Liquid fuel injection pump

A liquid fuel injection pumping apparatus for supplying fuel to an internal combustion engine and comprising a housing, a rotary distributor member mounted within the housing and which in use is driven in timed relationship with the associated engine, an injection pump also driven in use, in timed relationship with the engine, the injection pump including a pump chamber, the apparatus further including a delivery passage formed in the distributor member and communicating with the pump chamber, an outlet port formed in the housing and with which the delivery passage registers during an injection stroke of the injection pump, a feed port formed in the housing and a plurality of feed passages in the distributor member communicating with the pump chamber and registering in turn with said feed port, said feed port and a feed passage being brought into registration in the interval between injection strokes of the injection pump, a feed pump for supplying liquid fuel at a low pressure, a shuttle movable in a cylinder, a plurality of supply grooves on the distributor member for register in turn with a supply port communicating with the one end of the cylinder containing the shuttle, control means for controlling the flow of fuel to said one end of said cylinder through said supply grooves to the supply port whilst the other end of said cylinder is in communication with said feed port, the rate of movement of said shuttle towards said other end of the cylinder being reduced as the feed passage moves out of register with the feed port and the movement of the shuttle ceasing as the feed port and feed passage move out of register, measuring means for measuring the displacement of the shuttle which takes place while fuel is flowing from said other end of the cylinder, signal processing means responsive to the signal produced by the said measuring means for adjusting said control means in the event that the quantity of fuel supplied to the injection pump differs from the desired quantity of fuel, and means for returning the shuttle to the one end of the cylinder after the feed passage has moved out of register with the feed port comprising a first set of grooves interspaced with said feed passages and a second set of grooves interspaced with said supply grooves, said first and second sets of grooves being connected to a source of fuel under pressure and a drain respectively, whereby after fuel has been supplied to the injection pump, the shuttle will be returned to said one end of the cylinder.

A liquid fuel injection pumping apparatus for supplying fuel to an internal combustion engine and comprising:

• a housing, a rotary distributor member mounted within the housing and which in use is driven in timed relationship with the associated engine, an injection pump also driven in use, in timed relationship with the engine, the injection pump including a pump chamber, the apparatus further including a delivery passage formed in the distributor member and communicating with the pump chamber, an outlet port formed in the housing and with which the delivery passage registers during an injection stroke of the injection pump, a feed port formed in the housing and a feed passage in the distributor member communicating with the pump chamber, said feed port and feed passage being brought into registration in the interval between injection strokes of the injection pump, a feed pump for supplying liquid fuel at a low pressure, a shuttle movable in a cylinder, said shuttle and said cylinder being sized to accommodate a predetermined volume of fuel on either end of said shuttle, said predetermined volume of fuel being greater than the volume of fuel required during operation of said injection pump, control means for controlling the flow of fuel to one end of said cylinder while the other end of said cylinder is in communication with said feed port, the rate of movement of said shuttle towards said one end of the cylinder being reduced as the feed passage moves out of register with the feed port and the movement of the shuttle ceasing as the feed port and feed passage move out of register and prior to said shuttle reaching an end of said cylinder or any abutment within said cylinder, measuring means for measuring the displacement of the shuttle which takes place while fuel is flowing from said one end of the cylinder and signal processing means responsive to the signal produced by the said measuring means for adjusting said control means in the event that the quantity of fuel supplied to the injection pump differs from the desired quantity of fuel.