Patent Number: 6,332,652

Title: Tunnel excavator with variable pressure water jets

Abstract: An excavator including a center shaft rotatably provided in a shield body in concentric relation to an outer cone. An inner cone for crushing excavated materials in cooperation with the outer cone is eccentrically provided on the center shaft. A cutter head provided in front of the inner cone is mounted on the center shaft. An internally-toothed gear is secured to the inner cone in concentric relation to the center shaft. A plurality of externally-toothed gears rotated by driving motors whose rotational speed and torque are variably controllable are internally meshed with the internally-toothed gear. Rotation of the externally-toothed gears causes the center shaft to rotate through the inner cone. A plurality of water jet spray nozzles are provided on the cutter head. The spray pressure is switched between high pressure and low pressure.

Inventors: Nakakuro; Kenichi (Toyama-ken, JP)

Assignee: Nakakuro Construction Co., Ltd.

International Classification: E21D 9/10 (20060101); E21C 35/00 (20060101); E21C 35/23 (20060101); E21D 9/08 (20060101); E21D 009/11 (); E21C 025/60 ()

Expiration Date: 12/25/2018