Base frames, i.e. template frames for openings in walls or the like

Official title: Base frames, i.e. template frames for openings in walls or the like, provided with means for securing a further rigidly-mounted frame; Special adaptations of frames to be fixed therein {(E06B1/003, E06B1/24 take precedence; fastening door or window frames per se E06B1/56)}

E06B1/02 (Base frames, i.e. template frames for openings in walls or the like) appears on 160 US grants and 145 published applications in this corpus.