Endoscopic cutting instruments having improved cutting efficiency and reduced manufacturing costs

摘要

The present invention is directed to improving the cutting efficiency and reducing the manufacturing costs associated with endoscopic cutting instruments by eliminating the distal bearing surfaces or providing means for making the contact at the distal bearing intermittent so that surfaces do no undergo high localized heat and galling. In one embodiment, this goal is achieved by modifying or removing the axial constraints on the inner sliding member that are characteristic of conventional endoscopic shavers. In another embodiment, the improved cutting efficiency and reduced manufacturing cost is achieved by eliminating a closed end characteristic of conventional endoscopic shavers (e.g., removing the closed end of either the inner sliding member or the outer sliding member to thereby eliminate the associated bearing surface formed therebetween).