Patent US3821024A successfully refreshed from Google Patents.
US3821024A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current transfer brusher
Assignee: JOHN THOMPSON (PIPEWORK AND ORDNANCE DIVISION) Ltd
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Filing: 1973-02-23
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Granted: 1974-06-28
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Expires: 1993-02-23
Abstract
Abstract A current transfer brush is composed of refractory fibres, preferably high strength carbon fibres, with a metallic coating on the fibres which is composed of an under layer of a first metal and an over layer of a second metal. The over layer is of a highly conductive material such as silver and the under layer which improves coherence and adhesion of the over layer and thereby produces a very low brush voltage drop, is of a material such as nickel.
Inventors
- 👤 G Wilkin
- 👤 Nab I Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:18
CPC Classifications
H; H01; H01R; H01R39/00; H01R39/02; H01R39/18; H01R39/24; H01B; H01B1/00; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/929; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12625; Y10T428/12701; Y10T428/12771; Y10T428/12778; Y10T428/12861; Y10T428/12896; Y10T428/12944; Y10T428/12986; Y10T428/29; Y10T428/2913; Y10T428/2916; Y10T428/2918; Y10T428/2933; Y10T428/2938
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
36 words
A current transfer brush as claimed in claim 1 in which the under layer is composed of a metal selected from the group comprising titanium, vanadium, tantalum, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, and boron.
Claim 2
Dependent Claim
17 words
A current transfer brush as claimed in claim 2 in which the over layer is of silver.
Claim 3
Dependent Claim
28 words
A current transfer brush as claimed in claim 1 in which the over layer is selected from the group comprising silver, gold, copper, aluminium, cadmium, zinc, and lead.
Claim 4
Dependent Claim
44 words
A current transfer brush comprising refractory fibres each of which is coated with an under layer of a metal selected from chromium, iron, cobalt, and nickel and an over layer of a metal selected from silver, gold, copper, and alloys of silver and copper.
Claim 5
Dependent Claim
16 words
A current transfer brush as claimed in claim 5 in which the fibres are carbon fibres.
Claim 6
Dependent Claim
24 words
A current transfer brush as claimed in claim 6 in which the under layer is of nickel and the over layer is of silver.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |