The two ends of an article to be processed which is in the form of a sheet are held by means of a fixed clamp and a movable clamp, the article being held by applying bias by means of a biasing cylinder to the movable clamp in a direction such as would separate it from the fixed clamp and hole-forming...http://www.google.fr/patents/US6090330?utm_source=gb-gplus-shareBrevet US6090330 - Laser processing method
