SAND, GRAVEL, AND CRUSHED STONE ONTHEJOB .
GYRATORY CRUSHER A gyratory crusher breaks rock by squeezing the rock between an eccentrically gyrating spindle, which is cov ered by a wear resistant mant le, and the encl osing concav e hopper . As runofmine rock enters the top of the gyratory crusher, it becomes wedged and squeezed between the mantle and hopper.