Abstract: A screw and nut linear actuator has a threaded drive screw. A drive nut is threaded onto the drive screw and is axially translatable thereover by rotating the drive screw relative to the drive nut. The drive nut has a first member translatable along the drive screw upon rotation of the drive screw relative to the first member, and a second member mounted to the first member for rotation relative thereto. The drive screw and first member are allowed to rotate but not translate relative to the second member with the first member restrained from rotation relative to the drive screw. A limit stop is threaded onto the drive screw and is engageable by the first member to restrain rotation of the first member upon engagement by the first member. Engagement of the first member with the limit stop restrains further rotation of the first member thereby restraining further translation of the drive nut while allowing rotation of the drive screw and the first member relative to the second member.

Abstract: A load bearing, one-way, spring clutch assembly for use in a load bearing assembly where the load bearing assembly includes a housing, a shaft rotatably mounted to the housing, a drive for applying a first torsion load to the shaft, and a thrust load applying a second torsion load to the shaft in a direction opposite the first torsion load. The load bearing, one-way, spring clutch assembly has first and second clutch members, one of the clutch members secured to the shaft for rotation therewith, and the other clutch member mounted on the shaft for rotation about a common axis with the one clutch member. Thrust load bearings are between the clutch members for carrying the thrust load. A spring clutch allows rotation of the one clutch member relative to the other where the first torsion load is greater than the second torsion load, and locks the clutch members together so that the one clutch member cannot rotate relative to the other where the second torsion load is greater than the first torsion load.