| 摘要 |
<p>A full-open end wall structure (27) comprises a back scoreline central portion (40, 52) which is ruptured by Class 2 lever action upon lifting of a longitudinally rigid (non-lanced) tab opener (30, 51); the back scoreline legs (35, 36; 53, 54) help to determine the fulcrum axis for the tab opener (30, 51) as chisel point (33) at its working end ruptures a minor portion of peripheral scoreline (34) by Class 1 lever action. Continued movement of the handle end (37) of tab opener in the direction (46) toward the user, into contact with chime seam (47) provides for continued lever-action rupture of the peripheral scoreline by Class 1 lever action in which the chime seam acts as the fulcrum. Multi-layer folds of sheet metal, providing between layers transition-zone rounded-edge metal (73, 78) for shielding the raw edge of ruptured residual scoreline metal, are prefolded on the removable disc portion and that portion of the end closure structure which remains with the container.</p> |
