US Patent 11608037 Low-profile a-frame trailer jack

A low-profile trailer jack reduces the height of the jack above the trailer a-frame by over 50% eliminating pickup tailgate interference when lowered by a vehicle operator. This is accomplished using a two-stage concentric lead screw design rather than a single screw as described in prior art. The two-stage design also allows for increased lowering and raising speed of the jack foot by using the first stage, which is a larger outer screw with larger pitch, generating a faster speed when no load is present. The second stage inner screw is engaged when a load is present and a slower speed with greater mechanical advantage is required.