Timing signal generator for ignition and fuel injection systems in a 4-stroke internal combustion engine

Claim 1

Apparatus for generating control signals for controlling the timing of at least one of the events contained in the group comprising spark ignition and fuel injection in an internal combustion engine, having a plurality of cylinders, a crankshaft, and a camshaft that rotates at one-half of the rotational speed of the crankshaft, comprising: an integral circular member on said crankshaft having a plurality of teeth distributed about the circumference of said member and a plurality of timing position markings, each of said markings being associated with one of said cylinders, said timing position markings being divided into two groups, each of said two groups being associated with cylinders to be furnished with said control signals during one revolution of said crankshaft; a single mark on said camshaft extending over one-half the circumference of said camshaft, beginning at a shaft angle corresponding to a crankshaft position between two of said position markings from the same one of said two groups; sensing means including a first sensor for scanning said single mark, a second sensor for scanning said teeth, and a third sensor for scanning said position markings, where each of said sensors has an output; and an evaluating circuit responsive to said output of said first sensor and having an output for said control signals, said circuit connected to said outputs of said second and third sensors and including gating means for gating said output of said third sensor in response to the output of said first sensor and deriving said control signals therefrom in response to said position markings for one of said two groups during alternate revolutions of said crankshaft.