| 摘要 |
1,159,990. Making commutators; forging. NIPPON DENSO K. K. 28 Sept., 1966 [31 March, 1966], No. 43295/66. Headings B3A and B3H. A method of making commutators comprises placing a tubular blank in a die having a plurality of grooves corresponding to the number of spaces between the commutator segments and forming the blank by a punch having a plurality of teeth corresponding to the number of segments to form segments 5 interconnected by bridge pieces 6. A shaft fixing tube 9 is inserted in the bore of the workpiece and insulating material 8 is cast in between the tube 9 and the segments 5. When the material 8 has set, the bridge pieces 6 are machined away. Lugs 7 are formed in known manner prior to insertion of the tube 9. |
