Small inaccessible pipe pushing rig - is controlled for alignment by laser beam and cutter head correction cylinders

摘要

Pipes pressed horizontally from a trench through an embankment are prevented from deviating from the desired direction by a laser beam. This is directed from the trench to a photocell array in the cutter head. Any deviation is signalled back to a control station so that hydraulic adjustment cylinders for the cutter head can be actuated. This is a secure means of ensuring a correct alignment where the pipes are too small for access by personnel. The concrete pipes are pressed through the soil from a trench by a steel tube to which a hydraulic cylinder is coupled by a clamp. A cutter breaks up the soil and a water spray removes the cuttings to a pit. The direction of the shoes of the cutter head is controlled by hydraulic cylinders. A laser beam is directed from the transmitter to a photocell array. Any deviation is signalled through a cable to a display unit so that the hydraulic cylinders can be actuated and can correct the deviation.