US3818588A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical brushes
Assignee: National Research Development Corp UK
•
Filing: 1973-03-29
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Granted: 1974-06-25
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Expires: 1993-03-29
Abstract
Abstract An electrical brush is constructed by moulding an aligned array of metal coated carbon fibres into a block. The block may be several times the required length and width of a brush, in which case it is then cut into strips corresponding to the desired length of a brush. The coating is then removed for part only of the lengths of the brushes to expose the individual carbon fibres at one end but leaving them consolidated for connection to a conductor at the other end. The strips are finally cut up to form individual brushes.
Inventors
- 👤 J Bates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:46
CPC Classifications
H; H01; H01R; H01R39/00; H01R39/02; H01R39/18; H01R39/24; H01B; H01B1/00; H01R43/00; H01R43/12; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49119; Y10T29/49801
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
75 words
A method of manufacturing an electrical brush comprising the steps of forming a block of an aligned array of carbon fibres embedded in a matrix of conductive material and then removing the conductive material along part only of the Length of the block to expose the carbon fibres at one end but leaving the remaining parts of the fibres consolidated in the matrix of conductive material for enabling connection to be made to a conductor.
Claim 2
Independent Claim
75 words
A method of manufacturing an electrical brush comprising the steps of forming a block of an aligned array of carbon fibres embedded in a matrix of conductive material and then removing the conductive material along part only of the Length of the block to expose the carbon fibres at one end but leaving the remaining parts of the fibres consolidated in the matrix of conductive material for enabling connection to be made to a conductor.
Claim 3
Dependent Claim
47 words
The method as claimed in claim 1 in which the block has a length which is a plurality of times the desired length of an individual brush and is cut into individual lengths corresponding to the required length of a brush prior to removal of conductive material.
Claim 4
Dependent Claim
92 words
The method as claimed in claim 1 in which the block is formed in the shape of a plate of rectangular cross-section having a length and a width which are a plurality of times the desired length and width of an electrical brush and the block is first cut along its width into strips each having a length corresponding to the desired length of a brush and after the removal of the conductive material from one edge of each strip the strips are then cut along their lengths to provide individual brushes.
Claim 5
Dependent Claim
26 words
The method as claimed in claim 1 in which the thickness of the block of carbon fibres corresponds to the desired thickness of an electrical brush.
Claim 6
Dependent Claim
45 words
The method as claimed in claim 1 in which the carbon fibre block is formed by coating the carbon fibres with a suitable metal and then pressing the coated fibres together while heating them so that the coatings of the individual fibres are welded together.
Claim 7
Dependent Claim
18 words
The method as claimed in claim 5 in which the metal coating is applied by an electroplating process.
Claim 8
Dependent Claim
21 words
The method as claimed in claim 1 in which the conductive material is selected from the group comprising copper and tin.
Claim 9
Dependent Claim
39 words
The method as claimed in claim 1 in which the block is formed by wetting the carbon fibres with a suitable metal in liquid form, pressing the wetted carbon fibres together and then cooling them to solidify the metal.
Claim 10
Dependent Claim
40 words
The method as claimed in claim 1 in which a radius is formed at one end of each length of carbon block prior to removal of the conductive material from that end so as to improve contact with a commutator.
References Cited (Backward Citations)
US539454A
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US539453A
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US3382387A
Cited
US3550247A
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US3553820A
Cited
US3525006A
Cited
US3571901A
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US3668451A
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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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |