| 摘要 |
A plastic blow molded container (10) is disclosed as including a freestanding base structure (20) that is constructed with a plurality of alternating hollow legs 22 and curved ribs (34), and a hub (41) from which the legs and ribs extend radially with a construction that provides good stability against tipping as well as the capability of withstanding internal pressure. Each rib (34) has an outer upper end (36) with a circumferential width Wu and an inner lower end (38) with a circumferential width Wl that is greater than the circumferential width Wu of the upper rib end so the lower rib end is capable of resisting stress cracking. An intermediate rib portion (40) of a curved shape tapers between the ends with an included angle B in the range of about 1° to 8° and preferably about 2°. The legs (22) have lower flat feet (24) with an outer diameter Df, and the hub (41) has a periphery connected to the feet and ribs with a height Hp such that the ratio of the diameter Df over the height Hp is in the range of about 25 to 90 to maintain strength without the hub engaging the supporting surface on which the feet rest. In one embodiment the hub (41) has an upwardly extending shape; in another embodiment the hub (41') has a flat horizontally extending shape; and in a further embodiment the hub (41'') has a downwardly extending shape. The specific construction disclosed of the legs (22), ribs (34) and hub (41, 41', 41'') enhance the capability of the base structure in providing good stability as well as the capability of withstanding internal pressure and stress cracking.
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