| 摘要 |
<p>A moving web (11) is either perforated or cut using a knife cylinder (15) having at least one blade (16) and an anvil cylinder (18) having at least one raised anvil surface (19), and preferably a plurality (e.g. about 22) of alternating substantially uniform raised surfaces (21) and depressions (72). The knife cylinder (15) is substantially continuously rotated, and the anvil cylinder (18) is substantially continuously rotated by a servo motor (20), which also positively controls the position of the anvil cylinder (18) with respect to the knife cylinder (15) to selectively either effect perforation or cutting of the web, or no perforation or cutting. Position controlling is typically accomplished by substantially constantly and instantly indexing the anvil cylinder (18) in a reverse direction. Sensors may be utilized for sensing the locations of the knife and anvil cylinders and providing that information to a computer controller to facilitate indexing.</p> |
