The Robbins Company

Clayton H Crane

Hans A Adami

A bedplate is rigidly affixed relative to the tunnel floor and includes a centrally disposed shaft extending upwardly therefrom. A rotatable base member is mounted on the bedplate for rotation about the central shaft. A boring machine adapted to bore upwardly is secured to the rotatable base member. The boring machine is swung upwardly along a selected arc of vertical circle and the base member is rotated to a selected azimuth. Following rotation, the rotatable base member is itself rigidly affixed relative to the tunnel floor.

Growing community of inventors

Mercer Island, WA, United States of America

Clayton H Crane