CONNECTING DEVICE FOR CONNECTION OF BIT SHANK FOR HARD ROCK PERCUSSION DRILLING Russian patent published in 2011 - IPC E21B6/00 

FIELD: mining.

SUBSTANCE: bit shank connecting device having the possibility of being moved in axial direction relative to rotary sleeve located around the bit shank at installation of shank into the place to the above bit and rotating the shank includes at least one rotation transmitting surface relative to rotation direction, in fact in the direction of rotation axis, which is perpendicular to rotation direction and which faces the rotation direction; at that, shank includes equal number of rotation receiving surfaces, in fact, in the same direction and facing from rotation transmitting surfaces in rotation direction, and rotation transmitting elements; at that, rotary moment is transmitted at rotation from rotary sleeve by means of rotation transmitting surfaces and rotation receiving surfaces to the shank. Rotation transmitting elements are installed between each rotation transmitting surface and the appropriate rotation receiving surface so that at movement of the shank relative to rotary sleeve in longitudinal direction of rotation receiving and transmitting surfaces they are rotated along rotation transmitting surface and along rotation receiving surface respectively.

EFFECT: reduction of heating and wear of rotation transmitting surfaces.

17 cl, 10 dwg