Patent ID: 8727154

Claim:
A synthetic resin square bottle comprising: a body formed by multiple panel walls disposed in parallel to one another in a circumferential direction; and a waist portion made of a peripheral groove cut at a roughly middle height position of the body, the waist portion having a height range from a deepest portion of the groove to both of flat portions of the panel walls so as to divide each panel wall into an upper panel and a lower panel, wherein said bottle includes recessed areas for fingerhold use that are formed in at least a pair of opposing panel walls in certain areas ranging from the waist portion to an upper end portion of the lower panel and a pair of side ribs is formed on right and left sides of a lower portion of each recessed area in the lower panel of each panel wall, and each recessed area of the recessed areas is formed in such a manner that a continuous area including both insides of the waist portion and the lower panel are dented and, in order to improve stiffness of each recessed area, is reinforced by a circular-arc shaped underside rib disposed adjacent to a lowermost end of each recessed area along an outer edge of a vicinity portion of the lowermost end, and the pair of side ribs disposed at both side ends of the underside rib symmetrically about the lowermost end of each recessed area, wherein the underside rib is entirely oriented at a location between a rightmost side of a left one of the pair of side ribs and a leftmost side of a right one of the pair of side ribs, and at least a portion of the underside rib is disposed at a vertical position that overlaps a vertical position of the pair of side ribs.