UNDERGROUND BORING SYSTEMS AND APPARATUS

原文（中国語）

A steering head has a body and an auger extending through the body. An outer surface of the steering head may have a rear portion that does not extend beyond a maximum perimeter of the exterior of a forward portion. An outer surface of the steering head may have openings that receive respective steering flaps. The steering head may have cutting bits that pivot between extracted and retracted positions in response to the auger's rotation. The auger may have a helical blade that contacts an internal surface of the body. The steering head may have three light elements that emit light visible at the rear of the steering head.