摘要 |
The commutating poles of vehicular-type d-c motors, for example for trolley buses or trolley cars, are made by winding, on edge, a copper strip, permitting the wound copper strip to resiliently, spring-like expand so that the individual spiral loops thereof will be slightly spaced from each other, and then exposing the copper strip in a fluidized bed to an insulating powder, for example polyethylene or polyurethane, which is subsequently cured in a hardening or sintering process. |