Abstract: The number of blow mold stations being associated with a blow wheel of a blow molding machine determines a large pitch of the mandrel receiving positions of the blow wheel. Contrarily the mandrels carrying the parisons are disposed very close to each other on the heating wheel which thus has a substantially smaller pitch. The larger pitch of the blow wheel shall be maintained throughout the complete machine to simplify the transfer of the parison. Accordingly the heating wheel receives the same pitch as the blow wheel including additional mandrel receiving positions which are served in a plurality of subsequent revolutions of the heating wheel.

Abstract: In the art of blow molding thermoplastic articles a pair of blow mold halves is closed around a parison. A blowing medium is applied so that the parison is thus blown to a container configuration. In this blowing step very high closing forces are necessary to maintain the mold halves in closed position. The invention provides for a plurality of biased pistons which are actuated by a pressure medium to support the mold halves on a stationary frame.