Blow molding apparatus for staged inflation of an extruded parison

In an apparatus for making a blown container of a thermoplastic material, said apparatus including an extrusion station for forming freely pendant tubes along an extrusion axis, a first station displaced from the extrusion axis for blow molding said tubes into pre-forms and a second station for blow molding said pre-form into said container, said apparatus further including a pre-form mold having an interior cavity and a final mold having an interior cavity of the shape and size of the container;

• the improvement comprising:
• means for closing said pre-form mold at said extrusion station to enclose said pendant tube therein;
• means for displacing said closed pre-form mold from said extrusion station and from the extrusion axis to said first station;
• means for opening said pre-form mold at said first station;
• means for supporting said pre-form at said first station independently of said pre-form mold;
• means for closing said final mold on said pre-form supported on said supporting means;
• and
• means for blowing said pre-form interiorly of said closed final mold.

Apparatus for making a container or the like of a thermoplastic material, comprising:

• means for extruding a freely pendant tube from an annular orifice at a first station;
• a pre-form blow mold, said mold having an interior cavity;
• means for moving said pre-form blow mold to said first station and for enclosing the pre-form blow mold about said tube and for shifting said tube in said mold to a second station;
• a first blow tube means selectively insertable into said tube at said second station for blowing said tube into a pre-form to fill the interior cavity of said pre-form mold;
• said first blow tube means having means for supporting said blown pre-form independent of said pre-form mold;
• a final blow mold having an interior cavity the size and shape of the container;
• means for moving said final blow mold to said second station and for enclosing the blown pre-form within said final mold, and for shifting said blown pre-form in said final mold to a third station;
• and
• a second blow tube selectively insertable into said blown pre-form at said third station for blowing said blown pre-form to fill the cavity of said final blow mold.

Apparatus for making a container or the like of a thermoplastic material, comprising:

• means for extruding a freely pendant tube from an annular orifice at a first station;
• a pre-form blow mold positionable at a second station, said mold having an interior cavity;
• means for transporting said tube to said second station, said pre-form blow mold enveloping said tube at said second station;
• first blow tube means selectively insertable into said tube at said second station for blowing said tube into a pre-form to fill the interior cavity of said pre-form mold and for supporting said blown pre-form independent of said pre-form mold;
• a final blow mold having an interior cavity the size and shape of the container and positionable at a third station;
• means for transporting said blown pre-form from the second station to said third station;
• and
• second blow tube means for blowing said blown pre-form at said third station within said final blow mold.

Apparatus for making a container or the like of a thermoplastic material, comprising:

• means for extruding a freely pendant tube from an annular orifice at a first station;
• a pre-form blow mold, said mold having an interior cavity;
• means for moving said pre-form blow mold to said first station, for closing the pre-form blow mold about said tube and for shifting said tube in said mold to a second station;
• first blow tube means selectively insertable into said tube at said second station for blowing said tube into a pre-form to fill the interior cavity of said pre-form mold and for supporting said blown pre-form independent of said pre-form mold;
• a final blow mold having an interior cavity the size and shape of the container and positionable at a third station;
• means for transporting said blown pre-form from the second station to said third station;
• and
• second blow tube means for blowing said blown pre-form at said third station within said final blow mold.

Apparatus for making a container or the like of a thermoplastic material, comprising:

• means for extruding a freely pendant tube from an annular orifice at a first station;
• a pre-form blow mold, said mold having an interior cavity;
• means for moving said pre-form mold to said first station, for enclosing the pre-form blow mold about said tube and for shifting said tube in said mold to a second station;
• blow tube means selectively insertable into said tube at said second station for blowing said tube into a pre-form to fill the interior cavity of said pre-form mold and for supporting said blown pre-form independent of said pre-form mold;
• a final blow mold having an interior cavity the shape and size of the container and being reciprocable between said second station and a third station for enveloping said blown pre-form and accomodating the expansion of said pre-form to the size and shape of the container.

Apparatus for making a container or the like of a thermoplastic material, comprising:

• means for extruding a freely pendant tubular parison along an extrusion axis from an annular orifice at a first station;
• a pre-form blow mold, said mold having an interior cavity;
• means for moving said pre-form blow mold to said first station, for closing the pre-form blow mold about said parison and for shifting said parison in said closed mold from said extrusion axis to a second station;
• a blow tube insertable into said parison at said second station for blowing said parison into a pre-form to fill the interior cavity of said closed pre-form mold and for supporting said blown pre-form independently of said pre-form mold;
• means for opening said pre-form mold at said second station to expose the blown pre-form supported on said blow tube, and
• a final blow mold closable on said exposed blown pre-form as it is supported on said blow tube, said final blow mold having an interior cavity the size and shape of the container and the blown pre-form being inflatable interiorly of the final mold to form the container.

In an apparatus for blow molding thermoplastic articles and including means for extruding a pendant tubular parison, the improvements of a sectional pre-form blow mold, a sectional final blow mold, a reciprocal common carrying means for said blow molds, mold opening and closing means mounted on said carrying means for reciprocal movement therewith and for opening and closing said pre-form blow mold and said final blow mold, means for reciprocating said carrying means between two separate positions so that the two blow molds are collectively positionable at a total of three machine stations including a pair of blowing stations, only the pre-form blow mold being positionable at a first of said stations at which the parison is extruded, only the final blow mold being positionable at a second of said stations spaced from said first station, and both of said blow molds being positionable at said third station which is a blowing station, pre-form supporting means at said third station cooperable with both said pre-form blow mold and said final blow mold as said molds are alternately positioned at said third station, said supporting means retaining a blown pre-form at said third station (1) as the blow molds are opened by said mold opening and closing means to expose the blown pre-form intermediate the sections of the pre-form blow mold, (2) as the opened blow molds are both reciprocated by said carrying means to position the pre-form blow mold at said first station and to position said final blow mold at said third station, and (3) as the final blow mold is closed at said third station by said closing means to thereby enclose said blown pre-form in said final blow mold.