CA1059623A - Magnetic record/reproduce head and manufacturing method therefor - Google Patents
Magnetic record/reproduce head and manufacturing method thereforInfo
- Publication number
- CA1059623A CA1059623A CA237,790A CA237790A CA1059623A CA 1059623 A CA1059623 A CA 1059623A CA 237790 A CA237790 A CA 237790A CA 1059623 A CA1059623 A CA 1059623A
- Authority
- CA
- Canada
- Prior art keywords
- ferrite
- glass ceramic
- ceramic
- bars
- gap
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/187—Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to the recording medium; Pole pieces; Gap features
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (AREA)
Abstract
MAGNETIC RECORD AND/OR REPRODUCE HEAD
AND MANUFACTURING METHOD THEREFOR
ABSTRACT OF THE DISCLOSURE
Two magnetic ferrite pieces having longitudinal channels formed in the side faces thereof are bonded together with a gapping substance so that the resultant channels form a window. The bonded pieces are precisely slotted to a depth below the apex of the window to form a narrow track-defining comb-like array. The resulting slots are adapted to receive compatible ceramic wear support material which is so chosen as to wear slightly faster than the ferrite surfaces. In one embodiment, the slots contain ceramic-convertible glass which is devitrified by firing the array. The assembly is then processed lo form a ceramic-ferrite-ceramic or ceramic-ferrite transducer sandwich which may be further processed to form part of a magnetic record and/or reproduce head.
AND MANUFACTURING METHOD THEREFOR
ABSTRACT OF THE DISCLOSURE
Two magnetic ferrite pieces having longitudinal channels formed in the side faces thereof are bonded together with a gapping substance so that the resultant channels form a window. The bonded pieces are precisely slotted to a depth below the apex of the window to form a narrow track-defining comb-like array. The resulting slots are adapted to receive compatible ceramic wear support material which is so chosen as to wear slightly faster than the ferrite surfaces. In one embodiment, the slots contain ceramic-convertible glass which is devitrified by firing the array. The assembly is then processed lo form a ceramic-ferrite-ceramic or ceramic-ferrite transducer sandwich which may be further processed to form part of a magnetic record and/or reproduce head.
Description
~0596;~3 Field of the Invention The present invention relates in general to magnetic re-cording and reproduce heads, and more particularly to transducer assemblies having wear support surfaces, and to methods of manu-facturing such transducer assemblies. Although not so restricted, the invention has particular relevance to what shall hereinafter be defined as a narrow track head, and to methods of manufacture -thereof.
Description Relative to the Prior Art United States Patents 3,224,073 and 3,761,641 are repre-sentative of head manufacture techniques. As disclosed in each of these patents, two sets of slots are sliced into a relatively elongated ceramic block, the first set of slots being fitted with ferrite pieces which are bonded in place. The block and ferrite assembly is then halved longitudinally and, after a gapping sub-stance is deposited on the ends of the exposed ferrite pieces, ~;
the two block halves are precisely aligned and bonded back to-gether. Then the second set of slots is fitted with ferrite shield pieces which are bonded to both halves of the ceramic block.
The gap between each half of a ferrite piece corresponds to a given information track, the shield pieces being disposed, for example, between pairs of adjacent track-defining ferrite pieces.
The whole face assembly is then shaped to optimize the gap cross-sections, and after which the face assembly is fitted with a rear assembly, including magnetic elements, and coils, for completing the magnetic circuits of the track-defining ferrite pieces.
United States Patent 3,710,038 addresses the problem of providing a long-lived magnetic head which withstands a high relative head-to-tape speed and a substantial tape pressure on 30 the head-tips. As disclosed in this patent, the appreciable '
Description Relative to the Prior Art United States Patents 3,224,073 and 3,761,641 are repre-sentative of head manufacture techniques. As disclosed in each of these patents, two sets of slots are sliced into a relatively elongated ceramic block, the first set of slots being fitted with ferrite pieces which are bonded in place. The block and ferrite assembly is then halved longitudinally and, after a gapping sub-stance is deposited on the ends of the exposed ferrite pieces, ~;
the two block halves are precisely aligned and bonded back to-gether. Then the second set of slots is fitted with ferrite shield pieces which are bonded to both halves of the ceramic block.
