Patent ID: 7552833

Claim:
A synthetic resin container provided with at least one waist, which divides a main body portion of the container into upper and lower parts, wherein: said main body portion has a polygonal cross-section including four corner portions around said main body portion, said corner portions being a pillar comprising a longitudinally elongated nonplanar surface extending along a main axis of said container, said waist comprises an annular groove surrounding said main body portion so as to be convex toward the interior of said container, said annular groove is provided with reinforcing ribs each having a level higher than a groove bottom of said annular groove and lower than a surface of said main body portion, and each of said reinforcing ribs is arranged at a corner portion of the main body portion, each reinforcing rib having a width in the circumferential direction such that each end portion of each rib extends beyond an associated corner of the polygonal cross-section and into neighboring side surfaces of the waist.