US3824685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a ferrite head
Assignee: Bell and Howell Co
•
Filing: 1972-02-14
•
Granted: 1974-07-23
•
Expires: 1992-02-14
Abstract
Abstract In a method of manufacturing a ferrite magnetic head, a thin layer of glass is sputtered onto one or more discrete portions of a planar surface of each of two ferrite members, at least one of the glass layers extending out of a gap defined when the two members are positioned with their respective planar surfaces in confronting relation. A layer of refractory material is deposited on other portions of the ferrite surfaces, to a thickness equal to the desired gap length, to serve as a spacer when the two members are so positioned. A quantity of glass is placed adjacent the gap and in contact with at least one of the sputtered glass layers, and the assembly is heated to soften the glass layers and the quantity of glass; the quantity of glass is drawn into the remaining portion of the gap apparently in response to a reduced resistance to capillary flow provided by the softened glass layers within the gap.
Inventors
- 👤 N Burch
- 👤 L Tapia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:44
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/23; G11B5/232; G11B5/133; G11B5/1335; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49048; Y10T29/49055; Y10T29/49057
Claims Analysis
Total Claims: 100
Claim 1
Independent Claim
280 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising: 1. preparing a first ferrite member to have at least three spaced, coplanar first surfaces; 2. preparing a second ferrite member to have at least three spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith; 3. sputtering a first layer of glass on one of said first surfaces, said one positioned between two others of said first surfaces; 4. sputtering a second layer of glass on one of said second surfaces corresponding to said one of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less Than the desired gap length; 5. applying a layer of refractory material on said two others of said first surfaces, said refractory layer having a thickness equal to the desired gap length; 6. placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and said refractory layer in contact engagement with confronting ones of said second surfaces, for defining the gap; 7. placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap; 8. heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layer is maintained in contact engagement with confronting ones of said second surfaces, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 2
Dependent Claim
280 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising: 1. preparing a first ferrite member to have at least three spaced, coplanar first surfaces; 2. preparing a second ferrite member to have at least three spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith; 3. sputtering a first layer of glass on one of said first surfaces, said one positioned between two others of said first surfaces; 4. sputtering a second layer of glass on one of said second surfaces corresponding to said one of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less Than the desired gap length; 5. applying a layer of refractory material on said two others of said first surfaces, said refractory layer having a thickness equal to the desired gap length; 6. placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and said refractory layer in contact engagement with confronting ones of said second surfaces, for defining the gap; 7. placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap; 8. heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layer is maintained in contact engagement with confronting ones of said second surfaces, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 3
Dependent Claim
11 words
preparing a second ferrite member to have a planar second furface;
Claim 4
Dependent Claim
11 words
preparing a second ferrite member to have a planar second furface;
Claim 5
Dependent Claim
23 words
preparing a second ferrite member to have at least three spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 6
Dependent Claim
23 words
preparing a second ferrite member to have at least three spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 7
Dependent Claim
23 words
preparing a second ferrite member to have at least three spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 8
Dependent Claim
23 words
preparing a second ferrite member to have at least three spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 9
Dependent Claim
23 words
preparing a second ferrite member to have a plurality of spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 10
Dependent Claim
23 words
preparing a second ferrite member to have a plurality of spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 11
Dependent Claim
44 words
The method according to claim 1, wherein the glass of said first layer extends from said one of said first surfaces and, in step (7), said quantity of glass is placed in contact with the glass extending from said one of said first surfaces.
Claim 12
Dependent Claim
23 words
preparing a second ferrite member to have a plurality of spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 13
Dependent Claim
23 words
preparing a second ferrite member to have a plurality of spaced, coplanar second surfaces corresponding to said first surfaces for confronting relation therewith;
Claim 14
Dependent Claim
22 words
sputtering a first layer of glass on one of said first surfaces, said one positioned between two others of said first surfaces;
Claim 15
Dependent Claim
22 words
sputtering a first layer of glass on one of said first surfaces, said one positioned between two others of said first surfaces;
Claim 16
Dependent Claim
10 words
sputtering a first layer of glass on said first surface;
Claim 17
Dependent Claim
10 words
sputtering a first layer of glass on said first surface;
Claim 18
Dependent Claim
13 words
sputtering a first layer of glass on alternate ones of said first surfaces;
Claim 19
Dependent Claim
13 words
sputtering a first layer of glass on alternate ones of said first surfaces;
Claim 20
Dependent Claim
22 words
sputtering a first layer of glass on one of said first surfaces, said one positioned between two others of said first surfaces;
Claim 21
Dependent Claim
22 words
sputtering a first layer of glass on one of said first surfaces, said one positioned between two others of said first surfaces;
Claim 22
Dependent Claim
13 words
sputtering a first layer of glass on alternate ones of said first surfaces;
Claim 23
Dependent Claim
13 words
sputtering a first layer of glass on alternate ones of said first surfaces;
Claim 24
Dependent Claim
44 words
The method according to claim 1, wherein the glass of said second layer extends from said one of said second surfaces and, in step (7), said quantity of glass is placed in contact with the glass extending from said one of said second surfaces.
