Patent ID: 7510025

Claim:
A system for laser-beam guidance of a microtunnelling machine comprising: a boring head having a forward wall formed with an aperture, a boring bit forward of the forward wall of the boring head and rotatable relative to the boring head, a hollow drive shaft coupled at a forward end thereof to the boring bit and extending rearward from the boring head through the aperture in the forward wall of the boring head and a rearward end of the boring head, the aperture in the forward wall of the boring head permitting angular adjustment of the drive shaft relative to the boring head, liquid supply means for supplying water through the hollow drive shaft to the boring bit, vacuum assisted slurry removal means for creating an airstream for removing slurry from the boring bit to beyond the boring head, a target for the laser beam attached to the hollow drive shaft, a means for acquiring an image of the target and a laser strike position thereon and for conveying the image to an operator station situated remotely from the boring head, and an input means for operational adjustment of the direction of the forward end of the drive shaft, and wherein the forward wall of the boring head is formed with an air supply aperture in open communication with atmosphere for supplying air to a space forward of the forward wall and with an air removal aperture, and the vacuum assisted slurry removal means comprises a vacuum generator having a suction side, a motor connected for driving the vacuum generator, and a tube connecting the suction side of the vacuum generator to the air removal aperture, whereby the vacuum generator creates the airstream and the airstream flows through the air supply aperture to the space forward of the forward wall of the boring head, and through the air removal aperture and the vacuum tube to the suction side of the vacuum generator.