Self-retaining sleeve and bit

摘要

In a mining machine in which pick bits or point attack bits are held in a chain or wheel which moves next to coal or rock, a replaceable tool which is formed with a rear extension that is essentially cylindrical, that extension being split in circumferentially spaced slots so that portions will move resiliently in a radial direction. Outer radial projections interlock with annular surfaces or shoulders of a holding block to retain the tool in an operating position. The tool may be driven in or out of position without the need of clips or retaining rings. They may then rotate in the holding block to equalize wear on the tip.