Patent ID: 11953081
Assignee: GOODRICH ACTUATION SYSTEMS LIMITED
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A lead screw assembly comprising:
a screw shaft along which is formed a first helical groove;
a primary nut along which is form a second helical groove;
wherein the first helical groove and the second helical groove cooperate to define a track;
means for applying a pre-load of a predetermined value X to bias the primary nut into engagement with the screw shaft such that rotary motion of the screw is translated to linear motion of the nut via the track and vice versa;
a secondary nut arranged around the primary nut spaced from the first helical groove by the predetermined preload X, wherein when a load applied to the assembly exceeds the predetermined preload, the secondary nut engages with the first helical groove such that motion of the screw is transferred to motion of the secondary nut and bypasses the primary nut such that the load does not act on the primary nut;
torque tube; and
a transfer member provided between the primary nut and the torque tube to transfer the movement of the nut to the torque tube, wherein the secondary nut is provided between the transfer member and the torque tube.