Patent US2524636A successfully refreshed from Google Patents.
Patent US3664012A successfully refreshed from Google Patents.
US3664012A
Expired / Lapsed
US
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Method of making a commutator
Assignee: Robert Bosch GmbH
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Filing: 1970-06-26
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Granted: 1972-05-23
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Expires: 1990-06-26
Abstract
Abstract A pair of annular blanks, one consisting of copper and one consisting of another metal, are confined in a die. A stamp is introduced into the die and the material of the blanks is coldextruded through an annular gap defined between the stamp and the die, to form a commutator ring an inner annular zone of which consists of the other metal, whereas an outer annular zone consists at least at one axial endface of copper. The other metal may be aluminum and will be cold-welded or fused with the copper at the interface of the two metals.
Inventors
- 👤 Heinz Wilke
- 👤 Claus Bertram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:14
CPC Classifications
H; H01; H01R; H01R43/00; H01R43/06; H01R43/08; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49009; Y10T29/49011
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
107 words
In a method of making a commutator, the steps of making at least one blank of copper and at least one additional blank of another metal; subjecting said blanks jointly to cold pressing in a manner requisite to effect their deformation to a lamella-ring configuration with simultaneous flowing of the copper to an outer annular zone and of at least part of the other metal to an inner annular zone of said ring under concomitant cold-welding of said copper and other metal to one another at an interface thereof; affixing a hub of insulating material to the thus produced ring; and forming commutator segments from said ring.
Claim 2
Dependent Claim
107 words
In a method of making a commutator, the steps of making at least one blank of copper and at least one additional blank of another metal; subjecting said blanks jointly to cold pressing in a manner requisite to effect their deformation to a lamella-ring configuration with simultaneous flowing of the copper to an outer annular zone and of at least part of the other metal to an inner annular zone of said ring under concomitant cold-welding of said copper and other metal to one another at an interface thereof; affixing a hub of insulating material to the thus produced ring; and forming commutator segments from said ring.
Claim 3
Dependent Claim
74 words
In a method as defined in claim 1, both of said blanks being annular; and wherein the step of subjecting said blanks to cold-pressing comprises confining said blanks in a die, and inserting a cooperating stamp into said die to define therewith a narrow annular gap through which the material of said blanks is at least partly, forcibly extruded with concomitant strong stretching and cold-welding of the copper and other metal at their interface.
Claim 4
Dependent Claim
33 words
In a method as defined in claim 2, said blanks each having a conical endface; and wherein said endfaces abut when said blanks are in said die prior to insertion of said stamp.
Claim 5
Dependent Claim
40 words
In a method as defined in claim 2, said blanks having respective complementary endfaces each of which diverges conically in radially outward direction; and comprising the step of inserting said blanks into said die with said endfaces in mutual abutment.
Claim 6
Dependent Claim
51 words
In a method as defined in claim 2, said ram moving into said die in a predetermined direction; and wherein the material of the blank closer to said ram flows to said radially inner zone and the material of the blank farther from said ram flows to said radially outer zone.
Claim 7
Dependent Claim
42 words
In a method as defined in claim 2; and comprising the step of providing an outer circumferential surface of said ram with circumferentially distributed axially extending dovetail-shaped grooves, so as to obtain complementary configuration on the inner circumference of said lamella ring.
Claim 8
Dependent Claim
65 words
In a method as defined in claim 2, comprising extruding the material of the blank farther from said ram completely through said annular gap, and extruding the material of the blank closer to said ram only in part through said annular gap, whereby a shoulder is formed from the material of the blank closer to said ram at one axial side of said annular gap.
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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) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |