A brake assembly for braking relative rotational movement of a spindle that is moveable about a central axis relative to a hub. The brake assembly is comprised of a collar comprised of a pair of arcuate leg sections, having a first end pivotally linked together to allow pivoting movement of the leg sections. A factional surface is provided along the inner surface of each of leg section. An adjustable fastening assembly connects second ends of the leg sections together and clamps the leg sections to the spindle with the factional surface on the leg sections engaging the outer surface of the spindle. A stop member is connected to the hub and is disposed to engage a surface of the leg sections, wherein rotation of the spindle in a first direction about the axis causes a surface of one of the leg sections to engage the stop and to reduce factional engagement of one of said leg sections by releasing engagement with the spindle as the spindle moves in said first direction.
