Abstract: A spring assisted cover construction for an opening is disclosed which is easily opened and which can be laid back adjacent the opening essentially parallel to the plane of the opening if desired. Hinge member means are pivotally connected to the frame surrounding the opening to swing with the door from a lowered position within the opening to a raised position corresponding to the raised position of the door. The hinge member means is also pivotally connected to the door to allow the door to pivot relative to the hinge member means from the raised position to a fully open position adjacent the opening while the hinge member remains stationary. A first pair of torsion rods are arranged to be loaded or stressed when the door is swung down to a closed position from its raised position and a second pair of torsion rods are arranged to be stressed when the door is swung down to its fully open position from its raised position.