EXPANDING EDGE MECHANISM OF EXCAVATOR

摘要

PURPOSE: To simplify a structure and facilitate the direction correction by constituting a slide edge attached to an auger shaft by a pin connection in such a state as freely entering/retreating from a guide cylinder by the rotation of the auger shaft. CONSTITUTION: An enlarged edge mechanism 3 is so constituted that a slide edge 32 slidably held by a guide cylinder 34 provided in a cylinder part 21 and projecting its tip further outward than an excavation locus of a cutter held 2 in projected to the outside is attached to a bracket 31 projected to a rod part 12 via a pin 33. When the excavation diameter is enlarged, the cutter head 2 is pushed against a natural ground to restrict the rotation, an auger shaft 1 is inversely rotated to thrust the slide edge 32 and project it outside from the guide cylinder 34 so that an enlarged hole with a diameter larger than the excavation diameter of the cutter head 2 is excavated and this excavation can facilitate the correction of the direction.