US Patent 7624821 Constricting flow diverter

In one aspect of the present invention, a downhole assembly has a downhole tool string component with a bore adapted to accommodate drilling mud having a central passage and at least one periphery passage. At least two movable segments are peripherally positioned around a bore wall adapted to constrict a diameter of the central passage and are adapted to divert drilling mud into the at least one periphery passage. At least one opening mechanism is adapted to move a portion of the at least two movable segments toward the bore wall.