Metal frame corner strengthening fitting made using a folded punched sheet metal pattern in lieu of metal casting

摘要

A metal frame structure has members joining at a corner which is strengthened by a sheet metal fitting (1). The sheet metal fitting is punched from metal plate and folded to form a flat base (4) with two upright sides (2,3) and side-flanges (5,6,7). The fold between the base (4) and sides (2,3) is facilitated by a line of punched holes (13).