Claim 25
Dependent Claim
51 words
The method according to claim 1, wherein the glass of said first and second layers extend from said ones of said first and second surfaces respectively and, in step (7), said quantity of glass is placed in contact with the glass extending from said ones of said first and second surfaces.
Claim 26
Dependent Claim
44 words
sputtering a second layer of glass on alternate ones of said second surfaces corresponding to said alternate ones of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 27
Dependent Claim
44 words
sputtering a second layer of glass on alternate ones of said second surfaces corresponding to said alternate ones of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 28
Dependent Claim
42 words
sputtering a second layer of glass on one of said second surfaces corresponding to said one of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less Than the desired gap length;
Claim 29
Dependent Claim
42 words
sputtering a second layer of glass on one of said second surfaces corresponding to said one of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less Than the desired gap length;
Claim 30
Dependent Claim
44 words
sputtering a second layer of glass on alternate ones of said second surfaces corresponding to said alternate ones of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 31
Dependent Claim
44 words
sputtering a second layer of glass on alternate ones of said second surfaces corresponding to said alternate ones of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 32
Dependent Claim
28 words
sputtering a second layer of glass on said second surface, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 33
Dependent Claim
28 words
sputtering a second layer of glass on said second surface, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 34
Dependent Claim
42 words
sputtering a second layer of glass on one of said second surfaces corresponding to said one of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 35
Dependent Claim
42 words
sputtering a second layer of glass on one of said second surfaces corresponding to said one of said first surfaces for confronting relation therewith, the combined thickness of said first and second layers of glass being less than the desired gap length;
Claim 36
Dependent Claim
15 words
applying a first layer of refractory material on said two others of said first surfaces;
Claim 37
Dependent Claim
15 words
applying a first layer of refractory material on said two others of said first surfaces;
Claim 38
Dependent Claim
13 words
applying a first layer of refractory material on other ones of said surfaces;
Claim 39
Dependent Claim
13 words
applying a first layer of refractory material on other ones of said surfaces;
Claim 40
Dependent Claim
26 words
applying a layer of refractory material on said two others of said first surfaces, said refractory layer having a thickness equal to the desired gap length;
Claim 41
Dependent Claim
26 words
applying a layer of refractory material on said two others of said first surfaces, said refractory layer having a thickness equal to the desired gap length;
Claim 42
Dependent Claim
25 words
applying a layer of refractory material on other ones of said first surfaces, said refractory layer having a thickness equal to the desired gap length;
Claim 43
Dependent Claim
25 words
applying a layer of refractory material on other ones of said first surfaces, said refractory layer having a thickness equal to the desired gap length;
Claim 44
Dependent Claim
16 words
The method according to claim 1, wherein the desired gap length is less than 40 microinches.
Claim 45
Dependent Claim
21 words
placing said first and second ferrite members with said first and second surfaces in confronting relation with the gap defined therebetween;
Claim 46
Dependent Claim
21 words
placing said first and second ferrite members with said first and second surfaces in confronting relation with the gap defined therebetween;
Claim 47
Dependent Claim
25 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap;
Claim 48
Dependent Claim
25 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap;
Claim 49
Dependent Claim
38 words
The method according to claim 1, wherein said quantity of glass is of a type containing nucleating agents and, after the heating step, said ferrite members are cooled at a rate adjusted to cause devitrification of said glass.
Claim 50
Dependent Claim
37 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and said refractory layer in contact engagement with confronting ones of said second surfaces, for defining the gap;
Claim 51
Dependent Claim
37 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and said refractory layer in contact engagement with confronting ones of said second surfaces, for defining the gap;
Claim 52
Dependent Claim
30 words
applying a second layer of refractory material on other ones of said second surfaces, said first and second refractory layers having a combIned thickness equal to the desired gap length;
Claim 53
Dependent Claim
30 words
applying a second layer of refractory material on other ones of said second surfaces, said first and second refractory layers having a combIned thickness equal to the desired gap length;
Claim 54
Dependent Claim
31 words
applying a second layer of refractory material on said two others of said second surfaces, said first and second refractory layers having a combined thickness equal to the desired gap length;
Claim 55
Dependent Claim
31 words
applying a second layer of refractory material on said two others of said second surfaces, said first and second refractory layers having a combined thickness equal to the desired gap length;
Claim 56
Dependent Claim
37 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and said refractory layer in contact engagement with confronting ones of said second surfaces, for defining the gap;
Claim 57
Dependent Claim
37 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and said refractory layer in contact engagement with confronting ones of said second surfaces, for defining the gap;
Claim 58
Dependent Claim
25 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap;
Claim 59
Dependent Claim
25 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap;
Claim 60
Dependent Claim
33 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and confronting ones of said refractory layers in contact engagement, for defining the gap;
Claim 61
Dependent Claim
33 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and confronting ones of said refractory layers in contact engagement, for defining the gap;
Claim 62
Dependent Claim
25 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap;
Claim 63
Dependent Claim
25 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap;
Claim 64
Dependent Claim
50 words
heating said ferrite members to soften said layers of glass and said quantity of glass while first and second surfaces are maintained in confronting relation with said gap defined therebetween, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 65
Dependent Claim
50 words
heating said ferrite members to soften said layers of glass and said quantity of glass while first and second surfaces are maintained in confronting relation with said gap defined therebetween, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 66
Dependent Claim
21 words
The method according to claim 6, wherein said first and second layers of glass are of a type containing nucleating agents.
