| 摘要 |
<p>A rotary punching apparatus for punching openings in a moving web workpiece the openings having a predetermined length along the longitudinal axis of the we b and having a pair of die assemblies located on opposite sides of the path of the web and a drive for rotating the assemblies, a leading die mounted on one assembly, and being moveable for generally radially so as to punch a die opening throu gh the web, a mating die recess punched in the other of the assemblies; and, a trailing die adjacent to the leading die, being located to punch the web at a point adjacent the punched die opening so as to punch a second die opening in the web, the firs t die opening and the trailing die opening together defining a continuous opening having a predetermined length along the web.</p> |
