Mould assembly for footed container with ribs between the feet

摘要

A mold assembly for making a polymeric container that is shaped to exhibit superior characteristics of light weighting, stability against toppling and resistance to stress cracking includes a conventional cylindrical body portion having a longitudinal axis and a circumferential sidewall and a novel bottom portion. The bottom portion includes a central pushup area of uniformity that is substantially uniform within a spatial rotation about the longitudinal axis. The area of uniformity has a radius RG. The bottom also includes a plurality of support feet that surround and protrude downwardly from the pushup area. Each of the support feet have a bottom support surface with an inner point of contact and an outer point of contact. The outer points of contact together define an outer contact radius ROC. The bottom portion as a whole has a radius of maximum width RBASE. A plurality of ribs are positioned in valleys between the support feet. Each of these ribs is positioned between and helps define two of the support feet. At least one of the ribs has a localized radius of curvature RC that intersects an arc connecting inner points of contact of two adjacent support feet. Advantageously, the radius of uniformity is within the range of about 16% to about 26% of ROC; and RC is within the range of about 70% to about 10% of RBASE.