The gap between each half of a ferrite piece corresponds to a given information track, the shield pieces being disposed, for example, between pairs of adjacent track-defining ferrite pieces.
The whole face assembly is then shaped to optimize the gap cross-sections, and after which the face assembly is fitted with a rear assembly, including magnetic elements, and coils, for completing the magnetic circuits of the track-defining ferrite pieces.
United States Patent 3,710,038 addresses the problem of providing a long-lived magnetic head which withstands a high relative head-to-tape speed and a substantial tape pressure on 30 the head-tips. As disclosed in this patent, the appreciable '
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abrasion of the head~tips is reduced by surrounding the head-tips with guard surfaces. In this manner, the tape contact area of the magnetic head is increased and the tape contact force per unit area is correspondingly decreased with consequent extended head-tip life. The guard member is formed of a similar ferrite material and adjoins the pole tips. The guard material provides a total tape contact surface having a hardness substantially equal to or a little less than that of the pole tips alone. If the guard material is incorrectly chosen to have a hardness greater than the ferrite material, the head-tips are worn away more than the guard member to draw back its gap surface from the plane of the tape contact surface of the guard member. This results in incomplete contact between the head-tips and the mag-netic tape and lowers the high frequency component of the output from the magnetic head.
While this prior art head may be functionally acceptable, its structure is such as to leave something to be desired from a manufacturing standpoint~ The bonding of the two ceramic block halves requires a painstakingly precise alignment of the gap width of the ferrite pole pieces. Further, in bonding steps subsequent to deposition of the non-magnetic gap, the bonding material may - erode into the gap causing gap length taper, a problem commonly -encountered in the glass bonding art. If epoxy is used to bond these surfaces, it becomes difficult in a manufacturing environ-ment to prevent epoxy from collecting on the tape-contacting sur-face of the ferrite pieces. A head manufactured according to this method also has certain performance deficiencies. The geometry of construction constrains the back gap to the same width as the front gap. However, it is desirable to enlarge the back gap area without regard to track width in order to provide a - 105~Z3 low reluctance path for the magnetic flux and thereby optimize the magnetic circuit.
The current trend toward tape conservation and consequent narrow track widths adds to these manufacturing difficulties by requiring the tape-contacting head gap geometry to be e~tremely narrow. Such narrow ferrite pieces are brittle and subject to breakage both in manufacture and use. Prior art disclosure of guard members or wear shoes diminish this problem as to use, but increase the problem as to manufacture, since the brittle ferrite pieces must be additionally subjected to fabrication stresses for attachment of a guard member.
SUMMARY OF THE INVENTION
In its most basic form, the invention concerns narrow gap ferrite pieces with integrally supported wear support surface(s) of a ceramic material having wear and hardness characteristics which are slightly less than the wear and hardness characteristic -of the ferrite material. In the preferred embodiment, the ceramic material is selected from a glass material which may be devitri-fied to form what are called "glass ceramics", and which possess the desired hardness characteristics after devitrification.
Additionally, to avoid the prior art difficulty of aligning and supporting the brittle ferrite head pieces during manufacture, the invention bonds two ferrite core pieces with a gapping sub-stance and the precision slotting of this assembly to form a track-defining comb-like array. The slots receive a ceramic-convertible glass material which devitrifies upon firing of the assembly to form a wear support surface which is lntegrally bonded to the ferrite pieces and which possesses the previously mentioned wear characteristics. After cooling, the assembly is shaped and polished as in the prior art. The assembly is then .. . . .................... . ~ - ~ , .
OS5~6;~3 sliced through the ceramic or, alternately, through a ceramic and the ferrite. In this manner, a transducer is formed with integral wear support surfaces on either or both sides of the ferrite without need for any separate bonding steps or undue stress during fabrication.
To form a transducer with wear support surfaces integrally bonded in varying positions relative to the ferrite, the invention further proposes that each ferrite core piece be separately slot-ted previous to their mutual bonding. Ceramic-convertible glass may then be devitrified in one or both of the ferrite pieces.
