Abstract: A method of forming parisons in machines for making glass bottles which includes introducing a gob of molten glass into a blank mold, moving a cavity plunger to form a parison cavity and subsequently subjecting the gob to a predetermined pressure separate from the cavity plunger to apply pressure urging the molten glass into conformity with the mold.

Abstract: A method of forming glass bottles from a short parison is disclosed, which method includes the steps of mechanically elongating the parison in a blow mold to an extent that the exterior bottom of the elongated parison is near, but not at, the bottom of the blow mold cavity and subsequently expanding the elongated parison by vacuum on its exterior and/or by air pressure on its interior, and finally removing the blown bottle from the blow mold.

Abstract: An apparatus for manufacturing glass bottles is disclosed which includes consecutively delivering gobs of molten glass into a blank mold, forming each gob into a parison, transferring the parisons alternately into at least two sets of blow molds, allowing said parisons to reheat, and expanding the parisons in the blow molds. The sets of blow molds recipricate along a substantially vertical path. A first position where the parisons are alternately received by the blow molds and blown containers removed is located on the vertical path. The parisons are expanded and cooled in the blow molds by blowing them out or by applying a vacuum, or a combination of those means at a second position on the vertical path. The apparatus is an improvement to forming sections of the well known Hartford type I.S. machine.