US3799701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite fan blade and method of construction
Assignee: RTX Corp
•
Filing: 1972-02-28
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Granted: 1974-03-26
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Expires: 1992-02-28
Abstract
Abstract A composite fan blade is fabricated by bonding two complementary preformed outer shell halves defining an airfoil planform of composite material sandwiching a metal spar which spar extends beyond the airfoil planform to form the root of the blade.
Inventors
- 👤 E Rothman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:29
CPC Classifications
B; B23; B23P; B23P15/00; B23P15/04; F; F01; F01D; F01D5/00; F01D5/12; F01D5/28; F01D5/282; F04; F04D; F04D29/00; F04D29/26; F04D29/32; F04D29/38; F04D29/388; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
119 words
A blade fabricated from a composite material being made from a relatively high modulus filamentary reinforced composite having an airfoil planform, a leading edge, a trailing edge, a tip, and a root section, said airfoil planform having a camber side and a face side formed from a relatively thin layer of composite material and being bonded together at the leading and trailing edges and at the tip of the blade, a spar member sandwiched between the camber side and face side and having one end extending beyond the airfoil planform defining said root section, said spar member being the major structural element in the blade for transmitting the load from said planform through said spar to said root section.
Claim 2
Dependent Claim
119 words
A blade fabricated from a composite material being made from a relatively high modulus filamentary reinforced composite having an airfoil planform, a leading edge, a trailing edge, a tip, and a root section, said airfoil planform having a camber side and a face side formed from a relatively thin layer of composite material and being bonded together at the leading and trailing edges and at the tip of the blade, a spar member sandwiched between the camber side and face side and having one end extending beyond the airfoil planform defining said root section, said spar member being the major structural element in the blade for transmitting the load from said planform through said spar to said root section.
Claim 3
Dependent Claim
22 words
A blade as claimed in claim 1 wherein the root section forms the retention means for supporting the blade for rotary movement.
Claim 4
Dependent Claim
14 words
A blade as claimed in claim 2 wherein said composite material is boron aluminum.
Claim 5
Dependent Claim
14 words
A blade as claimed in claim 2 wherein said composite material is boron epoxy.
Claim 6
Dependent Claim
13 words
A blade as claimed in claim 2 wherein said spar member is titanium.
Claim 7
Dependent Claim
43 words
A blade as claimed in claim 2 wherein said spar member extends a substantial length relative to the length of the airfoil planform but short of the tip to leave a cavity between the end of the spar and tip of the blade.
Claim 8
Dependent Claim
123 words
A blade for a compressor, fan or prop-fan fabricated from a high modulus filamentary reinforced composite material having an airfoil planform and a root section, said airfoil planform having a camber side and a face side formed from a relatively thin layer of composite material, each of said sides having top, side and bottom edges, said camber side and face side being bonded together so that all of said sides are in alignment and defining a hollow cavity, a spar member extending in said hollow member filling at least a portion thereof and bonded to the inner wall of said camber side and said face side and having one end projecting throUgh the bottom edge of said sides for defining said root section.
Claim 9
Dependent Claim
123 words
A blade for a compressor, fan or prop-fan fabricated from a high modulus filamentary reinforced composite material having an airfoil planform and a root section, said airfoil planform having a camber side and a face side formed from a relatively thin layer of composite material, each of said sides having top, side and bottom edges, said camber side and face side being bonded together so that all of said sides are in alignment and defining a hollow cavity, a spar member extending in said hollow member filling at least a portion thereof and bonded to the inner wall of said camber side and said face side and having one end projecting throUgh the bottom edge of said sides for defining said root section.
Claim 10
Dependent Claim
14 words
A blade as claimed in claim 7 wherein said composite material is boron aluminum.
Claim 11
Dependent Claim
14 words
A blade as claimed in claim 7 wherein said spar is a metallic material.
Claim 12
Dependent Claim
13 words
A blade as claimed in claim 7 wherein said bond is an adhesive.
Claim 13
Dependent Claim
13 words
A blade as claimed in claim 7 wherein said bond is a braze.
Claim 14
Dependent Claim
14 words
A blade as claimed in claim 7 wherein said composite material is boron epoxy.
Claim 15
Dependent Claim
14 words
A blade as claimed in claim 7 wherein said spar is a composite material.
References Cited (Backward Citations)
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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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |