a molding device for the manufacture of hollow plastic articles comprising of a two part separable mold , a pre - cast station , a blow station , means for moving the mold halves between the closed and open positions , and means for moving the mold between the preform station and blow station . the mold is supported for movement between the open and closed position by a single supporting spar and locking means are employed for locking the mold parts in the closed position .