US3914631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capstan motor having a ceramic output shaft and an adhesively attached capstan
Assignee: International Business Machines Corp
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Filing: 1973-08-17
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Granted: 1975-10-21
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Expires: 1993-08-17
Abstract
Abstract A permanent magnet, direct current capstan motor for use in moving magnetic recording tape in a start/stop mode at a high repetition rate, wherein a lightweight motor armature is shaftconnected to a tape drive capstan by means of a nonmetallic, ceramic, monocrystalline aluminum oxide shaft. The capstan is adhesively attached to one end of the ceramic shaft. The shaft performs the multifunctions of maintaining a high mechanical resonant frequency for the motor''s rotating assembly, magnetically isolating the magnetic recording tape from the motor''s magnetic field, and heat insulating the capstan''s adhesive interface to the shaft from the heat source formed by the motor''s armature.
Inventors
- 👤 Adolfo M Guzman
- 👤 Harlan D Lawes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:43
CPC Classifications
H; H02; H02K; H02K7/00; H02K7/003; H02K7/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
109 words
A high torque - low inertia tape drive capstan motor, comprising: a stationary magnetic field structure providing an air gap, a rotatable armature positioned to rotate within said air gap, a ceramic shaft connected to be driven by said armature by having one end thereof attached to the center of rotation of said armature, and a tape drive capstan adhesively attached to the other end of said shaft in close physical proximity to said armature and said magnetic field structure, the heat insulation and magnetic reluctance properties of said shaft functioning to isolate said capstan and its adhesive interface from temperature rise and magnetic field induced by motor operation.
Claim 2
Dependent Claim
109 words
A high torque - low inertia tape drive capstan motor, comprising: a stationary magnetic field structure providing an air gap, a rotatable armature positioned to rotate within said air gap, a ceramic shaft connected to be driven by said armature by having one end thereof attached to the center of rotation of said armature, and a tape drive capstan adhesively attached to the other end of said shaft in close physical proximity to said armature and said magnetic field structure, the heat insulation and magnetic reluctance properties of said shaft functioning to isolate said capstan and its adhesive interface from temperature rise and magnetic field induced by motor operation.
Claim 3
Dependent Claim
15 words
The motor defined in claim 1 wherein said shaft is formed of a technical ceramic.
Claim 4
Dependent Claim
17 words
The motor defined in claim 2 wherein said shaft is formed of high purity polycrystalline aluminum oxide.
Claim 5
Dependent Claim
63 words
The motor defined in claim 2 wherein said armature is a hollow tubular armature which is cantilever supported at one end only by a hub which mechanically connects said armature to said shaft, and wherein said magnetic field structure includes a flux return rod member positioned within said armature and a plurality of permanent magnets disposed about the outside periphery of said armature.
Claim 6
Dependent Claim
27 words
The motor defined in claim 4 including: a magnetically permeable housing supporting said magnets, and a magnetically nonpermeable end bell including bearing means rotatably supporting said shaft.
Claim 7
Dependent Claim
34 words
The motor defined in claim 5 including a movable, temperature sensitive, tachometer disc connected to rotate with said capstan and a stationary tachometer assembly cooperating with said disc and mounted on said end bell.
Claim 8
Dependent Claim
46 words
The motor defined in claim 6 wherein said capstan and said disc are mounted on a metal sleeve to thus form a subassembly, and wherein said subassembly is attached to said other end of said shaft by an adhesive interface between said sleeve and said shaft.
Claim 9
Dependent Claim
17 words
The motor defined in claim 7 wherein said shaft is formed of high purity polycrystalline aluminum oxide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |