Patent ID: 7651170

Claim:
A boring apparatus for drilling laser guided microbore tunnels using a liquid stream to remove soil and an airstream to remove the soil and liquid mix created by the liquid stream, the boring apparatus having a bore head comprising: a substantially cylindrical body with a leading end wall and a trailing end wall, an axial wall dividing the body into a component compartment and a flow compartment, a passage through the flow compartment for liquid and soil mix, a passage through the flow compartment for air, the component compartment housing a steerable boring shaft which projects through the leading end wall to support a cutter, a shaft bearing fixed to the axial wall near the trailing end, a liquid path through at least part of the shaft which exits beyond the leading end wall, a laser target mounted on the shaft close to the leading end wall and the cutter and a camera mounted on the axial wall for shooting the target, the shaft being steered by rams mounted on the axial wall and acting at 90° to each other, up and down steering being provided by a first ram acting substantially parallel to the shaft and side to side steering being provided by a second ram acting transversely to the shaft.