Following flat lapping and deposition of the gap as in the prior art, the two ferrite halves are bonded together and sliced to form some known useful configuration of transducers with integrally formed wear support surfaces.
In this manner, the invention provides record and/or reproduce head structures with narrow gaps which lend themselves to efficient manufacture and possess extended lives when put into their intended uses.
The invention will be described with reference to the figures, wherein:
Figure 1 shows a track-defining comb-like array of ferrite material according to one embodiment of the invention;
Figure 2 shows a ferrite transducer with integral wear support surfaces; and Figures 3A to 3E are diagrammatic section views of the face assembly of various embodiments of the invention.
In Figure 1, a narrow track magnetic transducer is formed by bonding a first ferrite core piece 10 onto a second ferrite core piece 12 to form a ferrite assembly 14 with the desired head gap 15. Bonding techniques are ]~nown in the art and include ..:
~L05S~623 forming a bond with a high temperature glass to form the desired gap width. Alternately, the gap may be sputtered in place by known deposition techniques and then the two core pieces may be glass-bonded. Gap sputtering has the advantage of minimizing apex erosion due to glass not flowing into the gap. Each core piece 10 and 12 is preformed into a bar shape with a longitudinal channel formed in the side face thereof. When the ferrite pieces 10, 12 are joined into the assembly 14, the channels cooperate -to form a window 18 having an apex 20. The assembly is then pre-cision slotted in a known manner to a depth just below the apex20 to form slots 23. Wear support pieces 22, only one of which is illustrated, fit into the slots 23. Ferrite abutments 24 are left standing between slots 23, and each abutment has a width 26 i precisely equal to the desired track width of a finished trans-ducer. Also, the width 28 of each slot 23 is preferably main~
tained at more than twice the width of the desired thickness of -a wear support ceramic piece 22 to allow for material lost during slicing. -In a preferred embodiment, the ceramic pieces 22 are formed `
from a ceramic-convertible glass. Ceramic-convertible glass is a well-known commodity and is discussed in Glass Ceramics, P. W.
McMillan, Academic Press, Inc., 111 Fifth Avenue, New York, New York, Library of Congress Catalog Card No. 64-8067. Generally such glass will devitrify into ceramic material. The invention places no limits on the form of the ceramic-convertible glass which is employed other than that it "thermally devitrify" at a ;
temperature below the melting points of the ferrite pieces 10 and 12. Also, it is preferred that the hardness and wear properties ' of the ferrite be slightly greater than that of the glass-converted ceramic. One useful ceramic-convertible glass is known as Foto-ceram. Fotoceram has been discussed in Industrial and Engineering - ` ~059~Z3 Chemistry, Volume 45, page 115, January 1953, and is available from Corning Glass Works, Corning, New York.
The assembly 14, which includes the ceramic-convertible glass pieces 22, is fired to a temperature at which the glass ~-but not the ferrite -- melts, and devitrifies into ceramic.
When cooled, the result is an assembly of narrow track trans-ducers with integral wear support surfaces, and all without need for the separate, and relatively tedious, step of individually bonding ceramic wear support pieces to the ferrite. The assembly 14 is then contoured by known techniques along line 30 to dimen-sion the depth of the head gap 15, and finally polished and sliced.
For a double-sided ceramic-supported transducer, the assembly is diced through the ceramic along, for example, planes defined by lines 32 and 34. The resulting transducer is depicted in Figure 2, which shows a track-defining ferrite piece 24 sand-wiched between a first ceramic piece 22' and a second ceramic piece 22''. For a single-sided ceramic transducer, the assembly is diced through the ceramic and the ferrite along, for example, planes defined by lines 32 and 33. In this case, the dicing operation determines the gap width of the transducer. Typically, as best seen in Figure 2, the ferrite piece 24 has an integral coil supporting rear portion 38 for completing the magnetic cir- `
cuit corresponding to the ferrite parts of the transduc~r assembly. This rear portion 38 has a back gap whose width 36 is greater than its front gap width 26. Manufacture in accordance with the invention thus allows a high efficiency magnetic geometry to be maintained, i.e., the back gap area can be large without regard to track width. Finally, all the elements may be embedded 30 in potting material and fitted with terminal connections and ~-brackets.
