Abstract: A seal arrangement having a bore within which a component is to be received, in use, the seal arrangement comprising a seal member formed from a resilient material, the seal member having an inner periphery and an outer periphery and being provided with a fracture to define two ends of the seal member. When in a relaxed condition, the inner periphery of the seal member has a smaller diameter than the diameter of the component such that, when the component is received through the bore of the seal arrangement, the two ends of the seal member are caused to part, the resilience of the seal member causing the inner periphery of the seal member to form a substantially fluid tight seal with the component. The seal arrangement further comprises a support member upon which the seal member is mounted, the support member being of generally annular form and having inner and outer peripheries, wherein the inner periphery of the support member is of generally circular form except for a region of irregularity.

Abstract: A fuel injector comprises a first needle, and a second needle slidably 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. Load transmitting means are provided whereby movement of the first needle can be transmitted to the second needle. Also described is an injector in which a second needle is provided with formations defining an integral resilient biasing arrangement.

Abstract: A fuel injector comprising a valve needle which is slidable within a bore and engageable with a seating to control fuel delivery through first and second outlet openings. The valve needle is moveable between a closed position and first and second fuel injecting positions. The fuel injector further comprises a fuel supply passage for supplying fuel under pressure to the bore and a control chamber which is arranged to receive fuel from the fuel passage, in use. The valve needle is acted upon in use by a force due to fuel pressure within the control chamber. An actuator arrangement controls fuel pressure within the control chamber, and a damping means are provided for damping movement of the valve needle away from the seating into the first or second fuel injecting position. The supply passage for fuel may be provided with a restricted flow passage which serves to limit the amplitude of pressure waves within the supply passage.

Abstract: A metering valve for metering fuel flow, the valve having a flow rate control member moveable along an axis to control the rate of flow of metered fuel through the valve, and a piezo-electric bending device bendable in response to a control signal so as to cause the flow rate control member to move a desired distance in a selected direction along the axis.

Abstract: A piezoelectrically actuable fuel injector comprising an accumulator volume within which a piezoelectric stack is arranged, the accumulator volume being arranged to receive fuel from a source of pressurized fuel, in use. The piezoelectric stack carrying an end member which engages a surface associated with a piston member so as to apply a retracting force to the piston member upon a reduction in the axial length of the piezoelectric stack, the piston member being operable to control fuel pressure within a control chamber. A volume is defined between the end member and the surface associated with the piston member. The volume is provided with a vent arrangement to permit fuel within the volume to flow to a low pressure drain.

Abstract: A valve arrangement for a fuel injector arrangement, in which liquid fuel is drawn from a low pressure drain source and supplied from a pump at high pressure through a main fuel supply passage to an outlet of the injector arrangement. The valve arrangement includes a pressure regulating means which, during the course of an injection, regulates the pressure of fuel being supplied to the outlet. The pressure in the main fuel supply passage is regulated to a preselected pressure, which is intermediate drain pressure and pump supply pressure.

Abstract: An actuator housing for a piezoelectric actuator arrangement including a piezoelectric stack, the housing comprising a first housing portion for connecting leads which are electrically connected to the piezoelectric stack and a second housing portion for the piezoelectric stack. The first and second housing portions are integrally moulded and are formed from a material which permits flexing of the first housing portion and the connecting leads.

Abstract: A fuel injector comprising a valve member which is engageable with a valve seating to control fuel delivery from the injector, an actuator arrangement and an amplifier arrangement for transmitting movement of the actuator arrangement to the valve member. The amplifier arrangement comprises a piston member with which the actuator arrangement is cooperable to apply a retracting force to the piston member, and a control chamber for fluid. The amplifier arrangement preferably comprises a mechanical coupling arrangement for coupling movement of the piston member to the valve member upon application of an initial retracting force to the piston member.

Abstract: A fuel injector comprises a first needle, and a second needle slidably 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. Load transmitting means are provided whereby movement of the first needle can be transmitted to the second needle. Also described is an injector in which a second needle is provided with formations defining an integral resilient biasing arrangement.

Abstract: A nozzle for a fuel injector comprises a nozzle holder, a tip secured to the nozzle holder, the tip being provided with at least one outlet opening, and a feature provided on the tip providing an indication of the position(s) of the opening(s).

Abstract: A multi-chamber positive displacement pump comprises a unitary housing in which is formed a plurality of cylinders. A pumping plunger is slidably mounted in each cylinder to define a pumping chamber. Means are provided for reciprocating the pumping plungers in order cyclically to vary the volume of the pumping chambers to effect delivery of a pumped fluid from the pumping chambers. A delivery passage is connected to each of the pumping chambers to receive pumped fluid therefrom, the delivery passage comprising at least one gallery formed in the unitary housing and open to an end face of the housing and passageways which extend through the unitary housing from the galleries to the pumping chambers. The galleries are closed by an end plate which is secured to the unitary housing. Feed passages and working fluid passages may likewise be defined by combination of galleries in the end face and passageways in the unitary housing.

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 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 comprising a fuel inlet arranged, in use, to receive fuel under high pressure from a source of pressurised fuel, an outlet and an accumulator volume located between the inlet and the outlet. A piezoelectric actuator is located within the accumulator volume and is operable to move a control piston to modify the fuel pressure within a control chamber.

Abstract: An outwardly opening fuel injector comprises a valve needle movable within a bore and engageable with a seating to control the supply of fuel from the bore, the needle being moveable outwardly of the bore to move the needle away from its seating, the needle being biased towards its seating by a spring, the spring engaging a spring abutment arrangement associated with a part of the needle remote from the part thereof engageable with the seating, the spring abutment arrangement further acting to guide movement of the needle.

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 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 valve comprises a valve member which is engageable with a first seating to control communication between first and second ports and a second seating to control communication between second and third ports. The second seating is provided upon a separate seating member.

Abstract: A delivery valve includes a body defining a chamber into which from one end thereof extends a tubular support member. The interior of the member is connected to the outlet of a fuel pump and an outlet extends from the chamber to a fuel nozzle. Slidable about the support member is a first valve element which defines a seating in its end presented to the other end of the chamber. A second valve element is provided for engagement with the seating and a spring urges the first valve element into engagement with the second valve element. The first valve element also defines a surface against which the fuel pressure in the interior of the tubular member can act to lift the first valve element away from the second valve element to allow fuel flow from the outlet.

Abstract: A fuel injector comprises a valve needle biased into engagement with a seating by a spring, a fuel supply line arranged to permit fuel under pressure to be supplied towards the seating, a control chamber communicating through a restricted flow passage with the supply line, and a control valve arranged to control the fuel pressure within the control chamber, wherein the control chamber is defined, in part, by a surface associated with the valve needle, the surface being orientated such that the application of high pressure fuel to the control chamber applies a force to the surface acting in a direction opposing the action of the spring on the valve needle.