US1685238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Derrick walking beam
Assignee: Individual
•
Filing: 1926-07-14
•
Granted: 1928-09-25
•
Expires: 1946-07-14
Abstract
No abstract record available.
Inventors
- 👤 William R Mcdowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:22
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/12; E21B43/121; E21B43/126; E21B43/127; Y; Y10; Y10T; Y10T74/00; Y10T74/18; Y10T74/18888; Y10T74/1892; Y10T74/18968; Y10T74/21; Y10T74/2142; Y10T74/2154; Y10T74/2156
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) | 1931-09-25 | 1932-03-26 | 1932-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1935-09-25 | 1936-03-26 | 1936-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1939-09-25 | 1940-03-26 | 1940-09-25 | $7700.00 | Window Closed / Lapsed |