METHOD OF PRODUCING ROLLER DRILL BIT Russian patent published in 2013 - IPC E21B10/08 

FIELD: mining.

SUBSTANCE: proposed method comprises making locating and guide bores on leg ends after their finishing. Then basic locating bores are made on leg backs, roller cutters are secured art leg pins, lock pins are sealed, assembled sections are fitted on mating basic pins with axles, sections are turned by spring-loaded pushers fitted on posts of the appliance to contact with inverse cones of all cutters with inner surface of said appliance, i.e. ring gage. Then, thereafter, said ring gage with sections are fitted at electron beam welding chamber bottom. After door closing and sealing and exhaustion, scanner and ring gage base turn drive are used to lock the point of contact between sections and directions of three beams. On cutting on of the unit, ring gage with sections are lifted with the help of drive to upper chamber for sections to be welded together. After reaching the boundaries of seams and welding termination, ring gage with sections is moved back into lower chamber to remove vacuum, to open the door, to slide ring gage out and to take welded body therefrom. Said body after cooling is clamped in lathe chuck with lobes mating the leg back bores. Then conical surface aligned with body and chuck axes is made at cutter body pin end. Now, lathe rear stock mating cone aligned with body and chuck is fitted therein to prevent axles play in thread cutting.

EFFECT: minimised end and radial play, minimum diameter tolerances.

10 dwg