Abstract: Nut with positive and micrometric locking intended to be screwed on a shaft (1)(23)(60)(70) comprising a serrated part (2)(24)(59)(72) and locking segments (15)(37)(44)(75) having each one at least one tooth (19)(41)(58)(76), and which are intended to fix in rotation the nut (4)(26)(54)(73) on the shaft (1)(23)(60)(70), said locking segments (15)(37)(44)(75) being movable between a first locked position and a second unlocked position, the locking segments (15)(37)(44)(75) being constantly and independently radially stressed by a torical spring (21)(43)(45)(78).

Abstract: A locking nut for use with a shaft having a serrated thread employs a segmented, radially expandable locking element having serrations on its internal diameter. The locking element is disposed in a counterbore of the nut and is axially movable between a first locked position and a second unlocked position. The locking element is resiliently biased toward the axis of rotation of the nut and is also resiliently radially biased axially to the locked position. The nut is unlocked by overcoming the axial resilient bias and driving the locking element segments up a radially diverging ramp provided within the nut against the resilient radial bias.