# US 4,392,793 A · Fuel pumping apparatus

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- Number: US 4,392,793 A
- Document ID: US4392793A
- Status: Granted
- Kind: A
- Application number: 06/309,791
- Filed: 1981-10-08
- Granted: 1983-07-12
- Earliest claimed: 1980-12-05
- Assignees: Lucas Industries Limited
- Inventors: Dorian F. Mowbray
- Web page: https://patentgrep.com/patent/US4392793A

## CPC

- F02M 41/1411: {characterised by means for varying fuel delivery or injection timing}
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF

## Abstract

A fuel pumping apparatus of the rotary distributor type has cam followers comprising rollers supported by shoes interposed between the pumping plungers and the cam ring. Stop rings are provided to limit the outward movement of the followers and one of these rings is axially adjustable so that the amount of fuel supplied by the apparatus can be controlled. In order to provide reduced initial rate of injection of fuel the axial spacing of the surfaces on at least one of the followers which contact the stop rings, is smaller than in the case of the other plunger or plungers so that at the end of the filling stroke of the apparatus of the plunger associated with that follower will project outwardly further than the other plunger and hence will be moved inwardly before the other to provide delivery of fuel at a reduced rate.

## Claims

### Claim 1

A liquid fuel injection pumping apparatus for supplying fuel to an internal combustion engine and comprising a rotary distributor member located in a housing, bores formed in the distributor member and plungers therein, cam followers located at the outer ends of the plungers respectively for engagement with cam lobes formed upon the internal peripheral surface of an annular cam ring surrounding the distributor member, means for feeding fuel to the bores to effect outward movement of the plungers and followers, passage means for conveying fuel from the bores to outlets in the housing, a pair of stop rings positioned in the housing so as to be contacted by end surfaces defined on the cam followers, said end surfaces and the stop rings being shaped so that the axial setting of said stop rings will determine the extent of outward movement of the plungers during the time fuel is supplied to the bores thereby to determine the amount of fuel supplied at each delivery stroke of the apparatus, characterized in that the axial spacing between the end surfaces of at least one of said cam followers is arranged to be smaller than the axial spacing of the end of the other cam follower or followers whereby in use, at the end of the filling strokes of the plungers at least one plunger will be further from the axis of rotation of the distributor member than the other or others so that it will be moved inwardly to effect delivery of fuel before the other plunger or plungers.

### Claim 2 (depends on 1)

An apparatus according to claim 1 in which said cam followers each comprise a roller supported by a shoe, said rollers having conical ends for engagement with said stop rings.