Waveform count of teeth on an internal combustion engine flywheel

Apparatus for determining the number of teeth on the flywheel of an internal combustion engine comprising:

• tooth sensing means adapted to be disposed to sense the passage of each tooth of the flywheel of an internal combustion engine when the engine is rotating, said means providing a tooth signal each time that a tooth of the flywheel passes in proximity to said tooth sensing means;
• means for registering a plurality of standard data manifestations, each one representing a number indicative of a number of teeth permissible on a flywheel of an internal combustion engine of the type under test as established by industry standards;
• processing means responsive to the tooth signals presented by said tooth sensing means to generate manifestations indicative of the time intervals between said tooth sensing means sensing successive teeth over a time period which is at least a significant portion of one revolution of the engine, and responsive to the variations in said time intervals to identify the number of teeth sensed across an integral number of cylinder-related subcycles of an engine cycle and for generating a measured data manifestation therefrom, and responsive to said registering means for comparing said measured data manifestation with each of said standard data manifestations and for selecting one of said standard data manifestations as a result of the comparison;
• and
• means for presenting the selected one of said standard data manifestations as the determined number of teeth on the flywheel of the engine under test.

Apparatus for determining the number of teeth on the flywheel of an internal combustion engine comprising:

• tooth sensing means adapted to be disposed to sense the passage of each tooth of the flywheel of an internal combustion engine when the engine is rotating, said means providing a tooth signal each time that a tooth of the flywheel passes in proximity to said tooth sensing means;
• identification means adapted to be disposed for response to the presence of a particular member of the engine under test in a manner to present a signal corresponding to a known angle of revolution of the engine greater than the angle included by a plurality of said teeth, and for generating an ID signal in response to said engine member being in proximity with said identification means;
• processing means, responsive to the tooth signals presented by said tooth sensing means and to said identification means when said identification means is disposed for response to said engine member, for measuring the number of said tooth signals provided as the engine rotates through a known angle determined by said ID signals and presenting a measured data manifestation indicative of the number of teeth on said flywheel when said ID signals are present, and alternatively, when said ID signals are not present, responsive to the tooth signals presented by said tooth sensing means to generate manifestations indicative of the time intervals between said tooth sensing means successive teeth for a number of teeth corresponding to at least a significant portion of one revolution of the engine, and responsive to the variations in said time intervals to identify the number of teeth sensed across an integral number of cylinder-related subcycles of an engine cycle and for generating said measured data manifestation therefrom.

In the method of determining the number of teeth on the flywheel of a slowly rotating internal combustion engine, the steps of:

• electronically measuring the time intervals between the passage of corresponding successive ones of a large number of teeth of the flywheel past a fixed point;
• maintaining a running count of teeth respectively corresponding to each of said time intervals;
• from the magnitude of said time intervals, dividing said running count of teeth into cylinder-related subcycles of an engine revolution;
• determining the number of teeth related to each of said subcycles;
• and
• relating the number of teeth in each subcycle to a number of teeth corresponding to a full revolution of the engine to provide a measured number of teeth on the flywheel thereof.

In the method of determining the number of teeth on the flywheel of a slowly rotating internal combustion engine employing electronic processing apparatus including identification means adapted to be disposed for response to the presence of a particular member of the engine in a manner to present a cycle signal corresponding to a full engine cycle, and tooth sensing means adapted to be disposed to sense the passage of each tooth of the flywheel of the internal combustion engine when rotating, the steps of:

• determining whether said identification means is providing said cycle signal;
• if said cycle signal is present, counting the number of teeth sensed by said tooth sensing means between successive ones of said cycle signal to provide a measure of the number of teeth on the flywheel thereof;
• and, alternatively,
• if said cycle signal is not present, generating manifestations of the time intervals between the sensing of successive teeth over a number of teeth corresponding to at least a significant portion of one revolution of the engine, and responsive to the variation in said time intervals, identifying the number of teeth sensed across an integral number of cylinder-related subcycles of an engine cycle related said number to a full revolution of the engine to provide a measure of the number of teeth on the flywheel thereof.