Patent US2806537A successfully refreshed from Google Patents.
US2806537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter liner for oil wells or the like
Assignee: Individual
•
Filing: 1954-01-04
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Granted: 1957-09-17
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Expires: 1974-01-04
Abstract
No abstract record available.
Inventors
- 👤 Sr John Loyd Sparks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:02
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/02; E21B43/08; E21B43/082; Y; Y10; Y10S; Y10S277/00; Y10S277/918
Claims Analysis
Total Claims: 0
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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) | 1960-09-16 | 1961-03-18 | 1961-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-16 | 1965-03-18 | 1965-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-16 | 1969-03-18 | 1969-09-17 | $7700.00 | Window Closed / Lapsed |