| 摘要 |
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 cold-extruded 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. |
