US3720480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor construction
Assignee: RTX Corp
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Filing: 1971-06-29
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Granted: 1973-03-13
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Expires: 1991-06-29
Abstract
Abstract A rotor construction comprising a hub having a plurality of undercut slots defining a plurality of lugs in the periphery thereof, a plurality of filament reinforced composite blades having splayed roots in the slots engaging the lugs and a reinforcing insert disposed in the root portion of the blades extending in a direction transverse to the rotor axis, the ends of the insert engaging opposing walls of adjacent lugs and being of a material sufficiently strong in compression to resist lug bending due to blade loss.
Inventors
- 👤 J Plowman
- 👤 T Walsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:59
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/30; F01D5/32; F01D5/323
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
125 words
A rotor construction comprising: a hub having undercut slots defining a plurality of lugs in the periphery thereof, a plurality of filament reinforced composite blades arranged around the periphery of the hub, each blade comprising high modulus, high strength filaments embedded in a matrix material and extending in general spanwise alignment to form an airfoil portion and an enlarged root portion, said enlarged root portion received in said slots engaging said lugs, and at least one reinforcing insert disposed in the root portion of said blades extending in a direction transverse to the rotor axis, the ends of said insert engaging the opposing walls of adjacent lugs, said insert being of a material sufficiently strong in compression to resist lug bending due to blade loss.
Claim 2
Dependent Claim
125 words
A rotor construction comprising: a hub having undercut slots defining a plurality of lugs in the periphery thereof, a plurality of filament reinforced composite blades arranged around the periphery of the hub, each blade comprising high modulus, high strength filaments embedded in a matrix material and extending in general spanwise alignment to form an airfoil portion and an enlarged root portion, said enlarged root portion received in said slots engaging said lugs, and at least one reinforcing insert disposed in the root portion of said blades extending in a direction transverse to the rotor axis, the ends of said insert engaging the opposing walls of adjacent lugs, said insert being of a material sufficiently strong in compression to resist lug bending due to blade loss.
Claim 3
Dependent Claim
125 words
A rotor construction comprising: a hub having undercut slots defining a plurality of lugs in the periphery thereof, a plurality of filament reinforced composite blades arranged around the periphery of the hub, each blade comprising high modulus, high strength filaments embedded in a matrix material and extending in general spanwise alignment to form an airfoil portion and an enlarged root portion, said enlarged root portion received in said slots engaging said lugs, and at least one reinforcing insert disposed in the root portion of said blades extending in a direction transverse to the rotor axis, the ends of said insert engaging the opposing walls of adjacent lugs, said insert being of a material sufficiently strong in compression to resist lug bending due to blade loss.
Claim 4
Dependent Claim
125 words
A rotor construction comprising: a hub having undercut slots defining a plurality of lugs in the periphery thereof, a plurality of filament reinforced composite blades arranged around the periphery of the hub, each blade comprising high modulus, high strength filaments embedded in a matrix material and extending in general spanwise alignment to form an airfoil portion and an enlarged root portion, said enlarged root portion received in said slots engaging said lugs, and at least one reinforcing insert disposed in the root portion of said blades extending in a direction transverse to the rotor axis, the ends of said insert engaging the opposing walls of adjacent lugs, said insert being of a material sufficiently strong in compression to resist lug bending due to blade loss.
Claim 5
Dependent Claim
29 words
The invention of claim 1 wherein said blade root has a slot in its bottom portion extending through its side faces and said insert is received in said slot.
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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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |