US2709335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety exhaust system
Assignee: National Mine Service Co
•
Filing: 1953-10-22
•
Granted: 1955-05-31
•
Expires: 1973-10-22
Abstract
No abstract record available.
Inventors
- 👤 Benjamin H Van Vactor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:15
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/02; F01N3/04; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2687008A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-05-30 | 1958-11-29 | 1959-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-05-30 | 1962-11-29 | 1963-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-05-30 | 1966-11-29 | 1967-05-31 | $7700.00 | Window Closed / Lapsed |