US5042968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Propeller blade subassembly and method for making a propeller blade subassembly
Assignee: RTX Corp
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Filing: 1989-11-02
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Granted: 1991-08-27
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Expires: 2009-11-02
Abstract
Abstract A propeller blade spar/foam subassembly is manufactured by disposing a lamination of prepreg within a mold, closing the mold about a spar and injecting foam into mold cavities formed at the lead edge and the trailing edge of the spar.
Inventors
- 👤 Marcia A. Fecto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:29
CPC Classifications
B; B29; B29D; B29D99/00; B29D99/0025; B29C; B29C44/00; B29C44/02; B29C44/12; B29C44/14; B29C44/16; B29C70/00; B29C70/68; B29C70/86; B29C70/865; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316; Y10T29/49332; Y10T29/49336; Y10T29/49337
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
138 words
Method of constructing a spar/foam subassembly for a propeller blade, comprising the steps of: lining interior molding surfaces of a pair of mold halves with a layer of prepreg material; inserting a spar having a leading edge and a trailing edge between said mold halves; applying an adhesive to said spar for filling in gaps between camber and face sides of the spar and said mold; after said inserting step, said lining step, and said applying step mating said mold halves to form a first cavity between the molding surfaces and the leading edge of the spar and a second cavity between the molding surfaces and the trailing edge of the spar; after said mating step, injecting a foam within said first and second cavities; and after said injecting step, simultaneously curing said foam and said prepreg material.
Claim 2
Dependent Claim
138 words
Method of constructing a spar/foam subassembly for a propeller blade, comprising the steps of: lining interior molding surfaces of a pair of mold halves with a layer of prepreg material; inserting a spar having a leading edge and a trailing edge between said mold halves; applying an adhesive to said spar for filling in gaps between camber and face sides of the spar and said mold; after said inserting step, said lining step, and said applying step mating said mold halves to form a first cavity between the molding surfaces and the leading edge of the spar and a second cavity between the molding surfaces and the trailing edge of the spar; after said mating step, injecting a foam within said first and second cavities; and after said injecting step, simultaneously curing said foam and said prepreg material.
Claim 3
Dependent Claim
34 words
Method of constructing a spar/foam subassembly for a propeller blade, according to claim 1 further comprising the step of: prior to said lining step, applying a release agent to interior surfaces of said mold.
Claim 4
Dependent Claim
30 words
Method of constructing a spar/foam subassembly for a propeller blade, according to claim 2, wherein said curing step is performed by raising the temperature of the mold to 250° F.
Claim 5
Dependent Claim
16 words
A spar/foam subassembly, for a propeller blade, manufactured according to the process recited in claim 1.
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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) | 1994-08-26 | 1995-02-25 | 1995-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-26 | 1999-02-25 | 1999-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-26 | 2003-02-25 | 2003-08-27 | $7700.00 | Window Closed / Lapsed |