Abstract: A support assembly to stabilize a vehicle has a cylinder with a shaft extendable downward, a foot element comprising a foot plate and a dome, a bolt secured into a lower end of the shaft through a spacer tube, two washers separated vertically by an o-ring, and an articulation plate having a ring groove matching an end shape of the shaft, a lower surface having the shape of a portion of a sphere of the outside surface of the dome, and a central hole of a diameter substantially greater than the diameter of the spacer tube, the articulation plate resting on the dome of the foot element. With the shaft partially extended the foot element is loosely carried, with the shaft fully extended the assembly carries weight of the vehicle, and with the shaft fully retracted the foot element is rigidly secured.

Abstract: A support assembly has a cylinder fastened to a frame, the cylinder having an extendable shaft, a foot element comprising a foot plate with a dome having a spherical shape, the dome having a central hole, an adapter element joined to a the shaft, presenting a concave surface downward having a shape of the dome, and a post with a male threaded portion at a lower end, and a key element having a conical shape with a base having a hole along an axis. The key element is under the dome, base downward, with the post passing through the hole in the key element with the key element resting on a lock nut threaded onto the post, such that with the shaft partially extended the foot element is loosely carried by the key element in contact with a lower edge of the hole of the first diameter through the dome.