Abstract: An electromagnetically operable valve comprises a valve member slidable in a bore in which there is a seating. The valve member is moved to the closed position by a solenoid having an armature. A tubular coupling member is secured to the armature and is connected to the valve member through an overtravel spring housed within the coupling member. The coupling member has a flange for engagement with a stop surface to limit the movement of the armature after the valve member has contacted the seating. A return spring is also housed within the coupling member.

Abstract: An electromagnetic actuator includes a core structure defining a central pole piece and an annular pole piece surrounding the central pole piece in spaced relationship. A winding is provided which when energized causes the pole faces of the pole pieces to assume opposite magnetic polarity to draw an armature towards the pole faces. A further winding is located about the annular pole piece and an annular core component surrounds the annular pole piece in spaced relationship and extends beyond the pole faces to form a radial air gap 23 with the armature.

Abstract: A winding method for winding the coils of a stator structure which has one or more intermediate coils and a pair of end coils having a reduced number of turns. The coil or coils may be directly connected to supply terminals and the coils are connected in series. The method involves using a dummy connector to form a connection point between the two end coils, all the coils being wound from a single length of wire with the dummy connector forming the start and finish point for the winding operation.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine includes a valve means operable to control the spillage of fuel from a high pressure pump. The valve means includes first and second valve elements connected by a pivotal beam carried on a pivot movable in the direction of valve closure when an actuator is energized. The first valve element is biased by a spring to the open position and through the beam the second valve element is held in the closed position by the pressure developed by the pump and the second valve element is urged to the open position by the pressure but can be held closed against the pressure by the actuator. When the actuator is de-energized the second valve element is urged open by the pressure to lower the pressure and the spring then opens the first valve element and closes the second valve element.

Abstract: An electromagnetic device includes a stator structure defining spaced circumferential grooves in which are wound windings. Pole pieces are disposed between adjacent grooves and each pole piece has an axial slot in its periphery and a tangential slot formed in one side face, the tangential slot extending from the axial slot to adjacent the base wall of the groove. The slots accommodate the interconnection between the windings in adjacent grooves.

Abstract: An electromagnetic device comprises a stator structure having a central pole piece and axially spaced end pole pieces on opposite sides thereof. The device also includes an axially movable armature surrounding the stator structure and having a step which defines with said central pole piece an air gap extending in the direction of relative movement of the armature and stator structure. End portions of the armature define air gaps with the end pole pieces which extend normally to the axis of movement of the armature. The stator structure mounts a pair of windings on opposite sides of the central pole piece, the windings being connected so that when energized the magnetic flux due to the windings will flow in the same direction through the central pole piece.

Abstract: An electromagnetic device includes a stator having circumferential ribs which define grooves locating windings. An annular armature has internal ribs which extend into the grooves and the armature is divided along its length into at least two parts to enable assembly about the stator. The armature parts are secured at one end to an output member and at the other end are located by the wall of a surrounding body or a part carried thereby.

Abstract: A stator structure for an electromagnetic device includes a core of cylindrical form having pole pieces between which are defined grooves accommodating windings. The core is formed with a diametrical slot which extends the length of the core and which locates the connections between adjacent windings.