| 摘要 |
Small and regularly shaped holes are formed in a workpiece by the punch of a punch press while large and irregularly shaped holes are formed by a plasma-arc torch attached to the punch press. Fumes and molten metal resulting from operation of the torch are directed into an upright duct which underlies the workpiece, the upper end of the duct engaging the workpiece to prevent deformation thereof. When the punch is operating, the upper end of the duct is retracted downwardly to provide clearance for movable clamps which grip and position the workpiece. |
