Patent US4933040A successfully refreshed from Google Patents.
US4933040A
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Hollow article formed of composite material
Assignee: Biomagnetic Technologies Inc
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Filing: 1988-08-17
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Granted: 1990-06-12
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Expires: 2008-08-17
Abstract
Abstract A vacuum-tight, nonmetallic hollow article is fabricated from composite material of fibers in a resin matrix. The article has a closed end, and is laid up from sheets of the composite material and end pieces to form the closed end. The layers are mechanically worked and debulked repeatedly during layup between the addition of successive layers, to remove irregularities that can cause vacuum leaks. The joints between the sheets applied to the sidewalls and the end pieces are mechanically worked to effect a vacuum-tight seal, and the joints are staggered as between succeeding layers for strength and integrity. The laid up and debulked piece is finally cured.
Inventors
- 👤 Ronald C. Wesley, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:29
CPC Classifications
F; F17; F17C; F17C3/00; F17C3/02; F17C3/08; B; B29; B29C; B29C53/00; B29C53/56; B29C53/58; B29C53/60; B29C53/602; B29C70/00; B29C70/04; B29C70/28; B29C70/30; B29C70/304; B29D; B29D22/00; B29D22/003; B29L; B29L2031/00; B29L2031/712; F17C2203/00; F17C2203/01; F17C2203/014; F17C2203/018; F17C2203/03; F17C2203/0391; F17C2203/06; F17C2203/0602; F17C2203/0612; F17C2203/0626; F17C2203/0629; F17C2203/0634; F17C2203/0658; F17C2203/0663; F17C2209/00; F17C2209/21; F17C2209/2154; F17C2209/2163; F17C2221/00; F17C2221/01; F17C2221/016; F17C2221/017; F17C2223/00; F17C2223/01; F17C2223/0146; F17C2223/0153; F17C2223/0161; F17C2223/03; F17C2223/033; F17C2260/00; F17C2260/01; F17C2260/011; F17C2260/03; F17C2260/035; F17C2260/036; F17C2270/00; F17C2270/05; F17C2270/0509; F17C2270/0527
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
180 words
A process for preparing a hollow composite material article having a sidewall and a closed end, comprising the steps of: preparing a mandrel having the shape of the interior of the article; furnishing a plurality of end pieces of nonmetallic fiber composite material, each of which is sufficiently large to fit over the closed end of the article; applying a plurality of sheets of nonmetallic fiber composite material to the sidewall surface of the mandrel and the plurality of end pieces of composite material to the end of the mandrel in a layup operation to form a series of layers, alternating the sheets and end pieces and trimming the end pieces to form butt joints with the sheets along the sidewall surface, while axially staggering the seams between the sheets and end pieces; mechanically working and debulking the sheets and end pieces to avoid folds therein, and mechanically working the seams between the sheets and end pieces to effect a vacuum-tight joint therebetween, the mechanical working to occur at intermediate stages of the layup procedure; and curing the laid-up piece.
Claim 2
Dependent Claim
180 words
A process for preparing a hollow composite material article having a sidewall and a closed end, comprising the steps of: preparing a mandrel having the shape of the interior of the article; furnishing a plurality of end pieces of nonmetallic fiber composite material, each of which is sufficiently large to fit over the closed end of the article; applying a plurality of sheets of nonmetallic fiber composite material to the sidewall surface of the mandrel and the plurality of end pieces of composite material to the end of the mandrel in a layup operation to form a series of layers, alternating the sheets and end pieces and trimming the end pieces to form butt joints with the sheets along the sidewall surface, while axially staggering the seams between the sheets and end pieces; mechanically working and debulking the sheets and end pieces to avoid folds therein, and mechanically working the seams between the sheets and end pieces to effect a vacuum-tight joint therebetween, the mechanical working to occur at intermediate stages of the layup procedure; and curing the laid-up piece.
