US2743347A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat transfer unit
Assignee: DUBL DEE ENGINEERING Corp
•
Filing: 1954-04-06
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Granted: 1956-04-24
•
Expires: 1974-04-06
Abstract
No abstract record available.
Inventors
- 👤 Donald C Porter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:56
CPC Classifications
D; D06; D06F; D06F71/00; D06F71/32; D06F71/36; B; B29; B29C; B29C33/00; B29C33/02; B30; B30B; B30B15/00; B30B15/06; B30B15/062; B30B15/064
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1897197A
Cited
US1994759A
Cited
US2058511A
Cited
US2203620A
Cited
US2231251A
Cited
US2524886A
Cited
US2619580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-04-24 | 1959-10-24 | 1960-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-24 | 1963-10-24 | 1964-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-24 | 1967-10-24 | 1968-04-24 | $7700.00 | Window Closed / Lapsed |