US2650431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for measuring horizontal and vertical angles
Assignee: Individual
•
Filing: 1951-03-08
•
Granted: 1953-09-01
•
Expires: 1971-03-08
Abstract
No abstract record available.
Inventors
- 👤 Callahan Ezra Leo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:16
CPC Classifications
G; G01; G01C; G01C1/00; G01C1/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US297093A
Cited
US784511A
Cited
US799878A
Cited
US1224725A
Cited
US1420913A
Cited
US1399994A
Cited
AT100954B
Cited
GB236111A
Cited
US1665627A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-08-31 | 1957-03-02 | 1957-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-08-31 | 1961-03-02 | 1961-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-08-31 | 1965-03-02 | 1965-09-01 | $7700.00 | Window Closed / Lapsed |