US2556948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable derrick or mast
Assignee: WALDRIP ENGINEERING Co
•
Filing: 1947-05-26
•
Granted: 1951-06-12
•
Expires: 1967-05-26
Abstract
No abstract record available.
Inventors
- 👤 Clifford E Sommarstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:28
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/02; E21B7/023; E21B15/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1954-06-11 | 1954-12-11 | 1955-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-11 | 1958-12-11 | 1959-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-11 | 1962-12-11 | 1963-06-12 | $7700.00 | Window Closed / Lapsed |