DOWNHOLE DEVICE FOR FORMATION OF DIRECTED FRACTURES Russian patent published in 2001 - IPC

FIELD: mining. SUBSTANCE: device may be used for formation of fractures in boreholes for separation of blocks from rock mass, cutting of valuable crystalline raw materials and building stone. Downhole device includes tube, sealing bushing fitted on tube end, unit for rotation of tube relative to sealing bushing, rod accommodated in tube for longitudinal motion, vibrator attached to rod end, pipe union for forcing working fluid into tube. Tube end on side of sealing bushing has conical thread, and tube other end has fitted-on sleeve with central hole in bottom. Rod is passed through tube and central hole in sleeve bottom and has circular stop abut sleeve bottom from inside and circular protrusion on end free of vibrator. Helical groove is made over entire length of circular protrusion side surface. Sealing bushing is made of elastoplastic material. Pipe union for forcing of working fluid is installed on tube between circular stop and rod circular protrusion. EFFECT: higher reliability of device due to its simplified design. 1 dwg