Patent ID: 7219751
Filing Date: 2007-05-22
Classification: E21B

Abstract:
1. A steering head for use with a boring machine that allows a casing to be placed within a bore in the earth which comprises: a forward pivot block; a rearward pivot block; a central drive shaft, said drive shaft having a threaded portion and means for rotating the drive shaft bi-directionally to move the forward and rearward pivot blocks toward or away from each other; a drive nut, said drive nut including a threaded aperture, which threads correspond to those of the threaded portion of the central drive shaft; and a thread covering comprising a sleeve surrounding the threaded portion of the central drive shaft for preventing earthen debris from accessing the threads of the drive shaft and of the drive nut; wherein the casing includes a transverse gap within it, the forward pivot block is attached to the casing to one side of the gap and the rearward pivot block is attached to the casing to the other side of the gap, and the gap width is variable with rotation of the central drive shaft.