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~591~'~3 Referring now to Figures 3A through 3E, various configura-tions of the face portion of the transducer assembly are shown.
Eigure 3A illustrates a diagrammatic section of the face of the double-sided transducer as depicted in Figure 2. Figure 3D
illustrates a diagrammatic section of a single-sided transducer which has been diced through the ceramic and the ferrite along, for example, the planes defined by lines 32 and 33 of Figure 1.
Figures 3B, 3C, and 3E show various configurations possible when the transducer is formed according to embodiments of the invention.
To form these further configurations, fexrite core pieces 10 and 12 may be precision slotted either through one or both ferrite halves before bonding the two halves together. Glass-convertible ceramic pieces 22 of appropriate sizes are then bonded in the aforesaid manner to one or both of the halves: the assemblies are flat-lapped and then the gap length is defined, for example, by sputteriny. A low temperature glass may then be used to bond the ferrite pieces 10 and 12 together. Contouring, polishing, and dicing follows as set forth above. The result is a trans-ducer having a face configuration such as shown in Figures 3B, 3C, or 3E. However, these views are not to be construed as limiting the configurations possible according to this invention.
The invention has been described in detail with particular reference to preferred e~bodiments thereof, but it will be under-stood that variations and modifications can be effected within the spirit and scope of the invention.
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abrasion of the head~tips is reduced by surrounding the head-tips with guard surfaces. In this manner, the tape contact area of the magnetic head is increased and the tape contact force per unit area is correspondingly decreased with consequent extended head-tip life. The guard member is formed of a similar ferrite material and adjoins the pole tips. The guard material provides a total tape contact surface having a hardness substantially equal to or a little less than that of the pole tips alone. If the guard material is incorrectly chosen to have a hardness greater than the ferrite material, the head-tips are worn away more than the guard member to draw back its gap surface from the plane of the tape contact surface of the guard member. This results in incomplete contact between the head-tips and the mag-netic tape and lowers the high frequency component of the output from the magnetic head.
While this prior art head may be functionally acceptable, its structure is such as to leave something to be desired from a manufacturing standpoint~ The bonding of the two ceramic block halves requires a painstakingly precise alignment of the gap width of the ferrite pole pieces. Further, in bonding steps subsequent to deposition of the non-magnetic gap, the bonding material may - erode into the gap causing gap length taper, a problem commonly -encountered in the glass bonding art. If epoxy is used to bond these surfaces, it becomes difficult in a manufacturing environ-ment to prevent epoxy from collecting on the tape-contacting sur-face of the ferrite pieces. A head manufactured according to this method also has certain performance deficiencies. The geometry of construction constrains the back gap to the same width as the front gap. However, it is desirable to enlarge the back gap area without regard to track width in order to provide a - 105~Z3 low reluctance path for the magnetic flux and thereby optimize the magnetic circuit.
The current trend toward tape conservation and consequent narrow track widths adds to these manufacturing difficulties by requiring the tape-contacting head gap geometry to be e~tremely narrow. Such narrow ferrite pieces are brittle and subject to breakage both in manufacture and use. Prior art disclosure of guard members or wear shoes diminish this problem as to use, but increase the problem as to manufacture, since the brittle ferrite pieces must be additionally subjected to fabrication stresses for attachment of a guard member.
SUMMARY OF THE INVENTION
In its most basic form, the invention concerns narrow gap ferrite pieces with integrally supported wear support surface(s) of a ceramic material having wear and hardness characteristics which are slightly less than the wear and hardness characteristic -of the ferrite material. In the preferred embodiment, the ceramic material is selected from a glass material which may be devitri-fied to form what are called "glass ceramics", and which possess the desired hardness characteristics after devitrification.
Additionally, to avoid the prior art difficulty of aligning and supporting the brittle ferrite head pieces during manufacture, the invention bonds two ferrite core pieces with a gapping sub-stance and the precision slotting of this assembly to form a track-defining comb-like array. The slots receive a ceramic-convertible glass material which devitrifies upon firing of the assembly to form a wear support surface which is lntegrally bonded to the ferrite pieces and which possesses the previously mentioned wear characteristics. After cooling, the assembly is shaped and polished as in the prior art. The assembly is then .. . . .................... . ~ - ~ , .
