US5076871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming composite prepreg articles utilizing heat-shrinkable braided sleeves
Assignee: Boeing Co
•
Filing: 1990-01-11
•
Granted: 1991-12-31
•
Expires: 2010-01-11
Abstract
Abstract A method of forming composite prepreg articles. Prepreg plies (12) are laid up over a breakable mandrel (10), the mandrel having a configuration substantially matching the desired configuration of the composite prepreg article and being pre-coated to prevent the prepreg from sticking to it. A release film (14) is applied over the prepreg. A heat-shrinkable braided sleeve (16) is placed over the prepreg and release film and secured to the mandrel, thereby creating an assembly (28). The prepreg is first compacted by encapsulating the assembly and applying a vacuum, and is then substantially cured by exposing the assembly to heat. After curing, the braided sleeve and release film are removed. The cured prepreg, which serves as the desired composite prepreg article, is separated from the mandrel by breaking the mandrel.
Inventors
- 👤 Bradley A. Frye
- 👤 Marcia R. Riley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:29
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/42; B29C70/44; B29C70/446; B29C33/00; B29C33/44; B29C33/448; B29C33/56; B29C33/68; B29C61/00; B29C61/006; B29C43/00; B29C43/02; B29C43/10; B29C43/12
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
210 words
A method of forming composite prepreg articles, the method comprising: (a) applying at least one layer of a prepreg material over a breakable mandrel having a configuration substantially matching the desired configuration of the composite prepreg article, said prepreg material having a lengthwise dimension less than that of said mandrel, said breakable mandrel being pre-coated to prevent said prepreg material from sticking to it; (b) placing at least one pre-formed cylindrical braided sleeve formed of a heat-shrinkable material over said prepreg material; (c) securing said at least one pre-formed cylindrical braided sleeve to said mandrel to create an assembly by: (i) securing a first end of said heat-shrinkable braided sleeve to said mandrel at a position adjacent a first end of said prepreg material, (ii) applying a tensile force to a second end of said heat-shrinkable braided sleeve to reduce the cross-sectional dimension of said sleeve, and (iii) securing the second end of said heat-shrinkable braided sleeve to said mandrel at a position adjacent a second end of said prepreg material while said sleeve is under said tensile force; (d) compacting said prepreg material; (e) substantially curing said prepreg material by exposing said assembly to heat; and (f) separating said cured prepreg material from said mandrel by breaking said mandrel.
Claim 2
Independent Claim
210 words
A method of forming composite prepreg articles, the method comprising: (a) applying at least one layer of a prepreg material over a breakable mandrel having a configuration substantially matching the desired configuration of the composite prepreg article, said prepreg material having a lengthwise dimension less than that of said mandrel, said breakable mandrel being pre-coated to prevent said prepreg material from sticking to it; (b) placing at least one pre-formed cylindrical braided sleeve formed of a heat-shrinkable material over said prepreg material; (c) securing said at least one pre-formed cylindrical braided sleeve to said mandrel to create an assembly by: (i) securing a first end of said heat-shrinkable braided sleeve to said mandrel at a position adjacent a first end of said prepreg material, (ii) applying a tensile force to a second end of said heat-shrinkable braided sleeve to reduce the cross-sectional dimension of said sleeve, and (iii) securing the second end of said heat-shrinkable braided sleeve to said mandrel at a position adjacent a second end of said prepreg material while said sleeve is under said tensile force; (d) compacting said prepreg material; (e) substantially curing said prepreg material by exposing said assembly to heat; and (f) separating said cured prepreg material from said mandrel by breaking said mandrel.
Claim 3
Dependent Claim
20 words
The method of claim 1, wherein: said breakable mandrel is of linear configuration and has a substantially circular cross section.
Claim 4
Dependent Claim
13 words
The method of claim 2, wherein said breakable mandrel is composed of plaster.
Claim 5
Dependent Claim
17 words
The method of claim 2, wherein said breakable mandrel is configured to produce a composite prepreg duct.
