US2421771A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Approach protective system
Assignee: Individual
•
Filing: 1942-07-17
•
Granted: 1947-06-10
•
Expires: 1962-07-17
Abstract
No abstract record available.
Inventors
- 👤 Glenn H Browning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:14
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1718528A
Cited
US1731127A
Cited
US1780952A
Cited
GB346061A
Cited
US1845576A
Cited
US2103741A
Cited
US2112826A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-06-09 | 1950-12-09 | 1951-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-06-09 | 1954-12-09 | 1955-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-06-09 | 1958-12-09 | 1959-06-10 | $7700.00 | Window Closed / Lapsed |