Abstract: A prime mover having a central body with a plurality of elongated legs pivotally connected to said central body for movement both up and down and sideways and individual steerable drive means on each elongated leg to enable the prime mover to move over a wide variety of terrains. The drive means include ground supporting wheels or tracks. Carried on the prime mover are electro hydraulic control means for steering each of the drive means and electric control means for actuating each of the drive means for moving the prime mover along the ground. A work platform is supported on the central body, which is appropriately levelled and stabilized in work position by proper extension or retraction or vertical depression or elevation of the respective elongated legs. The prime mover has four independently mounted drive means or wheels, unconnected by common axles or mechanical linkage and having no fixed track, that are controlled in such a manner that the geometry of steering produces a coherent effect.

Abstract: A chipping hammer for cleaning welds or deburring the oxidized metal about the cut from a cutting torch which comprises a handle and a head of unique configuration secured to an end of the handle. The head is secured at right angles to the axis of the handle and has a hammer head portion at one end and a toothed chipping blade at the other end. The ends of the teeth lie along a concave curve wherein the rearmost tooth extends outwardly from the blade a greater extent than does the front tooth.