US3354540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing reliable magnetic heads having accurately predetermined dimensions
Assignee: US Philips Corp
•
Filing: 1966-03-07
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Granted: 1967-11-28
•
Expires: 1986-03-07
Abstract
No abstract record available.
Inventors
- 👤 Duinker Simon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:06
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/193; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49048; Y10T29/49055; Y10T29/49057; Y10T29/49075; Y10T29/49076; Y10T29/4998; Y10T29/49993
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
200 words
A METHOD OF MANUFACTURING PORTIONS OF MAGNETIC HEADS FOR VIDEO-FREQUENCY SIGNALS, COMPRISING: FORMING AT LEAST ONE SET OF TWO RELATIVELY SHALLOW GROOVES IN THE TOP FACE OF A FIRST FERRITE PLATE, EACH PAIR OF GROOVES OF OF SET MEETING AT ONE OF THE EDGES OF SAID TIP FACE, FILLING SAID GROOVES WITH A NOMAGNETIC STRENGTHENING MATERIAL AT A FIRST TEMPERATURE AT WHICH SAID MATERIAL FUSES AND IS BONDED TO SAID FERRITE, CUTTING A V-SHAPED GROOVE IN THE SIDE FACE OF SAID PLATE ABUTTING SAID EDGE, THE UPPER EDGE GROOVE EXTENDING PARALLEL TO SAID EDGE, THE UPPER EDGE OF SAID V-SHAPED GROOVE BEING AT A DISTANCE FROM SAID EDGE WHICH EXCEEDS THE DESIRED GAP HEIGHT OF THE HEAD, FILLING SAID V-SHAPED GROOVE WITH A NONMAGNETIC MATERIAL AT A SECOND TEMPERATURE AT WHICH SAID SECOND TEMPERATURE AND IS BONDED TO SAID FERRITE, SAID SECOND TEMPERATURE BEING LOWER THAN SAID FIRST TEMPERATURE, AND REMOVING SO MUCH OF SAID SIDE FACE THAT PORTIONS OF THE FERRITE PLATE WHICH APPEAR BETWEEN EVERY TWO PORTIONS OF STRENGTHENING MATERIAL LOCATED IN THE RELATIVELY SHALLOW GROOVES OF ONE SET HAVE A WIDTH WHICH IS EQUAL TO THE DESIRED WIDTH OF THE TRACK TO BE TRANSDUCED BY THE HEAD.
Claim 2
Independent Claim
200 words
A METHOD OF MANUFACTURING PORTIONS OF MAGNETIC HEADS FOR VIDEO-FREQUENCY SIGNALS, COMPRISING: FORMING AT LEAST ONE SET OF TWO RELATIVELY SHALLOW GROOVES IN THE TOP FACE OF A FIRST FERRITE PLATE, EACH PAIR OF GROOVES OF OF SET MEETING AT ONE OF THE EDGES OF SAID TIP FACE, FILLING SAID GROOVES WITH A NOMAGNETIC STRENGTHENING MATERIAL AT A FIRST TEMPERATURE AT WHICH SAID MATERIAL FUSES AND IS BONDED TO SAID FERRITE, CUTTING A V-SHAPED GROOVE IN THE SIDE FACE OF SAID PLATE ABUTTING SAID EDGE, THE UPPER EDGE GROOVE EXTENDING PARALLEL TO SAID EDGE, THE UPPER EDGE OF SAID V-SHAPED GROOVE BEING AT A DISTANCE FROM SAID EDGE WHICH EXCEEDS THE DESIRED GAP HEIGHT OF THE HEAD, FILLING SAID V-SHAPED GROOVE WITH A NONMAGNETIC MATERIAL AT A SECOND TEMPERATURE AT WHICH SAID SECOND TEMPERATURE AND IS BONDED TO SAID FERRITE, SAID SECOND TEMPERATURE BEING LOWER THAN SAID FIRST TEMPERATURE, AND REMOVING SO MUCH OF SAID SIDE FACE THAT PORTIONS OF THE FERRITE PLATE WHICH APPEAR BETWEEN EVERY TWO PORTIONS OF STRENGTHENING MATERIAL LOCATED IN THE RELATIVELY SHALLOW GROOVES OF ONE SET HAVE A WIDTH WHICH IS EQUAL TO THE DESIRED WIDTH OF THE TRACK TO BE TRANSDUCED BY THE HEAD.
References Cited (Backward Citations)
US2961709A
Cited
US3117367A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-11-27 | 1971-05-29 | 1971-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-11-27 | 1975-05-29 | 1975-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-11-27 | 1979-05-29 | 1979-11-28 | $7700.00 | Window Closed / Lapsed |