An anvil assembly for use with a surgical stapler is provided. The anvil assembly includes a cut ring assembly having a body and a cover. The cover has a first layer of material having a first hardness to allow penetration by a knife of a surgical stapler and at least one additional layer of material...http://www.google.de/patents/US20070181632?utm_source=gb-gplus-sharePatent US20070181632 - Anvil assembly with improved cut ring
