Carbon brushes for universal motor, have two electrically conductive active parts each, passive parts on outer sides in peripheral direction, and insulating films between active and passive parts

摘要

Each brush (9) has two electrically conductive active parts (11,13) and a passive part (19,21) on both outer sides of the active parts in the peripheral direction, with an insulating film (25,27) between the active and passive parts. The active and passive parts each consist of a material with the same abrasion characteristics.