Patent ID: 7658343

Claim:
A mineral breaker including a pair of breaker drum assemblies rotatably housed in a housing with their axes parallel, each drum assembly including a cylindrical shaft with circumferentially extending groups of teeth, the groups being spaced axially along the drum assembly to define a circumferentially extending channel between adjacent circumferential groups of teeth, the drum assemblies being arranged such that each circumferential group of teeth on one drum assembly is located to enter a circumferentially extending channel between a pair of neighboring circumferential groups of teeth on the other drum assembly, the cross-sectional shape and size of each tooth and channel being complementary such that the sides and tip of a tooth when entering a channel are closely spaced from the sides and bottom of the channel, and an elongate breaker bar extending longitudinally in a direction parallel to the axes of the drum assemblies, the breaker bar being located with its longitudinal axis positioned inbetween and beneath the axes of rotation of the drum assemblies, the breaker bar including a plurality of breaker teeth spaced along its length, each breaker tooth of the breaker bar projecting upwardly into a channel defined between a pair of circumferential groups of teeth on one of the drum assemblies, each breaker tooth being of a size and shape complementary to the channel into which it projects so as to be closely spaced from the sides and bottom of the channel to thereby substantially fill the channel from its periphery to its bottom.