Abstract: An electromagnetic actuating device comprises a solenoid coil to which a control current can be applied and an armature associated with the solenoid coil which is adapted to carry out movements which are dependent upon a control current flowing through the solenoid coil and a spring arrangement for biassing the armature into opposite directions, with a holding position being defined which is assumed by the armature at a holding current through the solenoid coil, with the holding current flowing through the solenoid coil being variable to a higher value or to a lower value with the armature not leaving the holding position, and both the higher and the lower current value being able to be dimensioned in such a manner that interference influences on the magnetic and spring forces which actuate the armature do not bring the armature from its holding position into an actuated position which is different from the holding position.

Abstract: A control valve of an engine fuel system includes a valve member which is coupled to an armature and is moved to engage a seating when a winding is energized. The current flow in the winding is first allowed to rise to a peak value to initiate movement of the armature and valve member at which time the winding is disconnected from the supply. The decay of current in the winding is controlled using two rates of current decay to ensure that the valve member moves into engagement with the seating with the minimum of bounce.

Abstract: A filter system is disclosed which comprises a housing having a first inlet and a first outlet. A filter element is located between the first inlet and the first outlet. A temperature sensitive valve controls communication between a first inlet side of the filter element communicating with the first inlet and a return line from a fuel pump so that when the fuel temperature is low, hot fuel returning from the pump is supplied to the first inlet side of the filter element. When the fuel temperature increases, the returned fuel is returned to the fuel reservoir rather than to the first side of the filter element.

Abstract: A rotary pump such as a rotary fuel injection pump comprises a pump body; a rotor rotatably supported by the pump body and responsive to mechanical pulses to pump a fluid; and a stator ring (208) supported by the pump body and having a ring of projections (209) arranged to deliver mechanical pulses to the rotor when the rotor rotates relative to the stator ring. The stator ring (208) has a vibrational mode which is induced by delivering the mechanical pulses to the rotor. The pump body supports the stator ring across an interface which is a complete annulus or a partial annulus. In order to reduce the transmission of vibration from the stator ring to the pump body, the interface and/or stator ring incorporate cavities at the antinodes of the vibrational mode of the stator ring.

Abstract: A filter comprises a filter cartridge located within a housing. Fuel flows through a filter medium of the cartridge, in use, from an outer chamber to an inner chamber. From the inner chamber, the fuel flows over and around a sedimentation baffle located within a sedimentation chamber. Fuel exits the sedimentation chamber through an outlet passage, an air collection chamber being arranged to collect air from the flow of fuel. Air exits the air collection chamber via openings.

Abstract: A fuel injector includes a center tube, a first valve separate from the center tube and surrounding a first end of the center tube and a second valve also separate from the center tube and surrounding a second end thereof. A solenoid is actuable to independently move the first and second valves and thereby control the application of fluid pressures to first and second ends of a check assembly, in turn to control injection of fuel into an associated engine cylinder.

Abstract: Fuel pump for delivering high pressure fuel to a fuel injection system of an internal combustion engine is provided. The fuel pump has a body, a drive shaft rotatably mounted in the body, at least one cam on the drive shaft, a plurality of pumping plungers mounted in the body for movement in the radial direction relative to the axis of rotation of the drive shaft, a pumping chamber defined radially outwardly of each plunger, and a delivery valve associated with each pumping chamber. Each pumping plunger is mounted in a support member which provides sliding support for its associated plunger in the circumferential direction of the drive shaft over substantially the entire length of the plunger in all working positions thereof. Each plunger is coupled to at least one cam by a pin which is secured to the plunger and extends outwardly from the plunger through a slot which extends through the support member in the axial direction of the drive shaft.

Abstract: A fuel pump is disclosed which comprises a plunger reciprocable under the influence of a cam surface. The cam surface is shaped to include a first region and a second region. As the plunger moves under the influence of the first region, a pressure wave is generated which is able to reach a spill valve prior to the plunger moving under the influence of the second region to generate a pressure sufficient to open a delivery valve.

Abstract: A fluid pressure-operated actuator comprises a cylinder body containing a piston slidable therein, the piston defining respective chambers at opposite sides thereof. A rod projects from one side of the piston and extends through an end wall of the cylinder and a plunger is slidable on the rod and also extends through the end wall. The arrangement is such that the application of fluid pressure simultaneously to the chambers results in movement of the piston lengthwise of the rod, the piston movement including a first part during which the plunger applies force to the rod in addition to that arising on the piston, and a second part during which the force from the plunger is absent.

