Abstract Apparatus to practice the method of forming foam molded articles without the defects caused by incompletely mixed reactants in the mold cavity is provided. A mixing chamber bounded by a sidewall portion having injection apertures, an outlet aperture which communicates with the mold cavity and a first ejector piston displaceable within the bore of the mixing chamber is provided. Opposite said outlet aperture is a second ejector piston which is retracted at the start of the mold filling operation to provide a receiving chamber in the mold wall. As the mold filling proceeds, this piston is displaced towards the mold cavity until its end surface forms a planar surface with the mold wall. Optionally, this piston may be displaced into the mold cavity to eject the molded article.
In an apparatus for supplying mixed foamable reactants to a mold comprising a mixing chamber bounded by a side wall portion containing injection apertures, a first ejector piston displaceable in the bore of the mixing chamber from a position behind the injection apertures to a position wherein its end surface forms a planar surface with a wall of the mold and an outlet aperture which communicates with the mold cavity, the improvement wherein a second ejector piston is provided in the mold wall opposite said outlet aperture and directly opposite said first piston, said second piston being retractable in a direction away from the mold cavity from a position wherein the end surface of said second piston forms a planar surface with said mold wall to a position wherein a receiving chamber is formed in said mold wall to catch any unmixed reactants.
Claim 2
Dependent Claim
143 words
In an apparatus for supplying mixed foamable reactants to a mold comprising a mixing chamber bounded by a side wall portion containing injection apertures, a first ejector piston displaceable in the bore of the mixing chamber from a position behind the injection apertures to a position wherein its end surface forms a planar surface with a wall of the mold and an outlet aperture which communicates with the mold cavity, the improvement wherein a second ejector piston is provided in the mold wall opposite said outlet aperture and directly opposite said first piston, said second piston being retractable in a direction away from the mold cavity from a position wherein the end surface of said second piston forms a planar surface with said mold wall to a position wherein a receiving chamber is formed in said mold wall to catch any unmixed reactants.
Claim 3
Dependent Claim
24 words
In the apparatus of claim 1 the further improvement wherein the second ejector piston is displaceable so as to intrude into the mold cavity.