| 摘要 |
The method involves placing a raw blank (1) between two anvils (6,7) and locking the latter to form two hollow imprints on the lateral faces (16,17) of the end of the blank. The anvils are then spaced and the product advanced for a predetermined distance in a longitudinal direction at least equal to the length of one imprint. The anvils are then locked again and the cycle repeated along the whole length of the product. During the formation of the imprinted sections , the returned part of the metal is formed into a channel at the level of the longitudinal edges of the principal faces of the blank to control the formation of folds on the faces. |
