Abstract: A method of energizing an electromagnetically operable valve which comprises a valve member movable into engagement with a seating when a winding is energized comprising connecting the winding to a DC supply to achieve a rapid rate of rise of current. The current is controlled at the peak value and is then reduced to a low value after an initial movement of the valve member. The valve member continues its movement towards the seating and the current is restored prior to engagement of the valve member with the seating to substantially eliminate bouncing of the valve member away from the seating.

Abstract: A two part pressure unloading delivery valve for a fuel injection pump comprises an annular valve member within which is slidable a plunger. The valve member is biased into engagement with a valve seat by means of a spring and is lifted from the seat by fuel under pressure supplied by the pump. The spring biases the plunger in the direction away from the seat and following closure of the valve member the plunger is moved in the direction towards the seat to allow relief of fuel under pressure from the pipeline connecting the valve with a fuel injection nozzle. After a predetermined movement of the plunger against the spring, damping means in part defined by a piston on the plunger, acts to damp the further movement of the plunger.

Abstract: A fuel pumping apparatus of the rotary distributor type has an annular cam ring (12) which is coupled to a tangentially disposed piston (15) slidable in a cylinder (16) formed in a body part (10). The body is formed from light alloy and the piston from steel. The piston is provided with a blind recess (28) at one end and a steel spigot (19) is slidable within the recess. The blind end of the recess communicates with the adjacent end of the cylinder (16) through a restricted passage (23) and a non-return valve (26). Fuel at a varying pressure is applied to the one end of the cylinder to vary the setting of the cam ring.