US Patent 11525298 Frame construction method

The invention is a method, an apparatus and a kit of parts for assembling a universal frame with at least two jambs, a lintel and a sill. The resulting frame is suitable for any size of opening and any size of door, with the option to include single doors or double doors as well as side screens and/or side lights. The frame is typically assembled by cutting the jambs (and optionally the sill and/or lintel) to a selected size, attaching keys to each end of each jamb and inserting the keys into keying channels in the sill and lintel.