Tunnelling frame with overhead shield - has shield hinge point as low as possible on guide member

摘要

The tunnelling frame has a sole plate structure and an overhead shield supported by a number of rams, while a guide member between them hinges on both. The hinge point (22) between the shield (13) on the member (12) is situated as low as possible, in the direction of the sole place structure (10). The two arms (17, 18) hinging together can be rigidly fixed to the member and shield respectively. One or more rams (21), acting between the member and the shield arm, hold the frame in a stable position.