US2809237A - Magnetic sound recording head - Google Patents

Magnetic sound recording head Download PDF

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Publication number
US2809237A
US2809237A US209250A US20925051A US2809237A US 2809237 A US2809237 A US 2809237A US 209250 A US209250 A US 209250A US 20925051 A US20925051 A US 20925051A US 2809237 A US2809237 A US 2809237A
Authority
US
United States
Prior art keywords
magnetic
sound recording
recording head
magnetic sound
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
Application number
US209250A
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English (en)
Inventor
Bergmann Friedrich
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by BASF SE filed Critical BASF SE
Application granted granted Critical
Publication of US2809237A publication Critical patent/US2809237A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • G11B5/133—Structure or manufacture of heads, e.g. inductive with cores composed of particles, e.g. with dust cores, with ferrite cores with cores composed of isolated magnetic particles
    • 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

Definitions

  • the magnetic sound recording head hitherto used insound recording and sound reproduction consists of a magnetic core and a wire coiling around the said core.
  • the electric oscillations flowing through the said wire coiling generate an alternating magnetic field in the vicinity of a slit provided in the magnetic core and this field imprints itself upon the permanently magnetisable sound carrier on being led past the said slit.
  • magnetic cores of highly permeable material as for example iron-nickel or iron-nickle-copper alloys which are known to have a very high initial permeability.
  • the core is made up of sheets which are insulated against each other from electricity.
  • the magnetic sound recording heads are markedly dependent as to their magnetic field from the frequency, in particular are the high frequencies notably affected, since the eddies in the magnetic core increase in proportion to the square of the frequency.
  • ferrites contemplated for use within the purview of my invention are nickel ferrite, nickel-zinc ferrite, manganese ferrite and manganese-zinc ferrite. These substances not only have high initial permeability but also a very low electric conductivity. They can be used in a compact from as a material for making magnetic cores, without eddy losses occurring and, as a result, the magnetic field being brought into dependency from the frequency at the slit provided in the magnet.
  • the magnet cores may be made by preparing a mixture of 9.4 percent of nickel oxide, 23.8 percent of zinc oxide and 66.8 percent of ferric oxide, either by intimately mixing the said oxides or by precipitating them jointly from their respective metal salt solutions, pressing the mixture into suitably shaped molds, annealing the resulting shaped body at a temperature of between about 1200 and 1300 C. in an atmosphere of oxygen and allowing it to cool down very slowly in this atmosphere.
  • More ease and conveniency in the manufacture of the cores will be afforded by giving the cores, instead of the standard circular form, a square-bar form in crosssection, because the ferrites may be more easily pressed and annealed in this shape. In practical use, three such bars are arranged to form a triangle with a slit being left at one of the intersectional points of the bars.
  • the ends of the bars and the sliding surface for the recorder band may be suitably shaped by abrasion.
  • 1 represents the squarebars made of ferrite
  • 2 represents the slit
  • 3 represents the wire coiling
  • 4 represents the recorder band.
  • Magnetic sound recording head having a core consisting exclusively of magnetic ferrite.
  • Magnetic sound recording head having a core consisting exclusively'of manganese ferrite.
  • Magnetic sound recording head having a core consisting exclusively of nickel-zinc ferrite.
  • Magnetic sound recording head having a core consisting exclusively of manganese-zinc ferrite.
  • Magnetic sound recording head having a core consisting of three bars made exclusively from ferrite and arranged to form a triangle with a slit being left at one of the intersection points of the bars.
  • a magnetic sound recording head comprising a magnetic core having legs separated by a slit, said core including the portions thereof adjacent said slit consisting solely of magnetic ferrite.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Magnetic Heads (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
US209250A 1950-02-06 1951-02-03 Magnetic sound recording head Expired - Lifetime US2809237A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE287606X 1950-02-06

Publications (1)

Publication Number Publication Date
US2809237A true US2809237A (en) 1957-10-08

Family

ID=6059352

Family Applications (1)

Application Number Title Priority Date Filing Date
US209250A Expired - Lifetime US2809237A (en) 1950-02-06 1951-02-03 Magnetic sound recording head

Country Status (5)

Country Link
US (1) US2809237A (fr)
CH (1) CH287606A (fr)
FR (2) FR1032056A (fr)
GB (1) GB717573A (fr)
IT (1) IT472736A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2933565A (en) * 1953-04-15 1960-04-19 Siemens Ag Magnetic transducers
US3079470A (en) * 1959-12-21 1963-02-26 Armour Res Found Magnetic transducer head
US3268987A (en) * 1959-05-11 1966-08-30 Adams Edmond Method of making transducer head cores
US4242711A (en) * 1977-04-13 1980-12-30 Nippon Gakki Seizo Kabushiki Kaisha Multilayer magnetic head core

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4188649A (en) * 1977-12-05 1980-02-12 Ibm Corporation Magnetic head having a jagged-edged gap, and method for producing such head

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2452529A (en) * 1941-10-24 1948-10-26 Hartford Nat Bank & Trust Co Magnet core
US2452531A (en) * 1943-05-31 1948-10-26 Hartford Nat Bank & Trust Co Process of manufacturing a magnetic material and magnetic core
US2452530A (en) * 1943-05-15 1948-10-26 Hartford Nat Bank & Trust Co Magnetic core
US2493742A (en) * 1945-08-22 1950-01-10 Brush Dev Co Magnetic transducing core for magnetic record transducers
US2536260A (en) * 1948-12-30 1951-01-02 Rca Corp Device for reproducing magnetic records
CH274288A (de) * 1948-11-12 1951-03-31 Alexander Dr Egerer Karl Magnetton-Aufzeichnungs- und Wiedergabekopf für bandförmige Tonträger.
US2592652A (en) * 1950-02-18 1952-04-15 Bell Telephone Labor Inc Magnetic transducer head

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2452529A (en) * 1941-10-24 1948-10-26 Hartford Nat Bank & Trust Co Magnet core
US2452530A (en) * 1943-05-15 1948-10-26 Hartford Nat Bank & Trust Co Magnetic core
US2452531A (en) * 1943-05-31 1948-10-26 Hartford Nat Bank & Trust Co Process of manufacturing a magnetic material and magnetic core
US2493742A (en) * 1945-08-22 1950-01-10 Brush Dev Co Magnetic transducing core for magnetic record transducers
CH274288A (de) * 1948-11-12 1951-03-31 Alexander Dr Egerer Karl Magnetton-Aufzeichnungs- und Wiedergabekopf für bandförmige Tonträger.
US2536260A (en) * 1948-12-30 1951-01-02 Rca Corp Device for reproducing magnetic records
US2592652A (en) * 1950-02-18 1952-04-15 Bell Telephone Labor Inc Magnetic transducer head

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2933565A (en) * 1953-04-15 1960-04-19 Siemens Ag Magnetic transducers
US3268987A (en) * 1959-05-11 1966-08-30 Adams Edmond Method of making transducer head cores
US3079470A (en) * 1959-12-21 1963-02-26 Armour Res Found Magnetic transducer head
US4242711A (en) * 1977-04-13 1980-12-30 Nippon Gakki Seizo Kabushiki Kaisha Multilayer magnetic head core

Also Published As

Publication number Publication date
FR62575E (fr) 1955-06-15
IT472736A (fr)
CH287606A (de) 1952-12-15
GB717573A (en) 1954-10-27
FR1032056A (fr) 1953-06-29

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