Claim 6
Dependent Claim
15 words
The method of claim 2, wherein said breakable mandrel is pre-coated with a parting lacquer.
Claim 7
Dependent Claim
19 words
The method of claim 2, wherein said prepreg material is compacted by encapsulation and the application of a vacuum.
Claim 8
Dependent Claim
33 words
The method of claim 2, wherein said heat-shrinkable braided sleeve is slightly elastomeric to allow said sleeve to be slightly expanded from its natural state to ease placing it over said prepreg material.
Claim 9
Dependent Claim
54 words
The method of claim 2, further comprising: after applying said prepreg material, applying a release material over the outermost layer of said prepreg material, said heat-shrinkable braided sleeve being placed over said release material and said prepreg material; and after substantially curing said prepreg material, removing said heat-shrinkable braided sleeve and said release material.
Claim 10
Dependent Claim
13 words
The method of claim 8, wherein said breakable mandrel is composed of plaster.
Claim 11
Dependent Claim
17 words
The method of claim 8, wherein said breakable mandrel is configured to produce a composite prepreg duct.
Claim 12
Dependent Claim
15 words
The method of claim 8, wherein said breakable mandrel is pre-coated with a parting lacquer.
Claim 13
Dependent Claim
19 words
The method of claim 8, wherein said prepreg material is compacted by encapsulation and the application of a vacuum.
Claim 14
Dependent Claim
15 words
The method of claim 8, wherein said release material is composed of fluorinated ethylene-propylene resin.
Claim 15
Dependent Claim
37 words
The method of claim 8, wherein said heat-shrinkable braided sleeve is slightly elastomeric to allow said sleeve to be slightly expanded from its natural state to ease placing it over said release material and said prepreg material.
Claim 16
Dependent Claim
60 words
The method of claim 1, wherein: said breakable mandrel is of branched configuration and has a substantially circular cross section; said at least one cylindrical braided sleeve is a plurality of heat-shrinkable braided sleeves; and said plurality of heat-shrinkable braided sleeves are secured to said mandrel at one end and to one or more other sleeves at the other end.
Claim 17
Dependent Claim
13 words
The method of claim 15, wherein said breakable mandrel is composed of plaster.
Claim 18
Dependent Claim
17 words
The method of claim 15, wherein said breakable mandrel is configured to produce a composite prepreg duct.
Claim 19
Dependent Claim
15 words
The method of claim 15, wherein said breakable mandrel is precoated with a parting lacquer.
Claim 20
Dependent Claim
19 words
The method of claim 15, wherein said prepreg material is compacted by encapsulation and the application of a vacuum.
Claim 21
Dependent Claim
33 words
The method of claim 15, wherein said heat-shrinkable braided sleeves are slightly elastomeric to allow said sleeves to be slightly expanded from their natural state to ease placing them over said prepreg material.
Claim 22
Dependent Claim
54 words
The method of claim 15, further comprising: after applying said prepreg material, applying a release material over the outermost layer of said prepreg material, said heat-shrinkable braided sleeves being placed over said release material and said prepreg material; and after substantially curing said prepreg material, removing said heat-shrinkable braided sleeves and said release material.
Claim 23
Dependent Claim
13 words
The method of claim 21, wherein said breakable mandrel is composed of plaster.
Claim 24
Dependent Claim
17 words
The method of claim 21, wherein said breakable mandrel is configured to produce a composite prepreg duct.
Claim 25
Dependent Claim
15 words
The method of claim 21, wherein said breakable mandrel is precoated with a parting lacquer.
Claim 26
Dependent Claim
19 words
The method of claim 21, wherein said prepreg material is compacted by encapsulation and the application of a vacuum.
Claim 27
Dependent Claim
15 words
The method of claim 21, wherein said release material is composed of fluorinated ethylene-propylene resin.
