| 摘要 |
An erosion device comprising at least one head and means for imparting to the head movements of rotation around an axis and of translation along said axis is improved due to the fact that: (a) the head comprises knives each having several teeth; on each knife two adjacent teeth are spaced apart from each other and leading edges of the teeth and their virtual extensions form a practically continuous line, called line of attack; (b) the teeth being capable of digging grooves in a material to be eroded, the groove corresponding to each tooth having a portion in common with at least one groove corresponding to a tooth of an adjacent knife. |
