PRESSURISED FLUID FLOW SYSTEM INCLUDING MULTIPLE WORKING CHAMBERS FOR A DOWN-THE-HOLE HAMMER DRILL AND NORMAL- AND REVERSE-CIRCULATION DOWN-THE-HOLE HAMMER DRILLS COMPRISING SAID SYSTEM

摘要

A pressurized fluid flow system for a down the hole drill hammer has a plurality of chambers that exert work, namely one or more auxiliary drive and lifting chambers besides two main chambers located at opposite ends of the piston, the auxiliary chambers each formed around respective waists on the piston and externally delimited by respective cylinders which are arranged longitudinally in series. Two or more internal chambers filled with the pressurized fluid are defined by recesses in the inner surfaces of the piston for supplying said fluid to the work chambers, controlled in a cooperative way by the piston and a control tube coaxially arranged within a central bore of the piston. One or more discharge chambers are formed in between the outer casing and the cylinders for emptying the work chambers through discharge ports in the cylinders. Reverse and normal circulation drill hammers are provided having this system.