ROTARY CUTTERHEAD FOR AN EARTH BORING MACHINE.

摘要

A main frame includes an annular beam by which the cutterhead is mounted onto an earth boring machine for a rotation about an axis of rotation. A plurality of radial spoke beams extend generally vertically at the front of cutterhead and curve rearwardly to intersect with the annular beam. Each radial spoke beam is constructed from a pair of spaced apart side plate members which define spaces between them for receiving a plurality of roller cutter mounts therebetween. Roller cutters, including gauge cutters, can be installed and removed from their associated cutter mounts from the rear side of the cutterhead. A plurality of generally radially elongate cut-ground-material passageways extend through the cutterhead in the regions between the radial spoke beams. A plurality of concentric, substantially circumferentially continuous face-support-ring members are located forwardly of the cutterhead main frame but rearwardly of the peripheral cutting edges of the cutters in at least the radial region of cutterhead in which the cut-ground-material passage ways are located. During rotation of the cutterhead, face-support-ring members support fractured material against the face of the tunnel while the roller cutters cut concentric kerfs with such material.