PROCEDIMIENTO Y DISPOSITIVO PARA EL FUNCIONAMIENTO DE UN ES-CUDO DE AVANCE.

摘要

A drive shield is formed with a series of drive or cutter members of elongate shape supported in side-by-side relationship around a tunnel wall by a frame and fluid rams are interposed between the frame and the members for effectively relative displacement. To preclude relative movement between the drive members when the frame is shifted by operating all the rams in unison a plurality of locking mechanisms with levers spring-biased into catch plates and effective between neighboring pairs of members ensures all the members lock together when they have all been shifted up by the rams. The levers are released by plates on the frame however when the frame becomes fully drawn up to permit the members to be displaced individually again. Alternatively an analogous hydraulic control system feeds identical flow rates of fluid to the rams when the frame is shifted independent of the prevailing forces or pressure to inhibit relative movement between the drive members.