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US4138702A Expired / Lapsed US ⏱️ 0.0 years remaining

Head arrangement for perpendicular recording information on a magnetic record carrier

Assignee: Bull SAS
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Filing: 1977-11-25
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Granted: 1979-02-06
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Expires: 1997-11-25
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Abstract

Abstract An arrangement for recording information on a magnetic record carrier, having at least one magnetic recording head which incorporates an electromagnet having a core, wherein said arrangement includes a magnetic shunt, said magnetic shunt and the magnetic core of the electromagnet being adapted to be arranged on either side of said record carrier and close thereto, so as to form a closed magnetic circuit in which the magnetic flux is substantially perpendicular to the surface of the carrier, the said core having a recording pole and a flux-closing pole and the cross-section of the recording pole being smaller than that of the flux-closing pole.

Inventors

  • 👤 Jean G. Magnenet

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 22:09
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1278

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 179 words
An arrangement for recording information on a magnetic record carrier comprising a plurality of magnetic recording heads, each said magnetic recording head including an electromagnet, a recording pole and a flux closing pole, the cross-section of the pole face of the recording pole being smaller than the cross-section of the pole face of the flux closing pole, a magnetic shunt, said magnetic shunt being disposed on one side of said record carrier and close thereto and each said magnetic recording head being disposed on the other side of said record carrier and close thereto, so as to form a gap of constant dimension with said magnetic shunt and a closed magnetic circuit in which the magnetic flux is substantially perpendicular to the surface of the carrier, nonmagnetic encapsulation means for supporting said recording heads as a modular unit in parallel arrangement, each said recording head being separated from the adjoining head by said nonmagnetic encapsulation means and a first and second side plate disposed over said encapsulation means and adjacent the end-most sides of said parallel arranged recording heads.
Claim 2
Dependent Claim 179 words
An arrangement for recording information on a magnetic record carrier comprising a plurality of magnetic recording heads, each said magnetic recording head including an electromagnet, a recording pole and a flux closing pole, the cross-section of the pole face of the recording pole being smaller than the cross-section of the pole face of the flux closing pole, a magnetic shunt, said magnetic shunt being disposed on one side of said record carrier and close thereto and each said magnetic recording head being disposed on the other side of said record carrier and close thereto, so as to form a gap of constant dimension with said magnetic shunt and a closed magnetic circuit in which the magnetic flux is substantially perpendicular to the surface of the carrier, nonmagnetic encapsulation means for supporting said recording heads as a modular unit in parallel arrangement, each said recording head being separated from the adjoining head by said nonmagnetic encapsulation means and a first and second side plate disposed over said encapsulation means and adjacent the end-most sides of said parallel arranged recording heads.
Claim 3
Dependent Claim 64 words
An arrangement according to claim 1 in which the magnetic shunt is a cylinder of a material having high magnetic permeability, and the magnetic record carrier is a film of magnetic material on the surface of the cylinder, and further including electric motor means for rotatably driving the cylinder such that the surface of the cylinder rotates past the poles of the recording heads.
Claim 4
Dependent Claim 64 words
An arrangement according to claim 1, in which the magnetic record carrier is an endless magnetic band and said magnetic shunt is a bar of high magnetic permeability, means for mounting said band on a plurality of rollers, the band being applied against the magnetic shunt, and electric motor means for rotatably driving one of the rollers, the other rollers being free to turn.
Claim 5
Dependent Claim 45 words
An arrangement according to claim 1, wherein the plurality of recording heads comprises two groups of heads, each group comprising a like number of heads, and the heads of one of said group being disposed in staggered relationship with the heads of the other group.
Claim 6
Dependent Claim 184 words
An arrangement for recording information on a magnetic record carrier comprising a plurality of magnetic recording heads, each said head including an electromagnet having a core and a winding, means for connecting said core windings to a current generator, each said core having a recording pole and a flux-closing pole and the cross-section of the pole face of the recording pole being smaller than that of the pole face of the flux-closing pole, a magnetic shunt, said shunt and said magnetic core of each said electromagnet being arranged on opposite sides of said record carrier and close thereto, so as to form gaps of constant dimension between the poles and the shunt and a closed magnetic circuit for each said core in which the magnetic flux associated with each core is perpendicular to the surface of said carrier such that the carrier is transversely magnetized, said magnetic shunt being a cylinder of material having high magnetic permeability, and the magnetic record carrier being film of magnetic material on the surface of the cylinder, and further including electric motor means for rotatably driving the cylinder.
Claim 7
Dependent Claim 184 words
An arrangement for recording information on a magnetic record carrier comprising a plurality of magnetic recording heads, each said head including an electromagnet having a core and a winding, means for connecting said core windings to a current generator, each said core having a recording pole and a flux-closing pole and the cross-section of the pole face of the recording pole being smaller than that of the pole face of the flux-closing pole, a magnetic shunt, said shunt and said magnetic core of each said electromagnet being arranged on opposite sides of said record carrier and close thereto, so as to form gaps of constant dimension between the poles and the shunt and a closed magnetic circuit for each said core in which the magnetic flux associated with each core is perpendicular to the surface of said carrier such that the carrier is transversely magnetized, said magnetic shunt being a cylinder of material having high magnetic permeability, and the magnetic record carrier being film of magnetic material on the surface of the cylinder, and further including electric motor means for rotatably driving the cylinder.
Claim 8
Dependent Claim 41 words
An arrangement according to claim 5 further including means for supporting said recording heads in parallel arrangement and forming a modular unit, each recording head of the modular unit being separated from the adjoining head by a member of nonmagnetic material.
Claim 9
Dependent Claim 183 words
An arrangement for recording information on a magnetic record carrier comprising a plurality of magnetic recording heads, each said head including an electromagnet having a core and a winding, means for connecting said core windings to a current generator, each said core having a recording pole and a flux-closing pole and the cross-section of the pole face of the recording pole being smaller than that of the pole face of the flux-closing pole, a magnetic shunt, said shunt and said magnetic core of each said electromagnet being arranged on opposite sides of said record carrier and close thereto, so as to form gaps of constant dimension between the poles and the shunt and a closed magnetic circuit for each said core in which the magnetic flux associated with each core is perpendicular to the surface of said carrier such that the carrier is transversely magnetized, said carrier being an endless magnetic band moveably supported about at least two rollers and said magnetic shunt being a bar of high magnetic permeability and further including electric motor means for rotatably driving one of said rollers.
Claim 10
Dependent Claim 183 words
An arrangement for recording information on a magnetic record carrier comprising a plurality of magnetic recording heads, each said head including an electromagnet having a core and a winding, means for connecting said core windings to a current generator, each said core having a recording pole and a flux-closing pole and the cross-section of the pole face of the recording pole being smaller than that of the pole face of the flux-closing pole, a magnetic shunt, said shunt and said magnetic core of each said electromagnet being arranged on opposite sides of said record carrier and close thereto, so as to form gaps of constant dimension between the poles and the shunt and a closed magnetic circuit for each said core in which the magnetic flux associated with each core is perpendicular to the surface of said carrier such that the carrier is transversely magnetized, said carrier being an endless magnetic band moveably supported about at least two rollers and said magnetic shunt being a bar of high magnetic permeability and further including electric motor means for rotatably driving one of said rollers.
Claim 11
Dependent Claim 17 words
An arrangement according to claim 7, wherein said magnetic band is held pressed against said magnetic shunt.
Claim 12
Dependent Claim 46 words
An arrangement according to claim 7, further including means for supporting said plurality of recording heads in parallel arrangement so as to form a modular unit, each recording head of the modular unit being separated from the adjoining head by a member of non magnetic material.

References Cited (Backward Citations)

US3427408A Cited
US3486220A Cited
US3810191A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-02-05 1982-08-07 1983-02-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-02-05 1986-08-07 1987-02-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-02-05 1990-08-07 1991-02-06 $7700.00 Window Closed / Lapsed

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