Boring machine steering system with force multiplier

摘要

A boring machine includes a steering head which is located behind a cutter head. The steering head has a plurality of steering openings spaced around its periphery. A steering component is mounted adjacent to each steering opening, and each steering component includes a steering paddle that is pivotally mounted with respect to the steering head so as to pivot about a paddle pivot axis. Each steering component also includes a linear actuator and a force multiplier. The linear actuator operates to direct an actuating force along a line that is parallel to the longitudinal axis of the steering head, and it cooperates with the force multiplier and the steering paddle so that upon operation of the linear actuator, a pivot force which is the product of the actuating force and a multiplier factor greater than one causes the steering paddle to pivot about the pivot axis.