US3200887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter rotor system having elastomeric bearings
Assignee: RJ Enstrom Corp
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Filing: 1963-08-09
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Granted: 1965-08-17
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Expires: 1983-08-09
Abstract
No abstract record available.
Inventors
- 👤 Alb C Ballauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:35
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/35
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
140 words
A HELICOPTER ROTOR SYSTEM TUNED TO ACHIEVE ADVANTAGEOUS OPERATING CHARACTERISTICS, COMPRISING MORE THAN TWO ROTOR BLADES, A ROTOR HUB HAVING FLAPPING HINGES FOR SAID BLADES AT EQUAL ANGULAR INTERVALS, A FEATHERING HINGE FOR EACH BLADE SECURED TO AND EXTENDING RADIALLY OUTWARD FORM THE FLAPPING HINGE AND INCLUDING MEANS AT ITS OUTBOARD END TO MOUNT THE BLADE, AND PILOT-CONTROL MEANS TO VERY THE PITCH OF THE BLADE IN THE FEATHERING HINGE THROUGHOUT AN ANGULAR RANGE DURING EACH CYCLE OR ROTATION OF THE HUB, THE MASSES OF THE BLADE AND ITS PITCH CONTROL MEANS HAVING, A ROTATIONAL SPEED CORRESPONDING TO A CHOSEN FLIGHT CONDITION, AN EQUIVALENT INTERTIA TORQUE SPRING RATE, THE BLADE RUTHER HAVING, AT SUCH FLIGHT CONDITION AND FOR THE ANGULAR RANGE OF PITCH CHAANGE CORRESPONDING THERETO, AN EQUIVALENT PROPELLER MOMENT SPRING RATE WHICH PARTIALLY OFFSETS THE INERTIA TORQUE SPRING RATE,
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) | 1968-08-16 | 1969-02-15 | 1969-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-16 | 1973-02-15 | 1973-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-16 | 1977-02-15 | 1977-08-17 | $7700.00 | Window Closed / Lapsed |