Crank connector for directional drilling

A crank connector adapted for having its angle varied by remote control comprising:

• a first tubular member adapted for being secured at the lower end of a drill string and having a longitudinal axis, a second tubular member adapted for being connected to a downhole motor for rotating a drill bit and having a longitudinal axis, a rotary fitting having an axis of rotation, said second tubular member being rotatable, with respect to its longitudinal axis, about said axis of rotation of said rotary fitting, said axis of rotation and said longitudinal axes of said first and second tubular members being separated from each other and converging substantially at the same point to define respective acute angles, said rotary fitting comprising a connecting shaft connecting said first and second tubular members together and being slidable therein with said shaft being fixedly rotatably secured to one of said first and second tubular members and movable into a lock position with respect to the other of said first and second tubular members for being rotatably secured thereto, said shaft being axially displaceable with respect to said other of said first and second tubular members for being disengaged therefrom, angle remote control means for varying it will the angular position of said second tubular member with respect to said first tubular member by pivoting said second tubular member, with respect to its longitudinal axis, about said axis of rotation, maintenance means for maintaining said tubular members in a selected angular position with respect to each other, remotely controlled displacing means for axially displacing said connecting shaft, and driving means for transforming an axial displacement of said connecting shaft from its locking position into a rotation of said second tubular member about said axis of rotation.