US3502140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Falling film heat exchanger
Assignee: Individual
•
Filing: 1967-10-25
•
Granted: 1970-03-24
•
Expires: 1987-10-25
Abstract
No abstract record available.
Inventors
- 👤 Ida Violet Dawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:42
CPC Classifications
F; F28; F28D; F28D3/00; F28D3/02; Y; Y10; Y10S; Y10S165/00; Y10S165/163; Y10S165/168
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR328401A
Cited
GB190403917A
Cited
US883147A
Cited
US2183509A
Cited
US2237107A
Cited
US2210200A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-23 | 1973-09-22 | 1974-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-23 | 1977-09-22 | 1978-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-23 | 1981-09-22 | 1982-03-24 | $7700.00 | Window Closed / Lapsed |