Patent US4677264A successfully refreshed from Google Patents.
US4677264A
Expired / Lapsed
US
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Contact material for vacuum circuit breaker
Assignee: Mitsubishi Electric Corp
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Filing: 1985-12-05
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Granted: 1987-06-30
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Expires: 2005-12-05
Abstract
Abstract The present invention provides a contact material for a vacuum circuit breaker containing therein copper (Cu) and chromium (Cr) with further addition of at least one kind of boride selected from borides of chromium (Cr), molybdenum (Mo) and tungsten (W). Such contact material possesses remarkable advantages of having large current breaking capability and high voltage withstand capability.
Inventors
- 👤 Mitsuhiro Okumura
- 👤 Eizo Naya
- 👤 Mitsuhiro Harima
- 👤 Shoji Murakami
- 👤 Seiichi Miyamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:29
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/02; H01H1/0203; H01H1/0206
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
82 words
A contact material for a vacuum circuit breaker comprising: copper, chromium and at least one kind of boride selected from the group consisting of (i) chromium boride, wherein said chromium boride is present in a range of from 0.2 to 9.3% by weight, (ii) molybdenum boride, wherein said molybdenum boride is present in a range of from 0.2 to 10% by weight, and (iii) tungsten boride, wherein said tungsten boride is present in a range of from 0.2 to 10% by weight.
Claim 2
Dependent Claim
82 words
A contact material for a vacuum circuit breaker comprising: copper, chromium and at least one kind of boride selected from the group consisting of (i) chromium boride, wherein said chromium boride is present in a range of from 0.2 to 9.3% by weight, (ii) molybdenum boride, wherein said molybdenum boride is present in a range of from 0.2 to 10% by weight, and (iii) tungsten boride, wherein said tungsten boride is present in a range of from 0.2 to 10% by weight.
Claim 3
Dependent Claim
21 words
A contact material for a vacuum circuit breaker according to claim 1, characterized in that said boride is boride of chromium.
Claim 4
Dependent Claim
30 words
A contact material for a vacuum circuit breaker according to claim 2, characterized in that the total content of chromium and boride of chromium is 80% by weight or less.
Claim 5
Dependent Claim
29 words
A contact material for a vacuum circuit breaker according to claim 2, characterized in that the chromium content is in a range of from 13.5 to 37% by weight.
Claim 6
Dependent Claim
22 words
A contact material for a vacuum circuit breaker according to claim 2, characterized in that boride of chromium is CrB 2 .
Claim 7
Dependent Claim
21 words
A contact material for a vacuum circuit breaker according to claim 1, characterized in that said boride is boride of molybdenum.
Claim 8
Dependent Claim
39 words
A contact material for a vacuum circuit breaker according to claim 6, characterized in that it contains copper, and, as other components, 12 to 38% by weight of chromium and 0.2 to 10% by weight of boride of molybdenum.
Claim 9
Dependent Claim
30 words
A contact material for a vacuum circuit breaker according to claim 6, characterized in that said boride of molybdenum is at least one selected from MoB and MoB 2 .
Claim 10
Dependent Claim
59 words
A contact material for a vacuum circuit breaker according to claim 6, characterized in that it contains 10% by weight or less of at least one kind of substance selected from low melting point metals such as bismuth, tellurium, antimony, tallium, lead, selenium, cerium, and calcium; alloys of these low melting point metals; intermetallic compounds thereof; and oxides thereof.
Claim 11
Dependent Claim
21 words
A contact material for a vacuum circuit breaker according to claim 1, characterized in that said boride is boride of tungsten.
Claim 12
Dependent Claim
30 words
A contact material for a vacuum circuit breaker according to claim 10, characterized in that the total content of chromium and boride of tungsten is 80% by weight or less.
Claim 13
Dependent Claim
29 words
A contact material for a vacuum circuit breaker according to claim 10, characterized in that the chromium content is in a range of from 10 to 40% by weight.
Claim 14
Dependent Claim
33 words
A contact material for a vacuum circuit breaker according to claim 10, characterized in that said boride of tungsten is at least one kind selected from WB and W 2 B 5 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |