Patent US2850941A successfully refreshed from Google Patents.
US2850941A
Expired / Lapsed
US
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Device for measuring light transmission
Assignee: Welch Allyn Inc
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Filing: 1955-08-10
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Granted: 1958-09-09
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Expires: 1975-08-10
Abstract
No abstract record available.
Inventors
- 👤 Walter K Long
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:52
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/205; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/251; G01N21/255
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1878847A
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US2163467A
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US2213534A
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US2355960A
Cited
US2331027A
Cited
DE765408C
Cited
GB637009A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-08 | 1962-03-10 | 1962-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-08 | 1966-03-10 | 1966-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-08 | 1970-03-10 | 1970-09-09 | $7700.00 | Window Closed / Lapsed |