US3793073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical steel sheets and strips having excellent punching and welding characteristics for the use of a laminated iron core
Assignee: Nippon Steel Corp
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Filing: 1971-09-15
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Granted: 1974-02-19
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Expires: 1991-09-15
Abstract
Abstract Electrical steel sheets and strips having excellent punching and welding characteristics for production of a laminated iron core, which comprises an organic type coating film applied on the surface of an electrical steel sheet and strip substrate having a surface roughness larger than 20 Hr.m.s. Mu inch.
Inventors
- 👤 M Kitayama
- 👤 M Nakamura
- 👤 K Matsui
- 👤 H Okada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:55
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/04; C; C21; C21D; C21D8/00; C21D8/12; C21D8/1277; C21D8/1283; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/14766; H01F1/14775; H01F1/14783; H01F1/16; H01F1/18; H01F27/00; H01F27/24; H01F27/245; C21D9/00; C21D9/46; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
46 words
Electrical steel sheets and strips according to claim 1 which further comprises a coating film composed of one or more materials selected from the group consisting of phosphoric acid, and chromic acid and salts thereof applied as an under coat for the organic type coating film.
Claim 2
Dependent Claim
115 words
Electrical steel sheets and strips having excellent punching and welding characteristics for the production of a laminated iron core which comprise an electrical steel sheet or strip substrate having a surface rougher than 20 Hr.m.s. Mu inch and having a coating film thereon composed of a mixture of one or more materials selected from the group consisting of phosphoric acid type and chromic acid and salts thereof and an organic resin selected from the group consisting of calcium lignin sulfonate, polyvinyl alcohol, anhydrous maleic acid resin, aminoacid resin, phenol resin, acrylic acid resin or its copolymers, vinyl acetate or its copolymers, alkyd resins, vinyl chloride or its copolymers, polyvinyl acetal, epoxy resins, and mixtures thereof.
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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |