Abstract: A first segment usually attached to a tractor is pivotally linked by a first bolt to a second pivotal segment. For example, which may be moved between an extended outward working position and a retracted, non-working inward position. A hydraulic cylinder and piston are mounted on the fixed segment and the free end of the piston is pivotally linked to the base of a substantially U-shaped member. One arm of the U-shaped member is pivotally linked to the fixed segment, and the other arm of the U-shaped member is pivotally linked to one end of a coupling member. The other end of the coupling member is pivotally linked to the pivotal segment. In the extended position, the arms of the U-shaped member pivot down wardly, and the end of the coupling member connected to the pivotal segment comes to rest between the arms of the U-shaped member in horizontal alignment with the links connecting the U-shaped member to the fixed segment and pivotal segment.