| 摘要 |
<p>A container formed of synthetic resinous material having a bottom structure the outer surface of which comprises a central concavity and a convex heel, the heel surrounding the concavity and merging therewith and with the container sidewall. A plurality of hollow convex ribs, distributed in a symmetrical array, interrupt the outer surface of the concavity and merge smoothly therewith, each rib extending longitudinally in the direction of the heel and downwardly from an inner portion of the concavity. The wall of the bottom structure generally decreases in thickness progressively from the innermost point of the concavity to the sidewall.</p> |
