US2607542A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic fluid brake
Assignee: AT&T Inc
•
Filing: 1949-03-22
•
Granted: 1952-08-19
•
Expires: 1969-03-22
Abstract
No abstract record available.
Inventors
- 👤 Gordon C Spillman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:05
CPC Classifications
B; B65; B65H; B65H59/00; B65H59/02; B65H59/04; Y; Y10; Y10S; Y10S137/00; Y10S137/909; Y10T; Y10T137/00; Y10T137/4456; Y10T137/4643
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2454830A
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US1144694A
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US2123936A
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US2006819A
Cited
DE691864C
Cited
US2219196A
Cited
US2334165A
Cited
US2507297A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-08-19 | 1956-02-18 | 1956-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-08-19 | 1960-02-18 | 1960-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-08-19 | 1964-02-18 | 1964-08-19 | $7700.00 | Window Closed / Lapsed |