Patent US3789505A successfully refreshed from Google Patents.
US3789505A
Expired / Lapsed
US
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Method of making a multi-core magnetic head with a non-magnetic holder
Assignee: Individual
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Filing: 1972-02-11
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Granted: 1974-02-05
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Expires: 1992-02-11
Abstract
Abstract A method of making a multi-core magnetic head whereby a plurality of slots are produced in the base portion of a U-shaped block of non-magnetic ceramic material, such as Zinc Ferrite. Pieces of magnetic ceramic material, such as Nickel Ferrite, which have been ground to the appropriate shape are each slipped into the slot and bonded therein, for example, by glass bonding, so as to extend into the region bounded by the legs of the block of non-magnetic ceramic material. This region is then filled with a potting material which lends mechanical strength. The pieces and block are then cut in half along a line which passes through each piece and the surface thus formed on each half gound, lapped and polished to profile the desired pole piece dimensions. If desired the base of the block can then be grooved and shields placed in the grooves to reduce cross-talk. Spacing material is then deposited, for example, Titantium by vacuum deposition, on the non-magnetic block to set the gap thickness. The two ground halves are then bonded together and potted to form the multi-core head.
Inventors
- 👤 R Huntt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:00
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/29; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49055; Y10T29/49059; Y10T29/4981; Y10T29/49812
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
212 words
A method of making a multi-core magnetic head compRising the steps of: producing a plurality of separated slots extending through the base portion of a block of non-magnetic ceramic material also having legs extending from the opposite ends of said base portion, placing a piece of magnetic ceramic material in each of said slots so that said pieces extend into a region bounded by the legs of said block, bonding each of said pieces of magnetic ceramic material to the non-magnetic material bounding the slot in which that piece has been placed, potting the region between said legs into which said pieces extend with potting material to provide mechanical strength, cutting said block and pieces bonded in the slots into two separate parts along a line passing through each of said pieces, removing material from the surfaces of each part formed by said cutting to profile the magnetic pieces to desired pole piece dimensions, and expose a gap surface for each pole piece, removing the potting material, depositing material on portions of said non-magnetic block adjacent said gap surfaces, and bonding the two parts together with gap surfaces from each part adjoining to form gaps and to form a multi-core head having pairs of pole legs extending upward from said non-magnetic block.
Claim 2
Independent Claim
212 words
A method of making a multi-core magnetic head compRising the steps of: producing a plurality of separated slots extending through the base portion of a block of non-magnetic ceramic material also having legs extending from the opposite ends of said base portion, placing a piece of magnetic ceramic material in each of said slots so that said pieces extend into a region bounded by the legs of said block, bonding each of said pieces of magnetic ceramic material to the non-magnetic material bounding the slot in which that piece has been placed, potting the region between said legs into which said pieces extend with potting material to provide mechanical strength, cutting said block and pieces bonded in the slots into two separate parts along a line passing through each of said pieces, removing material from the surfaces of each part formed by said cutting to profile the magnetic pieces to desired pole piece dimensions, and expose a gap surface for each pole piece, removing the potting material, depositing material on portions of said non-magnetic block adjacent said gap surfaces, and bonding the two parts together with gap surfaces from each part adjoining to form gaps and to form a multi-core head having pairs of pole legs extending upward from said non-magnetic block.
Claim 3
Dependent Claim
22 words
A method as in claim 1 including the further step of choosing said magnetic and non-magnetic materials to have similar mechanical properties.
Claim 4
Dependent Claim
20 words
A method as in claim 2 wherein said non-magnetic material is Zinc Ferrite and said magnetic material is Nickel Ferrite.
Claim 5
Dependent Claim
30 words
A method as in claim 1 including the further steps of producing grooves in said base portion between adjacent pieces and placing shield members in said grooves to reduce cross-talk.
Claim 6
Dependent Claim
57 words
A method as in claim 1 including the further steps of placing wire coils on said pole legs, placing a back bar between the pole legs of each pair to complete the magnetic circuit, potting the region between the legs of the non-magnetic block with potting material and removing sufficient potting material to expose the pole legs.
Claim 7
Dependent Claim
26 words
A method as in claim 1 wherein said step of bonding the magnetic ceramic material to the non-magnetic ceramic material includes the step of glass bonding.
Claim 8
Dependent Claim
50 words
A method as in claim 1 including the further step of grinding a quantity of magnetic ceramic material to a shape having a rough flat upper surface, a step surface, and a surface connecting said upper and step surfaces and inclined at an angle to said flat and step surfaces.
Claim 9
Dependent Claim
55 words
A method as in claim 1 including the further step of adding a further piece of ceramic material between the legs of said block of non-magnetic material and closing said region bounded by said legs of said block before said cutting and removing said further piece before said step of bonding the two parts together.
Claim 10
Dependent Claim
39 words
A method as in claim 1 including the further steps of hot pressing a ferrite ceramic to produce a block of said magnetic material, grinding said block of magnetic material and cutting said ground block to form said pieces.
Claim 11
Dependent Claim
18 words
A method as in claim 1 wherein said step of depositing includes the step of vacuum depositing titanium.
References Cited (Backward Citations)
US3064333A
Cited
US3502821A
Cited
US3404242A
Cited
US3466637A
Cited
US3478340A
Cited
US3668775A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |