MANUFACTURE OF THICK BOARD FLAT TYPE COMMUTATOR

PURPOSE:To increase the size of a sliding surface in thickness to obtain a commutator having high durability by making extrusion work for a thick board material having malleability to form a metal member. CONSTITUTION:First of all, a disc-like material requires cold extrusion work to form a metal member 1. The metal member 1 makes a disc section 10 of a thick board having the surface as a sliding surface and projections 20 and 30 having small and large diameters on the rear thereof. After that, the end of the projection 20 having a large diameter is pushed to form an enlargement section 20a, and the metal member 1 and a resin section are formed together as a unit. At that time, the projections 20 and 30 are thrown into the resin section 50, and binding force is increased. A hole 55 into which the shaft of a rotor is inserted is provided in the center of the resin section 50. After the formation of resin, seven slits 60 are cut to provide 7 segments 15, and a wire inserting slot 70 is provided in the central part of the peripheral surface of the segment 15 to complete a commutator. According to the constitution, a flat type commutator can be easily formed of the thick board.