Patent ID: 7938205
Filing Date: 2011-05-10
Classification: E21B

Abstract:
1. A boring head, comprising at least three boring head sections, arranged to define in a boring direction a first boring head section located at a front of the boring head and formed with discharge passages for directing soil loosened by the first boring head section rearwardly, said discharge passages being arranged in circumferential spaced-apart relationship to define blades there between, with the blades having a front end face extending perpendicular to a longitudinal axis of the boring head, a second boring head section following the first boring head section and having an outer surface formed with largely conical sections which rise in opposition to the boring direction, and a third boring head section having a base, said base fastening the boring head to a housing of a ground-boring device that displaces earth with a percussive action, wherein the front end face of the blades is sized to extend radially beyond a forward end of the second boring head section.