US2818197A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Head closure construction for vertical heat exchangers
Assignee: Griscom Russell Co
•
Filing: 1955-09-19
•
Granted: 1957-12-31
•
Expires: 1975-09-19
Abstract
No abstract record available.
Inventors
- 👤 Jr Frank Boui
- 👤 Karl A Gardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:51
CPC Classifications
F; F16; F16J; F16J13/00; F16J13/02; B; B01; B01J; B01J3/00; B01J3/03; C; C21; C21B; C21B9/00; C21B9/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1888899A
Cited
US2647656A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-12-30 | 1961-07-01 | 1961-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-30 | 1965-07-01 | 1965-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-30 | 1969-07-01 | 1969-12-31 | $7700.00 | Window Closed / Lapsed |