Abstract: A bottom roller drive mechanism for a subterranean soil processing tool is provided. The tool is connected to a string of Kelly bar sections. Each Kelly bar section has a preferably square, or other polygonal, cross-section. A plurality of roller wheels is mounted in a drive assembly connected to the bottom rotary drive plate. The roller wheel assembly engages the faces of each Kelly bar section and rotates the Kelly bar around a vertical axis A-A. The upper and lower ends of each Kelly bar section are tapered to form a reduced cross-section at each joint. The roller drive assembly is free to rotate at each joint without rotating the Kelly bar. This allows misaligned Kelly bar sections to pass through the drive mechanism.

Abstract: A steering shaft assembly for a vehicle uses a ball spline as a slip member. In general, the slip member includes an outer race member, an inner race member, and a pair of end return members. The outer race member includes one or more grooves or recesses, each groove forming an outer race. The inner race member includes a corresponding number of grooves and inner bores to form an outer race track and inner race tracks, respectively. Each outer race and corresponding outer race track form an outer ball recirculating track for transmitting torque through the recirculating ball bearings. Each inner race track forms an inner ball recirculating track for providing a circumferential path for the ball bearings. In one embodiment, the inner race member and end return members are generally cylindrical in cross sectional shape that is disposed within the outer race member. The outer race member, inner race member and end return member can be any desired cross sectional shape.

Abstract: A steering shaft assembly for a vehicle includes a slip joint. The slip joint includes a pair of members, each member includes first and second collar and one or more rods extending therebetween. The one or rods of one member are slidably supported by linear bearings mounted in one of the collars of the other member for providing relative axial movement of the members between a fully retracted position and a fully extended position.