Drilling tool incorporating suction jet - creates pressure difference accelerating flow of debris-laden mud, keeping tool clean, increasing drilling speed and reducing wear

摘要

Drilling tool incorporates a body rotated by a tool holder and having a cavity to receive a fluid under pressure through the tool holder. The body carriers a number of rotating parts with elements for attacking the ground on a working face, a means of irrigation able to deliver fluid jets directed towards the working face and a means of aspirating the fluid after it has irrigated the rotating parts. The means of irrigation comprises at least one calibrated orifice in the body of the tool communicating with the cavity and opening into a first space between two adjacent rotating parts. The means of suction comprises at least one second calibrated orifice situated above a second space between two adjacent rotating parts. The tool incorporates also at least one irrigation nozzle situated in the first space and presenting near its base two openings able to produce fluid jets respectively directed towards the two rotating parts between which the first space is defined. The appts. is an improvement on that described in the parent patent no. The ascending jet includes a depression in the annular space between the upper connection of the tool and the hole being drilled.