WALKING BEAM FOR A HORIZONTAL EARTH BORING MACHINE

摘要

An advancement mechanism for horizontal earth boring machinery which can automatically advance or retract the boring unit without independent manipulation of the locking unit associated with the advancement mechanism. The device comprises a set of dogs pivotally mounted on the advancement mechanism so as to engage rails provided to support the earth boring equipment. A variable volume pump is employed with a hydraulic cylinder to alternately advance the earth boring machine and the advancement mechanism. Further, a lever is employed which has the capability of automatically switching the direction of flow of the hydraulic pump to enable the progression of the total unit to be completely automatic.