US3531859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for accurately determining gap heights of pole pieces for magnetic heads
Assignee: US Philips Corp
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Filing: 1968-08-16
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Granted: 1970-10-06
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Expires: 1988-08-16
Abstract
No abstract record available.
Inventors
- 👤 Bastiaan Van Der Voo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:45
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/30; G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/1871; G11B5/193; G11B5/23; G11B5/232; H10N; H10N10/00; H10N10/01; H10W72/071; H10W72/073; H10W72/07331; H10W72/07337; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49037; Y10T29/49048; Y10T29/49055; Y10T29/49057
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3094772A
Cited
US3177475A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-10-05 | 1974-04-06 | 1974-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-10-05 | 1978-04-06 | 1978-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-10-05 | 1982-04-06 | 1982-10-06 | $7700.00 | Window Closed / Lapsed |