US5263462A
Expired / Lapsed
US
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System and method for detecting leaks in a vapor handling system
Assignee: Motors Liquidation Co
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Filing: 1992-10-29
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Granted: 1993-11-23
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Expires: 2012-10-29
Abstract
Abstract This invention relates to a diagnostic system that detects a leak in an engine vapor handling system by checking whether a predetermined pressure or vacuum is attained in a fuel tank when a corresponding temperature change occurs in the fuel tank while the engine was not running.
Inventors
- 👤 Sam R. Reddy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:50
CPC Classifications
F; F02; F02B; F02B77/00; F02B77/08; F02B77/088; F02M; F02M25/00; F02M25/08; F02M25/0809
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
83 words
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising: a means for detecting a temperature change in the fuel tank while the engine is not running, a means for detecting a pressure change in the fuel tank while the engine is not running, and a means for determining whether or not a leak exists in the vapor handling system by comparing said temperature change with said pressure change.
Claim 2
Dependent Claim
83 words
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising: a means for detecting a temperature change in the fuel tank while the engine is not running, a means for detecting a pressure change in the fuel tank while the engine is not running, and a means for determining whether or not a leak exists in the vapor handling system by comparing said temperature change with said pressure change.
Claim 3
Dependent Claim
89 words
A diagnostic system for detecting a leak in a vapor handling control system for an engine and having a fuel tank, said diagnostic system comprising: a means for detecting a predetermined increase of temperature in the fuel tank while the engine is not running, a means for detecting a predetermined pressure level of the fuel tank while the engine is not running, and a means to indicate a leak in the vapor handling system if the predetermined pressure level is not attained while the predetermined temperature increase is attained.
Claim 4
Dependent Claim
89 words
A diagnostic system for detecting a leak in a vapor handling control system for an engine and having a fuel tank, said diagnostic system comprising: a means for detecting a predetermined increase of temperature in the fuel tank while the engine is not running, a means for detecting a predetermined pressure level of the fuel tank while the engine is not running, and a means to indicate a leak in the vapor handling system if the predetermined pressure level is not attained while the predetermined temperature increase is attained.
Claim 5
Dependent Claim
88 words
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising: a means for detecting a decrease of temperature in the fuel tank, while the engine is not running, a means for detecting a predetermined vacuum level in the vapor handling system while the engine is not running, and a means for indicating a leak in the vapor handling system if the predetermined vacuum level is not attained while a predetermined temperature decrease is attained.
Claim 6
Dependent Claim
88 words
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising: a means for detecting a decrease of temperature in the fuel tank, while the engine is not running, a means for detecting a predetermined vacuum level in the vapor handling system while the engine is not running, and a means for indicating a leak in the vapor handling system if the predetermined vacuum level is not attained while a predetermined temperature decrease is attained.
Claim 7
Dependent Claim
86 words
A diagnostic system for detecting a leak in a vapor handling system according to claim 3, wherein said means for detecting a predetermined decrease of temperature in the fuel tank comprises: a device that measures the elapsed time the engine was on before shut off, and a temperature sensor that measures an engine temperature, wherein a predetermined decrease of temperature is indicated when the elapsed time the engine is on is greater than a selected time and the engine temperature is less than a preselected temperature.
Claim 8
Independent Claim
74 words
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of: measuring a temperature change in said fuel tank while the engine is not running, measuring a pressure change in said fuel tank while the engine is not running, and determining whether or not a leak exists in the engine vapor handling system by comparing said temperature change with said pressure change.
Claim 9
Independent Claim
74 words
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of: measuring a temperature change in said fuel tank while the engine is not running, measuring a pressure change in said fuel tank while the engine is not running, and determining whether or not a leak exists in the engine vapor handling system by comparing said temperature change with said pressure change.
Claim 10
Independent Claim
71 words
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of: measuring a temperature increase in said fuel tank while the engine is not running, measuring a pressure in said fuel tank while the engine is not running, and indicating a leak if said pressure is less than a selected pressure while said temperature increase exceeds a selected increment.
Claim 11
Independent Claim
71 words
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of: measuring a temperature increase in said fuel tank while the engine is not running, measuring a pressure in said fuel tank while the engine is not running, and indicating a leak if said pressure is less than a selected pressure while said temperature increase exceeds a selected increment.
Claim 12
Independent Claim
71 words
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of: detecting a temperature decrease in said fuel tank while the engine is not running, measuring a vacuum level in said fuel tank while the engine is not running, and indicating a leak if a predetermined vacuum level is not attained while said temperature decrease exceeds a selected decrement.
Claim 13
Independent Claim
71 words
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of: detecting a temperature decrease in said fuel tank while the engine is not running, measuring a vacuum level in said fuel tank while the engine is not running, and indicating a leak if a predetermined vacuum level is not attained while said temperature decrease exceeds a selected decrement.
Claim 14
Dependent Claim
64 words
A method of detecting a leak in the system as recited in claim 7, wherein the step of detecting a temperature decrease in said fuel tank, comprises the steps of: measuring the elapsed time that the engine is on, saving the elapsed time when the engine is turned off, measuring a temperature of the engine, and comparing the elapsed time with the engine temperature.
Claim 15
Dependent Claim
51 words
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising: means for determining whether the pressure in said fuel tank changes in a predetermined manner in response to changes in temperature while the engine is not running.
Claim 16
Dependent Claim
51 words
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising: means for determining whether the pressure in said fuel tank changes in a predetermined manner in response to changes in temperature while the engine is not running.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-22 | 1997-05-24 | 1997-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-22 | 2001-05-24 | 2001-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-22 | 2005-05-24 | 2005-11-23 | $7700.00 | Window Closed / Lapsed |