Abstract: A laser positioning and measuring system for an earth boring apparatus is disclosed which includes a unique measuring unit comprising a pair of lasers mounted in a back-to-back relation with targets at their free ends. The targets include a beam passage through which laser beams from the measuring units are emitted. The emitted laser beams strike a target on an adjacent measuring unit. The area of which the laser beam impinges upon the adjacent targets generates a signal to indicate the displacement of the laser beams with respect to the adjacent targets to provide a coordinate and angle signals. The signals are processed in the computer to indicate deviations between the measuring units. The measuring units are spaced along the bore, for example, by attachment near the joints of the individual pipe casings which are pushed through the bore by the earth boring apparatus.

Abstract: Apparatus for guiding and steering pipe casing bored and pushed underground by an earth boring machine is disclosed which includes hinge assemblies pivotally connecting a steering head to a front casing. Each hinge assembly includes two pivots. A first pivot has a horizontal pivot axis and a second pivot has a vertical pivot axis. Preferably, the hinge assemblies are compound hinges so that the pivots are carried by a unitary hinge assembly. Actuators are provided which impart an actuation force on the steering head to rotate the steering head about the first and second pivot axes. One of the actuators is provided by slidably mounting one of the hinge assemblies so that the first and second pivot axes of that hinge assembly are compounded and moved unitarily. A second actuator is connected to the steering head to move the steering head about the first pivot axis while the hinge assembly slides to pivot the steering head about the second axis.

Abstract: An apparatus and method for steering pipe casing laid underground is disclosed which includes a steerable pipe jacking head attached to a forward pipe casing and pushed through the ground by a string of pipe casings from a pipe pushing or jacking machine at a station below or above the ground. A steering wedge which may be rotated to a desired steering position and then extended from the forward end of the pipe jacking head is disclosed which accurately steers the pipe jacking head in horizontal and vertical directions. An inclinometer is used to measure the vertical position of the pipe jacking head. A directional heading sensor which includes a toroidal fluxgate magnetometer with a free floating ring core is utilized to measure the horizontal position of the pipe jacking head. Horizontal and vertical position signals, and the rotational position of the steering wedge, are measured and transmitted as serial data to a computer where the signals are processed and displayed graphically on a display screen.

Abstract: Apparatus and method for a directional drilling system is disclosed wherein a concrete pit is poured at a reference entry angle in the earth so that a drilling platform cartridge inserted into the concrete pit is set at the desired entry angle. A frame, including elongated guide ways extending between ends of the platform cartridge, guides a carriage that advances a drill string through the earth at the reference angle. Preferably, a drilling head at the end of the drill string and the remainder of the drill string are rotated by a drive motor carried on the carriage. A drill bit and drill bit motor are mounted coaxially and eccentric with respect to the drilling head. The center axis of the drill bit and drill bit motor, and the center axis of the rotating drilling head are offset and define a known relationship.