| 摘要 |
A rotary punch device for making window cut-outs in envelopes and cardboard boxes, with a clamping device for clamping a metal foil having a cutting edge etched out of the foil material. Vacuum bores in the cylindrical surface of the rotary punch retain the material for treatment in position while the punched-out portion of the window is initially also retained by a vacuum and blown away by an air blast on completion of the punch operation. |
