US2821368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water pre-heater
Assignee: Individual
•
Filing: 1955-06-21
•
Granted: 1958-01-28
•
Expires: 1975-06-21
Abstract
No abstract record available.
Inventors
- 👤 Essig William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:36
CPC Classifications
F; F28; F28D; F28D21/00; F28D21/0001; F28D21/0003; F28D21/0005; F28D21/0007
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |