US2674659A - Magnetic head and method of making same - Google Patents

Magnetic head and method of making same Download PDF

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Publication number
US2674659A
US2674659A US254537A US25453751A US2674659A US 2674659 A US2674659 A US 2674659A US 254537 A US254537 A US 254537A US 25453751 A US25453751 A US 25453751A US 2674659 A US2674659 A US 2674659A
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United States
Prior art keywords
ceramic
wafer
magnetic
coils
core
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 - Lifetime
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US254537A
Inventor
Frederick G Buhrendorf
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AT&T Corp
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Bell Telephone Laboratories Inc
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Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US254537A priority Critical patent/US2674659A/en
Priority to US324388A priority patent/US2674031A/en
Application granted granted Critical
Publication of US2674659A publication Critical patent/US2674659A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • G11B5/21—Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to the recording medium; Pole pieces; Gap features the pole pieces being of ferrous sheet metal or other magnetic layers
    • 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
    • G11B5/10—Structure or manufacture of housings or shields for heads
    • 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
    • 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
    • G11B5/147—Structure or manufacture of heads, e.g. inductive with cores being composed of metal sheets, i.e. laminated cores with cores composed of isolated magnetic layers, e.g. sheets
    • G11B5/1475—Assembling or shaping of elements
    • 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
    • G11B5/17—Construction or disposition of windings
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
    • Y10T29/49032—Fabricating head structure or component thereof
    • Y10T29/49048—Machining magnetic material [e.g., grinding, etching, polishing]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
    • Y10T29/49032—Fabricating head structure or component thereof
    • Y10T29/4906—Providing winding
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/4902—Electromagnet, transformer or inductor
    • Y10T29/49073—Electromagnet, transformer or inductor by assembling coil and core

Definitions

  • This invention relates to magnetic heads for use in magnetic recording, reproduction or obliteration.
  • the object of the present invention is to provide a magnetic head of stable design, which is suitable for high frequency recording and epr duc n
  • a magnetic core comprising one or more laminations of high permeability magnetic material, such as Permalloy, is wound around a ceramic wafer triangularly shaped at one end and notched at two opposite sides.
  • a coil, space wound on a ceramic form, is mounted adjacent each of said notched sides.
  • the magnetic core is threadedlthrough each of said coils and disposed between the triangular sides of said ceramic wafer and a low resistancemetallic shield to form two pole tips.
  • the entire assembly is coated with a ceramic material and fired to. form a glazed coating.
  • the pointed end of the wafer is then ground and lapped until the desired separation of the pole tips is obtained.
  • the coating of the magnetic head with a ceramic glaze provides a rigidly clamped pole tip assembly held permanently. in adjustment once properly lapped.
  • Fig.1 is a view in front elevation of the assembled magnetic, head
  • Fig, 2 is a sectional view taken on the line 2-2 of Fig, 1;
  • Fig. 3 is. a sectional view taken on the line 3-3 of Fig. 1;
  • Fig. 4 is a View in perspective partially expanded to show the structural features of the head components
  • Fig. 5 is a sectional view taken on the line 5-5 of Fig. 1;
  • Fig. 6 is a view in front elevation showing the actual dimensions of the magnetic head.
  • 2 is a ceramic wafer triangularly shaped at one end and notched at two opposite sides.
  • the ceramic forms 4, about which the recording and reproducing coils 6 are wound, are mounted adj acent the notched sides of the wafer 2 and are held in position by means of the notched portions 8 and the magnetic core l0 which is wound around the water 2 and threaded through each of the forms 4 and the coils B.
  • the ends of the magnetic core W are disposed between the triangular sides of the wafer 2 and a low resistance, nonmagnetic shield l2 which is held in position adjacent the wafer 2 by means of the ceramic pin l4.
  • the shield l2 may be made of a material such as copper.
  • the core II which may be in the form of a ribbon having a thickness of 0.001 inch, is made ofmagnetic material, such as Permalloy.
  • the surface of the ribbon is coated with a layer of suitable inert insulating material, such as Alundum in order to prevent metal contact between the core 10 and the shield l2 or the terminal wires It.
  • the terminal wires IS, the coils 6 and the wires l8 which connect the coils 6 in series are preferably of tungsten.
  • the terminal wires l6 and the connecting wires 18 are Welded to the coils 6.
  • the triangularly-shaped wafer 2 and the forms 4- may be made of a material such as steatite.
  • the ceramic forms 4 comprise .a male portion 20 and a female portion 22 which, when joined and held together by the coil 6, support the wires I6 and I8.
  • the magnetic head After the magnetic head is assembled, as shown in Fig. 1, it is coated with a ceramic material and fired.
  • the ceramic coating should be so selected that the firing temperature of the coating coincides with the heat treating temperature of the magnetic core so that the glazing will be completed simultaneously with the heat treatment of the magnetic material.
  • a ceramic material consisting of the following componentshas been found to be satisfactory for this purpose when Permalloy is employed as the magnetic material:
  • the heat treatment of the magnetic core after assembly is a desirable feature since it avoids handling of the core after heat treatment, a procedure which is known to lower the magnetic qualities of thin Permalloy laminations.
  • the unwanted ends of the magnetic core or ribbon ID are clipped and the pointed end of the entire assembly, including the shield I2, is ground.
  • the magnetic head unit may be mounted on its associated equipment by means of the mounting holes 28 in the shield [2.
  • a magnetic recording-reproducing head coated with a ceramic glaz comprising a ceramic wafer triangularly shaped at one end, an energizing coil wound on a ceramic member disposed adjacent said ceramic waier, an eddy current shielding member disposed about the triangularly-shaped portion of said ceramic wafer, a core comprising a thin lamination of magnetic material disposed around said ceramic wafer and threaded through said ceramic member and said coil, the ends of said core being disposed between the triangular sides of said ceramic wafer and said shielding member to form two spaced pole tips, said ceramic wafer, said energizing coil, said shielding member and said core being fixedly positioned by said glazed ceramic coating.
  • a magnetic recording-reproducing head comprising a core of magnetic material, said head being coated with a ceramic glaze, said magnetic material having an annealing temperature coinciding with the firing temperature of said ceramic coating.
  • a magnetic recording-reproducing head coated with a ceramic glaze comprising a ceramic wafer two opposite sides of which converge to form a point at one end, said opposite sides having notched portions, a pair of serially connected energizing coils, each of said coils wound on a cylindrically-shaped ceramic member, said ceramic members being disposed within the notched portions of said opposite sides of said ceramic wafer, an eddy current shielding member disposed about and secured to the pointed end of said ceramic wafer, a ribbon of magnetic material disposed around said ceramic wafer and threaded through said cylindrically-shaped ceramic members and said energizing coils, the ends of said ribbon of magnetic material being disposed between the converging sides of said ceramic wafer and said shielding member to form two spaced pole tips, said ceramic wafer, said energizing coils, said shielding member and said ribbon of magnetic material being fixedly positioned by said glazed ceramic coating.

Description

p i 1954 F. G. BUHRENDORF v 2,574,659
MAGNETIC HEAD AND METHOD OF MAKING SAME Filed Nov. 2, 1951 2 Sheets-Sheet 1 FIG.
' .llh
INVENTOR By F. G. BUHRENDORF VV-QQM A T TOR/LIE V April 6, 1954 F. G. BUHRENDORF 2,674,659
MAGNETIC HEAD AND METHOD OF MAKING SAME Filed Nov. 2, 1951 2 Sheets-Sheet 2 FIG. 4
- FIG. 5 FIG. 5 2
/4 v v l2 INVENTOR F. G. BUHRENDORF A TTORNE V Patented Apr. 6, 1954 MAGNETIC HEAD AND METHOD OF MAKING SAME Frederick G. Buhrendorf, Westfield, N. .L, assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New.
York
Application November 2, 1951, Serial No. 254,537
7 Claims. 1
This invention relates to magnetic heads for use in magnetic recording, reproduction or obliteration.
The object of the present invention is to provide a magnetic head of stable design, which is suitable for high frequency recording and epr duc n In accordancewith the general features of this invention a magnetic core comprising one or more laminations of high permeability magnetic material, such as Permalloy, is wound around a ceramic wafer triangularly shaped at one end and notched at two opposite sides. A coil, space wound on a ceramic form, is mounted adjacent each of said notched sides. The magnetic core is threadedlthrough each of said coils and disposed between the triangular sides of said ceramic wafer and a low resistancemetallic shield to form two pole tips. The entire assembly is coated with a ceramic material and fired to. form a glazed coating. The pointed end of the wafer is then ground and lapped until the desired separation of the pole tips is obtained.
The coating of the magnetic head with a ceramic glaze provides a rigidly clamped pole tip assembly held permanently. in adjustment once properly lapped.
The nature of the invention and its distinguishing features and advantages will be more clearly. understood from the. following detailed description and the accompanying drawings in which:
Fig.1 is a view in front elevation of the assembled magnetic, head;
Fig, 2is a sectional view taken on the line 2-2 of Fig, 1;
Fig. 3 is. a sectional view taken on the line 3-3 of Fig. 1;
Fig. 4 is a View in perspective partially expanded to show the structural features of the head components;
Fig. 5 is a sectional view taken on the line 5-5 of Fig. 1; and
Fig. 6 is a view in front elevation showing the actual dimensions of the magnetic head.
Referring now to the embodiment of the present invention shown in the accompanying drawings, 2 is a ceramic wafer triangularly shaped at one end and notched at two opposite sides. The ceramic forms 4, about which the recording and reproducing coils 6 are wound, are mounted adj acent the notched sides of the wafer 2 and are held in position by means of the notched portions 8 and the magnetic core l0 which is wound around the water 2 and threaded through each of the forms 4 and the coils B. The ends of the magnetic core W are disposed between the triangular sides of the wafer 2 and a low resistance, nonmagnetic shield l2 which is held in position adjacent the wafer 2 by means of the ceramic pin l4.
The shield l2 may be made of a material such as copper. The core II), which may be in the form of a ribbon having a thickness of 0.001 inch, is made ofmagnetic material, such as Permalloy. The surface of the ribbon is coated with a layer of suitable inert insulating material, such as Alundum in order to prevent metal contact between the core 10 and the shield l2 or the terminal wires It. The terminal wires IS, the coils 6 and the wires l8 which connect the coils 6 in series are preferably of tungsten. The terminal wires l6 and the connecting wires 18 are Welded to the coils 6. The triangularly-shaped wafer 2 and the forms 4- may be made of a material such as steatite.
.As shown in Fig. 4, the ceramic forms 4 comprise .a male portion 20 and a female portion 22 which, when joined and held together by the coil 6, support the wires I6 and I8.
After the magnetic head is assembled, as shown in Fig. 1, it is coated with a ceramic material and fired. The ceramic coating should be so selected that the firing temperature of the coating coincides with the heat treating temperature of the magnetic core so that the glazing will be completed simultaneously with the heat treatment of the magnetic material. A ceramic material consisting of the following componentshas been found to be satisfactory for this purpose when Permalloy is employed as the magnetic material:
Parts by weight Sodium oxide 11.2 Potassium oxide 5.0 Boron oxide 13.0 Aluminum oxide 8.1 Silicon dioxide 55.3 Calcium fluoride 4.2 Cobalt oxide 2.4 Lithium oxide -i 0.8
The heat treatment of the magnetic core after assembly is a desirable feature since it avoids handling of the core after heat treatment, a procedure which is known to lower the magnetic qualities of thin Permalloy laminations.
After the magnetic head assembly has been fired, the unwanted ends of the magnetic core or ribbon ID are clipped and the pointed end of the entire assembly, including the shield I2, is ground.
