Patent US4922145A successfully refreshed from Google Patents.
US4922145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stepper motor
Assignee: Eastman Kodak Co
•
Filing: 1988-11-17
•
Granted: 1990-05-01
•
Expires: 2008-11-17
Abstract
Abstract A stepper motor is disclosed which is comprised of planar elements. The motor comprises a disc-shaped rotor which includes a multipolar permanent magnet and generally planar stator coils mounted on opposite sides of the rotor. In order to provide a stepper motor which is efficient and is also relatively thin in the axial direction, generally planar pole plates having radially extending teeth are used to define the magnetic poles of the stator.
Inventors
- 👤 Boris A. Shtipelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:50
CPC Classifications
H; H02; H02K; H02K37/00; H02K37/10; H02K37/12; H02K37/125; H02K3/00; H02K3/04; H02K3/26
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
195 words
A stepper motor comprising: an disc-shaped rotor disposed in said motor for rotation about an axis, said rotor including a plurality of discrete permanent magnets evenly distributed around the periphery thereof; means for mounting said rotor for rotation, said mounting means including a cylindrical element having a central opening therein along said axis for receiving a driven element; a stator which includes a generally planar first coil mounted on one side to said rotor and a generally planar second coil mounted on an opposite side thereof; generally planar annular pole plates mounted on opposite sides of said rotor, a first pole plate being located between said first coil and said rotor, a second pole plate being located between said second coil and said rotor, each of said pole plates including a plurality of circumferentially spaced radially extending teeth; and a first housing which extends around said first coil and is in contact with said first pole plate and a second housing which extends around said second coil and is in contact with said second pole plate, said housings being formed of a magnetizable material, and said housings supporting said mounting means and rotor for rotation.
Claim 2
Dependent Claim
195 words
A stepper motor comprising: an disc-shaped rotor disposed in said motor for rotation about an axis, said rotor including a plurality of discrete permanent magnets evenly distributed around the periphery thereof; means for mounting said rotor for rotation, said mounting means including a cylindrical element having a central opening therein along said axis for receiving a driven element; a stator which includes a generally planar first coil mounted on one side to said rotor and a generally planar second coil mounted on an opposite side thereof; generally planar annular pole plates mounted on opposite sides of said rotor, a first pole plate being located between said first coil and said rotor, a second pole plate being located between said second coil and said rotor, each of said pole plates including a plurality of circumferentially spaced radially extending teeth; and a first housing which extends around said first coil and is in contact with said first pole plate and a second housing which extends around said second coil and is in contact with said second pole plate, said housings being formed of a magnetizable material, and said housings supporting said mounting means and rotor for rotation.
Claim 3
Dependent Claim
26 words
A stepper motor, as defined in claim 1, wherein the radially-extending teeth in each of said plates are formed by a serpentine cut in the plate.
Claim 4
Dependent Claim
29 words
A stepper motor, as defined in claim 1, wherein one of said pole plates is offset circumferentially relative to the other plate by one quarter of a pole pitch.
Claim 5
Dependent Claim
39 words
A stepper motor, as defined in claim 1, wherein each of said pole plates has a number of radial teeth therein, and the number of teeth in each plate is equal to the number of magnets in said rotor.
Claim 6
Dependent Claim
14 words
A stepper motor, as defined in claim 1, wherein said coils are photofabricated coils.
Claim 7
Dependent Claim
16 words
A stepper motor, as defined in claim 1, wherein each of said coils has helical windings.
References Cited (Backward Citations)
US3459982A
Cited
US4207483A
Cited
US4340833A
Cited
US4501981A
Cited
US4517478A
Cited
US4639084A
Cited
US4672247A
Cited
US4733115A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |