GB875130A - Improvements in self-regulating reciprocating pumps, and in particular in internal combustion engine fuel injection pumps - Google Patents

Abstract

875,130. Fuel injection pumps. BESSIERE, P. E. March 17, 1958 [March 18, 1957 ; April 9, 1957], No. 8493/58. Class 102(1). A fuel injection pump comprises a main piston 2 which on its upward stroke first actuates a valve 12 to close a conduit 9 and then delivers to a chamber 7a actuating a shuttle piston 5 which delivers fuel in a chamber 7b through outlet 15 until a by-pass 17 is opened. On the suction stroke of the piston 2 the valve 12 opens the conduit 9 and the shuttle piston 5 moves downwardly under the action of a spring 6 and, after closing the by-pass 17, delivers fuel from chamber 7a through conduit 9 and throttle 8 to chamber 7b until the shuttle opens conduit 72 when the fuel is delivered more quickly to the chamber 7b. The shuttle thus moves slowly over a first portion of its movement and then quickly on opening the conduit 72. When the speed of the piston 2 increases above a predetermined value it performs its next upward stroke before the shuttle completes its downward stroke and thus the quantity of fuel delivered is reduced. The conduit 9 may lead to the outside instead of to the chamber 7b in which case the valve 12 is extended to control the conduit 72. In a further modification the conduit 9 opens into the chamber 7b at a position where it is closed by the shuttle before it reaches its uppermost position, and a second conduit leading to the outside and provide with a throttle opens into chamber 7a below the by-pass 17, the distance between these two conduits being approximately equal to the length of the shuttle. Specification 861,754 is referred to.