Patent ID: 8307961

Claim:
A rail vehicle brake slack adjuster, comprising an axially movable, sleeve-shaped driver element adapted to receive an axially applied braking force in a brake application direction, a spindle axially movable within the driver element, an adjuster nut in non-self-locking thread engagement with the spindle, clutch means between the driver element and the adjuster nut, and a barrel spring biasing the spindle in the brake application direction, wherein the combination of a first clutch comprising a clutch surface on the driver element directed in the brake application direction and a corresponding clutch surface on the adjuster nut and a second clutch comprising a clutch surface on the driver element directed in the direction opposite to the brake application direction and a corresponding clutch surface on an adjuster nut sleeve, the adjuster nut sleeve a) being axially movable on the adjuster nut and, b) being biased in the brake application direction by a leader spring and, c) having an end position in the brake application direction in relation to the adjuster nut such that the minimum axial distance between the clutch surfaces on the adjuster nut and the adjuster nut sleeve exceeds the axial distance between the two clutch surfaces on the driver element, and d) defining a control distance or “A”-measure with a control sleeve, which is axially fixed in relation to the driver sleeve and the adjuster nut.