US2677531A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Built-up, plate type heat exchanger having spiral flow
Assignee: HOCK SR
•
Filing: 1950-08-04
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Granted: 1954-05-04
•
Expires: 1970-08-04
Abstract
No abstract record available.
Inventors
- 👤 Sr Alvin Hock
- 👤 Leva Max
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:47
CPC Classifications
F; F28; F28F; F28F3/00; F28F3/08; F28F3/083; Y; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/356; Y10S165/361
Claims Analysis
Total Claims: 0
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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) | 1957-05-03 | 1957-11-02 | 1958-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-03 | 1961-11-02 | 1962-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-03 | 1965-11-02 | 1966-05-04 | $7700.00 | Window Closed / Lapsed |