Abstract: A lead screw assembly having a lead screw rotatable within a hollow tubular portion of a reinforcing rail. A nut engages with threads of the lead screw and is movable along the reinforcing rail. The lead screw includes plurality of first threaded portions having an outer diameter and extending lengthwise of the lead screw; and at least one second gap portion having an outer diameter that is less than the outer diameter of the first threaded portions. The second gap portion is positioned between adjacent first threaded portions of the lead screw. At least one generally U-shaped bearing is secured within the reinforcing rail and contacts the lead screw at a second gap portion. Each U-shaped bearing supports the lead screw along its length as the screw rotates within the rail, so that the lead screw assembly can be safely operated at high speeds over comparatively long distances while minimizing whipping and vibration of the lead screw.

Abstract: A lead screw assembly having a lead screw rotatable within a hollow tubular portion of a reinforcing rail. A nut engages with threads of the lead screw and is movable along the reinforcing rail. The lead screw includes plurality of first threaded portions having an outer diameter and extending lengthwise of the lead screw; and at least one second gap portion having an outer diameter that is less than the outer diameter of the first threaded portions. The second gap portion is positioned between adjacent first threaded portions of the lead screw. At least one generally U-shaped bearing is secured within the reinforcing rail and contacts the lead screw at a second gap portion. Each U-shaped bearing supports the lead screw along its length as the screw rotates within the rail, so that the lead screw assembly can be safely operated at high speeds over comparatively long distances while minimizing whipping and vibration of the lead screw.

Abstract: The reinforced lead screw has a hollow, elongated reinforcing rail surrounding a lead screw and a nut-bearing movable along the reinforcing rail. The nut-bearing has a portion projecting through a slot in the reinforcing rail and includes threads to engage the threads on the lead screw such that when the lead screw is rotated in either direction, the nut will translate along the rail. A wedge is slidably mounted on the nut-bearing and is biased towards a central axis. The wedge has a pair of bearing surfaces which engage surfaces of the reinforcing rail to restrict rotation of the nut-bearing. The rail may be provided with a sleeve-bearing which, in combination with the rail, serves not only as a guide for movement of the nut but lateral support for the lead screw.