OS5~6;~3 sliced through the ceramic or, alternately, through a ceramic and the ferrite. In this manner, a transducer is formed with integral wear support surfaces on either or both sides of the ferrite without need for any separate bonding steps or undue stress during fabrication.
To form a transducer with wear support surfaces integrally bonded in varying positions relative to the ferrite, the invention further proposes that each ferrite core piece be separately slot-ted previous to their mutual bonding. Ceramic-convertible glass may then be devitrified in one or both of the ferrite pieces.
Following flat lapping and deposition of the gap as in the prior art, the two ferrite halves are bonded together and sliced to form some known useful configuration of transducers with integrally formed wear support surfaces.
In this manner, the invention provides record and/or reproduce head structures with narrow gaps which lend themselves to efficient manufacture and possess extended lives when put into their intended uses.
The invention will be described with reference to the figures, wherein:
Figure 1 shows a track-defining comb-like array of ferrite material according to one embodiment of the invention;
Figure 2 shows a ferrite transducer with integral wear support surfaces; and Figures 3A to 3E are diagrammatic section views of the face assembly of various embodiments of the invention.
In Figure 1, a narrow track magnetic transducer is formed by bonding a first ferrite core piece 10 onto a second ferrite core piece 12 to form a ferrite assembly 14 with the desired head gap 15. Bonding techniques are ]~nown in the art and include ..:
~L05S~623 forming a bond with a high temperature glass to form the desired gap width. Alternately, the gap may be sputtered in place by known deposition techniques and then the two core pieces may be glass-bonded. Gap sputtering has the advantage of minimizing apex erosion due to glass not flowing into the gap. Each core piece 10 and 12 is preformed into a bar shape with a longitudinal channel formed in the side face thereof. When the ferrite pieces 10, 12 are joined into the assembly 14, the channels cooperate -to form a window 18 having an apex 20. The assembly is then pre-cision slotted in a known manner to a depth just below the apex20 to form slots 23. Wear support pieces 22, only one of which is illustrated, fit into the slots 23. Ferrite abutments 24 are left standing between slots 23, and each abutment has a width 26 i precisely equal to the desired track width of a finished trans-ducer. Also, the width 28 of each slot 23 is preferably main~
tained at more than twice the width of the desired thickness of -a wear support ceramic piece 22 to allow for material lost during slicing. -In a preferred embodiment, the ceramic pieces 22 are formed `
from a ceramic-convertible glass. Ceramic-convertible glass is a well-known commodity and is discussed in Glass Ceramics, P. W.
McMillan, Academic Press, Inc., 111 Fifth Avenue, New York, New York, Library of Congress Catalog Card No. 64-8067. Generally such glass will devitrify into ceramic material. The invention places no limits on the form of the ceramic-convertible glass which is employed other than that it "thermally devitrify" at a ;
temperature below the melting points of the ferrite pieces 10 and 12. Also, it is preferred that the hardness and wear properties ' of the ferrite be slightly greater than that of the glass-converted ceramic. One useful ceramic-convertible glass is known as Foto-ceram. Fotoceram has been discussed in Industrial and Engineering - ` ~059~Z3 Chemistry, Volume 45, page 115, January 1953, and is available from Corning Glass Works, Corning, New York.
The assembly 14, which includes the ceramic-convertible glass pieces 22, is fired to a temperature at which the glass ~-but not the ferrite -- melts, and devitrifies into ceramic.
When cooled, the result is an assembly of narrow track trans-ducers with integral wear support surfaces, and all without need for the separate, and relatively tedious, step of individually bonding ceramic wear support pieces to the ferrite. The assembly 14 is then contoured by known techniques along line 30 to dimen-sion the depth of the head gap 15, and finally polished and sliced.
