Apparatus for blow molding hollow articles

Claim 2

In apparatus for making a plastic article by blowing a blank in an enclosing mold, the combination of extrusion means for extruding a tube through an annular orifice, mold means for enclosing the extruded tube in an article forming cavity to form said blank, and means for injecting a gaseous medium into the blank to expand it to the shape of the cavity, said mold means comprising a pair of separable mold sections defining said cavity, each of said sections having an extensible pinch bar seated in its parting face at a location spaced from its cavity portion and in abutting relation to the pinch bar of the other section when such sections are closed and means for urging said pinch bars to extended positions outward of the parting faces when said mold sections are open and operable when said sections are moved toward closed positions to allow said pinch bars to abut to close the end of an extruded tube and to return to seated positions as an incident to closing of said mold sections, said mold sections having face portions of relatively substantial areas located between said pinch bars and cavity portions to collapse a portion of the end of the closed tube when the sections approach their closed positions so as to expel a gaseous medium therefrom into the remainder of the closed tube to inflate the blank a limited amount during its formation.

Claim 3

In apparatus for making a plastic article according to claim 1, wherein the last-named means comprises a piston housed in a cylinder in each mold section and connected to its associated pinch bar, each piston being responsive to low-pressure air in its cylinder to move the pinch bar to its extended position and responsive to forces exerted thereon when the sections close and the pinch bars come into abutting relation to retract so as to allow the pinch bars to return to seated positions.

Claim 4

In apparatus for making a plastic article acCording to claim 1, wherein said mold sections when closed form a cavity defining a hollow article having an opening at one end, and wherein said pinch bars are located relative to said cavity diametrically opposite from the opening at said one end.

Claim 5

In apparatus for making a plastic article according to claim 1, wherein said mold sections, pinch bars and urging means are arranged so that when said mold sections are open said pinch bars are spaced apart to allow said tube to be extruded therebetween.

Claim 6

In apparatus for making a plastic container having a hollow handle by blowing a blank in an enclosing mold, the combination of extrusion means for extruding a tube through an annular orifice, mold means for enclosing the extruded tube in a container-forming cavity to form said blank, and means for injecting a gaseous medium into the blank to expand it to the shape of the cavity, said mold means comprising a pair of separable mold sections defining said cavity and including complementary lands for engagement of the extruded tube during the closing of the sections to provide a blank with a main body portion and a tubular handle portion, each of said sections having an extensible pinch bar seated in its parting face at a location spaced from its cavity portion and in abutting relation to the pinch bar of the other section when such sections are closed, and means for urging said pinch bars to extended positions outward of the parting faces when said mold sections are open for closing the end of an extruded tube and operable when said sections are moved toward closed positions to allow said pinch bars to abut and to return to seated positions as an incident to closing of said mold sections, said mold sections having face portions of relatively substantial areas located between said pinch bars and cavity portions to collapse a portion of the closed tube and to expel gas from the collapsed portion into the blank to inflate partially the main body and tubular portions thereof.

Claim 7

In apparatus for making a plastic container having a hollow handle by blowing a blank in an enclosing mold, the combination of extrusion means for extruding a tube through an annular orifice, mold means for enclosing the extruded tube in a container-forming cavity to form said blank, and means for injecting a gaseous medium into the blank to expand it to the shape of the cavity, said mold means comprising a pair of separable mold sections defining said cavity and including complementary lands for engagement of the extruded tube during the closing of the sections to provide a blank with a main body portion and a tubular handle portion, each of said sections having an extensible pinch bar seated in its parting face at a location spaced from its cavity portion and in abutting relation to the pinch bar of the other section when such sections are closed, and means for urging said pinch bars to extended positions outward of the parting faces when said mold sections are open for closing the end of an extruded tube and operable when said sections are moved toward closed positions to allow said pinch bars to abut and to return to seated positions as an incident to closing of said mold sections, said mold sections having face portions of relatively substantial areas located between said pinch bars and cavity portions to collapse a portion of the closed tube and to expel gas from the collapsed portion into the blank to inflate partially the main body and tubular portions thereof.