and/or lapped until the desired separation of the pole tips 24 and 28 is obtained. The magnetic head unit may be mounted on its associated equipment by means of the mounting holes 28 in the shield [2.
It is to be understood that the above-described arrangements are illustrative of the application of the principles of the invention. Other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention.
What is claimed is:
l. A magnetic recording-reproducing head coated with a ceramic glaze and comprising a ceramic member two opposite sides of which converge to form a point at one end, an eddy current shielding member disposed about the pointed end of said ceramic member, and a ribbon of magnetic material wound around said ceramic member and disposed between the converging sides of said ceramic member and said shielding member to form two pole tips spaced by the pointed end of said ceramic member, said ceramic member, said shielding member and said ribbon being fixedly positioned by means of said glazed ceramic coating.
2. A magnetic recording-reproducing head coated with a ceramic glaz and comprising a ceramic wafer triangularly shaped at one end, an energizing coil wound on a ceramic member disposed adjacent said ceramic waier, an eddy current shielding member disposed about the triangularly-shaped portion of said ceramic wafer, a core comprising a thin lamination of magnetic material disposed around said ceramic wafer and threaded through said ceramic member and said coil, the ends of said core being disposed between the triangular sides of said ceramic wafer and said shielding member to form two spaced pole tips, said ceramic wafer, said energizing coil, said shielding member and said core being fixedly positioned by said glazed ceramic coating.
3. A magnetic recording-reproducing head coated with a ceramic glaze and comprising a ceramic Wafer two opposite sides of which converge to form a point at one end, a pair of energizing coils, each of said coils wound on a ceramic member, said ceramic members being disposed adjacent said opposite sides of said ceramic wafer, an eddy current shielding member disposed about the pointed end of said ceramic wafer, a ribbon of magnetic material disposed around said ceramic wafer and threaded through said ceramic members and said coils, the ends of said ribbon being disposed between the converging sides of said ceramic wafer and said shielding member to form two spaced pole tips, said ceramic wafer, said energizing coils, said shielding member and said ribbon being fixedly positioned by said glazed ceramic coating.
4. A magnetic recording-reproducing head coated with a ceramic glaze and comprising a ceramic wafer triangularly shaped at one end, a pair of serially connected coils, each of said coils wound on a cylindrically-shaped ceramic member, said cylindrically-shaped members being disposed adjacent opposite sides of said wafer, an eddy current shielding member disposed about the triangularly-shaped portion of said wafer, a core comprising a. thin lamination of magnetic material disposed around said wafer and threaded through said cylindrically-shaped ceramic members and said coils, the ends of said core being disposed between the triangular sides of said wafer and said shielding member to form two spaced pole tips, said wafer, said cylindricallyshaped ceramic members, said shielding member and said core being fixedly positioned by means of said glazed ceramic coating.
5. A magnetic recording-reproducing head comprising a core of magnetic material, said head being coated with a ceramic glaze, said magnetic material having an annealing temperature coinciding with the firing temperature of said ceramic coating.
6. A magnetic recording-reproducing head coated with a ceramic glaze and comprising a ceramic wafer two opposite sides of which converge to form a point at one end, said opposite sides having notched portions, a pair of serially connected energizing coils, each of said coils wound on a cylindrically-shaped ceramic member, said ceramic members being disposed within the notched portions of said opposite sides of said ceramic wafer, an eddy current shielding member disposed about and secured to the pointed end of said ceramic wafer, a ribbon of magnetic material disposed around said ceramic wafer and threaded through said cylindrically-shaped ceramic members and said energizing coils, the ends of said ribbon of magnetic material being disposed between the converging sides of said ceramic wafer and said shielding member to form two spaced pole tips, said ceramic wafer, said energizing coils, said shielding member and said ribbon of magnetic material being fixedly positioned by said glazed ceramic coating.
7. A magnetic recording-reproducing head in accordance with claim 6 wherein the annealing temperature of the ribbon of magnetic material coincides with the firing temperature of the ceramic coating.
References Cited in the file of this patent UNITED STATES PATENTS
US254537A 1951-11-02 1951-11-02 Magnetic head and method of making same Expired - Lifetime US2674659A (en)

