Patent US3909931A successfully refreshed from Google Patents.
US3909931A
Expired / Lapsed
US
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Method for securing winding bars in slots of electric generators
Assignee: Kraftwerk Union AG
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Filing: 1974-05-23
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Granted: 1975-10-07
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Expires: 1994-05-23
Abstract
Abstract Means to secure winding bars in slots of electric machines. A spring is mounted under a wedge in the slot. The spring is in the form of a corrugated leaf spring corrugated in a direction so that the corrugations extend transversely of the longitudinal length of the leaf spring. The spring has a spring characteristic selected such that the spring, when installed in the slot, can be compressed at least 80% of its expanded state, and the spring pressure or biasing force is always higher than the total pulsating or changing bar pressure.
Inventors
- 👤 Dietrich Lambrecth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:57
CPC Classifications
H; H02; H02K; H02K3/00; H02K3/46; H02K3/48; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009; Y10T29/49826; Y10T29/49863
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
116 words
Method for securing a winding bar in a slot of an electric machine, said slot being adapted to receive a wedge comprising the steps of: inserting a corrugated spring in said slot on top of said bar, said spring extending in the longitudinal direction of the slot, inserting a pressure member on top of said spring, and applying tensioning force to said spring, solely by inserting a wedge into said slot in said longitudinal direction, said spring having a spring characteristic which is linear up to 70% of the maximum expanded state of the spring, said spring being compressed solely through the insertion of the slot closing wedge to at least 80% of its expanded state.
Claim 2
Dependent Claim
116 words
Method for securing a winding bar in a slot of an electric machine, said slot being adapted to receive a wedge comprising the steps of: inserting a corrugated spring in said slot on top of said bar, said spring extending in the longitudinal direction of the slot, inserting a pressure member on top of said spring, and applying tensioning force to said spring, solely by inserting a wedge into said slot in said longitudinal direction, said spring having a spring characteristic which is linear up to 70% of the maximum expanded state of the spring, said spring being compressed solely through the insertion of the slot closing wedge to at least 80% of its expanded state.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |