US3970451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical contact materials and methods of making the same
Assignee: Schneider Electric USA Inc
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Filing: 1974-11-25
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Granted: 1976-07-20
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Expires: 1994-11-25
Abstract
Abstract The contact materials comprise silver with additions of mercury or mercury and tellurium and silver-cadmium oxide compositions with additions of mercury and tellurium. The methods of making the materials include the steps of adding a silver-mercury alloy to molten silver and to a molten silver-tellurium powder mixture. The materials including cadmium oxide are produced by heating a mixture of powders of silver, a cadmium-tellurium compound, cadmium oxide, and mercuric oxide powders in a reducing atmosphere and then reoxidizing.
Inventors
- 👤 Terrence Ardern Davies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:25
CPC Classifications
C; C22; C22C; C22C5/00; C22C5/06; H; H01; H01B; H01B1/00; H01B1/02; H01H; H01H1/00; H01H1/02; H01H1/021; H01H1/023; H01H1/0237
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
33 words
An electrical contact material which consists of a mixture of silver and not more than 3.0 weight per cent of mercury and which includes not more than 3.0 weight per cent of tellurium.
Claim 2
Dependent Claim
33 words
An electrical contact material which consists of a mixture of silver and not more than 3.0 weight per cent of mercury and which includes not more than 3.0 weight per cent of tellurium.
Claim 3
Dependent Claim
23 words
An electrical contact material as claimed in claim 1 wherein the mercury concentration is in the range 0.001 to 0.5 weight per cent.
Claim 4
Dependent Claim
23 words
An electrical contact material as claimed in claim 1 wherein the tellurium concentration is in the range 0.001 to 0.25 weight per cent.
Claim 5
Dependent Claim
23 words
An electrical contact material as claimed in claim 2 wherein the tellurium concentration is in the range 0.001 to 0.25 weight per cent.
Claim 6
Dependent Claim
12 words
An electrical contact formed of the material as claimed in claim 3.
Claim 7
Independent Claim
98 words
A method of producing an electrical contact material including the steps of providing silver and tellurium powder; mixing the silver and tellurium powders together to provide a mixture containing not more than 3.0 weight per cent of tellurium; melting the silver-tellurium powder mixture under an inert atmosphere to provide a molten alloy; providing a silver-mercury master alloy; adding the master alloy to the molten silver-tellurium alloy under the inert atmosphere to provide a molten silver-tellurium-mercury alloy containing not more than 3.0 weight per cent of mercury and of tellurium; and casting the silver-tellurium-mercury alloy to form an ingot.
Claim 8
Independent Claim
98 words
A method of producing an electrical contact material including the steps of providing silver and tellurium powder; mixing the silver and tellurium powders together to provide a mixture containing not more than 3.0 weight per cent of tellurium; melting the silver-tellurium powder mixture under an inert atmosphere to provide a molten alloy; providing a silver-mercury master alloy; adding the master alloy to the molten silver-tellurium alloy under the inert atmosphere to provide a molten silver-tellurium-mercury alloy containing not more than 3.0 weight per cent of mercury and of tellurium; and casting the silver-tellurium-mercury alloy to form an ingot.
Claim 9
Dependent Claim
17 words
A method as claimed in claim 6 wherein the powder mixing is effected by dry tumble milling.
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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) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |