Patent US3938378A successfully refreshed from Google Patents.
US3938378A
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Engine compression testing
Assignee: United States Department of the Army
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Filing: 1974-08-26
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Granted: 1976-02-17
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Expires: 1994-08-26
Abstract
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.
Inventors
- 👤 Howard E. Fineman
- 👤 Steven M. Schlosser
- 👤 Lawrence M. Hill
- 👤 Richard E. Hanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:40
CPC Classifications
G; G01; G01L; G01L23/00; G01L23/08; G01L23/085
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
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.
Claim 2
Independent Claim
141 words
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.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-16 | 1979-08-18 | 1980-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-16 | 1983-08-18 | 1984-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-16 | 1987-08-18 | 1988-02-17 | $7700.00 | Window Closed / Lapsed |