Socket hinged construction casting assembly

In a construction casting assembly of the type having a cover with a top surface, a bottom surface, a thickness dimension between the top and bottom surfaces and a perimeter supported in an opening of a frame with the cover resting on a flange of the frame that is below the top surface of the frame, the cover being openable from resting on the flange so as to gain access through the opening in the frame, the improvement wherein:

• a neck extends from the perimeter of the cover along an axis of the neck;
• an enlarged head is attached to the neck, wherein the head is reduced in dimension in a direction through the head that is parallel to the thickness dimension of the cover;
• the frame includes a socket having an upwardly opening first opening located thereon that receives the head in a first orientation of the cover in which the reduced dimension of the head is aligned so as to clear the first opening of the socket and that captures the head in a second orientation of the cover in which the cover is rotated about the axis of the neck relative to the first orientation to be closed over the opening in the frame;
• and
• wherein the cover may be moved from a horizontal position overlying the frame to a substantially vertical position with the head and socket acting as a hinge between the cover and frame, and the cover rotated from the second orientation to the first orientation about the axis of the neck with the head and socket supporting the cover relative to the frame during said rotation and the head lifted through the first opening out of the socket so that the cover can be separated from the frame.