US3525391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchanger and method of making same
Assignee: Waterdome Corp
•
Filing: 1969-01-21
•
Granted: 1970-08-25
•
Expires: 1989-01-21
Abstract
No abstract record available.
Inventors
- 👤 Phillip E Day
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:05
CPC Classifications
F; F28; F28F; F28F9/00; F28F9/02; F28F9/026; F28F9/0265; F28D; F28D9/00; F28D9/0031; F28F1/00; F28F1/02; F28F1/06; F28F13/00; F28F13/06; F28F13/12
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US893921A
Cited
US1730719A
Cited
US1922838A
Cited
US1992097A
Cited
US2263534A
Cited
US2877000A
Cited
US2969956A
Cited
FR1212129A
Cited
US3111982A
Cited
US3232280A
Cited
US3422884A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-08-24 | 1974-02-23 | 1974-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-08-24 | 1978-02-23 | 1978-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-08-24 | 1982-02-23 | 1982-08-25 | $7700.00 | Window Closed / Lapsed |