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US4425594A Expired / Lapsed US ⏱️ 0.0 years remaining

Ceramic-ferrite head

Assignee: OBEDINENI ZAVODI ZA ZAPAMETYAVASHTI USTROYSTVA A CORP OF BULGARIA
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Filing: 1981-09-28
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Granted: 1984-01-10
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Expires: 2001-09-28
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Abstract

Abstract A ceramic-ferrite head for use with a flexible data-storage disk comprises a cylindrical body composed of magnetically soft ferrite and formed internally with a cup-shaped recess open at one end and a boss provided with a window at the opposite end. The core assembly is received in this boss and is bonded therein with a glass-resin composition while the coils of the assembly are found in the recess and are connected, together with the ground lead through a cap of the same material as the body, to a printed circuit board on the opposite side of this cap. The recess is lined with a conductive coating which is likewise grounded to the printed circuit board by the ground conductor.

Inventors

  • 👤 Petko V. Kodjabashev
  • 👤 Georgi P. Malinovski
  • 👤 Atanas T. Atanassov

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 17:08
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/10; G11B5/11; G11B5/127; G11B5/265; G11B5/2651

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 244 words
A ceramic-ferrite head for use with a flexible disk information storage medium which comprises: a cylindrically magnetically soft ferrite body provided with an internal recess opening axially at one end of said body and formed at the opposite end of said body with an axial boss having a window opening into said recess; a magnetic core assembly affixed to said body and comprising a recording-reading magnetic core having a portion positioned in said window and another portion extending into said recess, a recording-reading coil on said other portion of said recording-reading core, a pair of erasing magnetic cores, each having a portion disposed in said window and provided with a second coil and a pair of ceramic wafers, flanking the portions of said cores disposed in said window; a glass-resin bonding agent bonding said assembly to said wafers in said window; a conductive layer lining said recess; a cap of magnetically soft ferrite closing said one end of said body and having a passage communicating with said recess; a printed circuit board affixed to said cap externally of said recess and provided with a plurality of connecting terminals and a ground terminal; respective leads extending through said recess from said coils to said connecting terminals; and a ground lead connected to said cores and to said lining and extending to said ground terminal, said leads traversing said passage, said glass-resin, said body and said assembly all having substantially the same coefficient of linear extension.
Claim 2
Dependent Claim 244 words
A ceramic-ferrite head for use with a flexible disk information storage medium which comprises: a cylindrically magnetically soft ferrite body provided with an internal recess opening axially at one end of said body and formed at the opposite end of said body with an axial boss having a window opening into said recess; a magnetic core assembly affixed to said body and comprising a recording-reading magnetic core having a portion positioned in said window and another portion extending into said recess, a recording-reading coil on said other portion of said recording-reading core, a pair of erasing magnetic cores, each having a portion disposed in said window and provided with a second coil and a pair of ceramic wafers, flanking the portions of said cores disposed in said window; a glass-resin bonding agent bonding said assembly to said wafers in said window; a conductive layer lining said recess; a cap of magnetically soft ferrite closing said one end of said body and having a passage communicating with said recess; a printed circuit board affixed to said cap externally of said recess and provided with a plurality of connecting terminals and a ground terminal; respective leads extending through said recess from said coils to said connecting terminals; and a ground lead connected to said cores and to said lining and extending to said ground terminal, said leads traversing said passage, said glass-resin, said body and said assembly all having substantially the same coefficient of linear extension.

References Cited (Backward Citations)

US3975771A Cited
US3964103A Cited
US4176384A Cited
US4291354A Cited
US4356524A Cited
US4293883A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-01-09 1987-07-11 1988-01-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-01-09 1991-07-11 1992-01-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-01-09 1995-07-11 1996-01-10 $7700.00 Window Closed / Lapsed

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