Rotary pneumatic drill for mines etc. - rotor cams form spaces divided by seals into active and idle chambers

摘要

Pneumatic drill for shotholes, blasting, tunnels, drifting etc comprises rotary tool with striker, housing bored for air distributor and striker piston acting on the tool shank, together with front head for the shank and a steel holder with converter for rotating the tool. Conversion is by compressed air motor fitted with a cylinder, rotor and cam whose ramps ride along the cylinder and connect with the cylinder interior so as to form spaces. These spaces are divided into active and idle chambers by seals carried in the grooves on the cylinder so as to bear against the rotor cam. There is one pair less of these twin chambers than there are pairs of spaces formed by the cam ramps. Each active space connects to an air feed channel and each idle chamber to an atmosphere bleed with the result that the rotor and coupled tool steel shank are set rotating by the air supplied to the active chambers.