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 for delivering fuel to a combustion space comprises a valve needle which is movable within a bore provided in a nozzle body and which is engageable with a seating to control the supply of fuel from the bore. The injector further comprises means for permitting fuel to escape from the bore to a low pressure drain upon initial movement of the valve needle away from its seating. The injector may include a cover member which defines, together with the nozzle body, a part of a return passage for fuel through which fuel flows, in use, to reduce the temperature of the nozzle body.

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: 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 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 fuel injector comprising a nozzle body provided with a first bore and defining a first seating, a valve member engageable with the first seating to control fuel flow from the first bore towards an outlet opening located downstream of the first seating, the valve member being provided with a second bore defining a second seating. A valve needle is slidable within the second bore and is engageable with the second seating to control fuel flow from the second bore towards a second outlet opening provided in the valve member. The fuel injector also includes a transmission arrangement whereby movement of the valve needle beyond a predetermined position is transmitted to the valve member.

Abstract: A fuel injector including a nozzle body having a bore defining a seating, a valve member having a plurality of passages providing fluid communication between the bore and a plurality of outlet openings, the outlet openings defining a first group of openings at a lower axial position on the valve member and a second group of openings at a higher axial position on the valve member. The valve member is slidable within the bore and is engageable with the seating to control fuel flow from the outlet openings. The outlet openings are shaped and orientated such that the sprays formed at the first and second groups of outlet openings do not interfere with one another.

Abstract: An injector is described which comprises a valve needle engageable with a seating and biased towards the seating by a spring. The spring is located within a spring chamber and engages a moveable stop. The spring chamber communicates through a restricted passage with a low pressure drain. The injector further includes valve means which, when open, permits fuel to escape from the spring chamber at a higher rate.

Abstract: A fuel pumping apparatus is disclosed which comprises a pumping plunger reciprocable within a bore. A spill valve communicates with the bore. A pilot piston is exposed to the fuel pressure within the bore, the pilot piston being arranged to move under the action of the fuel pressure to supply a pilot quantity of fuel to an injector. The pilot piston is arranged so that, in one position, only part of an end face thereof is exposed to the fuel pressure within the bore.