in a single - row and expandable into a multi - row stretch blow molding method and apparatus , a robot having a universal gripper assembly is used to pick up molded preforms during the clamp opening stroke of a preform - molding unit and then transfer the preforms at variable time intervals to a conditioning , stretch blow molding and discharge unit , releases finished hollow articles and returns to a waiting position at the preform - molding unit independent of the preform - molding cycle . simultaneously , component transfer devices pick up external components , i . e . labels , valves or handles during the stretch blow molding phase and release the components into the blow - mold cavities while the universal gripper assembly is in the waiting position . the universal gripper assembly can alternatively also be pivoted to pick up preforms from a lateral reheat unit to supplement the molded preform supply . a modular stack - blow - mold clamp assembly is equipped with a plurality of pivoting spacing means which open and close the blow - mold halves and align their respective parting lines to correspond with the center - row distances of the preform molds , conditioning and stretch blow means . prior to the transfer of the molded preforms to a conditioning station , internal components , i . e . sleeves or liners can be inserted into the neck and body portion of the preforms . further , a secondary robot with a gripper assembly can pick up pretreated preforms from the first set of blow molds and transfer them into one or several consecutive blow mold assemblies .