Patent ID: 8887834

Claim:
A drilling tool steering device comprising consecutively from upstream to downstream, a main body ( 1 ) and a steerable housing ( 2 ); a deflection system ( 7 ); and a flexible transmission shaft ( 3 ) which crosses the main body, the steerable housing, and the deflection system longitudinally, said transmission shaft being substantially fixed in the longitudinal direction with respect to the main body and the steerable housing while being moveable in the radial direction, and being connected to the main body ( 1 ) and to the steerable housing ( 2 ) by at least three connections forming bearings ( 4 , 5 , 6 ), wherein the connection between the main body ( 1 ) and the shaft ( 3 ) is made by an upper bearing ( 4 ) of pivot, sliding pivot, ball joint or annular linear type, and a center bearing ( 6 ) of pivot, sliding pivot, annular or ball joint type, those two bearings being situated in proximity to both the respective ends of the main body ( 1 ), wherein the center bearing ( 6 ) is in the direction of the steerable housing ( 2 ), wherein the connection between the steerable housing ( 2 ) and the flexible transmission shaft ( 3 ) is made by a lower bearing ( 5 ) of pivot type, situated in proximity to the end of the steerable housing ( 2 ) locating in the direction of the drilling tool ( 16 ), and wherein the deflection system ( 7 ) is configured to bend said transmission shaft by radially displacing the upper end of the steerable housing ( 2 ) in relation to the lower end of the main body ( 1 ).