Fitting apparatus of an acess trap to underground civil engineering building works

摘要

The system has a flat hatch plate (3) engaging with a fixed frame (1) with a hinge plate engaging the walls of a subterranean chamber. A support lug (8) welded to the plate may accommodate a threaded rod (10) connected (11) to a link (15) with a long slot. A round hole at the other end accommodates a bolt connecting it to a lug in the middle of the hatch.