Claim 67
Dependent Claim
33 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and confronting ones of said refractory layers in contact engagement, for defining the gap;
Claim 68
Dependent Claim
33 words
placing said first and second ferrite members with corresponding ones of said first and second surfaces in confronting relation and confronting ones of said refractory layers in contact engagement, for defining the gap;
Claim 69
Dependent Claim
26 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap; and
Claim 70
Dependent Claim
26 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap; and
Claim 71
Dependent Claim
51 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layer is maintained in contact engagement with confronting ones of said second surfaces, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 72
Dependent Claim
51 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layer is maintained in contact engagement with confronting ones of said second surfaces, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 73
Dependent Claim
26 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap; and
Claim 74
Dependent Claim
26 words
placing a quantity of glass adjacent to and contacting one or both of said first and second layers of glass, for being adjacent the gap; and
Claim 75
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 76
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 77
Dependent Claim
51 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layer is maintained in contact engagement with confronting ones of said second surfaces, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 78
Dependent Claim
51 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layer is maintained in contact engagement with confronting ones of said second surfaces, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 79
Dependent Claim
38 words
The method according to claim 8, wherein the glass of said first layer extends from said First surfaces and, in step (7), said quantity of glass is placed in contact with the glass extending from said first surfaces.
Claim 80
Dependent Claim
44 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layers are maintained in contact engagement, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 81
Dependent Claim
44 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layers are maintained in contact engagement, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 82
Dependent Claim
44 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layers are maintained in contact engagement, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 83
Dependent Claim
44 words
heating said ferrite members to soften said layers of glass and said quantity of glass while said refractory layers are maintained in contact engagement, at least a portion of the softened quantity of glass flowing into the gap for bonding the two members together.
Claim 84
Dependent Claim
38 words
The method according to claim 8, wherein the glass of said second layer extends from said second surfaces and, in step (7), said quantity of glass is placed in contact with the glass extending from said second surfaces.
Claim 85
Dependent Claim
45 words
The method according to claim 8, wherein the glass of said first and second layers extend from said first and second surfaces respectively and, in step (7), said quantity of glass is placed in contact with the glass extending from said first and second surfaces.
Claim 86
Dependent Claim
16 words
The method according to claim 8, wherein the desired gap length is less than 40 microinches.
Claim 87
Dependent Claim
38 words
The method according to claim 8, wherein said quantity of glass is of a type containing nucleating agents and, after the heating step, said ferrite members are cooled at a rate adjusted to cause devitrification of said glass.
Claim 88
Dependent Claim
21 words
The method according to claim 13, wherein said first and second layers of glass are of a type containing nucleating agents.
Claim 89
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 90
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 91
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 92
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 93
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 94
Dependent Claim
32 words
In a method for manufacturing a magnetic head having at least one pole tip pair, the tips of each pair separated by a nonmagnetic gap of a desired length, the steps comprising:
Claim 95
Dependent Claim
38 words
The method according to claim 17, wherein the glass of said first layer extends from said first surface and, in step (6), said quantity of glass is placed in contact with the glass extending from said first surface.
Claim 96
Dependent Claim
38 words
The method according to claim 17, wherein the glass of said second layer extends from said second surface and, in step (6), said quantity of glass is placed in contact with the glass extending from said second surface.
Claim 97
Dependent Claim
45 words
The method according to claim 17, wherein the glass of said first and second layers extend from said first and second surfaces respectively and, in step (6), said quantity of glass is placed in contact with the glass extending from said first and second surfaces.
Claim 98
Dependent Claim
16 words
The method according to claim 17, wherein the desired gap length is less than 40 microinches.
Claim 99
Dependent Claim
38 words
The method according to claim 17, wherein said quantity of glass is of a type containing nucleating agents and, after the heating step, said ferrite members are cooled at a rate adjusted to cause devitrification of said glass.
Claim 100
Dependent Claim
21 words
The method according to claim 22, wherein said first and second layers of glass are of a type containing nucleating agents.
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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) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |