ROCKING SINGLE-CONE DRILL BIT Russian patent published in 2001 - IPC

FIELD: drilling equipment; applicable in drilling machines and plants for drilling of blast holes and slim holes in driving of workings and mineral mining by drilling and blasting method. SUBSTANCE: rocking single-cone drill bit has cone with conical working surface reinforced with hard alloy teeth and centering hard alloy pin pressed in hole of cone top, drive essential shaft with connecting threaded head and cam, supporting bushing with spherical internal surface conjugated with drive eccentric shaft, thrust ball and radial needle bearings. Cone is mounted on drive eccentric shaft installed along bit axis coaxial to connecting threaded head and deflected relative to axis of bit by cam of drive eccentric shaft through acute angle. in the course of drill bit operation, cone is fixed in center of blast hole bottom with the help of hard-alloy pin in top of cone working surface and during rotation of drive eccentric shaft cam deflects cone relative to drill bit axis to provide for rocking motion of cone without sliding to bring into contact with bottom of part of teeth to cut rock over entire blast hole bottom. EFFECT: simplified design of single-cone drill bits, higher strength of bearings, stability of drill bit and efficiency of drilling of blast holes and slim holes in hard rocks. 2 dwg