Office folder has flaps and ribs across sides to reinforce rigidity of loaded folder in vertical position

摘要

Folder (1) has back wall (2) and side walls (3, 4) with flaps (7, 8) that can be locked with (9 a, b). Transversal ribs (10 a, b) go through side walls and flaps, join at edge (11, 12) and is intercepted by larger rib (14) next to back wall. Double ribs (15) are placed at superior and inferior edges of side walls. All ribs also reinforce stability and rigidity of folder.