| 摘要 |
A machine for boring a hole in a plate workpiece comprises a support, a lower clamp arm carried on this support and having an upper clamp surface adapted to support the workpiece, an upper clamp arm carried on the support and having a vertically displaceable lower clamp surface adapted to press the workpiece down against the upper clamp surface, a lower drill arm pivotal about a horizontal axis on the support and having an outer end provided with an upwardly directed boring tool, and an upper drill arm pivotal about a horizontal axis on the support and having an outer end provided with a downwardly directed boring tool. Respective motors in the support for the machine pivot the arms and rotate the tools. |
