FRAME, ESPECIALLY REVISION FRAME OR COVER FRAME OF A REVISION COVER FOR WALL AND CEILING INSTALLATION

摘要

An inner frame for a cover and an outer frame for an inspection opening can be formed with frame members having flanges projecting from the plane of the frame and formed with tongues at their ends engageable by resilient hooks of the respective corner elements which fit without play against the frame members. The frame ends are cut at right angles to the longitudinal edges of the frame member in the case of the outer frame and are provided with abutting miters in the case of the inner frame.