H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
H01R39/00—Rotary current collectors, distributors or interrupters
H01R39/02—Details for dynamo electric machines
H01R39/08—Slip-rings
H01R39/085—Slip-rings the slip-rings being made of carbon