US3756745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite blade root configuration
Assignee: RTX Corp
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Filing: 1972-03-15
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Granted: 1973-09-04
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Expires: 1992-03-15
Abstract
Abstract In a fiber reinforced composite blade, having a root comprising a plurality of tangs, the fibers are brought from the airfoil into the root and arranged within the root to control the relative flexibility of the tangs. With a suitable arrangement of fibers within the root, the operational stresses on the blade can be distributed between the several tangs to best advantage.
Inventors
- 👤 A Alver
- 👤 W Pilpel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:39
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/12; F01D5/28; F01D5/282; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
A composite blade, having an airfoil and root, the root being adapted to fit within a slot on the periphery of a rotor, the slot including a radially inner bearing surface and radially outer bearing surface for taking blade operational loads, said root having a radially inner tang including a bearing surface adapted to mate with said inner bearing surface and a radially outer tang including a bearing surface adapted to mate with said outer bearing surface, the airfoil having a longitudinal axis and including fibers oriented in a substantially spanwise direction, said fibers extending from the airfoil into the root, the root including an arrangement of said fibers within the inner tang that is different from that of the arrangement within the outer tang, to control the flexibility of the radially inner tang relative to the flexibility of the radially outer tang to assure that said root bearing surfaces mate with the disc bearing surfaces.
Claim 2
Dependent Claim
156 words
A composite blade, having an airfoil and root, the root being adapted to fit within a slot on the periphery of a rotor, the slot including a radially inner bearing surface and radially outer bearing surface for taking blade operational loads, said root having a radially inner tang including a bearing surface adapted to mate with said inner bearing surface and a radially outer tang including a bearing surface adapted to mate with said outer bearing surface, the airfoil having a longitudinal axis and including fibers oriented in a substantially spanwise direction, said fibers extending from the airfoil into the root, the root including an arrangement of said fibers within the inner tang that is different from that of the arrangement within the outer tang, to control the flexibility of the radially inner tang relative to the flexibility of the radially outer tang to assure that said root bearing surfaces mate with the disc bearing surfaces.
Claim 3
Dependent Claim
51 words
A composite blade according to claim 1, wherein the arrangement of fibers within each of said tangs includes a greater volume ratio of fibers to nonfibers within the radially inner tang than within the radially outer tang to increase the flexibility of the outer tang with respect to the inner tang.
Claim 4
Dependent Claim
55 words
The composite blade according to claim 1, wherein said arrangement of fibers within each of said tangs includes fibers at an angle with respect to said longitudinal axis, said angle being greater within the inner tang than within the outer tang to increase the flexibility of the outer tang with respect to the inner tang.
Claim 5
Dependent Claim
48 words
The composite blade according to claim 1, wherein said arrangement of fibers within each of said tangs includes a greater depth of penetration of fibers within the inner tang than within the outer tang to increase the flexibility of the outer tang with respect to the inner tang.
Claim 6
Dependent Claim
63 words
The composite blade according to claim 2, wherein the arrangement of fibers within each of said tangs includes fibers at an angle with respect to said longitudinal axis, the angle of the fibers within the outer tang being less than the angle of the fibers within the inner tang to increase the flexibility of the outer tang with respect to the inner tang.
Claim 7
Dependent Claim
48 words
The composite blade according to claim 5, wherein the arrangement of fibers within each of said tangs includes a greater depth of penetration of fibers within the inner tang than within the outer tang to increase the flexibility of the outer tang with respect to the inner tang.
Claim 8
Dependent Claim
88 words
The composite blade according to claim 6, wherein said arrangement of fibers within each of said tangs includes a bundle of fibers curved into the radially inner tang and a bundle of fibers curved into the radially outer tang, the resulting angle of said bundle with respect to said longitudinal axis and the resulting depth of penetration of said fibers within each tang being greater within the inner tang than within the outer tang to increase the flexibility of the outer tang with respect to the inner tang.
Claim 9
Dependent Claim
16 words
The composite blade according to claim 7, wherein said root is of the double dovetail configuration.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |