Abstract: A disc-shaped rotary cutter for continuous excavation of hard mineral rock layers according to the invention includes a supporting element having a plurality of end faces and a plurality of cutting elements formed on a circumference of the supporting element and the plurality of end faces. According to the invention, the rotary cutter provides a cylindrical compressive strength of equal to or greater than 20 MPa.

Abstract: A digging wheel assembly includes a supporting wheel having a peripheral zone and a plurality of receiving elements affixed to the supporting wheel in the peripheral zone in a spaced, circumferential distribution. Each receiving element has a receiving pocket and a receiving slot. Digging tool components are disposed along the peripheral zone of the supporting wheel in a circumferential distribution. Each digging tool component is disposed between two circumferentially adjoining receiving elements; one being a leading receiving element and one being a trailing receiving element as viewed in the rotary working direction of the assembly. Each digging tool component has a leading part extending from a front end of the digging tool component in the rotary working direction and being accommodated in the receiving pocket of the leading receiving element.