US3607063A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of carbon filaments of high strength and modulus
Assignee: RTX Corp
•
Filing: 1969-10-09
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Granted: 1971-09-21
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Expires: 1989-10-09
Abstract
Abstract A method for continuously producing carbon strand of high tensile strength and modulus comprising passing carbonized filament through an electrically conductive enclosure, generating a current of radiofrequency in an oscillatory circuit connected to the enclosure and establishing an electric field axially oscillating at the radiofrequency within the enclosure of sufficient density to heat the carbon filament to graphitization temperature.
Inventors
- 👤 Frank C Douglas
- 👤 Thomas K Gregory
- 👤 Robert W Stielau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:02
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/16
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
65 words
In those processes for continuously manufacturing high-strength, high-modulus carbon filaments by heating pyrolyzed polymeric filaments to 2,000*-3,500* C. the improvement which comprises electromagnetically coupling the filaments to radiofrequency source means by passing said filaments axially through a cavity coupler to expose said filaments to an axial oscillating electric field having a density sufficiently high to cause current flow in the filaments to effect said heating.
Claim 2
Dependent Claim
14 words
The invention of claim 2 wherein said cavity coupler is a quarter-wave cavity coupler.
Claim 3
Independent Claim
67 words
A method for the continuous manufacture of high-strength, high-modulus carbon filaments comprising moving preformed pyrolyzed polymeric filaments axially through a quarter-wave cavity and a capacitor located within the cavity and establishing a radiofrequency electric field within said cavity with a peak density between the plates of the capacitor of sufficient intensity whereby current is caused to flow in said filaments to heat the same to graphitization temperature.
References Cited (Backward Citations)
US2364526A
Cited
US3313597A
Cited
US3263052A
Cited
US3449213A
Cited
US3327086A
Cited
US3399252A
Cited
US3457385A
Cited
US3461261A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |