US4263367A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Discontinuous graphite fiber reinforced glass composites
Assignee: RTX Corp
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Filing: 1979-11-07
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Granted: 1981-04-21
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Expires: 1999-11-07
Abstract
Abstract A graphite reinforced glass composite is described comprising discontinuous graphite fibers in substantially planar orientation in a glass matrix with strength and fracture toughness greater than the unreinforced glass matrix. The resulting composite has superior strength, fluid impermeability, wear resistance, failure strain and fracture toughness. In fact, the stress-strain, curve for composites of the invention resembles that of metal making it particularly suitable for a variety of moldable shapes and machinable designs.
Inventors
- 👤 Karl M. Prewo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:00
CPC Classifications
C; C03; C03C; C03C14/00; C03C14/002; C03C2214/00; C03C2214/02; Y; Y10; Y10S; Y10S428/00; Y10S428/902; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249924; Y10T428/24994; Y10T428/249942; Y10T428/249945; Y10T428/26; Y10T428/268; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/2933; Y10T428/294; Y10T428/2958; Y10T428/298; Y10T428/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
44 words
A graphite fiber reinforced glass composite comprising high strength and high modulus of elasticity discontinuous graphite fibers laid up in substantially in-plane random orientation in a glass matrix so as to produce strength and fracture toughness properties greater than that of the glass matrix.
Claim 2
Dependent Claim
44 words
A graphite fiber reinforced glass composite comprising high strength and high modulus of elasticity discontinuous graphite fibers laid up in substantially in-plane random orientation in a glass matrix so as to produce strength and fracture toughness properties greater than that of the glass matrix.
Claim 3
Dependent Claim
13 words
The composite of claim 1 having a flexural strength greater than 10,000 psi.
Claim 4
Dependent Claim
13 words
The composite of claim 2 having a flexural strength greater than 20,000 psi.
Claim 5
Dependent Claim
15 words
The composite of claim 1 having a fracture toughness greater than 3 MPa/m 3/2 .
Claim 6
Dependent Claim
15 words
The composite of claim 4 having a fracture toughness greater than 5 MPa/m 3/2 .
Claim 7
Dependent Claim
12 words
The composite of claim 1 wherein the glass matrix is borosilicate glass.
Claim 8
Dependent Claim
21 words
The composite of claim 1 wherein the graphite fiber is present in an amount about 30% to about 50% by volume.
Claim 9
Dependent Claim
65 words
A graphite fiber reinforced glass composite comprising about 20% to about 50% by volume high strength, high modulus of elasticity graphite fibers having an average length of about 1 cm to about 3 cm laid up in substantially in-plane random orientation in a low coefficient of thermal expansion glass matrix producing a composite with flexural strength and fracture toughness properties greater than the glass matrix.
Claim 10
Dependent Claim
65 words
A graphite fiber reinforced glass composite comprising about 20% to about 50% by volume high strength, high modulus of elasticity graphite fibers having an average length of about 1 cm to about 3 cm laid up in substantially in-plane random orientation in a low coefficient of thermal expansion glass matrix producing a composite with flexural strength and fracture toughness properties greater than the glass matrix.
Claim 11
Dependent Claim
37 words
The composite of claim 8 wherein the glass matrix is borosilicate glass, the average length of the fiber is about 2 cm, and the fiber is present in an amount about 30% to about 35% by volume.
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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) | 1984-04-20 | 1984-10-20 | 1985-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-20 | 1988-10-20 | 1989-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-20 | 1992-10-20 | 1993-04-21 | $7700.00 | Window Closed / Lapsed |