For a double-sided ceramic-supported transducer, the assembly is diced through the ceramic along, for example, planes defined by lines 32 and 34. The resulting transducer is depicted in Figure 2, which shows a track-defining ferrite piece 24 sand-wiched between a first ceramic piece 22' and a second ceramic piece 22''. For a single-sided ceramic transducer, the assembly is diced through the ceramic and the ferrite along, for example, planes defined by lines 32 and 33. In this case, the dicing operation determines the gap width of the transducer. Typically, as best seen in Figure 2, the ferrite piece 24 has an integral coil supporting rear portion 38 for completing the magnetic cir- `
cuit corresponding to the ferrite parts of the transduc~r assembly. This rear portion 38 has a back gap whose width 36 is greater than its front gap width 26. Manufacture in accordance with the invention thus allows a high efficiency magnetic geometry to be maintained, i.e., the back gap area can be large without regard to track width. Finally, all the elements may be embedded 30 in potting material and fitted with terminal connections and ~-brackets.
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~591~'~3 Referring now to Figures 3A through 3E, various configura-tions of the face portion of the transducer assembly are shown.
Eigure 3A illustrates a diagrammatic section of the face of the double-sided transducer as depicted in Figure 2. Figure 3D
illustrates a diagrammatic section of a single-sided transducer which has been diced through the ceramic and the ferrite along, for example, the planes defined by lines 32 and 33 of Figure 1.
Figures 3B, 3C, and 3E show various configurations possible when the transducer is formed according to embodiments of the invention.
To form these further configurations, fexrite core pieces 10 and 12 may be precision slotted either through one or both ferrite halves before bonding the two halves together. Glass-convertible ceramic pieces 22 of appropriate sizes are then bonded in the aforesaid manner to one or both of the halves: the assemblies are flat-lapped and then the gap length is defined, for example, by sputteriny. A low temperature glass may then be used to bond the ferrite pieces 10 and 12 together. Contouring, polishing, and dicing follows as set forth above. The result is a trans-ducer having a face configuration such as shown in Figures 3B, 3C, or 3E. However, these views are not to be construed as limiting the configurations possible according to this invention.
The invention has been described in detail with particular reference to preferred e~bodiments thereof, but it will be under-stood that variations and modifications can be effected within the spirit and scope of the invention.
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Claims (11)
1. Structure for use in a magnetic record and/or repro-duce head comprising:
(a) a track defining ferrite piece, said piece being com-prised of first and second parts which are bonded together to form a transducer gap; and (b) first and second glass ceramic pieces sandwiching said track-defining ferrite piece and being bonded with said track-defining ferrite piece against the respective width-wise sides of said gap, thereby to form a ferrite-supported integral assembly of said ferrite piece and said glass ceramic by means of said glass ceramic.
(a) a track defining ferrite piece, said piece being com-prised of first and second parts which are bonded together to form a transducer gap; and (b) first and second glass ceramic pieces sandwiching said track-defining ferrite piece and being bonded with said track-defining ferrite piece against the respective width-wise sides of said gap, thereby to form a ferrite-supported integral assembly of said ferrite piece and said glass ceramic by means of said glass ceramic.
2. The structure of Claim 1 wherein said glass ceramic is, at least in part, of a chemically machineable type.
3. The structure of Claim 1 wherein said glass ceramic pieces and track-defining ferrite piece have wear characteristics which are such that said glass ceramic wears slightly faster than said track-defining ferrite piece when frictionally contacted by magnetic tape.
4. A video magnetic record and/or reproduce head, com-prising an assembly for completing a magnetic circuit, said assembly comprising:
(a) glass ceramic;
(b) first and second ferrite members, said glass ceramic being bonded to at least one of said members by means of said glass ceramic, said ferrite members and glass ceramic being arranged to define a face portion exposing glass ceramic and said first and second ferrite member, said ferrite members having a hardness which is slightly greater than the hardness of said glass ceramic so that said glass ceramic wears faster than said ferrite members when said face portion frictionally contacts magnetic tape; and (c) non-magnetic means for bonding said first and second ferrite members together so that said first ferrite member aligns with said second ferrite member to form a gap between the aligned ferrite members.
