IN-TUBE EXCAVATOR

PURPOSE: To extend an auger tube in long size into a pit, and to unfasten consolidated soil and sand easily when the pit is joined and press-fitted deeply. CONSTITUTION: One or a plurality of manifolds 4a, 4b... are inserted slidably into an auger tube 1, in which a spiral blade 2 is set up to a periphery. Grooves and projections being mutually fitted slidably in the axial direction of these tubes and being used for detent are formed oppositely to the sliding-contacting surfaces of the auger tube 1 and the manifold 4a and the sliding-contacting surfaces of the manifold 4a. Mutually engaged stoppers 7, 8 are projected from the upper-end inner circumference of the auger tube 1 and the lower-end outer circumference of the manifold 4a and the upper-end inner circumference of the manifold 4a and the lower-end outer circumference of the manifold 4b. The upper end section of the manifold 4b inserted on the innermost side is installed and borne to the rotary driving section 11 of a control box 10, and the chucking section 12 of a pile 9 is mounted on the underside of the control box 10.