DRILLING TOOL FOR HOLE REAMING Russian patent published in 1995 - IPC

FIELD: mining. SUBSTANCE: drilling tool for hole reaming includes body with axial channel and means for connecting drill pipe set and upper and lower flanges secured to body square to its axis. Located between flanges mounted for turning round axis are blades with rock cutting bits. There are guiding members for blades in form of grooves and pins moving in grooves. Drilling tool has drive for turning blades to working and transportation positions in form of spring-loaded piston installed in axial channel of body for moving in axial direction and kinematically connected with blades having washout holes and nozzles for cleaning hole bottom. Blades are made in form of plates helically bent and located round body surface and secured to lower flange for turning round axis parallel to tool rotation axis. Groove of guiding members is made on upper flange, and pin of guiding member is fastened to blade upper part. Piston of blade drive is locked to prevent its rotation round body. EFFECT: higher efficiency. 12 cl, 8 dwg