Abstract: An adaptor assembly for an earth boring machine includes a thrust bearing housing removably attachable to the bulkhead plate of an earth boring machine surrounding the torque hub flange. A rear drive flange is attached to the torque hub and a front drive flange is mounted within the housing and carries a thrust bearing movable into and out of contact with the housing. The front drive flange has an extension which projects beyond the housing for attachment of an auger and boring head and is connected to the rear drive flange for rotational movement therewith and axial movement relatively thereof.

Abstract: An earth boring tool for forming a bore underground at a desired percent of grade and a grade sensor (A) for sensing percent of grade as the bore is formed are disclosed. The earth boring tool includes a pipe casing (10) and cutting head (12). Sensor (A) includes dielectric fluid chambers (30b, 32b) formed by chamber plates (30, 32) and a sandwiched capacitor plate (34). Capacitors (34a, 34b) are contacted by the dielectric fluid in the chambers. A differential capacitance signal is produced as a fluid level (80) variably covers and uncovers capacitors (34a, 34b) to produce a varying differential output signal. The differential output signal is converted into a linearly changing percent grade signal (64) by a conversion circuit (44a). The percent of grade signal is displayed on a monitor (C) by which an operator may steer the casing to a desired grade.

Abstract: A combined steering and lubricating apparatus for use with earth boring apparatus includes a casing extension pivotally attached to one end of a casing section and controlled by an elongate tube which is movable along an axis parallel to the axis of the casing to pivot the casing extension. The invention includes a first connector for connecting one end of the tube to the casing extension and a second connector assembly connected to the other end of the tube for moving the tube and pivoting the casing extension and for providing lubricating fluid to the tube and first connector for deposit on the exterior of the casing.