TUNNEL SHIELD Russian patent published in 2000 - IPC

FIELD: construction of tunnels in various types of ground by shields of rotary type. SUBSTANCE: tunnel shield has body, rotor located in front part of body whose working surface carries turning cutting members, burster with cutting members located in rotor head part, rotor drive and mechanism for removal of ground in the form of hydraulic transport facility. Central part of rotor working surface is projecting and it carries rigidly secured burster in the form of spider whose ends carry cutting members in the form of hard-alloy inserts arranged at an angle to one another. The other surface of rotor also carried slotting tools. Each cutting member on the other working surface of rotor is made in the form of rocker movably attached with its one end to rotor recess, and attached to free ends of rocker are hard-alloy inserts, some of them are located at a right angle, while the other, at an acute angle to surface where they are attached. Each slotting tool is installed between walls of base secured to rotor and made in the form of member located on axle and whose working part is made in the form of right prism whose upper ribs carry hard-alloy inserts, and support surface is made cylindrical and located between two bases. Side surfaces of member are located at an angle to prism side faces and internal walls of base forming support surfaces of slotting tool. EFFECT: higher reliability and productivity of shield and simplification of its design. 2 cl, 3 dwg