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US4020506A Expired / Lapsed US ⏱️ 0.0 years remaining

Tape cartridge with track position indicator

Assignee: International Business Machines Corp
•
Filing: 1975-06-30
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Granted: 1977-04-26
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Expires: 1995-06-30
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Abstract

Abstract A magnetic tape cartridge includes a housing for supporting the tape for movement therein and for enclosing a portion of the tape. The tape is expandable from a particular reference point along its width by virtue of temperature and humidity changes. A track position indicator attached to the cartridge includes indicia thereon relative to track positions along the width of the tape. The indicator has a coefficient of expansion closely similar to the coefficient of expansion of the tape, and in the preferred embodiment is made of the same material as the magnetic tape substrate material.

Inventors

  • 👤 Michael Conan Barrett
  • 👤 Eric Sigfried Petterson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 09:36
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 179 words
A magnetic tape cartridge comprising: a magnetic tape; a housing enclosing a portion of said tape and supporting said tape for movement therein; one end of a track position indicator attached to said housing, said indicator including indicia thereon indicative of track positions of magnetic recording tracks extending longitudinally along said tape and positioned in substantially parallel relation across a width of said tape, said indicator having a coefficient of thermal and hygroscopic expansion closely similar to the coefficient of thermal and hygroscopic expansion of said magnetic tape; and a reference edge surface contacting one edge of said tape, said reference edge surface attached to said housing of said cartridge and said reference edge surface being perpendicular to said tape, the other edge of said tape being spring biased toward said reference edge surface and exapandable away from said reference edge surface due to temperature and humidity, said indicator being attached to said housing at said reference edge surface, said tape and said indicator expanding substantially the same amounts in the same direction upon changes in temperature and humidity.
Claim 2
Dependent Claim 179 words
A magnetic tape cartridge comprising: a magnetic tape; a housing enclosing a portion of said tape and supporting said tape for movement therein; one end of a track position indicator attached to said housing, said indicator including indicia thereon indicative of track positions of magnetic recording tracks extending longitudinally along said tape and positioned in substantially parallel relation across a width of said tape, said indicator having a coefficient of thermal and hygroscopic expansion closely similar to the coefficient of thermal and hygroscopic expansion of said magnetic tape; and a reference edge surface contacting one edge of said tape, said reference edge surface attached to said housing of said cartridge and said reference edge surface being perpendicular to said tape, the other edge of said tape being spring biased toward said reference edge surface and exapandable away from said reference edge surface due to temperature and humidity, said indicator being attached to said housing at said reference edge surface, said tape and said indicator expanding substantially the same amounts in the same direction upon changes in temperature and humidity.
Claim 3
Dependent Claim 19 words
The magnetic tape cartridge of claim 1 wherein said indicator is spring biased away from said reference edge surface.
Claim 4
Dependent Claim 29 words
The magnetic tape cartridge of claim 2 wherein said indicator and a substrate material of said magnetic tape each comprise a relatively flexible polymeric film of the same composition.
Claim 5
Dependent Claim 179 words
A magnetic tape cartridge comprising: a magnetic tape; a housing enclosing a portion of said tape and supporting said tape for movement therein; a mounting bar fixedly mounted between opposing walls of the housing transversely of said tape; a mounting plate shorter than said mounting bar; a track position indicator having a central portion thereof attached along said mounting bar between said mounting plate and said mounting bar, said attachment of said track position indicator being adjacent a central portion of said magnetic tape between opposite edges of said magnetic tape, said indicator including indicia thereon indicative of track positions of magnetic recording tracks extending longitudinally along said tape, said indicator having a coefficient of thermal and hygroscopic expansion closely similar to the coefficient of thermal and hygroscopic expansion of said magnetic tape; and wherein said tape and said indicator expand bi-directionally in substantially the same amounts toward opposite edges along the width of said tape and said track position indicator from said central portions of said tape and said track position indicator upon changes of temperature and humidity.
Claim 6
Dependent Claim 179 words
A magnetic tape cartridge comprising: a magnetic tape; a housing enclosing a portion of said tape and supporting said tape for movement therein; a mounting bar fixedly mounted between opposing walls of the housing transversely of said tape; a mounting plate shorter than said mounting bar; a track position indicator having a central portion thereof attached along said mounting bar between said mounting plate and said mounting bar, said attachment of said track position indicator being adjacent a central portion of said magnetic tape between opposite edges of said magnetic tape, said indicator including indicia thereon indicative of track positions of magnetic recording tracks extending longitudinally along said tape, said indicator having a coefficient of thermal and hygroscopic expansion closely similar to the coefficient of thermal and hygroscopic expansion of said magnetic tape; and wherein said tape and said indicator expand bi-directionally in substantially the same amounts toward opposite edges along the width of said tape and said track position indicator from said central portions of said tape and said track position indicator upon changes of temperature and humidity.
Claim 7
Dependent Claim 25 words
The tape cartridge of claim 4 wherein said indicator and a substrate of said tape comprise a relatively flexible polymeric film of the same composition.

References Cited (Backward Citations)

US2779826A Cited
US3576553A Cited
US3570735A Cited
US3660810A Cited
US3641529A Cited
US3723980A Cited
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US3859662A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-04-25 1980-10-25 1981-04-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-04-25 1984-10-25 1985-04-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-04-25 1988-10-25 1989-04-26 $7700.00 Window Closed / Lapsed

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