We manufacture and supply rock & soil drilling accessories and spare parts, e.g. drilling adapters, driver sub/drive chuck, top sub/back adapters, bit retainer rings/stop ring, special wrenches, piston, piston case/external cylinder etc.
A down-the-hole percussive hammer includes a cylindrical casing adapted to carry a drill bit, and a piston mounted in the casing for reciprocal movement to repeatedly strike the drill bit. A top sub is mounted at a rear portion of the casing, the top sub including a front face facing the piston. A feed tube is mounted to the top sub and extends forwardly along a center axis of the casing and defines an air-conducting passage. The piston includes an axial through-hole which slidably receives the feed tube. The front face and the feed tube together define a recess opening toward the piston. A removable volume-changer is insertable into the recess to vary a volume of a space in which the piston slides, and thus control a pressure at which the piston operates.
Zuanshan Mining Machinery Co., Ltd will always focus on the strategic conception of "Survival by quality & service, Development by credit", to provide users with the whole premium quality drilling solutions.
