Improvements in and relating to Rock Drills.

Реферат: 5097. McCulloch, J. March 8. Rock drills, percussive, valves and valve gear for. Relates to improvement on the valve arrangements described in Specification No. 15,403, A.D. 1898. The motive fluid is delivered at the end e instead of on the top, and the pressure acting in the recess in the end of the cylindrical valve keeps it pressed against the adjustable conical pivot f. The valve has a central longitudinal inlet port a<1>, and an exhaust port on either side leading to the exhaust passage j<1>. It is oscillated by vanes b, preferably two in number, working in chambers b<1>, b<2>, which are cross-connected by passages c in the valve and are connected to pressure and exhaust through ports d covered and uncovered by the main piston. Buffer blocks b<3> with springs b<4> lie on either side of one of the vanes b.