Road manhole cover lock - has inclined lug face engaging frames downward inclined support cam face

摘要

Slightly rounded gable-shaped support cams are located in the shaft frame, in a cover, esp. of cast iron, with locking mechanism, for shafts and manholes under roads and paths. The cover locking lug (1) has its sloping face, inclined relative to the shaft frame (2), engaging the sloping face of the cover support cam (4) which runs out downwards on the frame. The frame can have a number of offset support cams, while the cover has a number of locking lugs, each able to turn, swivel or slide. The cover is not forced out by sewer backwash, and does not rattle, and the lock does not rust.