A blow molding apparatus having a pair of blow mold sections cooperably defining a blow mold cavity in which a parison is inflated to a final blown article. The mold sections are activated to open and closed positions by a linkage including a pivot plate and a link to each mold section. The parison is inserted into blowing position and the blown article is removed by passing between the mold sections. The linkage is such that the links are moved relatively vertically when the sections are open thereby increasing the clearance for parison insertion and article removal, and the links are horizontally aligned when the sections are closed to increase the mold closing force during blowing.