Patent US2781133A successfully refreshed from Google Patents.
US2781133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum
Assignee: —
•
Filing: —
•
Granted: 1957-02-12
•
Expires: 1974-02-12
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:57
CPC Classifications
B; B01; B01D; B01D33/00; B01D33/06; B01D33/073; B01D33/44; B01D33/46; B01D33/466; B01D33/58
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2351652A
Cited
US1036174A
Cited
US1214152A
Cited
US1724436A
Cited
US1940993A
Cited
US2024955A
Cited
US2068511A
Cited
US2221210A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-02-12 | 1960-08-13 | 1961-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-02-12 | 1964-08-13 | 1965-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-02-12 | 1968-08-13 | 1969-02-12 | $7700.00 | Window Closed / Lapsed |