Liquid fuel injection pumping apparatus

Claim 1

A liquid fuel injection pumping apparatus for supplying fuel to a multicylinder internal combustion engine and of the kind comprising in combination, a body part, an injection pump mounted in the body part and operable in synchronism with the associated engine, a plurality of outlet ports formed in the body part and which, in use, are connected respectively to injection nozzles which direct fuel into the cylinders of the engine, a rotary distributor member mounted in the body part, a passage in the distributor member, said passage opening onto the periphery of the distributor member at a position to register with the outlet ports in turn during successive injection strokes of the injection pump, the passage also communicating with the injection pump, the apparatus being characterized by a plurality of accumulator chambers communicating respectively with the outlet ports, each accumulator chamber comprising a cylinder one end of which is in communication with the associated outlet port and the other end of which is in communication with a lower pressure than the pressure which occurs in the outlet port during the delivery of fuel by the injection pump, a slidable plunger within the cylinder, resilient means acting on said plunger to urge the plunger towards said one end of the cylinder and the arrangement being such that during the initial delivery of fuel of the injection pump to an outlet port, the plunger of the accumulator chamber associated with the port, will be displaced its maximum extent against the action of the resilient means and when the delivery of fuel by the injection pump ceases the pressure at the outlet port will be maintained at a further low pressure by the action of the resilient means.