US3100539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter rotor blade
Assignee: Bell Aerospace Corp
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Filing: 1961-08-14
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Granted: 1963-08-13
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Expires: 1981-08-14
Abstract
No abstract record available.
Inventors
- 👤 John K Hulbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:54
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46; B64C21/00; B64C21/02; B64C21/06; B64C2230/00; B64C2230/04; B64C2230/22; B64C2230/28; Y; Y02; Y02T; Y02T50/00; Y02T50/10; Y10; Y10S; Y10S415/00; Y10S415/914
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
IN A HELICOPTER, AN ELONGATE ROTOR BLADE HAVING AN OUTER SKIN OF AIRFOIL SECTION PRESENTING A HOLLOW MEMBER ALONG ITS LENGTH, SAID BLADE BEING ADAPTED FOR ROTATION ABOUT A TRANSVERSE AXIS ADJACENT THE INNER END THEREOF AND BEING CLOSED ADJACENT SUCH END WHILE BEING OPEN AT ITS OPPOSITE, OUTER END, WHEREBY ROTATION OF THE BLADE AS AFORESAID WILL CREATE A NEGATIVE PRESSURE GRADIENT FROM ITS INNER TO ITS OUTER END, AND SAID SKIN HAVING OPENINGS THEREIN INCREASING THE AVAILABLE LIFT OF SAID BLADE TO PERMIT INCREASE INFORWARD FLIGHT SPEED OF A CRAFT WITH WHICH IT IS ASSOCIATED AND TO MINIMIZE RETREATING BLADE BUFFETING, SAID SKIN OPENINGS BEING OF DECREASING TOTAL AREA FROM THE OUTER END OF THE BLADE TOWARD SAID INNER END THEREOF.
Claim 2
Dependent Claim
123 words
IN A HELICOPTER, AN ELONGATE ROTOR BLADE HAVING AN OUTER SKIN OF AIRFOIL SECTION PRESENTING A HOLLOW MEMBER ALONG ITS LENGTH, SAID BLADE BEING ADAPTED FOR ROTATION ABOUT A TRANSVERSE AXIS ADJACENT THE INNER END THEREOF AND BEING CLOSED ADJACENT SUCH END WHILE BEING OPEN AT ITS OPPOSITE, OUTER END, WHEREBY ROTATION OF THE BLADE AS AFORESAID WILL CREATE A NEGATIVE PRESSURE GRADIENT FROM ITS INNER TO ITS OUTER END, AND SAID SKIN HAVING OPENINGS THEREIN INCREASING THE AVAILABLE LIFT OF SAID BLADE TO PERMIT INCREASE INFORWARD FLIGHT SPEED OF A CRAFT WITH WHICH IT IS ASSOCIATED AND TO MINIMIZE RETREATING BLADE BUFFETING, SAID SKIN OPENINGS BEING OF DECREASING TOTAL AREA FROM THE OUTER END OF THE BLADE TOWARD SAID INNER END THEREOF.
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) | 1966-08-12 | 1967-02-11 | 1967-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-08-12 | 1971-02-11 | 1971-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-08-12 | 1975-02-11 | 1975-08-13 | $7700.00 | Window Closed / Lapsed |