Fuel injection pumping apparatus

Claim 1

A fuel injection pumping apparatus comprising an injection pump operable to deliver fuel during a delivery stroke, a feed pump for supplying fuel to the injection pump during a filling stroke, a housing, a valve within said housing for controlling the output fluid pressure of the feed pump so that the pressure varies in accordance with the speed at which the apparatus is driven, means connecting said feed pump with said injection pump, a throttle within said connecting means for varying the quantity of fuel supplied by the feed pump to the injection pump, said throttle comprising an axially movable member located within a cylindrical portion formed by said housing, said axially moveable member being subjected at one end to said fluid pressure and being movable by an increase in said pressure, resilient means applied to said member in a direction to reduce the amount of fuel supplied by the feed pump to the injection pump said axially moveable member being further provided with a central passage and a groove formed on the outer periphery thereof in communication with said central passage, said passage extending from said one end of said member, an insert secured within said central passage and forming an oriface at the end of said member which is subjected to said fluid pressure, the cylindrical portion formed by said housing and retaining said member including a port in the wall thereof formed by said housing and connecting with said injection pump, the groove and port having variable communication, the extent of which determines the volume of fuel supplied to the injection pump, and fluid pressure responsive means for adjusting the timing of delivery of fuel by said feed pump.