US4430124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum type breaker contact material of copper infiltrated tungsten
Assignee: Mitsubishi Electric Corp
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Filing: 1982-03-22
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Granted: 1984-02-07
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Expires: 2002-03-22
Abstract
Abstract This invention provides a vacuum type breaker contact material prepared by infiltrating copper into a sintered tungsten matrix, wherein elementary particle size and the growth of the particle size by heat processing are controlled in such a manner that the ratio of the largest value/the smallest value of tungsten particle size becomes not more than 10, and that the maximum value of tungsten particle size is not larger than 2 μm and the minimum value of tungsten particle size is not smaller than 0.3 μm.
Inventors
- 👤 Masaru Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:27
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/02; H01H1/0203; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/1216; Y10T428/12174
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
51 words
A vacuum type breaker contact material prepared by infiltrating copper into a sintered tungsten matrix, wherein the maximum value of tungsten particle size within the finished material is not larger than 2 μm and the minimum value of tungsten particle size within the finished material is not smaller than 0.5 μm.
Claim 2
Dependent Claim
51 words
A vacuum type breaker contact material prepared by infiltrating copper into a sintered tungsten matrix, wherein the maximum value of tungsten particle size within the finished material is not larger than 2 μm and the minimum value of tungsten particle size within the finished material is not smaller than 0.5 μm.
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) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |