US3818690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stepping motor for watch movement
Assignee: Timex Group USA Inc
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Filing: 1973-11-21
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Granted: 1974-06-25
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Expires: 1993-11-21
Abstract
Abstract A single phase reluctance stepping motor suitable for driving a time indicating gear train in a watch which incorporates a detent for holding the rotor of the stepping motor in a stable position and a timed pulse generator providing DC pulses of sufficient duration to advance the rotor from one stable position to the next.
Inventors
- 👤 G Schwarzschild
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:31
CPC Classifications
G; G04; G04C; G04C13/00; G04C13/08; G04C13/10; G04C13/11
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
156 words
In a horological device, the combination of: a reluctance-type stepping motor comprising; a. a single phase stator winding disposed on a core comprising laminations of temporarily magnetizable material and having oppositely disposed pole pieces defining circumferentially spaced teeth of uniform pitch thereon, b. a rotor of temporarily magnetizable material having uniformly spaced teeth of the same pitch as said stator teeth and forming an air gap therewith, c. detent means arranged to position said rotor in a stable position with the rotor teeth extending into the spaces between stator teeth so as to initiate unidirectional rotation when said winding is energized, a time indicating gear train driven by said rotor, and a timed pulse generator connected to supply DC pulses to said winding of sufficient duration to initiate rotation of said rotor and to cause the rotor to advance by one tooth pitch to the next stable position and to be arrested by said detent means.
Claim 2
Dependent Claim
156 words
In a horological device, the combination of: a reluctance-type stepping motor comprising; a. a single phase stator winding disposed on a core comprising laminations of temporarily magnetizable material and having oppositely disposed pole pieces defining circumferentially spaced teeth of uniform pitch thereon, b. a rotor of temporarily magnetizable material having uniformly spaced teeth of the same pitch as said stator teeth and forming an air gap therewith, c. detent means arranged to position said rotor in a stable position with the rotor teeth extending into the spaces between stator teeth so as to initiate unidirectional rotation when said winding is energized, a time indicating gear train driven by said rotor, and a timed pulse generator connected to supply DC pulses to said winding of sufficient duration to initiate rotation of said rotor and to cause the rotor to advance by one tooth pitch to the next stable position and to be arrested by said detent means.
Claim 3
Dependent Claim
15 words
The combination according to claim 1, wherein said rotor is comprised of soft iron laminations.
Claim 4
Dependent Claim
30 words
The combination according to claim 1, wherein said detent means comprises a permanent magnet disposed adjacent the rotor periphery and performing a detenting action with successive teeth of the rotor.
Claim 5
Dependent Claim
28 words
The combination according to claim 1, wherein said detent means comprises a permanent magnet disposed between the pole pieces and forms an air gap with successive rotor teeth.
References Cited (Backward Citations)
US3539845A
Cited
US3731125A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |