Device for grinding a thread into stone material or the like

摘要

The invention relates to a device for grinding a thread into stone material, in particular in a stair slab. A grinding tool is fastened to a rotatable threaded bush which is screwed into a fixed threaded ring, the thread pitch of the bush being equal to the pitch of the thread to be ground into the step slab. By means of an eccentric lever, the grinding tool is pressed transversely against the wall of a previously drilled hole and the threaded bush is rotated, as a result of which the grinding tool performs a circular movement and an axial movement and the thread is ground into the hole.