Patent US4575807A successfully refreshed from Google Patents.
US4575807A
Expired / Lapsed
US
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Method and apparatus for leak test
Assignee: Motors Liquidation Co
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Filing: 1983-08-29
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Granted: 1986-03-11
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Expires: 2003-08-29
Abstract
Abstract To measure the leak rate in a transmission partially filled with a transmission fluid but having an air space of unknown volume, air is supplied to the transmission to pressurize the cavity to a preset value. The flow rate of air to the transmission is measured and that rate is integrated in a computer to determine the mass air flow which is proportional to the volume of the air space in the transmission. The decline of pressure in the air space as a result of fluid leakage from the transmission is monitored by the computer and the leak rate is determined on the basis of that rate and the derived volume of the air space.
Inventors
- 👤 Roger C. Dodge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:06
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/26
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
79 words
The method of measuring the leak rate of fluid from a vessel having an unknown air space volume comprising the steps of filling the air space with air to a preset pressure, measuring the air flow amount during the filling step thereby obtaining a value proportional to the air space volume, after the filling step measuring the pressure decline rate caused by fluid leakage, and calculating the leak rate from the air flow amount and the pressure decline rate.
Claim 2
Independent Claim
79 words
The method of measuring the leak rate of fluid from a vessel having an unknown air space volume comprising the steps of filling the air space with air to a preset pressure, measuring the air flow amount during the filling step thereby obtaining a value proportional to the air space volume, after the filling step measuring the pressure decline rate caused by fluid leakage, and calculating the leak rate from the air flow amount and the pressure decline rate.
Claim 3
Independent Claim
127 words
The method of testing the leak rate of fluid from a transmission partially filled with fluid and having an air space of unknown volume to determine whether the leak rate exceeds a pre-determined limit, comprising the steps of pressurizing the air space with air to a preset pressure, measuring the air flow amount required to pressurize the air space, thereby obtaining a measure of the air space, monitoring the pressure decline caused by fluid leakage over a time period to measure a variable value representing leakage, calculating from the measured air flow amount and a preset leak rate value, a limit value as a function of the pressure decline and time, and comparing the variable value with the limit value thereby determining whether the limit is exceeded.
Claim 4
Independent Claim
127 words
The method of testing the leak rate of fluid from a transmission partially filled with fluid and having an air space of unknown volume to determine whether the leak rate exceeds a pre-determined limit, comprising the steps of pressurizing the air space with air to a preset pressure, measuring the air flow amount required to pressurize the air space, thereby obtaining a measure of the air space, monitoring the pressure decline caused by fluid leakage over a time period to measure a variable value representing leakage, calculating from the measured air flow amount and a preset leak rate value, a limit value as a function of the pressure decline and time, and comparing the variable value with the limit value thereby determining whether the limit is exceeded.
Claim 5
Dependent Claim
160 words
Apparatus for testing the leak rate of fluid from a transmission having an air space of unknown volume comprising means for supplying air under pressure to pressurize the air space to a preset value, means for measuring the flow rate to the air space during the pressurizing step, means for measuring the pressure in the air space, and computer means connected to each measuring means and programmed to (a) integrate the measured flow rate to determine flow to the air space thereby determining the volume of the air space, (b) determine from the air flow and a preset leak rate limit, a limit value of a variable parameter in terms of an allowable pressure drop within a set time period or an allowable minimum time period for a preset pressure drop, (c) monitor the pressure decline to measure the variable parameter, and (d) compare the measured variable parameter with the limit value, thereby determining whether the leak rate is excessive.
Claim 6
Dependent Claim
160 words
Apparatus for testing the leak rate of fluid from a transmission having an air space of unknown volume comprising means for supplying air under pressure to pressurize the air space to a preset value, means for measuring the flow rate to the air space during the pressurizing step, means for measuring the pressure in the air space, and computer means connected to each measuring means and programmed to (a) integrate the measured flow rate to determine flow to the air space thereby determining the volume of the air space, (b) determine from the air flow and a preset leak rate limit, a limit value of a variable parameter in terms of an allowable pressure drop within a set time period or an allowable minimum time period for a preset pressure drop, (c) monitor the pressure decline to measure the variable parameter, and (d) compare the measured variable parameter with the limit value, thereby determining whether the leak rate is excessive.
Claim 7
Dependent Claim
109 words
Apparatus for measuring the leak rate of fluid from a vessel having an air space of unknown volume comprising means for pressurizing the vessel to a preset value by flowing air thereto, means for measuring the air flow rate to the vessel during the pressurizing step, and means for measuring the pressure in the vessel, and computer means connected to each measuring means and programmed to (a) integrate the air flow rate to obtain air flow thereby obtaining a measure of the volume of the air space, (b) monitor the pressure decline rate, and (c) calculate the leak rate from the measured pressure decline and the calculated air flow.
Claim 8
Dependent Claim
109 words
Apparatus for measuring the leak rate of fluid from a vessel having an air space of unknown volume comprising means for pressurizing the vessel to a preset value by flowing air thereto, means for measuring the air flow rate to the vessel during the pressurizing step, and means for measuring the pressure in the vessel, and computer means connected to each measuring means and programmed to (a) integrate the air flow rate to obtain air flow thereby obtaining a measure of the volume of the air space, (b) monitor the pressure decline rate, and (c) calculate the leak rate from the measured pressure decline and the calculated air flow.
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) | 1989-03-10 | 1989-09-09 | 1990-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-10 | 1993-09-09 | 1994-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-10 | 1997-09-09 | 1998-03-11 | $7700.00 | Window Closed / Lapsed |