METHOD AND APPARATUS FOR FORMING OPPOSING HOLES IN A SIDE WALL OF A TUBULAR WORKPIECE

摘要

A method of cutting opposing holes in a side wall (17) of a tubular workpiece (13) and removing the cut out slugs (46, 47), in which first and second axially aligned punches (18, 29) are applied to opposite side walls (17) of a pressurized workpiece (13). The second punch (29) has a larger width than the first punch (18), and reciprocates in a passageway (28) extending laterally from the workpiece (13). The punches (18, 29) are reciprocated so that the first punch (18) passes through both side walls (17), and first and second slugs (46, 47) are cut out. The end of the first punch (18) is advanced towards the end of the second punch (29) to capture the cut out slugs (46, 47) between the ends of the first and second punches (18, 29), and the punches (18, 29) are moved so that the ends of the punches (18, 29) and the slugs (46, 47) captured between them progress along the passageway (28) away from the workpiece (13). The ends of the punches (18, 29) are separated at a region of the passageway (28) spaced from the workpiece (13), and the released slugs (46, 47) are removed from the ends of the punches (18, 29).