US3416618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shrouded bit
Assignee: Dresser Industries Inc
•
Filing: 1966-10-28
•
Granted: 1968-12-17
•
Expires: 1986-10-28
Abstract
No abstract record available.
Inventors
- 👤 Elmer A Kunnemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:10
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/02; E21B10/04; E21B21/00; E21B21/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3273660A
Cited
US1961362A
Cited
US1996322A
Cited
US2261546A
Cited
US2657016A
Cited
US2786652A
Cited
US3151690A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-12-17 | 1972-06-17 | 1972-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-12-17 | 1976-06-17 | 1976-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-12-17 | 1980-06-17 | 1980-12-17 | $7700.00 | Window Closed / Lapsed |