| 摘要 |
A metal ring having a greatest circumferential length 2 is held in the shape of a substantially true circle, and other metal rings 2 are arrayed in the order of increasing circumferential length toward the metal ring of the greatest circumferential length 2. At least three holder rods 8 are lowered into the metal rings 2 to hold the metal rings 2 in substantially coaxial alignment with each other. Presser rods 9 are pressed from outside of the metal rings 2 toward the centre of the metal rings 2, thereby deforming the metal rings 2 into a shape including curved portions projecting radially and having a reduced diameter. The deformed metal rings 2 are delivered successively in the array from terminal ends of the presser rods 9 into the metal ring of the greatest circumferential length 2. The deformed metal rings 2 that are released off the presser rods 9 restore their original shape within the metal ring of the greatest circumferential length 2, and are laminated to the metal ring of the greatest circumferential length 2. <IMAGE> |
