Engine fuel supply control system

Claim 1

An engine fuel supply system comprising a main fuel conduit having a fuel pump driven by the engine whereby the output of said pump is functionally dependent upon the engine''s rotational speed, said main fuel conduit having a fuel metering device disposed downstream of said fuel pump, a flow restrictor located in said main fuel conduit between said fuel pump and said metering device, a governor having a pressure responsive member includIng oppositely disposed pressure surfaces, a first passage communicating with one of said pressure surfaces and said main conduit at a point located upstream of said restrictor and downstream of said fuel pump, a second passage communicating with the other of said pressure surfaces and said main conduit at a point downstream of said metering device, control means responsive to the position of said pressure responsive member to control the fuel supply passing to the downstream end of the main fuel conduit, a spill duct communicating with the main fuel conduit downstream of said flow restrictor and upstream of said fuel metering device and means for varying the flow through the spill duct inversely with variations in the fuel density, said fuel metering device comprising a valve member disposed in a chamber and axially slidable therein, said chamber being divided by said valve member into two spaces, one of said spaces being in direct communication with said main fuel conduit, said valve member having a restricted flow passage for delivering fuel from said one space to the other of said spaces, said other of said spaces having an outlet port which communicates through an outlet valve with a low pressure area, said control means including a lever having one arm operatively connected to said outlet valve and connected to said valve member by way of a spring, said lever having a second arm, means controlled by said governor for positioning said second arm.