MULTI-INSERT CUTTER BIT

摘要

A cutter bit is disclosed having a shank with a forward working portion and multiple inserts mounted on the forward working portion. One of the inserts is a lead insert facing and projecting foremost in the direction of rotation or travel of the bit. A clearance face is provided rearwardly of the lead insert so as to reduce the rubbing action that occurs between the cutter bit and the material formation to be removed. The lead insert can be a laminated insert with a metal shim between individual inserts. Another insert is located rearwardly of the lead insert in the clearance face of the bit and projects out of said clearance face to control the wear of the clearance face during the life of the cutter bit. A cutting edge may be formed on the wear controlling insert projecting from the clearance face.