US3309072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recuperator tubes
Assignee: Shenango Ceramics Inc
•
Filing: 1962-06-04
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Granted: 1967-03-14
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Expires: 1982-06-04
Abstract
No abstract record available.
Inventors
- 👤 Howard B Cummings
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:45
CPC Classifications
F; F28; F28F; F28F21/00; F28F21/04; Y; Y10; Y10S; Y10S165/00; Y10S165/051; Y10S165/052; Y10S165/063
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
55 words
A REFRACTORY CERAMIC RECUPERATOR TUBE HAVING A DEEPLY CORRUGATED WALL OF SUBSTANTIALLY UNIFORM THICKNESS AND EXTENDING PARALLEL TO THE TUBE AXIS THROUGHOUT THE MAJOR PORTION OF ITS LENGTH TO A SPIGOT END, AN INTEGRAL BELL FORMED AT THE OPPOSITE END OF THE TUBE, THE INNER WALL SURFACE OF THE BELL BEING OF A DIAMETER SUFFICIENT
Claim 2
Dependent Claim
55 words
A REFRACTORY CERAMIC RECUPERATOR TUBE HAVING A DEEPLY CORRUGATED WALL OF SUBSTANTIALLY UNIFORM THICKNESS AND EXTENDING PARALLEL TO THE TUBE AXIS THROUGHOUT THE MAJOR PORTION OF ITS LENGTH TO A SPIGOT END, AN INTEGRAL BELL FORMED AT THE OPPOSITE END OF THE TUBE, THE INNER WALL SURFACE OF THE BELL BEING OF A DIAMETER SUFFICIENT
References Cited (Backward Citations)
FR597898A
Cited
US2733908A
Cited
US783886A
Cited
US1657704A
Cited
US1771160A
Cited
US1743830A
Cited
FR803115A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-03-13 | 1970-09-12 | 1971-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-03-13 | 1974-09-12 | 1975-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-03-13 | 1978-09-12 | 1979-03-14 | $7700.00 | Window Closed / Lapsed |