Cover for use with a receptacle

摘要

A cover of generally rectangular shape having a deformation reinforced central section comprises thermoforming top and bottom sheets of thermoplastic to form a specially configured arrangement of strengthening ribs which extend in longitudinal and oblique directions and of a post and receptacle centrally of the sheets, and pressing the sheets together to form a closed interior. The longitudinal ribs on the bottom sheet intersect and are welded to the oblique ribs or the top sheet respective and the post is welded into the receptacle to reinforce the center of the cover. The sheet edges are welded together to reinforce the cover shape and form a reinforced hinge support.