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US254537A US2674659A (en) 1951-11-02 1951-11-02 Magnetic head and method of making same
US324388A US2674031A (en) 1951-11-02 1952-12-05 Method of making electromagnetic transducers

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Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2855466A (en) * 1955-03-03 1958-10-07 Armour Res Found Magnetic transducer head
US2895015A (en) * 1953-09-17 1959-07-14 Rca Corp Magnetic record transducer
US2914621A (en) * 1956-09-05 1959-11-24 Int Standard Electric Corp Electromagnetic transducer
US2941045A (en) * 1954-01-29 1960-06-14 Lawrence H Connell Magnetic recording
US2958835A (en) * 1958-01-31 1960-11-01 Gen Motors Corp Pickup instrument for measuring device
US3004111A (en) * 1957-05-24 1961-10-10 Hollingsworth R Lee Complementary magnetic cores for selective magnetic record readout
US3016427A (en) * 1956-08-24 1962-01-09 North American Aviation Inc Saturable magnetic head
US3024318A (en) * 1955-10-04 1962-03-06 Philips Corp Glass gap spacer for magnetic heads
US3031736A (en) * 1957-07-24 1962-05-01 Bell Telephone Labor Inc Fabrication of magnetic core structures
US3042999A (en) * 1958-10-29 1962-07-10 Ibm Method of fabricating magnetic printer write heads
US3104455A (en) * 1959-08-10 1963-09-24 Clevite Corp Method of manufacturing magnetic transducer head
US3120001A (en) * 1958-12-08 1964-01-28 Ibm Magnetic transducer
US3140361A (en) * 1960-12-30 1964-07-07 Ampex Magnetic head assembly
US3163720A (en) * 1959-02-05 1964-12-29 Webcor Inc Magnetic head
US3175049A (en) * 1960-07-15 1965-03-23 Minnesota Mining & Mfg Magnetic scanning head
US3177297A (en) * 1959-06-16 1965-04-06 Sony Corp Boundary displacement multi-channel magnetic head
US3188400A (en) * 1961-01-09 1965-06-08 Ampex Ferrite coating
US3233046A (en) * 1960-11-04 1966-02-01 William D Moehring Magnetic head assembly
US3243519A (en) * 1961-04-06 1966-03-29 Burroughs Corp Electromagnetic transducer with twisted wire core
US3246384A (en) * 1961-04-25 1966-04-19 Gen Instrument Corp Method of making a transducer
US3258542A (en) * 1961-04-17 1966-06-28 Ampex Wedge-shaped magnetic transducer
US3268987A (en) * 1959-05-11 1966-08-30 Adams Edmond Method of making transducer head cores
US3495045A (en) * 1964-08-18 1970-02-10 Peter F Varadi Magnetic transducer head having a ceramic gap spacer
US3777369A (en) * 1967-11-24 1973-12-11 Rca Corp Method of making a magnetic recording head
EP0032230A2 (en) * 1980-01-14 1981-07-22 Siemens Aktiengesellschaft Integrated magnetic transducer and method of manufacturing the same
FR2585168A1 (en) * 1985-07-16 1987-01-23 Eurofarad LONG-LASTING MONOLITHIC MAGNETIC HEAD WITH INTEGRATED SOLENOID, AND METHOD FOR THE PRODUCTION THEREOF

