US3633186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transducer accessing mechanism utilizing centrifugal force
Assignee: International Business Machines Corp
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Filing: 1970-07-02
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Granted: 1972-01-04
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Expires: 1990-07-02
Abstract
Abstract A servomechanism for rotating a magnetic head and accessing it from track to track. A rotating head is caused to scan one of a plurality of concentric tracks on a stationary disk. The net centrifugal force of the head and a larger counterweight mass is used to move the head from track to track and to adjust the rotational velocity to achieve a constant linear bit density.
Inventors
- 👤 John J Lynott
- 👤 Robert C Treseder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:03
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/012
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
98 words
An apparatus for rotating a magnetic transducer about an axis and for positioning said transducer in cooperative relationship with a selected one of a plurality of concentric circular recording tracks of a stationary magnetic surface, comprising: counterweight means coupled to said transducer and responsive to changes in angular velocity of said transducer for varying the radius of rotation of said transducer, and force means coupled to said counterweight means for balancing the net centrifugal force of said counterweight means and said transducer, whereby for a given angular rotation, said transducer will be positioned over a selected recording track.
Claim 2
Independent Claim
98 words
An apparatus for rotating a magnetic transducer about an axis and for positioning said transducer in cooperative relationship with a selected one of a plurality of concentric circular recording tracks of a stationary magnetic surface, comprising: counterweight means coupled to said transducer and responsive to changes in angular velocity of said transducer for varying the radius of rotation of said transducer, and force means coupled to said counterweight means for balancing the net centrifugal force of said counterweight means and said transducer, whereby for a given angular rotation, said transducer will be positioned over a selected recording track.
Claim 3
Dependent Claim
47 words
The apparatus of claim 1 wherein the centrifugal force of said counterweight means is greater than the centrifugal force of said transducer means, so that said transducer is positioned at an inner track for a high velocity and at an outer track for a low angular velocity.
Claim 4
Dependent Claim
140 words
A rotating and positioning apparatus, comprising: a rotatable capstan mounted for rotation about an axis, motor means for driving said capstan at a variable angular velocity, stationary magnetic surface means having a plurality of data tracks concentric to said axis, transducer means mounted to said capstan for rotation about said axis in cooperative relationship with one of said plurality of concentric data tracks, counterweight means mechanically coupled to said transducer and also mounted for rotation with said capstan, said transducer means and said counterweight means being radially moveable within a plane perpendicular to said axis, force means mounted within said capstan and coupled to said counterweight means for balancing the net centrifugal force of said counterweight means and said transducer means, whereby said transducer is positioned over the selected data track in accordance with the angular velocity of said capstan.
Claim 5
Dependent Claim
140 words
A rotating and positioning apparatus, comprising: a rotatable capstan mounted for rotation about an axis, motor means for driving said capstan at a variable angular velocity, stationary magnetic surface means having a plurality of data tracks concentric to said axis, transducer means mounted to said capstan for rotation about said axis in cooperative relationship with one of said plurality of concentric data tracks, counterweight means mechanically coupled to said transducer and also mounted for rotation with said capstan, said transducer means and said counterweight means being radially moveable within a plane perpendicular to said axis, force means mounted within said capstan and coupled to said counterweight means for balancing the net centrifugal force of said counterweight means and said transducer means, whereby said transducer is positioned over the selected data track in accordance with the angular velocity of said capstan.
Claim 6
Dependent Claim
49 words
The apparatus of claim 3 wherein the centrifugal force of Said counterweight means is greater than the centrifugal force of said transducer means, so that said transducer means is positioned at an outside track for a low angular velocity and at an inside track for a high angular velocity.
Claim 7
Dependent Claim
16 words
The apparatus of claim 4 further including counterbalance means for achieving rotational stability and eliminating vibration.
Claim 8
Dependent Claim
27 words
The apparatus of claim 4 wherein said counterweight means comprises piston means, and wherein said counterweight means and said transducer are mechanically coupled by piston rod means.
Claim 9
Dependent Claim
27 words
The apparatus of claim 3 wherein said force means comprises a variable-force spring acting on a counterweight reference piston which is hydraulically coupled with said counterweight means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |