Abstract: A frame mounted to the bottom opening of an air duct for supporting a variety of interchangeable air control devices. The frame has a top section with a central opening that permanently mounts to and surrounds the perimeter of the bottom opening of an air duct, and a bottom section which is foldably connected to the top section. The bottom section connects to the top section by means of a hinge joint at one end and a latching mechanism at the other, which together removably holds the bottom section to the top section in a folded and closed position. The bottom section has an interior stepped portion for removably securing an interchangeable air control device. When released, the bottom section swings downward into an open position to allow easy access to the interchangeable air control device.

Abstract: A method and system for optimizing truss cutting and pre-cutting of lumber having a computer controlled sequence for cutting based on data representative of truss members, optimizing the combination of said lengths of a plurality of members to be cut from stock to minimize waste and identifying the order for cutting said stock into member lengths. The system and method iteratively compares member lengths to stock lumber lengths to optimize the cutting process and determines storage and cutting sequences.