US3428557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling boiler systems
Assignee: Calgon Corp
•
Filing: 1966-09-19
•
Granted: 1969-02-18
•
Expires: 1986-09-19
Abstract
No abstract record available.
Inventors
- 👤 Hubert M Rivers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:24
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/68; C02F1/685; C02F1/686; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0324; Y10T137/0329; Y10T137/034; Y10T137/0374
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1145509A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-02-18 | 1972-08-19 | 1973-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-18 | 1976-08-19 | 1977-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-18 | 1980-08-19 | 1981-02-18 | $7700.00 | Window Closed / Lapsed |