US2857922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for cleaning tube bundles
Assignee: Shell Development Co
•
Filing: 1951-10-09
•
Granted: 1958-10-28
•
Expires: 1971-10-09
Abstract
No abstract record available.
Inventors
- 👤 Robert T Effinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:15
CPC Classifications
C; C23; C23G; C23G3/00; C23G3/04
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-27 | 1962-04-28 | 1962-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-27 | 1966-04-28 | 1966-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-27 | 1970-04-28 | 1970-10-28 | $7700.00 | Window Closed / Lapsed |