US4062232A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Testing compression in engines from starter motor current waveform
Assignee: RCA Corp
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Filing: 1976-10-12
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Granted: 1977-12-13
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Expires: 1996-10-12
Abstract
Abstract The relative compression in the cylinders of an internal combustion engine is tested by analyzing the starter motor current waveform when the engine is cranked with the ignition or the fuel inhibited. In asymmetrical engines, where the compression strokes of individual cylinders are unequally spaced in time, the starter current waveform may contain double-hump cycles. The area under each double-hump cycle is integrated, and the integration peaks are compared. The compression in one or more cylinders is deficient if the minimum integration peak is less than the maximum integration peak by a significant percentage such as 15 percent or more.
Inventors
- 👤 Eldon Marvin Sutphin, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:04
CPC Classifications
G; G01; G01L; G01L23/00; G01L23/08; G01L23/085
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
102 words
Apparatus to detect unsatisfactory compression in individual cylinders of an internal combustion engine having compression strokes, comprising means for detecting the starter motor current waveform when the engine is cranked with the ignition or fuel inhibited, said waveform having cycles each corresponding with at least one compression stroke, means for integrating the area under each of said cycles to produce corresponding integration signals, and means for comparing the amplitudes of the smallest and largest integration signals and indicating when their ratio is less than a predetermined value, whereby to register unsatisfactory compression in at least one of the cylinders of the engine.
Claim 2
Dependent Claim
102 words
Apparatus to detect unsatisfactory compression in individual cylinders of an internal combustion engine having compression strokes, comprising means for detecting the starter motor current waveform when the engine is cranked with the ignition or fuel inhibited, said waveform having cycles each corresponding with at least one compression stroke, means for integrating the area under each of said cycles to produce corresponding integration signals, and means for comparing the amplitudes of the smallest and largest integration signals and indicating when their ratio is less than a predetermined value, whereby to register unsatisfactory compression in at least one of the cylinders of the engine.
Claim 3
Dependent Claim
24 words
Apparatus defined in claim 1 wherein said engine is asymmetrical, and said cycles each correspond with a group of at least two compression strokes.
Claim 4
Independent Claim
101 words
A method to detect unsatisfactory compression in individual cylinders of an internal combustion engine having compression strokes, comprising the steps of detecting the starter motor current waveform when the engine is cranked with the ignition or fuel inhibited, said waveform having cycles each corresponding with at least one compression stroke, integrating the area under each of said cycles to produce corresponding integration signals, and comparing the amplitudes of the smallest and the largest integration signals and indicating when their ratio is less than a predetermined value, whereby to register unsatisfactory compression in at least one of the cylinders of the engine.
Claim 5
Independent Claim
101 words
A method to detect unsatisfactory compression in individual cylinders of an internal combustion engine having compression strokes, comprising the steps of detecting the starter motor current waveform when the engine is cranked with the ignition or fuel inhibited, said waveform having cycles each corresponding with at least one compression stroke, integrating the area under each of said cycles to produce corresponding integration signals, and comparing the amplitudes of the smallest and the largest integration signals and indicating when their ratio is less than a predetermined value, whereby to register unsatisfactory compression in at least one of the cylinders of the engine.
Claim 6
Dependent Claim
26 words
A method as defined in claim 3 wherein said engine is asymmetrical and said cycles each correspond with a group of at least two compression strokes.
References Cited (Backward Citations)
US3765233A
Cited
US3952586A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-12 | 1981-06-13 | 1981-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-12 | 1985-06-13 | 1985-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-12 | 1989-06-13 | 1989-12-13 | $7700.00 | Window Closed / Lapsed |