APPARATUS FOR DIRECTIONAL DRILLING

摘要

The invention provides an improved apparatus for directional boring and in particular an improved system for boring through hard and rocky substrates frequently encountered when boring under obstacles such as roadways. According to one aspect of the invention, a directional drilling apparatus includes a drilling head (30) having a front face (62) angled relative to the lengthwise axis of the tool and configured for steering the drilling apparatus, a housing (32) having an internal chamber for mounting an electronic locating device therein rearwardly of the drilling head (30) for transmitting a signal indicating the orientation of the angled face of the drilling head (30), and a joint (200) at which the drilling head is removably mounted to the housing of the locating device. The joint (200) includes a splined connection for passing torque from the sonde housing (32) to the bit (31) and an interlock mechanism which mechanically secures the bit (31) to the sonde housing (32) in a manner permitting the bit (31) to be manually removed from the housing (32) without undue difficulty.