Rock drill with helical dust conveying groove

摘要

A rock drill, especially for rotary blow machines and drifters or stoppers with drilling cutting edges and at least one drilling dust conveying groove which in axial direction is confined by a web which extends around the drill axis and one lateral surface of which forms a drilling dust supporting surface which merges with the bottom of the drilling dust conveying groove. The bottom of the drilling dust conveying groove extends from the drilling dust supporting surface at an acute angle with regard to the drill axis rectilinearly up to the back surface of the web. The ratio of the width of the drilling dust conveying groove, measured in axial direction of said drill, to the width of the back of the web is greater than 5:1.