BLADBERANDE RAM TILL MASKINER FOR SAGNING AV MARMOR, GRANIT OCH HARD STEN

摘要

A rotary/percussive drill assembly consists of a drill rod 1 and a hollow core drill body 2. The rod 1 has a frusto conical taper 11 on which is frictionally engaged a complementary tapered aperture 13 of the drill body 2 so that a skirt 13 of the drill body extends towards a chisel-bit end cutting part 3 of the drill rod. The end of the skirt 13 adjacent the chisel bit 3 has an array of cutting parts 15. Extending longitudinally through the drill rod is a passage 7 having an inlet port 8 and an outlet port 10 by which flushing fluid such as air under pressure is directed into the region of cutting to facilitate the removal of detritus and permit relatively high drilling rates with increased life for the cutting parts.