US3127093A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ducted sustaining rotor for aircraft
Assignee: —
•
Filing: —
•
Granted: 1964-03-31
•
Expires: 1981-03-31
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:15
CPC Classifications
F; F04; F04D; F04D19/00; F04D19/02; F04D19/024; B; B64; B64C; B64C11/00; B64C11/001; F04D29/00; F04D29/26; F04D29/32; F04D29/38; F04D29/384; F04D29/386
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
97 words
AN AIRCRAFT SUSTAINING ROTOR SYSTEM COMPRISING: A CIRCULAR SHIELDING DUCT; A HUB AXIALLY MOUNTED IN SAID DUCT; A PAIR OF DRIVEN, COUNTER-ROTATING ROTORS OPERATIVELY MOUNTED ON SAID HUB IN AXIALLY SPACED RELATION, EACH ROTOR HAVING A PLURALITY OF BLADES AND BEING SUBSTANTIALLY SHIELDED FROM TRANSVERSE AIRFLOW BY SAID DUCT; EACH OF SAID BLADES BEING OF LOW ASPECT RATIO AND INCREASING IN CHORD FROM ROOT TO TIP; THE ANGLE OF INCIDENCE OF EACH BLADE DECREASING FROM ROOT TO TIP, WITH THE MAJOR OUTER PORTION OF EACH BLADE HAVING AN ANGLE OF INCIDENCE OF LESS THAN FIVE DEGREES POSITIVE.
Claim 2
Dependent Claim
97 words
AN AIRCRAFT SUSTAINING ROTOR SYSTEM COMPRISING: A CIRCULAR SHIELDING DUCT; A HUB AXIALLY MOUNTED IN SAID DUCT; A PAIR OF DRIVEN, COUNTER-ROTATING ROTORS OPERATIVELY MOUNTED ON SAID HUB IN AXIALLY SPACED RELATION, EACH ROTOR HAVING A PLURALITY OF BLADES AND BEING SUBSTANTIALLY SHIELDED FROM TRANSVERSE AIRFLOW BY SAID DUCT; EACH OF SAID BLADES BEING OF LOW ASPECT RATIO AND INCREASING IN CHORD FROM ROOT TO TIP; THE ANGLE OF INCIDENCE OF EACH BLADE DECREASING FROM ROOT TO TIP, WITH THE MAJOR OUTER PORTION OF EACH BLADE HAVING AN ANGLE OF INCIDENCE OF LESS THAN FIVE DEGREES POSITIVE.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-03-31 | 1967-09-30 | 1968-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-03-31 | 1971-09-30 | 1972-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-03-31 | 1975-09-30 | 1976-03-31 | $7700.00 | Window Closed / Lapsed |