摘要 |
Apparatus is disclosed for forming plural rows of holes in a web of sheet material being advanced longitudinally along a unidirectional path of travel, the apparatus including a continuous wave laser and beam delivery apparatus. Beam delivering means delivers substantially the entire energy of the laser beam for predetermined periods of time to discrete web portions spaced apart across the web and includes means periodically interposed into and removed from the path of the laser beam for deflecting the beam periodically toward the web portions. |