GB421818A - Oil or other liquid fuel-injection pumps - Google Patents

Abstract

421,818. Fuel - injection pumps. OLDHAM, R., Holmwood, Cleethorpes, Lincolnshire. June 21, 1933, No. 17646. [Class 102 (i)] In a fuel-injection pump in which a recess in the plunger is formed with inclined edges controlling the point of relief and thus the termination of injection, both ends of the recess are closed during at least a part of the effective forcing stroke and the plunger is formed with an axial passage or slot communicating with a groove which co-operates with a suction or relief port or forms a liquid seal. As shown in Fig. 3, the suction port 4 is controlled by the head of the plunger, but the point at which injection commences is controlled by an inclined groove 8 co-operating with a relief port 5<x> and communicating with an axial passage 7 in the plunger. The relief recess 6 is formed with an inclined edge 6<x> co-operating with an axial slot 3 in the barrel and has an edge 6<@y> at a different inclination co-operating with a relief port 5. The plunger may be formed with a groove which makes communication with the slot 3 before the relief port 5 is uncovered. In a modification, Fig. 4, the recess 8 communicating with the compression space by a slot 7, is above the recess 6 and has oppositely inclined edges 9<x>, 9<y> co-operating with the axial passage 3 and with a relief port 5 to determine the commencement of injection. The edges 6<x>, 6<y> of the recess 6 co-operate with the same ports to determine the end of injection. In modifications the recess 6 is replaced by a single helical groove, or by two helical grooves 6, 6<a>, Fig. 9, each co-operating with an inclined recess 3, 3<a>, and with a relief port 5, 5<a>, in the barrel. The axial passage 7 in the plunger communicates with a recess 8 which co-operates with a relief port 5<x> to determine the point of commencement of injection.