TUNNELING SHIELD Russian patent published in 2002 - IPC

FIELD: underground construction, particularly, tunneling shields with rotor working member; applicable in construction of tunnels in various types of grounds, including hard rocks and inclusions of boulders, limestone, etc. SUBSTANCE: tunneling shield has a body, shield hydraulic jacks, rotor working member for ground excavation, ground grinding mechanism presenting conical cavity in working member. Conical cavity is expanding on the side of shield head part. Located in cavity is immovable shaft with eccentricity relative to axis of rotor working member and with channels for supply of water and discharge channel. Made in rotor working member on the side of narrowing conical cavity is additional circular cavity coaxial to main conical cavity and connected with it with annular clearance between immovable shaft and internal surface of rotor working member. Value of eccentricity is made to ensure minimal said clearance which is smaller than size of fractions required for transportation through discharge channel which is located beyond the limits of main conical cavity in zone of minimal clearance. EFFECT: higher efficiency and operating reliability of tunneling shield. 4 dwg