US Patent 8454263 Production-optimized manhole cover

A manhole cover is made of a fiberglass reinforced saucer-like shell that is filled with concrete. The interior surface of the shell is rough and the shell has a maximum thickness of 5 mm. An adhesive agent may be provided between the base and the filling, to obtain a reliable bond between base and filling. The concrete for the filling may be pure mineral concrete. One or more lifting handles are embedded in the filling. To this end, a recess for each handle is formed in the filling. The ends of the handle are embedded in the concrete and the lifting portion of the handle is curved upward and is held in the recess such that there is a space between the curved portion and the bottom of the recess, so that the handle may be easily grasped.