Abstract: A downhole drilling subassembly for use with a pressurized fluid carrying drill string extending from a well head and having a portion down a bore hole. A first tubular housing is provided which is adapted to couple to the portion of the drill string in the bore hole. A second tubular housing is carried by the first tubular housing. Each of the housings has a generally circular cross-section and extends along a longitudinal axis. The second tubular housing is longitudinally movable relative to the first tubular housing between a first position at least partially retracted within the first tubular housing and a second position at least partially extended from the first tubular housing. An assembly responsive to moving the second tubular housing from its first position to its second position is carried by the first and second tubular housings for rotating the first and second tubular housings with respect to one another in the bore hole between first and second relative angular positions.

Abstract: A downhole drilling subassembly for use with a pressurized fluid carrying drill string extending from a well head down to a bottom of a bore hole. The drill string includes upper and lower sections disposed at an angle relative to each other and having respective upper and lower longitudinal axes. An upper subassembly portion is adapted to couple to the upper section of the drill string. A lower subassembly portion is rotatably carried by the upper subassembly portion and is adapted to couple to the lower section of the drill string. The upper and lower subassembly portions are hollow so as to permit the pressurized fluid to pass therethrough. An assembly responsive to raising the drill string off the bottom of the bore hole and lowering the drill string back onto the bottom of the bore hole is provided for rotating the upper and lower subassembly portions with respect to one another between first and second relative angular positions.

Abstract: A movable traffic barrier for dividing adjacent lanes of traffic in a roadway which includes a number of hollow cylindrical barriers laid end to end and projecting above the roadway, and a cable for rotating said cylindrical barriers to position them on the roadway.