In the construction of impact crushers wherein the rocks are impelled against anvils or breaker elements by rotating impeller means, the impeller means in the form of shoes must be securely anchored on the rotative drive disc. It is customary to clamp the shoes between upper and lower plates for firm attachment, but it has been found that such shoes are apt to fracture from the compressive forces of the clamping means, particularly since heavy strains are already applied thereto by the impelling action they impart to the rock load.