Patent ID: 6305754
Filing Date: 2001-10-23
Classification: E21C,E21D

Abstract:
A tunnel excavator comprising:a pair of cutters arranged side by side at a front portion of the tunnel excavator and adapted to rotate in opposite directions for excavating the earth to form excavation and gathering the excavated earth toward a center area between the pair of cutters;a cutter supporting body for supporting the pair of cutters;a screw cutter extending horizontally behind the pair of cutters at a lower level and having a pair of flights spiraling in opposite directions toward the center from opposite ends of the screw cutter for gathering the excavated earth to the center of the screw cutter;a soil plate attached to arm members swingably supported from the cutter supporting body, which soil plate extends generally along and behind the screw cutter for pushing the excavated earth as the tunnel excavator advances; anda soil outlet formed in the soil plate for allowing the excavated earth to pass therethrough;the soil plate having an ""S"" cross section to cover an upper portion of the screw cutter and also having tapered portions to facilitate movements of the excavated earth toward the soil outlet, an approximate lower half of the soil plate covering an approximate upper rear quarter of the screw cutter.