Abstract: The paper has researched the generating principles of “skipping” and “get out” defects in the process of even cutting leather. It is put forward that the generating reasons of “skipping” and “get out” are lower cutting force and larger extruding action from spiral blade. Then, proceed to fie raising front angle and reducing spiral guiding angle of the blade, so that the structural edge angle and the cutting edge angle of the blade are reduced, to reinforce cutting action of the blade, with the result that solving problems of “skipping” and “get out”. Also, it gives a selecting range of optimum data for front angle and spiral guiding angle of the blade, after the principles are demonstrated theoretically.

Key words: 刀具, 皮革, 切削, 跳动