DEVICE FOR SINKING HOLES OF NONCIRCULAR CROSS-SECTION Russian patent published in 1995 - IPC

FIELD: hole drilling. SUBSTANCE: device for sinking holes of noncircular cross-section has auger drill string having drilling tool made in form of body with main set of cutting tool as well as supporting members and pipeline column containing water supply line and ventilation line. Device also has drives for rotation and feed of drill string. Body of drilling tool has part protruding beyond the dimensions of cross-section of main set of drilling tool from the outer side of drill string. In front of the protruding part are installed additional means of hole widening and located in the rear is pipeline column. Additional means for hole widening may be made in form of circular jib having cutting chain, drive sprocket and bypass members. Drive sprocket is secured to shaft of main set of drilling tool and bypass members are installed on body protruding part. Additional means for hole widening may be also made in form of jet-shaping devices communicated with high-pressure water source by means of additional pipeline column. Ventilation line of pipeline column may be made in form of rigid sectional pipeline whose front part is attached to body protruding part, and the rear part, to drive of drill string. Pipeline may be made with telescopic section provided with hydraulic cylinders for extending pipes. EFFECT: higher efficiency. 4 cl, 6 dwg