APPARATUS AND CUTTING TOOL FOR CUTTING OPENINGS IN OPERATING PIPELINE Russian patent published in 2004 - IPC

FIELD: systems for transporting liquids and gases by means of pipeline transport, cutting-in branch pipes in operating pipeline. SUBSTANCE: apparatus includes arranged in housing hollow spindle where screw and nut screwed on said screw are arranged, cutting tool, mechanism for rotating spindle and axial motion mechanism both having worm pair, two gear wheels having different quantity of teeth and mounted on spindle with possibility of mutual engagement by means of block of two pinions. Said block is joined with mechanism for radial motion of it. First gear wheel is rigidly joined with worm gear of worm pair. Axial motion mechanism is joined with spindle; it includes hollow shaft arranged outside spindle and joined with it at least by means of one axially movable key joint, and sleeve rigidly joined with second gear wheel and with screw. Groove for movable key joint is provided in hollow shaft and in first gear wheel. Pinions of pinion block have the same number of teeth; teeth of one pinion are corrected. Cutting tool has central drill and annular drill. Central drill has recesses on its outer surface for placing gripping members made with possibility of radial motion. Said recesses are in the form of lengthwise grooves mutually connected through lateral opening. Gripping members are in the form of folded ends of springy rod arranged in said lateral opening. EFFECT: enlarged manufacturing possibilities, improved safety and operational reliability of apparatus. 4 cl, 1 dwg