US3521956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distance measuring apparatus which compensates for ambient atmospheric refractive index
Assignee: National Research Development Corp UK
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Filing: 1964-11-09
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Granted: 1970-07-28
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Expires: 1984-11-09
Abstract
No abstract record available.
Inventors
- 👤 Keith Davy Froome
- 👤 Robert Howard Bradsell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:20
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/08; G01S17/32; G01S17/36; G01S17/10; G01S7/00; G01S7/48; G01S7/481; G01S7/4811; G01S7/4814; G01S7/491
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-27 | 1974-01-26 | 1974-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-27 | 1978-01-26 | 1978-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-27 | 1982-01-26 | 1982-07-28 | $7700.00 | Window Closed / Lapsed |