US Patent 9308894 Fast adjust trailer jack

A fast-adjust trailer jack has three telescoping tubular segments, an upper, an intermediate and a lower. A lead screw is used to operatively couple the upper to the intermediate and a tension spring is coupled between the intermediate and the lower to normally urge the retraction of the lower into the intermediate. A spring-biased pin and hole based detent mechanism is employed to allow setting of the degree of extension of the lower tubular segment with respect to the intermediate tubular segment.