Abstract: A blade assembly for a walk-behind trencher is described. The trencher includes a restraining bar which is affixed to the roller boom and which extends horizontally over the roller boom/digging chain assembly. When rotation of the digging chain is disengaged and the roller boom digger, including the retraining bar, is placed essentially horizontal position, the front end of the backfill blade assembly is mounted on the restraining bar and the rear end of the backfill blade assembly is releasably affixed to the side of the trencher. The trencher itself, after digging a trench, can raise the roller boom to which the restraining bar is attached to a horizontal position, the backfill blade assembly can be quickly installed and the trencher can then be positioned so as to drive over the trench pushing dirt from the side of the trench back into it. A stabilizing bar is longitudinally adjustable so that the backfill blade assembly can be used with differing roller boom lengths.

Abstract: A method of excavating an underground continuous ditch by rotating a chain type cutter 4 while pressing the cutter horizontally against the ground A, with the cutter positioned underground. According to this method, when a lower ground portion is left unexcavated due to a deficiency in traversing force at the lower portion of the cutter particularly during excavation at a large depth, the rotating direction of the cutter 4 is changed from a rake-up direction in normal excavation to a rake-down direction and excavation is performed while the cutter is moved vertically, to excavate the lower ground portion (A1) left unexcavated.

Abstract: A low draft, high yield, dragline bucket system that has about half the weight of current art. It has a low wide configuration with special highly efficient ground engaging, loading and dumping qualities. The strength, cube accomplishment, simplicity, and unit weight combine to compound efficiencies up to 150% of former buckets. This also compounds the ability of the dragline's scope while reducing its specifications and increasing its capacity. A special precise tilt back and hold and rigging system further increases the bucket capacity and further increases its operating range.