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1827571A (en) * 1930-10-08 1931-10-13 Gen Electric Insulation of electrical apparatus
US1872261A (en) * 1930-05-30 1932-08-16 Rola Company Method of making loud speakers
US2587097A (en) * 1948-11-19 1952-02-26 Berlant Associates Magnetic transducer head and mount therefor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1872261A (en) * 1930-05-30 1932-08-16 Rola Company Method of making loud speakers
US1891404A (en) * 1930-05-30 1932-12-20 Rola Company Loud speaker
US1827571A (en) * 1930-10-08 1931-10-13 Gen Electric Insulation of electrical apparatus
US2587097A (en) * 1948-11-19 1952-02-26 Berlant Associates Magnetic transducer head and mount therefor

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2895015A (en) * 1953-09-17 1959-07-14 Rca Corp Magnetic record transducer
US2941045A (en) * 1954-01-29 1960-06-14 Lawrence H Connell Magnetic recording
US2855466A (en) * 1955-03-03 1958-10-07 Armour Res Found Magnetic transducer head
US3024318A (en) * 1955-10-04 1962-03-06 Philips Corp Glass gap spacer for magnetic heads
US3016427A (en) * 1956-08-24 1962-01-09 North American Aviation Inc Saturable magnetic head
US2914621A (en) * 1956-09-05 1959-11-24 Int Standard Electric Corp Electromagnetic transducer
US3004111A (en) * 1957-05-24 1961-10-10 Hollingsworth R Lee Complementary magnetic cores for selective magnetic record readout
US3031736A (en) * 1957-07-24 1962-05-01 Bell Telephone Labor Inc Fabrication of magnetic core structures
US2958835A (en) * 1958-01-31 1960-11-01 Gen Motors Corp Pickup instrument for measuring device
US3042999A (en) * 1958-10-29 1962-07-10 Ibm Method of fabricating magnetic printer write heads
US3120001A (en) * 1958-12-08 1964-01-28 Ibm Magnetic transducer
US3163720A (en) * 1959-02-05 1964-12-29 Webcor Inc Magnetic head
US3268987A (en) * 1959-05-11 1966-08-30 Adams Edmond Method of making transducer head cores
US3177297A (en) * 1959-06-16 1965-04-06 Sony Corp Boundary displacement multi-channel magnetic head
US3104455A (en) * 1959-08-10 1963-09-24 Clevite Corp Method of manufacturing magnetic transducer head
US3175049A (en) * 1960-07-15 1965-03-23 Minnesota Mining & Mfg Magnetic scanning head
US3233046A (en) * 1960-11-04 1966-02-01 William D Moehring Magnetic head assembly
US3140361A (en) * 1960-12-30 1964-07-07 Ampex Magnetic head assembly
US3188400A (en) * 1961-01-09 1965-06-08 Ampex Ferrite coating
US3243519A (en) * 1961-04-06 1966-03-29 Burroughs Corp Electromagnetic transducer with twisted wire core
US3258542A (en) * 1961-04-17 1966-06-28 Ampex Wedge-shaped magnetic transducer
US3246384A (en) * 1961-04-25 1966-04-19 Gen Instrument Corp Method of making a transducer
US3495045A (en) * 1964-08-18 1970-02-10 Peter F Varadi Magnetic transducer head having a ceramic gap spacer
US3777369A (en) * 1967-11-24 1973-12-11 Rca Corp Method of making a magnetic recording head
EP0032230A2 (en) * 1980-01-14 1981-07-22 Siemens Aktiengesellschaft Integrated magnetic transducer and method of manufacturing the same
EP0032230A3 (en) * 1980-01-14 1982-01-13 Siemens Aktiengesellschaft Integrated magnetic transducer and method of manufacturing the same
FR2585168A1 (en) * 1985-07-16 1987-01-23 Eurofarad LONG-LASTING MONOLITHIC MAGNETIC HEAD WITH INTEGRATED SOLENOID, AND METHOD FOR THE PRODUCTION THEREOF
EP0210105A1 (en) * 1985-07-16 1987-01-28 Eurofarad-Efd Long life monolithic magnetic head with integrated solenoid, and process for its manufacture

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