US3282352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual air screw propeller
Assignee: Individual
•
Filing: 1965-10-01
•
Granted: 1966-11-01
•
Expires: 1985-10-01
Abstract
No abstract record available.
Inventors
- 👤 Fred M Siptrott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:21
CPC Classifications
B; B64; B64C; B64C11/00; B64C11/46; B64C11/48
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
148 words
A MULTI-BLADE SCREW PROPELLER, COMPRISING A SUPSUPPORTING HUB HAVING TWO PROPELLERS WITH BLADES EXTENDING RADIALLY IN AXIALLY SPACED PARALLEL AND PARTIALLY OVERLAPPING RELATION AT OPPOSITE SIDES OF SAID HUB, SAID BLADES BEING OF UNIFORMLY DIMINISHING CHORD FROM SAID HUB TO THE TIPS THEREOF, AND CHARACTERIZED BY THE FACT THAT THE LEADING EDGES OF THE BLADES OF THE FORWARD PROPELLER ARE DISPOSED AT A SWEPT BACK ANGLE WITH RESPECT TO A RADIAL LINE PASSING THROUGH THE BODY OF THE BLADE AND A TRAILING EDGE DISPOSED REARWARDLY OF AND PARALLEL WITH SAID RADIAL LINE, AND FURTHER CHARACTERIZED BY THE FACE THAT THE LEADING EDGE OF THE REARWARD PROPELLER BLADES HAVE THEIR LEADING EDGES FORWARD OF AND PARALLEL WITH SAID RADIALLY EXTENDING LINE AND TRAILING EDGES REARWARDLY OF AND DISPOSED AT A SWEPT FORWARD ANGLE WITH RESPECT TO SAID RADIAL LINE WITH THE PITCH OF SAID BLADES INCREASING TOWARD THEIR ENDS.
Claim 2
Dependent Claim
148 words
A MULTI-BLADE SCREW PROPELLER, COMPRISING A SUPSUPPORTING HUB HAVING TWO PROPELLERS WITH BLADES EXTENDING RADIALLY IN AXIALLY SPACED PARALLEL AND PARTIALLY OVERLAPPING RELATION AT OPPOSITE SIDES OF SAID HUB, SAID BLADES BEING OF UNIFORMLY DIMINISHING CHORD FROM SAID HUB TO THE TIPS THEREOF, AND CHARACTERIZED BY THE FACT THAT THE LEADING EDGES OF THE BLADES OF THE FORWARD PROPELLER ARE DISPOSED AT A SWEPT BACK ANGLE WITH RESPECT TO A RADIAL LINE PASSING THROUGH THE BODY OF THE BLADE AND A TRAILING EDGE DISPOSED REARWARDLY OF AND PARALLEL WITH SAID RADIAL LINE, AND FURTHER CHARACTERIZED BY THE FACE THAT THE LEADING EDGE OF THE REARWARD PROPELLER BLADES HAVE THEIR LEADING EDGES FORWARD OF AND PARALLEL WITH SAID RADIALLY EXTENDING LINE AND TRAILING EDGES REARWARDLY OF AND DISPOSED AT A SWEPT FORWARD ANGLE WITH RESPECT TO SAID RADIAL LINE WITH THE PITCH OF SAID BLADES INCREASING TOWARD THEIR ENDS.
References Cited (Backward Citations)
US890973A
Cited
US1977072A
Cited
US2116054A
Cited
US2116055A
Cited
US2390879A
Cited
FR1010026A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-10-31 | 1970-05-02 | 1970-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-10-31 | 1974-05-02 | 1974-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-10-31 | 1978-05-02 | 1978-11-01 | $7700.00 | Window Closed / Lapsed |