US2421747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Object locating system
Assignee: AT&T Inc
•
Filing: 1943-07-14
•
Granted: 1947-06-10
•
Expires: 1963-07-14
Abstract
No abstract record available.
Inventors
- 👤 George B Engelhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:34
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/04; G01S7/06; G01S7/10; G01S7/12; G01S7/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2130912A
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US2085940A
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US2205866A
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US2231929A
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US2241809A
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US2189549A
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US2288740A
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US2275974A
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GB542634A
Cited
US2332253A
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 |