Abstract: A ball nut and screw system provides a helical raceway for load bearing balls disposed to occupy portions of the turns of the helical groove in the nut. The nut has a passage extending generally radially from its exterior surface to its interior to permit the balls to be fed into a ball-occupied portion of the turns. A snap-in crossover button inserted into the nut passage has an axially diagonal ball return channel in its underface for channeling the balls from one portion of one of the adjacent turns over an intervening land surface on the screw to a portion of another turn to recirculate them. The nut passage and snap-in button comprise a laterally compressible system with passage recesses and snap-in button projections received in the recesses which is operable automatically upon insertion of the button to a predetermined position to locate the button radially in a position in which the crossover channel aligns helically with the turns.

Abstract: A ball nut and screw system has a ball nut with adjacent helical groove turns providing a helical raceway with a screw for load bearing balls received in the raceway. The nut has an opening extending from its exterior to its interior to permit balls to be fed into the raceway. A compressible snap-in crossover, sized for compressed insertion into the opening, provides an axially diagonal, ball return passage in its underface for channeling balls from one portion of one of the adjacent turns over an intervening land surface on the screw to a portion of another turn to recirculate them. The crossover has opposed portions with nut groove entering projections thereon shaped to be snapped into the turns to define unoccupied turn portions on opposite sides of ball-occupied turn portions when the projections clear the opening upon insertion. For some purposes, wedging retainers can be received in the crossover once it is installed.

Abstract: A method of making ball screw and nut assemblies, and the products which result, wherein the nut is provided with a deformable wall portion of decreased compressive strength interjacent the ends of the nut. A compressive force is applied to the nut to axially deform the portion of decreased compressive strength while not changing the lead of adjacent lands and grooves in the non-compressed portion of the nut. The axial position of the lands and grooves in the non-compressed portion is thereby axially displaced such as to preload a recirculating train of balls traveling along the non-compressed portion of the nut relative to the lands and grooves of the screw, when the screw, nut, and balls are assembled.

Abstract: A ball nut and screw assembly has a conventional helical raceway and balls received therein that react load through the centerline of the assembly and an added helical raceway and balls received therein that react radial load on the ball nut to the relief of the first mentioned raceway and balls.