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US 3,938,378 AGranted
Engine compression testing
AssigneeThe United States of America as represented by the Secretary of the Army
InventorsHoward E. Fineman, Steven M. Schlosser, Lawrence M. Hill, Richard E. Hanson
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Abstract
A method of testing compression capabilities of multi-cylinder engines wh are cranked with electrically-energized starter motors. The cylinders are prevented from firing, and the engine is cranked by the starter motor. During the cranking period measurements are taken of the starter motor current. A comparison of the peak current and average current provides an indication of the compression capability of the engine.
Claims1
A method of testing compression capabilities of multi-cylinder engines:
- said method comprising the step of cranking the engine with an electrically-energized starter motor;
- providing a first analog signal representative of instantaneous peak starter motor current;
- providing a second analog signal representative of average starter motor current;
- applying the first and second signals to a comparator;
- providing a NAND gate;
- applying to the NAND gate a third signal representative of engine operating temperature;
- applying to the NAND gate a fourth signal representing combustion inhibition;
- applying to the NAND gate a fifth signal representative of piston position in the engine cylinder;
- applying to the NAND gate a sixth signal representing the attainment of steady state starter motor operation;
- applying the outputs of the comparator and NAND gate to a NOR gate;
- and applying the output of the NOR gate to an indicator mechanism.
8 more elements
Dependencies are inferred from the claim text.