Abstract: A fitting having members threaded together to a desired position is provided with an arrangement for locking the members against relative rotation so as to maintain the members within a predetermined angular range of rotation relative to each other which encompasses the desired position. The locking arrangement includes longitudinally extending recesses in the outer surfaces of the fitting members which are axially aligned, and an insert which is fitted in a set of axially aligned recesses to lock the members against relative rotation. The recesses are keyhole shaped. The insert is also keyhole shaped in cross section, or is cylindrical. The insert may be made of suitable plastic such as nylon, or may be metallic. When the insert is of a material that is resiliently deformable, it may be laid over and then pressed into the recesses. A metallic or other less deformable insert, such as a rod or wire segment of safety wire, piano wire, etc.

Abstract: In a screw drive, in particular a ball screw drive, a double nut, formed of a pair of individual nuts, is tightened on a threaded spindle and the individual nuts are secured together against relative rotation by a locking member. The locking member is secured within a radially extending recess formed in and bridging the individual nuts. The locking member can be inserted with a certain amount of play into the recess or borehole and then secured within the recess by a cement or similar material so that it cannot be displaced. Various types of locking members can be used, such as locking bolts or threaded bolts. When the locking member is connected into the recess or ball it prevents any rotation of the individual nuts relative to one another.