ARTICULATE SHIELD EXCAVATOR.

摘要

This invention relates to an articulate shield excavator suitably used to make excavation along a sharp curve by a two-folded articulate shield. In a conventional articulate shield excavator, the front end portion of a shield jack often interferes with a front shield, and increasing the strength of the shield jack costs a great deal. According to the present invention, a trunnion (10) is provided on a shield jack (7) to support the shield jack (7) at the front portion of a rear shield (1b) so that the shield jack (7) can be turned toward the center of a shield body (1). The trunnion (10) is provided therein with an elastic member (11) for urging the front end portion of the shield jack (7) toward the center of the shield body (1). Therefore, an excavation operation along a sharp curve can be carried out without accompanying such interference as mentioned above even when a two-folded articulate shield is used. Moreover, the construction of the excavator can be simplified and such an excavator can be obtained at a lower price.