MECHANISM FOR CUTTING OUT OPENINGS IN CASING TUBES Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: this is primarily used in horizontal drilling in developing productive beds. Device has body which accommodates unit for converting rotation from vertical direction to horizontal. Unit is in the form of taper gearing, cutting setup, bar, and milling cutter. Milling cutter is in the form of endless cutting chain which is mounted on bar for rotation around working shaft. Also provided is unit for extending endless chain out of body and it is made in the form of pulley connected with bar for its possible displacement from body axis over radius. Rope with springs is brought around pulley for its rotation. End of rope is fastened to one of springs. Other end of rope is connected with spring of chain return into body. This spring can interact with bottom hole. EFFECT: high efficiency. 2 cl, 4 dwg