly in the pump housing 10.

Abstract: A method of operating a drive circuit of a solenoid of an electromagnetic device including an armature, the drive circuit including switch means in series with the solenoid, comprising closing the switch means to achieve a high rate of current increase in the solenoid, opening the switch means when the current reaches a predetermined level and allowing the current to decay, the movement of the armature from a first to a second position being completed whilst the current is decaying and monitoring the decaying current using a sensing circuit which includes means responsive to a discontinuity in the decaying current flow when the armature reaches the second position.

Abstract: A brake and actuator assembly is disclosed, and includes a brake having an actuating shaft operable to cause friction elements of the brake to be urged against a rotary braking member. The assembly also includes a brake actuating mechanism to which the shaft is operably connected for brake actuation. The shaft forms a splined connection, at a location spaced from the actuating mechanism, with a coupling device coupled to an output member of a power device, enabling the position of force application from the power device to the shaft to vary along the shaft to accommodate friction element wear in the brake. The line of force application between the output member and the shaft lies generally in a radial plane extending through the member, coupling device and splined connection.

Abstract: A commutation control strategy for eliminating torque ripple and noise from a brushless motor which has a plurality of motor phases connected in a bridge, each phase having a top switching device provided between a phase winding and a positive voltage supply and a bottom switching device provided between the phase winding and a less positive voltage supply in which following commutations of the motor, when the current flowing in a first phase is decaying towards zero and the current in a second phase is rising from zero, the switching devices are operative between a state in which the current flowing in the first phase is caused to decay at a first rate, and another state in which the current flowing in the first phase is caused to decay at a second rate which is lower than the first rate so that the rate of decay of the current in the first phase substantially matches the rate of rise of the current in the second phase.

Abstract: A fuel injection nozzle is disclosed which comprises a valve needle slidable along a first axis to control fuel delivery by the nozzle, and an actuator including a member moveable along a second axis to control movement of the valve needle. The first and second axes are offset from one another, thus the wall of a body housing the valve needle and actuator includes a region of relatively great thickness.

Abstract: The clamping device comprises at least one plunger (30) which is displaceable in the direction of a plunger axis (C) for applying a brake pad to a brake disc, and at least one eccentric (24) which is rotatable about a transverse axis (B). A roll body (28) is carried on the eccentric (24) for transmitting actuating forces to the plunger (30). An adjusting member (70) is rotatable about an adjusting axis (D) extending at an angle to the transverse axis (B) to compensate for lining wear. A pin (76) is fixed to the eccentric (24) and cooperates with the adjusting member (70) to transmit the torque for effecting an adjustment to compensate for lining wear. The pin (76) forms part of a safety mechanism (76, 98) by which the roll body (28) is prevented from inadmissibly moving in the direction of the transverse axis (B) with respect to the eccentric (24).

Abstract: An electrically operated trigger valve for a fuel injection pump includes a valve member secured to an armature to form an armature and valve member assembly. The valve member is slidably mounted in a bore and controls communication between the fuel inlet and a fuel outlet. In use, the valve is maintained in its closed position by energizing a stator coil to attract the armature. When the stator is de-energized the armature and valve member assemblies moved in the valve opening direction by a valve opening spring. The length of the valve opening spring is such that when the valve is in the fully open position a gap exists between one end of the opening spring and its adjacent seat. Accordingly, initial movement of the armature and valve member assembly in the closing position, upon subsequent energization of the state of coil, is not opposed by the spring until the gap has been eliminated by initial movement of the armature.

Abstract: A pump is disclosed having a variable cam arrangement under the influence of which a plunger is reciprocable. The variable cam arrangement comprises a plurality of cam rings which in an embodiment of the pump are relatively moveable in order to adjust the shape of the effective cam surface of the cam arrangement, and hence adjust the delivery rate of the pump.

Abstract: A vehicle anti-lock braking (ABS) system having a motor-driven pump (10) for providing a hydraulic supply to the ABS system. The pump motor (10) is controlled by a series device in the form of an electronic switch (16), such as a MOSFET, to enable frequent testing of the motor circuit by short pulses which produce no significant noise. Feedback to control motor speed is obtained by measuring the e.m.f. generated by the motor (16) after it has been switched off and after a delay to allow the back e.m.f., caused by switching off the motor, to decay (preferably to zero) before the measurement operation begins. The generated voltage is integrated during a motor switch-off period, the motor speed being established in this period by subtracting the measured integrated voltage when acting as a generator from the main supply voltage (B+) .