Patent US3865908A successfully refreshed from Google Patents.
Patent US3143175A successfully refreshed from Google Patents.
US3143175A
Expired / Lapsed
US
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Variable pitch propellers
Assignee: Dowty Rotol Ltd
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Filing: 1960-10-13
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Granted: 1964-08-04
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Expires: 1980-10-13
Abstract
No abstract record available.
Inventors
- 👤 Elmes Robert Terence
- 👤 Lane Arthur Hampton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:26
CPC Classifications
B; B64; B64C; B64C11/00; B64C11/30; B64C11/38; B64C11/385
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
121 words
A VARIABLE PITCH PROPELLER HAVING PITCH CONTROL MEANS COMPRISING A HYDRAULIC PISTON-AND-CYLINDER MOTOR CONNECTED TO THE PROPELLER BLADES TO ALTER THE PITCH THEREOF, A PLURALITY OF STOPS OPERABLE TO PREVENT RELATIVE MOVEMENT OF THE PISTON AND CYLINDER, IN A SENSE TO FINE THE PROPELLER PITCH, BEYOND RESPECTIVE PREDETERMINED FINE PITCH SETTINGS, SUPPLY CONDUITS FOR SUPPLYING PRESSURE FLUID TO OPPOSITE ENDS OF THE CYLINDER OF SAID MOTOR, A SOURCE OF PRESSURE FLUID, A FURTHER FLUID CONDUIT WHICH IS INDEPENDENT OF SAID SUPPLY CONDUITS AND WHICH IS CONNECTED TO SAID SOURCE, MEANS FOR EFFECTING SUCCESSIVE INCREASES IN THE PRESSURE IN SAID FURTHER CONDUIT, AND WITHDRAWAL MEANS FOR WITHDRAWING SAID STOPS SUCCESSIVELY WHEN SAID SUCCESSIVE INCREASES OF PRESSURE OCCUR IN SAID FURTHER FLUID CONDUIT.
Claim 2
Dependent Claim
121 words
A VARIABLE PITCH PROPELLER HAVING PITCH CONTROL MEANS COMPRISING A HYDRAULIC PISTON-AND-CYLINDER MOTOR CONNECTED TO THE PROPELLER BLADES TO ALTER THE PITCH THEREOF, A PLURALITY OF STOPS OPERABLE TO PREVENT RELATIVE MOVEMENT OF THE PISTON AND CYLINDER, IN A SENSE TO FINE THE PROPELLER PITCH, BEYOND RESPECTIVE PREDETERMINED FINE PITCH SETTINGS, SUPPLY CONDUITS FOR SUPPLYING PRESSURE FLUID TO OPPOSITE ENDS OF THE CYLINDER OF SAID MOTOR, A SOURCE OF PRESSURE FLUID, A FURTHER FLUID CONDUIT WHICH IS INDEPENDENT OF SAID SUPPLY CONDUITS AND WHICH IS CONNECTED TO SAID SOURCE, MEANS FOR EFFECTING SUCCESSIVE INCREASES IN THE PRESSURE IN SAID FURTHER CONDUIT, AND WITHDRAWAL MEANS FOR WITHDRAWING SAID STOPS SUCCESSIVELY WHEN SAID SUCCESSIVE INCREASES OF PRESSURE OCCUR IN SAID FURTHER FLUID CONDUIT.
References Cited (Backward Citations)
US2655999A
Cited
US2944769A
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US2934154A
Cited
GB818612A
Cited
FR1185252A
Cited
US3024848A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-08-04 | 1968-02-03 | 1968-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-08-04 | 1972-02-03 | 1972-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-08-04 | 1976-02-03 | 1976-08-04 | $7700.00 | Window Closed / Lapsed |