US2327467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary draw works
Assignee: National Supply Co
•
Filing: 1938-01-18
•
Granted: 1943-08-24
•
Expires: 1958-01-18
Abstract
No abstract record available.
Inventors
- 👤 John D Spalding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:36
CPC Classifications
E; E21; E21B; E21B3/00; E21B3/02; E21B3/04; E21B3/06; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19023; Y10T74/19074; Y10T74/19079; Y10T74/19084
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1946-08-23 | 1947-02-22 | 1947-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1950-08-23 | 1951-02-22 | 1951-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1954-08-23 | 1955-02-22 | 1955-08-24 | $7700.00 | Window Closed / Lapsed |