EXCAVATOR

PROBLEM TO BE SOLVED: To provide an excavator capable of smoothly pushing an excavation shear caused by excavation to the rear side and performing efficient excavating operation. SOLUTION: The excavator comprises a casing pipe 11, a rod 13 disposed in the casing pipe 11 to which thrust, an impact force and a rotating force are transmitted in the direction of an axial line O, a device 14 attached to the tip of the rod 13, and a drilling bit 15 attached to the top end of the device 14. The drilling bit 15 includes a head 15a and a skirt 15b. A cylindrical casing top 12 movable in the axial line direction to the casing pipe 11 and rotatable around the axial line is attached to the top end of the casing pipe 11 so as to be fitted to the outer circumferential part of the drilling bit 15, and a thrust and impact force transmission part 24 is formed between the inner circumferential part of the casing top 12 and the outer circumferential part of the skirt 15b. COPYRIGHT: (C)2009,JPO&INPIT