Patent ID: 9506344
Filing Date: 2016-11-29
CPC Classification: E21B,E21D

Claim Text:
1. A tunneling apparatus comprising: a drill head including a main body having a distal end and an oppositely disposed proximal end; a steering shell disposed at the distal end of the drill head and being movable relative to the main body of the drill head, the steering shell being pivotally movable relative to the main body of the drill head; and a universal joint disposed between the steering shell and the main body of the drill head for allowing the steering shell to be pivoted relative to the main body of the drill head, wherein the drill head includes a plurality of pistons mounted in a plurality of piston cylinders for altering the relative position between the steering shell and the main body of the drill head, and wherein the pistons have multi-piece configurations including main piston bodies and outer feet, the pistons having pivoting joints provided between the main piston bodies and outer feet.