Abstract: A brake master cylinder (10) for a hydraulic vehicle brake system has a master cylinder housing (32) and at least one pressure chamber (40) designed therein. Connected to the pressure chamber (40) is a hydraulic fluid reservoir which, furthermore, is provided for connection to a precharge pump of a brake pressure regulating system. Moreover, the brake master cylinder (10) has a hydraulic fluid return connection (30) which makes a fluid connection between the delivery side of the precharge pump, the reservoir and the at least one pressure chamber (40). A throttle (60) is arranged in this liquid connection, said throttle not impeding a hydraulic fluid stream out of the reservoir into the at least one pressure chamber (40) and throttling a hydraulic fluid stream from the return connection (30) into the reservoir. The throttle (60) makes it possible to cause the precharge pump to act on the at least one pressure chamber (40), without an electromagnetic valve being interposed.

Abstract: An electromagnetic actuator assembly is described which comprises a stator housing having a slot extending across the diameter thereof. A stator core is located within the slot, the core carrying a coil. The core is conveniently shaped to permit the use of an increased diameter coil and to increase the area of the pole faces of the core.

Abstract: A control circuit for an electromagnetically operable fuel control valve of a vehicle engine includes a tank capacitor which upon closure of first and second controllable switches supplies current to the winding of the valve to achieve a high rate of rise of current in the winding and rapid operation of the valve. Following operation of the valve it is maintained in its operated state by current chopping action, the current rise being achieved by drawing current from a low voltage source through a third controllable switch. The current fall is at a high rate and the resultant high voltage induced in the winding is utilized to recharge the tank capacitor.

Abstract: An ignition exciter for an engine, comprising a pulse generator for generating output pulses for an igniter plug, and an oscillator for repeatedly triggering the pulse generator at a repetition rate such that each output pulse is produced before ionization caused by a preceding output pulse has substantially disappeared.

Abstract: A valve arrangement is disclosed which comprises a valve member engageable with a seating. The valve member includes a relatively flexible region whereby damage to the valve arrangement, in use, can be reduced and the tolerance to manufacturing inaccuracies can be improved. The valve member is conveniently shaped so that the application of fuel at high pressure thereto biases the valve member towards the seating. A further arrangement is disclosed in which the valve member is permitted to move laterally to center the valve on its seating, the application of fuel to the valve member biasing the valve member towards its seating. Another arrangement is disclosed in which the position of the seating is adjustable.

Abstract: A fuel injector includes a valve member disposed at the upper end of the injector case adjacent a valve recess. The valve member includes a bore and a counterbore, and a tube having a bore is slidably disposed within the counterbore. The valve member bore and the tube bore define a fuel flow passage substantially coincident with the central axis of the injector. The valve member is spring biased to an open position to communicate fuel at transfer pump pressure to the valve recess. At the initiation of the injection cycle, an actuator, preferably an electrical solenoid, closes the valve against the spring force so that fuel is communicated along the central passage to a nozzle.

Abstract: A ring fastener, with a circular configuration in the rest condition, comprising two ring ends (11, 12) spaced from each other, an essentially constant cross-section over at least 150.degree. of its circumference, and in the area of each ring end (11, 12) a recess (13, 14) opening toward its inner circumference, enables an easy installation. A special apparatus enables a particularly effective installation of the ring fastener in very confined conditions.

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: An injector is disclosed which comprises a valve needle moveable within a bore of a nozzle body. The valve needle is engageable with a seating, and downstream of the seating, the nozzle body and valve needle together define a chamber. Passages communicate with the chamber to supply fuel from the chamber to outlet ports. The ports are located so as to be covered by the valve needle when the needle engages its seating, movement of the needle away from its seating beyond a predetermined distance uncovering the ports.

Abstract: A filter comprises a housing, a support member located within the housing and an adapter member securing the support member to the housing. The support member is provided with a coupling component in the form of a screw-threaded opening for cooperation with a screw-threaded projection of a filter head to secure the filter housing to the filter head.

Abstract: A filter arrangement comprises a filter head and a filter body. The filter body and filter head are provided with components arranged to cooperate with one another to permit the filter body to be secured to the filter head by sliding the filter body in a lateral direction thereof relative to the filter head.