US4349384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the manufacture of segments for commutators
Assignee: SGL Carbon SE
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Filing: 1980-06-27
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Granted: 1982-09-14
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Expires: 2000-06-27
Abstract
Abstract A segment of a commutator made by (a) placing a first layer of copper powder and on top thereof a second layer of a mixture of carbon powder and a binder into a die with a cavity shaped like the segment, (b) densifying the powder layers to produce a blank having the form of the segment, and (c) sintering the blank at an elevated temperature to cause the powder particles to cohere and the layers to firmly join together.
Inventors
- 👤 Hans Weinert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:56
CPC Classifications
B; B22; B22F; B22F7/00; B22F7/06; H; H01; H01R; H01R43/00; H01R43/06; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009; Y10T29/49011; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12049; Y10T428/12056
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
Method for the manufacture of segments having a base part of copper and an upper layer of carbon joined to the base part, for a commutator, which comprises: (a) placing a first layer of copper powder and on top thereof a second layer of a mixture consisting entirely of carbon powder and a pyrolyzable, carbonaceous binder into a die with a cavity shaped like the segment, (b) densifying the powder layers to produce a blank having the form of the segment, (c) sintering the blank at an elevated temperature to cause the powder particles to cohere and the layers to firmly join together, and (d) providing the base part with recesses for receiving insulating material.
Claim 2
Dependent Claim
115 words
Method for the manufacture of segments having a base part of copper and an upper layer of carbon joined to the base part, for a commutator, which comprises: (a) placing a first layer of copper powder and on top thereof a second layer of a mixture consisting entirely of carbon powder and a pyrolyzable, carbonaceous binder into a die with a cavity shaped like the segment, (b) densifying the powder layers to produce a blank having the form of the segment, (c) sintering the blank at an elevated temperature to cause the powder particles to cohere and the layers to firmly join together, and (d) providing the base part with recesses for receiving insulating material.
Claim 3
Dependent Claim
29 words
Method according to claim 1, wherein another layer of a mixture of copper powder and carbon powder is arranged between said copper powder layer and said carbon powder layer.
Claim 4
Dependent Claim
22 words
Method according to claim 1, wherein the powder layers are densified by the simultaneous action thereon of superatmospheric pressure and elevated temperature.
Claim 5
Dependent Claim
22 words
Method according to claim 2, wherein the powder layers are densified by the simultaneous action thereon of superatmopsheric pressure and elevated temperature.
Claim 6
Dependent Claim
24 words
Method according to claim 1, wherein the thickness of said upper layer of carbon is less than 30% of the height of the segment.
Claim 7
Dependent Claim
24 words
Method according to claim 2, wherein the thickness of said upper layer of carbon is less than 30% of the height of the segment.
Claim 8
Dependent Claim
13 words
Method according to claim 5, wherein the segment has a trapezoidal cross section.
Claim 9
Dependent Claim
13 words
Method according to claim 6, wherein the segment has a trapezoidal cross section.
Claim 10
Dependent Claim
29 words
Segments having a base part of copper and an upper layer of carbon joined to the base part, for a commutator produced according to the method of claim 1.
Claim 11
Dependent Claim
29 words
Segments having a base part of copper and an upper layer of carbon joined to the base part, for a commutator produced according to the method of claim 2.
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) | 1985-09-13 | 1986-03-15 | 1986-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-13 | 1990-03-15 | 1990-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-13 | 1994-03-15 | 1994-09-14 | $7700.00 | Window Closed / Lapsed |