US3943698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor for electronic wristwatch step motor
Assignee: Suwa Seikosha KK
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Filing: 1974-12-09
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Granted: 1976-03-16
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Expires: 1994-12-09
Abstract
Abstract A high performance rotor for an electronic wristwatch step motor and method of forming same is provided. A rotor pinion has a high performance permanent magnet rotor mounted thereto. The permanent magnet rotor includes a brittle permanent magnet core, and a reinforcing plate, the combination of the permanent magnet core and reinforcing plate allowing the high performance magnetic rotor to be interference fit upon the rotor pinion to effect an improved rotor construction.
Inventors
- 👤 Yoshikazu Ono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:06
CPC Classifications
G; G04; G04C; G04C13/00; G04C13/08; G04C13/10; G04C13/11
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
45 words
A rotor construction for an electronic wristwatch step motor comprising a rotor pinion and a high performance permanent magnet rotor mounted thereto, said permanent magnet rotor including a brittle permanent magnet core defining at least two diametrically opposite polarity poles and a nonmagnetizable reinforcing plate.
Claim 2
Dependent Claim
45 words
A rotor construction for an electronic wristwatch step motor comprising a rotor pinion and a high performance permanent magnet rotor mounted thereto, said permanent magnet rotor including a brittle permanent magnet core defining at least two diametrically opposite polarity poles and a nonmagnetizable reinforcing plate.
Claim 3
Dependent Claim
22 words
A rotor construction as claimed in claim 1 wherein said permanent magnet rotor includes a bush between same and said rotor pinion.
Claim 4
Dependent Claim
25 words
A rotor construction as claimed in claim 1 wherein said reinforcing plate is comprised of one of the group of stainless steel, brass and plastic.
Claim 5
Dependent Claim
18 words
A rotor construction as claimed in claim 1 wherein said brittle permanent magnet is formed of barium ferrite.
Claim 6
Dependent Claim
19 words
A rotor construction as claimed in claim 1 wherein said brittle permanent magnet core is formed of samarium cobalt.
Claim 7
Dependent Claim
26 words
A rotor construction as claimed in claim 5 wherein said reinforcing plate is formed of one of the group that comprise stainless steel, plastic and brass.
Claim 8
Dependent Claim
27 words
A rotor construction as claimed in claim 1 wherein said permanent magnet rotor includes an additional non-magnetizable reinforcing plate, said reinforcing plates sandwiching said brittle permanent magnet.
Claim 9
Dependent Claim
22 words
A rotor construction as claimed in claim 7 wherein said permanent magnet rotor includes a bush between same and said rotor pinion.
Claim 10
Dependent Claim
25 words
A rotor construction as claimed in claim 7 wherein the reinforcing plates are comprised of one of the group of stainless steel, brass and plastic.
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) | 1979-03-16 | 1979-09-15 | 1980-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-16 | 1983-09-15 | 1984-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-16 | 1987-09-15 | 1988-03-16 | $7700.00 | Window Closed / Lapsed |