Patent US4138251A successfully refreshed from Google Patents.
US4138251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical contact material
Assignee: Texas Instruments Inc
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Filing: 1977-05-31
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Granted: 1979-02-06
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Expires: 1997-05-31
Abstract
Abstract An electrical contact material comprising a homogeneous, pressed and sintered mixture of from 85 to 90 percent silver metal powder, from 7.5 to 14.3 percent cadmium oxide powder, and from 0.50 to 3.0 percent zinc oxide powder, by weight, and having a weight ratio of zinc oxide to cadmium oxide content in the range from 0.05 to 0.25, is shown to display remarkably improved arc erosion and welding properties.
Inventors
- 👤 Hans G. Hirsbrunner
- 👤 Stephen B. Goldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:15
CPC Classifications
H; H01; H01H; H01H1/00; H01H1/02; H01H1/021; H01H1/023; H01H1/0237; H01H1/02372; H01H1/02374
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
62 words
An electrical contact material comprising a homogeneous, pressed and sintered mixture of from 85 to 90 percent silver metal powder, from 7.5 to 14.3 percent cadmium oxide powder, and from 0.50 to 3.0 percent zinc oxide powder, by weight, wherein the weight ratio of the zinc oxide to cadmium oxide content of the material is in the range from 0.05 to 0.25.
Claim 2
Dependent Claim
62 words
An electrical contact material comprising a homogeneous, pressed and sintered mixture of from 85 to 90 percent silver metal powder, from 7.5 to 14.3 percent cadmium oxide powder, and from 0.50 to 3.0 percent zinc oxide powder, by weight, wherein the weight ratio of the zinc oxide to cadmium oxide content of the material is in the range from 0.05 to 0.25.
Claim 3
Dependent Claim
32 words
An electrical contact material as set forth in claim 1 comprising about 85 percent silver, from 12.00 to 14.35 percent cadmium oxide, and from 0.65 to 3.00 percent zinc oxide, by weight.
Claim 4
Dependent Claim
32 words
An electrical contact material as set forth in claim 1 comprising about 87.5 percent silver, from 10.50 to 11.50 percent cadmium oxide, and from 1.00 to 2.00 percent zinc oxide, by weight.
Claim 5
Dependent Claim
32 words
An electrical contact material as set forth in claim 1 comprising about 90 percent silver, from 8.00 to 9.25 percent cadmium oxide, and from 0.75 to 2.00 percent zinc oxide, by weight.
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) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |