US4730299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for preventing vibration of a disc motor shaft in a disc playback device
Assignee: Nippon Gakki Co Ltd
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Filing: 1986-06-03
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Granted: 1988-03-08
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Expires: 2006-06-03
Abstract
Abstract In a disc playback device of a type in which a turntable is connected to a disc motor shaft, a device for preventing vibration of the disc motor shaft comprises magnetic biasing means for generating a magnetic force biasing the disc motor shaft in an axial or radial direction of the shaft. The magnetic biasing means is constructed by securing one of magnetic substance and a magnet to the turntable and disposing the other below the turntable or securing one of two magnets to the turntable and disposing the other magnet below the turntable. For preventing vibration of the disc motor shaft in the radial direction, a yoke plate is fixed to the magnet in such a manner that a part of the yoke plate is positioned on the lateral side of the magnetic substance or the other magnet.
Inventors
- 👤 Yasuhiko Kamoshita
- 👤 Kazuo Urata
- 👤 Mikio Ogusu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:09
CPC Classifications
G; G11; G11B; G11B17/00; G11B17/02; G11B17/04; G11B17/057; G11B17/022; G11B17/028; G11B17/035; G11B19/00; G11B19/20; G11B19/2009; G11B19/2018; G11B33/00; G11B33/02; G11B33/08
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
74 words
A device for preventing vibration of a disc motor shaft in a disc playback device comprising: a disc motor having a rotatable disc motor shaft; a turntable fixedly connected to said disc motor shaft for placing a disc thereon; and magnetic biasing means for generating a magnetic force biasing said disc motor shaft in a predetermined direction other than rotational to prevent vibration of the disc motor shaft with respect to the disc motor.
Claim 2
Independent Claim
74 words
A device for preventing vibration of a disc motor shaft in a disc playback device comprising: a disc motor having a rotatable disc motor shaft; a turntable fixedly connected to said disc motor shaft for placing a disc thereon; and magnetic biasing means for generating a magnetic force biasing said disc motor shaft in a predetermined direction other than rotational to prevent vibration of the disc motor shaft with respect to the disc motor.
Claim 3
Dependent Claim
28 words
A device for preventing vibration of a disc motor shaft as defined in claim 1 wherein said predetermined direction is an axial direction of said disc motor shaft.
Claim 4
Dependent Claim
28 words
A device for preventing vibration of a disc motor shaft as defined in claim 1 wherein said predetermined direction is a radial direction of said disc motor shaft.
Claim 5
Dependent Claim
48 words
A device for preventing vibration of a disc motor shaft as defined in claim 2 wherein said magnetic biasing means comprises magnetic substance and a magnet one of which is secured to the lower surface of said turntable and the other of which is provided below said turntable.
Claim 6
Dependent Claim
24 words
A device for preventing vibration of a disc motor shaft as defined in claim 4 wherein a yoke plate is secured to said magnet.
Claim 7
Dependent Claim
48 words
A device for preventing vibration of a disc motor shaft as defined in claim 2 wherein said magnetic biasing means comprises a magnet secured to the lower surface of said turntable and another magnet provided below said turntable in such a manner that said magnets attract each other.
Claim 8
Dependent Claim
24 words
A device for preventing vibration of a disc motor shaft as defined in claim 6 wherein a yoke plate is secured to said magnet.
Claim 9
Independent Claim
28 words
A device for preventing vibration of a disc motor shaft biasing means is constructed by forming said turntable with magnetic substance and providing a magnet below said turntable.
Claim 10
Independent Claim
28 words
A device for preventing vibration of a disc motor shaft biasing means is constructed by forming said turntable with magnetic substance and providing a magnet below said turntable.
Claim 11
Dependent Claim
24 words
A device for preventing vibration of a disc motor shaft as defined in claim 2 wherein a yoke plate is secured to said magnet.
Claim 12
Dependent Claim
71 words
A device for preventing vibration of a disc motor shaft as defined in claim 3 wherein said magnetic biasing means comprises magnetic substance and a magnet one of which is secured to the lower surface of said turntable and the other of which is provided below said turntable,and a yoke plate secured to said magnet, a part of said yoke plate being positioned on the lateral side of said magnetic substance.
Claim 13
Dependent Claim
73 words
A device for preventing vibration of a disc motor shaft as defined in claim 3 wherein said magnetic biasing means comprises a magnet secured to the lower surface of said turntable, another magnet provided below said turntable in such a manner that said magnets attract each other and a yoke plate secured to one of said magnets, a part of said yoke plate being positioned on the lateral side of said magnetic substance.
Claim 14
Dependent Claim
39 words
A device for preventing vibration of a disc motor shaft as defined in claim 1 wherein the magnetic force generated by said magnetic biasing means has an axial component and a radial component with respect to the motor shaft.
Claim 15
Dependent Claim
33 words
A device for preventing vibration of a disc motor as defined in claim 1 wherein the motor has at least one bearing and wherein the biasing means biases the shaft against the bearing.
Claim 16
Independent Claim
124 words
A device for preventing vibration of a disc motor shaft in a disc playback device comprising: a disc motor having a disc motor shaft; a turntable fixedly connected to said disc motor shaft for placing a disc thereon; and magnetic biasing means for generating a magnetic force biasing said disc motor shaft in a radial and an axial direction with respect to said disc motor shaft, wherein said magnetic biasing means comprises a magnetic substance and a magnet one of which is secured to the lower surface of said turntable and the other of which is provided below said turntable, and a yoke plate secured to said magnet, a part of said yoke plate being positioned on the lateral side of said magnetic substance.
Claim 17
Independent Claim
124 words
A device for preventing vibration of a disc motor shaft in a disc playback device comprising: a disc motor having a disc motor shaft; a turntable fixedly connected to said disc motor shaft for placing a disc thereon; and magnetic biasing means for generating a magnetic force biasing said disc motor shaft in a radial and an axial direction with respect to said disc motor shaft, wherein said magnetic biasing means comprises a magnetic substance and a magnet one of which is secured to the lower surface of said turntable and the other of which is provided below said turntable, and a yoke plate secured to said magnet, a part of said yoke plate being positioned on the lateral side of said magnetic substance.
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) | 1991-03-08 | 1991-09-07 | 1992-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-08 | 1995-09-07 | 1996-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-08 | 1999-09-07 | 2000-03-08 | $7700.00 | Window Closed / Lapsed |