Patent US2717434A successfully refreshed from Google Patents.
US3671086A
Expired / Lapsed
US
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Empty-load changeover apparatus
Assignee: Westinghouse Air Brake Co
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Filing: 1970-12-16
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Granted: 1972-06-20
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Expires: 1990-12-16
Abstract
Abstract THIS INVENTION RELATES TO A BRAKE CYLINDER PRESSURE PROPORTIONAL VALVE DEVICE FOR INTERPOSITION IN A BRAKE CONTROL PIPE CONNECTING A BRAKE CONTROL VALVE AND A BRAKE CYLINDER AND A NOVEL MECHANISM ADJUSTABLE ACCORDINGLY AS THE VEHICLE IS EMPTY OR LOADED TO CAUSE THE PROPORTIONAL VALVE DEVICE TO OPERATE ONLY WHILE THE VEHICLE IS EMPTY AND SUBSEQUENT TO A CHOSEN BUILD-UP OF AN INSHOT PRESSURE IN THE BRAKE CYLINDER, TO CUT OFF FLOW OF FLUID UNDER PRESSURE FROM THE BRAKE CONTROL VALVE TO THE BRAKE CYLINDER AT A VALVE PROPORTIONAL TO THE PRESSURE ESTABLISHED IN THE CONTROL PIPE BY THE BRAKE CONTROL VALVE FOR THE REDUCTION OF PRESSURE EFFECTED IN THE BRAKE PIPE.
Inventors
- 👤 Daniel G Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:35
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/18; B60T8/1837; B60T8/185
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |