US3681525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital rotation motor
Assignee: Victor Company of Japan Ltd
•
Filing: 1971-02-17
•
Granted: 1972-08-01
•
Expires: 1991-02-17
Abstract
Abstract A digital rotation or stepping motor contains oil of suitable viscosity which fills the space between a rotor and a stator. The motor is digitally and intermittently stepped in response to input pulses. The viscosity of the oil is selected to prevent a hunting which might otherwise be produced when the rotor stops its intermittent rotation.
Inventors
- 👤 Yoshiyo Wada
- 👤 Hisao Kinjo
- 👤 Seiichi Takashima
- 👤 Fumio Akuwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:05
CPC Classifications
H; H02; H02K; H02K37/00; H02K37/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
186 words
A magnetic recording and reproducing apparatus comprising a rotary magnetic medium, at least one magnetic head, and means comprising said head for recording concentric circular tracks of video signals on said medium, means comprising a digital rotation motor for successively moving said magnetic head in a stepping action, said digital rotation motor comprising a stator having at least one stator winding, a rotor disposed in opposition to said stator, there being a space between said rotor and said stator, means for applying an input pulse derived from said video signal to said winding for intermittently generating a rotary magnetic field, said rotor being digitally and intermittently rotated by said rotary magnetic field during a repetitive interval appearing in said video signal, and silicone oil filling said space between the rotor and the stator, said silicone oil having a viscosity which provides resistance to the rotation of said rotor and prevents hunting at the time of stopping the intermittent rotation of said rotor so that the magnetic head records all video signals between said intervals and does not trace a noncircular track on the rotary magnetic medium.
Claim 2
Dependent Claim
186 words
A magnetic recording and reproducing apparatus comprising a rotary magnetic medium, at least one magnetic head, and means comprising said head for recording concentric circular tracks of video signals on said medium, means comprising a digital rotation motor for successively moving said magnetic head in a stepping action, said digital rotation motor comprising a stator having at least one stator winding, a rotor disposed in opposition to said stator, there being a space between said rotor and said stator, means for applying an input pulse derived from said video signal to said winding for intermittently generating a rotary magnetic field, said rotor being digitally and intermittently rotated by said rotary magnetic field during a repetitive interval appearing in said video signal, and silicone oil filling said space between the rotor and the stator, said silicone oil having a viscosity which provides resistance to the rotation of said rotor and prevents hunting at the time of stopping the intermittent rotation of said rotor so that the magnetic head records all video signals between said intervals and does not trace a noncircular track on the rotary magnetic medium.
Claim 3
Dependent Claim
44 words
The apparatus of claim 1, wherein said rotor is of a shape having teeth on a cylindrical surface of the rotor body and has a construction for causing the viscous resistance of said oil to act on said teeth during rotation of said rotor.
Claim 4
Dependent Claim
15 words
The apparatus of claim 1, wherein the viscosity of said oil is approximately 10,000 centi-stokes.
Claim 5
Dependent Claim
44 words
The apparatus of claim 1, wherein said motor comprises a housing having a rotary shaft journaled therein, said motor further comprising oil sealing packings for preventing a leaking of said oil, said packings being provided over the journal bearings which journal said rotary shaft.
Claim 6
Dependent Claim
101 words
The apparatus of claim 1 which further comprises means including a rotary viscosity loading part containing said oil, fan means in said part containing said oil, loading rotary shaft means receiving viscous resistance from the oil contained in said loading part, and an electromagnetic clutch means for connecting the rotary shaft of said rotor and said loading rotary shaft, and means whereby said electromagnetic clutch detaches said rotary shaft from said loading rotary shaft at the starting time of rotation of said rotor and connects said rotary shaft and said loading rotary shaft after the starting of rotation of said rotor.
References Cited (Backward Citations)
US2823324A
Cited
US3054304A
Cited
US3286109A
Cited
US3469123A
Cited
US3389277A
Cited
US3469124A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |