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Patent US2681767A successfully refreshed from Google Patents.
US2681767A
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Calculating machine
Assignee: Friden Calculating Machine Co Inc
•
Filing: 1950-10-12
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Granted: 1954-06-22
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Expires: 1970-10-12
Abstract
No abstract record available.
Inventors
- 👤 George W Hopkins
- 👤 Arthur J Malavazos
- 👤 Donald L Rolph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:23
CPC Classifications
G; G06; G06C; G06C7/00; G06C7/02; G06C7/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2177817A
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US2360005A
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US2427271A
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US2459862A
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US2557457A
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US923269A
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US975180A
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US1028135A
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US1045258A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-06-21 | 1957-12-21 | 1958-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-06-21 | 1961-12-21 | 1962-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-06-21 | 1965-12-21 | 1966-06-22 | $7700.00 | Window Closed / Lapsed |