Abstract: An earth auger presents a shank having a spiral earth removing structure therearound. The structure first presents a series of spirally positioned housings with cutting teeth therein followed by a spiral cutting edge about the shank. The teeth are radially, vertically and angularly oriented so as to remove earth in a stair-step fashion with a pneumatic drill-like action. The cutting teeth are further arranged so that each subsequent cutting tooth, as measured from the initial shank penetrating end, removes earth prior to the contact of the preceding cutting tooth housing so as to preclude earth contact. The earth relief, the spiral cutting teeth arrangement, the radial displacement of the teeth relative to the shank, the vertical displacement among the teeth and the angular relationship of the teeth, alone and in combination, enhance drilling.

Abstract: A post hole digger for attachment to the three-point hitch of a tractor comprises a mainframe having a position control/lock down assembly mounted thereto for raising and lowering the frame and securing the frame to the tractor. A pair of bipartite booms having first and second angled arms are pivotally mounted to the frame. A drill assembly is swingably mounted to a cross beam extending between the second boom arms of each boom. A pair of cylinders extending between the first boom arms and frame pivots the boom arms into and away from a ground drilling position. During the drilling process the bipartite boom configuration compensates for the tendencies of the drill to divert from a true vertical line. The driller transfers the weight of the tractor to the boom arms and the drill connected thereto so as to effectively drill holes in rock-laden soils.