GB468958A - Improvements in fuel injection pumps for internal combustion engines - Google Patents

Abstract

468,958. Fuel - injection pumps. ALCOCK, J. F., and HOLT, G. A. Jan. 15, 1936, No. 1264. [Class 102 (i)] In a fuel-injection pump of the type in which injection is terminated by the opening of a spill port, the spill takes place into a closed chamber against an elastic pressure, and is returned to the pump chamber at the next suction stroke. As shown the suction port F and the spill port G are controlled by the plunger C<1> which has a helical edge C<6> for controlling the spill port. The spill takes place into a chamber K containing an elastic metallic diaphragm K<1> acted on by a spring. A second diaphragm may be provided between the interior of the diaphragm K<1> and the exterior of the pump for giving a visible signal should the diaphragm K<1> break. Alternatively a frangible disc K<3> may be provided which permits discharge of the spill to the suction passage through a pipe K<5>, should the diaphragm K<1> break. The spill passage may enter the chamber K at its highest point, as shown, in order to prevent the accumulation of gases in the chamber. Alternatively a separate passage may be provided, controlled by a hand-operated valve, for the discharge of gases. In a modification the diaphragm K<1> is replaced by a spring-pressed piston. Alternatively, an air cushion is employed, or the compressibility of the fuel provides the required elastic force.