Claim 28
Dependent Claim
37 words
The method of claim 21, wherein said heat-shrinkable braided sleeves are slightly elastomeric to allow said sleeves to be slightly expanded from their natural state to ease placing them over said release material and said prepreg material.
Claim 29
Dependent Claim
120 words
The method of claim 1, wherein: said breakable mandrel is of linear configuration and has a non-circular cross section; said at least one cylindrical braided sleeve is a single substantially non-shrinkable braided sleeve; and said securing step comprises: (i) securing a first end of said substantially non-shrinkable braided sleeve to said mandrel at a position adjacent a first end of said prepreg material, (ii) applying a tensile force to a second end of said substantially non-shrinkable braided sleeve to reduce the cross-sectional dimension of said sleeve, and (iii) securing the second end of said substantially non-shrinkable braided sleeve to said mandrel at a position adjacent a second end of said prepreg material while said sleeve is under said tensile force.
Claim 30
Dependent Claim
34 words
The method of claim 28, wherein said substantially non-shrinkable braided sleeve is slightly elastomeric to allow said sleeve to be slightly expanded from its natural state to ease placing it over said prepreg material.
Claim 31
Dependent Claim
56 words
The method of claim 28, further comprising: after applying said prepreg material, applying a release material over the outermost layer of said prepreg material, said substantially non-shrinkable braided sleeve being placed over said release material and said prepreg material; and after substantially curing said prepreg material, removing said substantially non-shrinkable braided sleeve and said release material.
Claim 32
Dependent Claim
38 words
The method of claim 30, wherein said substantially non-shrinkable braided sleeve is slightly elastomeric to allow said sleeve to be slightly expanded from its natural state to ease placing it over said release material and said prepreg material.
Claim 33
Dependent Claim
16 words
The method of claim 28, wherein said substantially non-shrinkable braided sleeve is composed of polyvinyl alcohol.
Claim 34
Dependent Claim
61 words
The method of claim 1, wherein: said breakable mandrel is of branched configuration and has a non-circular cross section; said at least one cylindrical braided sleeve is a plurality of substantially non-shrinkable braided sleeves; and said plurality of substantially non-shrinkable braided sleeves are secured to said mandrel at one end and to one or more other sleeves at the other end.
Claim 35
Dependent Claim
34 words
The method of claim 33, wherein said substantially non-shrinkable braided sleeves are slightly elastomeric to allow said sleeves to be slightly expanded from their natural state to ease placing them over said prepreg material.
Claim 36
Dependent Claim
56 words
The method of claim 33, further comprising: after applying said prepreg material, applying a release material over the outermost layer of said prepreg material, said substantially non-shrinkable braided sleeves being placed over said release material and said prepreg material; and after substantially curing said prepreg material, removing said substantially non-shrinkable braided sleeves and said release material.
Claim 37
Dependent Claim
38 words
The method of claim 35, wherein said substantially non-shrinkable braided sleeves are slightly elastomeric to allow said sleeves to be slightly expanded from their natural state to ease placing them over said release material and said prepreg material.
Claim 38
Dependent Claim
16 words
The method of claim 33, wherein said substantially non-shrinkable braided sleeve is composed of polyvinyl alcohol.
Claim 39
Dependent Claim
18 words
The method of claim 1, wherein said prepreg material comprises a fibrous material impregnated with uncured thermosettable resin.
Claim 40
Dependent Claim
21 words
The method of claim 38, wherein said fibrous material is selected from the group consisting of aramid fiber and glass fiber.
Claim 41
Dependent Claim
22 words
The method of claim 38, wherein said uncured thermosettable resin is selected from the group consisting of polyester resin and epoxy resin.
References Cited (Backward Citations)
US2652093A
Cited
US2772696A
Cited
US3429522A
Cited
US3936336A
Cited
US3669157A
Cited
US3773593A
Cited
JPS4934910A
Cited
JPS4934911A
Cited
US4271329A
Cited
US4204897A
Cited
US4216047A
Cited
US4532169A
Cited
US4741087A
Cited
US4777859A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |