Mine or tunnel rock cutting head tool - has rotating roller chisel on protruding spindle in top side slit

摘要

As used in coal mining, or for driving tunnels, the cutting tool for a revolving cutter head has a shaft for insertion in an aperture in the head, with widened top as seat, and element for detachable fixture in position. There is a slit (7) in the side of the tool top (4) facing away from the shaft (3), for penetration by a spindle (10). This bears a twisting roller chisel (11) which has one part (12) sited inside the slit, while the other part (13) protrudes from the top of the tool, away from the shaft. It may be rotatably mounted on the spindle, or fixed on a rotating spindle; or both may rotate.