(a) glass ceramic;
(b) first and second ferrite members, said glass ceramic being bonded to at least one of said members by means of said glass ceramic, said ferrite members and glass ceramic being arranged to define a face portion exposing glass ceramic and said first and second ferrite member, said ferrite members having a hardness which is slightly greater than the hardness of said glass ceramic so that said glass ceramic wears faster than said ferrite members when said face portion frictionally contacts magnetic tape; and (c) non-magnetic means for bonding said first and second ferrite members together so that said first ferrite member aligns with said second ferrite member to form a gap between the aligned ferrite members.
5. The magnetic head of Claim 4 wherein said glass ceramic comprises at least one ferrite-spanning ceramic piece which spans, at least in part, at least one side of both of said bonded first and second ferrite members so that said ferrite members are integrally supported longitudinally and, at least in part, across their non-magnetic gap.
6. The magnetic head of Claim 4 wherein said assembly further comprises a back portion exposing said first and second ferrite members, said non-magnetic gap further comprising a face gap on said face portion and a back gap on said back portion, said back gap being wider than said face gap.
7. The magnetic head of Claim 4 wherein said exposed face portion of said first ferrite member is wider than said exposed face portion of said second ferrite member.
8. The method of manufacturing a structure for use in the manufacture of a magnetic record and/or reproduce head comprising the steps of:
(a) bonding two ferrite bars together so that a predetermined gap is maintained between said bars;
(b) slotting said bars so as to produce ferrite abutments between the slots;
(c) bonding ceramic wear support pieces which wear faster than said ferrite bars in each of the slotted portions of said bars;
(d) machining said bonded bars and ceramic pieces to form a contoured, polished assembly; and (e) dicing said assembly to produce a magnetic transducer structure having integrally formed ceramic wear support surfaces.
(a) bonding two ferrite bars together so that a predetermined gap is maintained between said bars;
(b) slotting said bars so as to produce ferrite abutments between the slots;
(c) bonding ceramic wear support pieces which wear faster than said ferrite bars in each of the slotted portions of said bars;
(d) machining said bonded bars and ceramic pieces to form a contoured, polished assembly; and (e) dicing said assembly to produce a magnetic transducer structure having integrally formed ceramic wear support surfaces.
9. The method of Claim 8 wherein said ferrite bars are slotted after said bars are bonded together.
10. The method of Claim 8 wherein the step of bonding two ferrite bars further comprises the step of depositing a gap-defining substance on at least one surface of one of said bars so that, when the bars are bonded together, a predetermined gap is maintained between said bars.
11. The method of Claim 8 wherein said ceramic wear sup-port pieces are, at least in part, of a glass ceramic type and wherein the step of bonding said glass ceramic wear support pieces comprises fitting said glass ceramic into each slotted portion of said bars and firing said combination of glass ceramic and ferrite bars to cause said glass ceramic to devitrify.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US51935874A | 1974-10-29 | 1974-10-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1059623A true CA1059623A (en) | 1979-07-31 |
Family
ID=24067960
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA237,790A Expired CA1059623A (en) | 1974-10-29 | 1975-10-16 | Magnetic record/reproduce head and manufacturing method therefor |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5167119A (en) |
| CA (1) | CA1059623A (en) |
| DE (1) | DE2548435A1 (en) |
| FR (1) | FR2289996A1 (en) |
| GB (1) | GB1528599A (en) |
| NL (1) | NL7512688A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5972638A (en) * | 1982-10-19 | 1984-04-24 | Sumitomo Special Metals Co Ltd | Manufacture of composite magnetic head |
-
1975
- 1975-10-16 CA CA237,790A patent/CA1059623A/en not_active Expired
- 1975-10-27 JP JP12917675A patent/JPS5167119A/en active Pending
- 1975-10-28 GB GB4442875A patent/GB1528599A/en not_active Expired
- 1975-10-29 FR FR7532997A patent/FR2289996A1/en active Granted
- 1975-10-29 DE DE19752548435 patent/DE2548435A1/en not_active Withdrawn
- 1975-10-29 NL NL7512688A patent/NL7512688A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| FR2289996A1 (en) | 1976-05-28 |
| JPS5167119A (en) | 1976-06-10 |
| NL7512688A (en) | 1976-05-04 |
| FR2289996B1 (en) | 1982-01-22 |
| DE2548435A1 (en) | 1976-05-06 |
| GB1528599A (en) | 1978-10-11 |
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