Fuel injection pump assembly

Claim 1

A fuel injection pump assembly for an engine having a plurality of cylinders, comprising: a pump cylinder having a pair of fuel inlet ports, a plurality of fuel distribution ports which are equal in number to the cylinders of the engine and which lead to the cylinders, a pressurization chamber; a plunger rotatably and telescopically mounted in said pump cylinder and having fuel supply slots for selective communication between said fuel inlet ports and said pressurization chamber, and a passageway held in selective communication between said pressurization chamber and said fuel distribution ports, said fuel supply slots being half the number of the cylinders of the engine and angularly equally spaced at a first angle, said fuel inlet ports being angularly spaced from each other at a second angle which is equal to the product of said first angle and (1/2)+n where n=0 or a positive integer, said plunger being rotatable about its own axis in response to rotation of the engine and reciprocable in strokes which are equal in number to the cylinders of the engine per rotation of the engine for selectively supplying fuel from said fuel inlet ports through said fuel supply slots, through said pressurization chamber, and through said passageway to said fuel distribution ports; and means for selectively opening and closing said fuel inlet ports, whereby selected ones of the cylinders of the engine can be disabled when said fuel inlet ports are selectively closed by said means so that incomplete fuel combustion in prevented and smelly exhaust gas is reduced.