Claim 3
Dependent Claim
22 words
The process of claim 1, wherein during the step of curing compression is applied perpendicular to the layers of fiber composite material.
Claim 4
Dependent Claim
22 words
The process of claim 1, wherein the mechanical working of the layers is accomplished in part by a shrink tape wound thereover.
Claim 5
Dependent Claim
26 words
The process of claim 1, wherein the debulking is accomplished by applying a compressive force to the laid up part perpendicular to the fiber composite material.
Claim 6
Dependent Claim
13 words
The process of claim 1, wherein the fiber composite material includes graphite fibers.
Claim 7
Dependent Claim
13 words
The process of claim 1, wherein the fiber composite materials includes kevlar fibers.
Claim 8
Dependent Claim
19 words
The process of claim 1, wherein the finished part includes from 7 to 11 layers of fiber composite material.
Claim 9
Dependent Claim
16 words
The process of claim 1, wherein the finished part includes 7 layers of fiber composite material.
Claim 10
Dependent Claim
27 words
The process of claim 1, wherein an extra inserted layer of the end pieces is provided to radially stagger at least a portion of the laid-up layers.
Claim 11
Dependent Claim
36 words
The process of claim 1, including the further step of preparing a second hollow article having a closed end that fits within the first article, using the same series of steps as recited in claim 1.
Claim 12
Dependent Claim
34 words
The process of claim 10, including the further step of placing the second article within the first article, and joining the tops of the articles by an upper closure to form a Dewar flask.
Claim 13
Dependent Claim
14 words
The process of claim 1, wherein the article container is circular in cross section.
Claim 14
Dependent Claim
9 words
A container prepared by the process of claim 1.
Claim 15
Dependent Claim
10 words
A Dewar flask prepared by the process of claim 11.
Claim 16
Dependent Claim
188 words
A process for preparing a vacuum-tight, nonmetallic cryogenic container closed at one end, comprising the steps of: furnishing a mandrel having a lateral surface in the shape of the inner surface of the container; furnishing a plurality of end pieces of nonmetallic fiber composite material; furnishing a plurality of lateral surface sheets of nonmetallic fiber composite material; applying the plurality of lateral surface sheets of fiber composite material to the lateral surface of the mandrel and the plurality of end pieces of composite material to the end of the mandrel in a layup operation to form a series of layers, alternating the lateral surface sheets and end pieces and trimming the end pieces to form butt joints with the sheets along the lateral surface, while axially staggering the seams between the lateral surface sheets and end pieces; mechanically working and debulking the lateral surface sheets and end pieces to avoid folds therein, and mechanically working the seams between the lateral surface sheets and end pieces to effect a vacuum-tight joint therebetween, the mechanical working to occur at intermediate stages of the layup procedure; and curing the laid-up piece.
Claim 17
Dependent Claim
188 words
A process for preparing a vacuum-tight, nonmetallic cryogenic container closed at one end, comprising the steps of: furnishing a mandrel having a lateral surface in the shape of the inner surface of the container; furnishing a plurality of end pieces of nonmetallic fiber composite material; furnishing a plurality of lateral surface sheets of nonmetallic fiber composite material; applying the plurality of lateral surface sheets of fiber composite material to the lateral surface of the mandrel and the plurality of end pieces of composite material to the end of the mandrel in a layup operation to form a series of layers, alternating the lateral surface sheets and end pieces and trimming the end pieces to form butt joints with the sheets along the lateral surface, while axially staggering the seams between the lateral surface sheets and end pieces; mechanically working and debulking the lateral surface sheets and end pieces to avoid folds therein, and mechanically working the seams between the lateral surface sheets and end pieces to effect a vacuum-tight joint therebetween, the mechanical working to occur at intermediate stages of the layup procedure; and curing the laid-up piece.
Claim 18
Dependent Claim
21 words
The process of claim 15, wherein the number of lateral surface sheets is not equal to the number of end pieces.
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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) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |