| 摘要 |
A hole is formed in a workpiece by advancing together a pair of cutter-carrying boring bars from opposite sides of the workpiece. Rotation of the boring bars is synchronized to maintain the cutter-carrying portion of each boring bar in alignment with an axial recess in the boring bar. As the boring bars converge, the cutter-carrying portions enter the respective recesses whereby the cutter bits pass one another axially to complete the hole. The axes of rotation can be aligned to form a circular hole, or mutually spaced to form an oval hole. |
