Patent US2640503A successfully refreshed from Google Patents.
US2640503A
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Refractory tube
Assignee: Saint Gobain Abrasives Inc
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Filing: 1950-11-21
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Granted: 1953-06-02
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Expires: 1970-11-21
Abstract
No abstract record available.
Inventors
- 👤 Lowell H Milligan
- 👤 Jr Osgood J Whittemore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:28
CPC Classifications
F; F16; F16L; F16L9/00; F16L9/14; C; C21; C21C; C21C5/00; C21C5/28; C21C5/42; C21C5/46; C21C5/4606; C21C5/4613
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
72 words
A REFRACTORY TUBE CONSISTING OF AT LEAST TWO PORTONS CONCENTRICALLY RELATED AND INTEGRALLY JOINED, ONE OF SAID PORTIONS BEING INNER OF THE OTHER OF SAID PORTIONS, ONE OF SAID PORTIONS BEING OF CERAMIC BONDED SILICON CARBIDE, SAID CERAMIC BONDED SILICON CARBIDE PORTION BEING AT LEAST 50% BY WEIGHT SILICON CARBIDE, SAID OTHER PORTION BEING AT LEAST 50% BY WEIGHT SILICATE, SAID SILICATE BEING SELECTED FROM THE GROUP CONSISTING OF MULLITE AND ZIRCON.
Claim 2
Dependent Claim
72 words
A REFRACTORY TUBE CONSISTING OF AT LEAST TWO PORTONS CONCENTRICALLY RELATED AND INTEGRALLY JOINED, ONE OF SAID PORTIONS BEING INNER OF THE OTHER OF SAID PORTIONS, ONE OF SAID PORTIONS BEING OF CERAMIC BONDED SILICON CARBIDE, SAID CERAMIC BONDED SILICON CARBIDE PORTION BEING AT LEAST 50% BY WEIGHT SILICON CARBIDE, SAID OTHER PORTION BEING AT LEAST 50% BY WEIGHT SILICATE, SAID SILICATE BEING SELECTED FROM THE GROUP CONSISTING OF MULLITE AND ZIRCON.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |