Distributor type fuel injection pumps

Claim 1

A distributor type fuel injection apparatus comprising a body, a rotary distributor member located in the body, an injection pump including a pumping chamber in which is located a reciprocable pump plunger, cam means for imparting movement to the plunger to displace fuel from said pumping chamber, a delivery passage in said distributor member in communication with said pumping chamber, a plurality of outlet ports in said body and with which said delivery passage registers in turn during successive delivery strokes of the injection pump, a source of fuel under pressure, first valve means through which fuel can flow to the injection pump during the filling strokes thereof and means for controlling the amount of fuel supplied to the injection pump during the filling strokes, said means including a shuttle movable axially in a bore, one end of said bore being connectible through said first valve means to said pumping chamber, second valve means operable to place said one end of the bore in communication with said source of fuel, an electrically operable valve for allowing fuel to escape from the other end of said bore during at least part of the time said one end of the bore is in communication with said source of fuel, third valve means operable to connect said other end of the bore to said source of fuel, and control circuit means including a sensor for sensing the position of the shuttle during the time said electrically operable valve is open, and for effecting closure of said electrically operable valve when the shuttle has moved the required amount away from said one end of the bore, the fuel contained in said one end of the bore being delivered to the injection pump at the next filling stroke thereof.