Patent US4011692A successfully refreshed from Google Patents.
US4011692A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and device for grinding grooves
Assignee: US Philips Corp
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Filing: 1975-06-26
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Granted: 1977-03-15
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Expires: 1995-06-26
Abstract
Abstract A method of grinding fine grooves in workpieces of a ceramic material with wires disposed in grooves on the outer circumference of a rotatable drum. A part of the cross-section of each wire extends above the circumferential face of the drum. This grinding method is used to produce magnetic head cores in conjunction with various joining and severing steps.
Inventors
- 👤 Jules Bos
- 👤 Gunter Von Der Kall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:40
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/265; G11B5/2651; G11B5/187; G11B5/1871; G11B5/29; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49048
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
148 words
A method of manufacturing the core for a magnetic head comprising the following steps: providing a first block of ferrite; providing a number of mutually parallel grooves in a surface of said first block of ferrite said grooves being ground by pressing said first block against a rotating drum having a circumferential groove and at least one metal wire disposed in said groove with at least a part of the cross section of said wire projecting above the surface of said drum; providing a second block of ferrite; positioning said surface of said first block against a surface of said second block of ferrite connecting said first and second blocks with a non-magnetic material intermediate at least portion of said surface of said first block and said surface of said second block; severing the resulting assembly into individual head cores by making sawcuts extending parallel to said grooves.
Claim 2
Independent Claim
148 words
A method of manufacturing the core for a magnetic head comprising the following steps: providing a first block of ferrite; providing a number of mutually parallel grooves in a surface of said first block of ferrite said grooves being ground by pressing said first block against a rotating drum having a circumferential groove and at least one metal wire disposed in said groove with at least a part of the cross section of said wire projecting above the surface of said drum; providing a second block of ferrite; positioning said surface of said first block against a surface of said second block of ferrite connecting said first and second blocks with a non-magnetic material intermediate at least portion of said surface of said first block and said surface of said second block; severing the resulting assembly into individual head cores by making sawcuts extending parallel to said grooves.
Claim 3
Dependent Claim
17 words
A core for a magnetic head manufactured in accordance with the method as claimed in claim 1.
Claim 4
Independent Claim
132 words
A method of manufacturing a core for a magnetic head comprising the following steps: providing first and second blocks of ferrite; providing a quantity of non-magnetic material; connecting together a surface of said first block of ferrite to a surface of said second block of ferrite by means of said non-magnetic material; forming a number of mutually parallel grooves extending transversely to the connection surfaces, said grooves being ground by pressing said first block, second block and non-magnetic material against a rotating drum having a circumferential groove and at least one metal wire disposed in said groove with at least a part of the cross section of said wire projecting above the surface of said drum; severing the resulting assembly into individual head cores by marking sawcuts extending parallel to said grooves.
Claim 5
Independent Claim
132 words
A method of manufacturing a core for a magnetic head comprising the following steps: providing first and second blocks of ferrite; providing a quantity of non-magnetic material; connecting together a surface of said first block of ferrite to a surface of said second block of ferrite by means of said non-magnetic material; forming a number of mutually parallel grooves extending transversely to the connection surfaces, said grooves being ground by pressing said first block, second block and non-magnetic material against a rotating drum having a circumferential groove and at least one metal wire disposed in said groove with at least a part of the cross section of said wire projecting above the surface of said drum; severing the resulting assembly into individual head cores by marking sawcuts extending parallel to said grooves.
Claim 6
Dependent Claim
17 words
A core for a magnetic head manufactured in accordance with the method as claimed in claim 3.
References Cited (Backward Citations)
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Cited
US3440360A
Cited
US3516153A
Cited
US3478732A
Cited
US3918151A
Cited
US3846906A
Cited
US3845550A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |