Sound damping drill for shot firing holes - has core of drilling rod surrounded by sound damping material

摘要

Sound damping drilling equipment for producing shot firing holes in mining and tunnel driving consists preferably of a hand held percussive and rotating drilling machine and a drilling tool. The drilling tool is inserted in a rod with one or more removable drilling crowns at its free end with cutting edges. The drilling rod (1-3) consists of a number of concentric layers with the core transmitting the energy of the drilling machine to the cutting edges. The layers (3) surrounding the core (1) are built up from a sound damping material. The section of the core (1) is either round or has a number of sides with rounded corners and the outer profile of the rod is circular. An outer layer is made from a wear resisting material and the percusive piston and the housing of the drilling machine are surrounded with a sound damping material.