Three-Cone Rolling Cutter Bit
Definition - What does Three-Cone Rolling Cutter Bit mean?
Three-cone rolling cutter bits are boring heads that use a crushing action to break up the rock at the cutting face to advance the drill. Three cones mounted on the bit rotate individually as the drill string turns. The teeth on each cone grind away at the rock face creating cuttings (small pieces of rock) that are removed from the bore.
Trenchlesspedia explains Three-Cone Rolling Cutter Bit
There are different kinds of teeth on three-cone rolling cutter bits that create the grinding and crushing action on the cutting face. Milled teeth are formed as part of the bit itself.
Teeth are widely spaced for softer ground and closely spaced for hard rock. On the other hand, tungsten carbide inserts are pressed into the bit cones. They can also be formed with different sizes and shapes according to the ground conditions. Long chisel-shaped teeth are used for soft ground and short round teeth for hard ground.