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US3846906A
Expired / Lapsed
US
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Methods of manufacturing magnetic transducing heads
Assignee: Fujitsu Services Ltd
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Filing: 1973-06-05
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Granted: 1974-11-12
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Expires: 1993-06-05
Abstract
Abstract A method of manufacturing magnetic transducing heads to facilitate testing of individual components of the head is disclosed. A head for digital recording on magnetic discs is made of a slider profiled for co-operation with the disc and contains a pair of gapped pole pieces and a yoke assembly includes a yoke for completing the magnetic circuit and a resilient mounting for the head. The slider and the yoke assembly are tested individually.
Inventors
- 👤 D Case
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:08
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/455; G11B5/127; G11B5/1272; G11B5/133; G11B5/1335; G11B5/187; G11B5/193; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49004; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49036; Y10T29/49041; Y10T29/49048
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
A method of manufacturing a magnetic transducing head including the steps of fabricating a pole piece unit having at least one pair of ferrite pole pieces spaced apart by a predetermined non-magnetic transducing gap, the pole pieces being located within a glass-ceramic block having an operating surface with a profile effective to cause the transducing head to fly out of contact over a record medium; independently fabricating a yoke assembly having a magnetic yoke for each pair of pole pieces, each yoke having at least one coil electromagnetically coupled thereto; dynamically testing the profiled pole piece unit in conjunction with the record medium independently of said yoke assembly; testing said yoke assembly independently of said pole piece unit; and aligning and securing together a satisfactorily tested yoke assembly and a satisfactorily tested pole piece unit so that the magnetic yoke and the pole pieces constitute a core for a magnetic transducing head.
Claim 2
Independent Claim
152 words
A method of manufacturing a magnetic transducing head including the steps of fabricating a pole piece unit having at least one pair of ferrite pole pieces spaced apart by a predetermined non-magnetic transducing gap, the pole pieces being located within a glass-ceramic block having an operating surface with a profile effective to cause the transducing head to fly out of contact over a record medium; independently fabricating a yoke assembly having a magnetic yoke for each pair of pole pieces, each yoke having at least one coil electromagnetically coupled thereto; dynamically testing the profiled pole piece unit in conjunction with the record medium independently of said yoke assembly; testing said yoke assembly independently of said pole piece unit; and aligning and securing together a satisfactorily tested yoke assembly and a satisfactorily tested pole piece unit so that the magnetic yoke and the pole pieces constitute a core for a magnetic transducing head.
Claim 3
Dependent Claim
65 words
A method as claimed in claim 1 including the steps of temporarily securing the profiled pole piece unit to a satisfactory yoke assembly mounted resiliently in a test apparatus to form a head assembly operative to fly out of contact with a record medium; and testing the head assembly in conjunction with the record medium to assess the performance of the profiled pole piece unit.
Claim 4
Independent Claim
191 words
A method of manufacturing a magnetic transducing head including the steps of fabricating a pole piece unit having at least one pair of ferrite pole pieces spaced apart by a predetermined non-magnetic transducing gap, the pole pieces being located within a glass-ceramic block having an operating surface shaped to co-operate with a record medium; independently fabricating a yoke assembly having a magnetic yoke for each pair of pole pieces, each yoke having at least one coil electromagnetically coupled thereto; testing the pole piece unit independently of the yoke assembly; fabrIcating a resilient support member for the transducing head; securing the support member to the yoke assembly; mounting the yoke assembly by means of its resilient support member in a test apparatus; temporarily securing a satisfactory pole piece unit to the yoke assembly to form a head assembly; testing the head assembly in conjunction with the record medium to assess the performance of the yoke assembly being tested; and aligning and securing together a satisfactorily tested yoke assembly and a satisfactorily tested pole piece unit so that the magnetic yoke and the pole pieces constitute a core for a magnetic transducing head.
Claim 5
Independent Claim
191 words
A method of manufacturing a magnetic transducing head including the steps of fabricating a pole piece unit having at least one pair of ferrite pole pieces spaced apart by a predetermined non-magnetic transducing gap, the pole pieces being located within a glass-ceramic block having an operating surface shaped to co-operate with a record medium; independently fabricating a yoke assembly having a magnetic yoke for each pair of pole pieces, each yoke having at least one coil electromagnetically coupled thereto; testing the pole piece unit independently of the yoke assembly; fabrIcating a resilient support member for the transducing head; securing the support member to the yoke assembly; mounting the yoke assembly by means of its resilient support member in a test apparatus; temporarily securing a satisfactory pole piece unit to the yoke assembly to form a head assembly; testing the head assembly in conjunction with the record medium to assess the performance of the yoke assembly being tested; and aligning and securing together a satisfactorily tested yoke assembly and a satisfactorily tested pole piece unit so that the magnetic yoke and the pole pieces constitute a core for a magnetic transducing head.
Claim 6
Independent Claim
140 words
A method of manufacturing a magnetic transducing head including the steps of fabricating a pole piece unit having at least one pair of ferrite pole pieces spaced apart by a predetermined non-magnetic transducing gap, the pole pieces being located within a glass-ceramic block having an operating surface shaped to co-operate with a record medium; independently fabricating a yoke assembly having a magnetic yoke for each pair of pole pieces, each yoke having at least one coil electromagnetically coupled thereto; dynamically testing the pole piece unit in conjunction with the record medium independently of said yoke assembly; testing the yoke assembly independently of the pole piece unit; and aligning and securing together a satisfactorily tested yoke assembly and a satisfactorily tested pole piece unit so that the magnetic yoke and the pole pieces constitute a core for a magnetic transducing head.
Claim 7
Independent Claim
140 words
A method of manufacturing a magnetic transducing head including the steps of fabricating a pole piece unit having at least one pair of ferrite pole pieces spaced apart by a predetermined non-magnetic transducing gap, the pole pieces being located within a glass-ceramic block having an operating surface shaped to co-operate with a record medium; independently fabricating a yoke assembly having a magnetic yoke for each pair of pole pieces, each yoke having at least one coil electromagnetically coupled thereto; dynamically testing the pole piece unit in conjunction with the record medium independently of said yoke assembly; testing the yoke assembly independently of the pole piece unit; and aligning and securing together a satisfactorily tested yoke assembly and a satisfactorily tested pole piece unit so that the magnetic yoke and the pole pieces constitute a core for a magnetic transducing head.
Claim 8
Dependent Claim
48 words
A method as claimed in claim 4 including the steps of temporarily securing a satisfactory pole piece unit to the yoke assembly to form a head assembly; and testing the head assembly in conjunction with the record medium to assess the performance of the yoke assembly being tested.
Claim 9
Dependent Claim
44 words
A method as claimed in claim 4 including the steps of temporarily securing the pole piece unit to a satisfactory yoke assembly; and testing the head assembly in conjunction with the record medium to assess the performance of the pole piece unit being tested.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |