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US4525757A Expired / Lapsed US ⏱️ 0.0 years remaining

Rotary head assembly

Assignee: Panasonic Holdings Corp
•
Filing: 1983-07-05
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Granted: 1985-06-25
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Expires: 2003-07-05
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Abstract

Abstract This invention relates to a rotary head assembly in which a magnetic tape runs while being would helically, consisting of a fixed cylinder 21 having a fixed cylindrical part, and a rotatable rotary member 19 having a diameter approximately equal to that of said fixed cylinder 21, being disposed coaxially with a very small gap and holding a magnetic head 29, wherein pump-out type spiral grooves 20 are provided either partly or wholly on either plane of the confronting planes formed in the relative rotating part between said fixed cylinder 21 and said rotary member 19 in order to create a buoyancy on a running magnetic tape by air pressure not only in the rotary cylinder area but also in the fixed cylinder area, to realize a stable and smooth tape running, and to radically eliminate the tape chirping phenomenon, sticking phenomenon, and tape damage and cylinder wear accompanying sliding.

Inventors

  • 👤 Kiyokazu Imanishi
  • 👤 Takashi Ichiyanagi
  • 👤 Yasuo Sakurai
  • 👤 Hirouki Naka
  • 👤 Koji Nakagawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 22:12
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/60; G11B15/61

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 83 words
A rotary head assembly consisting of a fixed cylinder having a cylindrical part and a rotary cylinder, having a cylindrical part with a diameter approximately equal to that of the cylindrical part of this fixed cylinder, which rotates relatively with respect to said fixed cylinder in close contact with said fixed cylinder and supports the tape together with said fixed cylinder, wherein pump-out type spiral grooves are provided on either plane of the confronting end faces of said rotary cylinder and fixed cylinder.
Claim 2
Dependent Claim 83 words
A rotary head assembly consisting of a fixed cylinder having a cylindrical part and a rotary cylinder, having a cylindrical part with a diameter approximately equal to that of the cylindrical part of this fixed cylinder, which rotates relatively with respect to said fixed cylinder in close contact with said fixed cylinder and supports the tape together with said fixed cylinder, wherein pump-out type spiral grooves are provided on either plane of the confronting end faces of said rotary cylinder and fixed cylinder.

References Cited (Backward Citations)

US4012792A Cited
US4257076A Cited
US4266255A Cited
US4395745A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-06-24 1988-12-24 1989-06-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-06-24 1992-12-24 1993-06-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-06-24 1996-12-24 1997-06-25 $7700.00 Window Closed / Lapsed

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