Tunneling machine for boring a side drift

In an earth boring machine for forming an excavation by disintegrating earth formations, including main beam means for longitudinal disposition within said excavation thereby establishing a longitudinal axis, rotary cutterhead means connected to said main beam for disintegrating earth formations to form the excavation, side steering means and main gripper means for extension generally horizontally relative to said longitudinal axis and contacting the sidewalls of the excavation to form a reaction base for operating the machine under normal conditions wherein the excavation has both sidewalls, thrust means connected to said main gripper means and operably connected to said rotary cutterhead means for forcing said rotary cutterhead means into contact with said earth formations, and power means coupled to said cutterhead means for providing power to said cutterhead means, the improvement for operation under conditions wherein at least one sidewall is absent, comprising:

• supplemental gripper means in sliding contact with said main beam means for establishing a reaction base to allow the cutterhead means to be forced into contact with the earth formations and properly guided, said supplemental gripper means including:
• a first vertical gripper unit connected to said main gripper means for engaging the invert and back of the excavation,
• a second vertical gripper unit spaced along said main beam means from said first vertical gripper unit for engaging the invert and back of the excavation, and
• guiding thrust means in sliding contact between said second gripper unit and said main beam means for providing a guiding thrust force.

An earth boring machine for forming an excavation through earth formations by disintegrating a portion of the earth formations, said excavation including walls at some locations and lacking at least one wall at other locations, said excavation including a back and an invert, comprising:

• main beam means;
• cutterhead support means connected to said main beam means;
• side steering shoes connected to said cutterhead support means for selectively contacting the walls of the excavation and providing a side steering force;
• a cutterhead connected to said cutterhead support means for disintegrating earth formations;
• power means coupled to said cutterhead for providing power to said cutterhead;
• main gripper means slidably connected to said main beam means for establishing a reaction base to allow the cutterhead to be forced into contact with the earth formations, said main gripper means including a first gripper unit substantially horizontal to said main beam means for selectively gripping the walls of the excavation and a second gripper unit positioned substantially vertical to said main beam means for selectively gripping the back and invert of the excavation;
• a forward gripper assembly slidably connected to said main beam means for establishing a reaction base, said forward gripper assembly including a forward vertical gripper means for selectively gripping the back and invert of the excavation;
• guiding thrust means slidably connected between said forward vertical gripper means and said main beam for providing a guiding thrust force;
• and
• thrust means operably connected between said main gripper means and said cutterhead support means for forcing said cutterhead into contact with said earth formations.

A machine for boring a tunnel in a subterranean formation, comprising:

• a main beam assembly for longitudinal disposition within said tunnel, said main beam assembly establishing a longitudinal axis;
• a cutterhead support assembly connected to said main beam;
• a cutterhead assembly including a cutterhead mounted on said cutterhead support assembly for rotation generally about said longitudinal axis;
• power means coupled to said cutterhead assembly for rotation of said cutterhead;
• main gripper means acting generally horizontal to said longitudinal axis for facilitating the advance of said main beam, cutterhead support, cutterhead assembly, and cutterhead longitudinally through said tunnel;
• a first vertical gripper assembly positioned around said main beam assembly slidably connected to said main beam assembly and engageable with the back and the invert of said tunnel for facilitating the advance and guidance of said main beam, cutterhead support, cutterhead assembly, and cutterhead through said tunnel;
• guiding thrust means between said first vertical gripper assembly and said main beam assembly for providing a horizontal force to said main beam assembly;
• a second vertical gripper assembly positioned around said main beam assembly slidably connected to said main beam assembly and engageable with the back and invert of said tunnel for facilitating the advance of said main beam, cutterhead support, cutterhead assembly, and cutterhead longitudinally through said tunnel;
• and
• thrust means for forcing said cutterhead against said subterranean formation.