Fluid distributor for use in extruding foamed polymeric materials

Claim 1

In an apparatus for forming tubular extrudate of foamed polymeric material having a skin of unfoamed polymeric material on the inside surface, the combination comprising: a. a die defining an annular orifice from which an extrudate emerges; and b. a fluid distributor for directing a fluid onto the inside surface of the extrudate comprising: 1. first and second members, coaxially spaced apart and defining a frusto-conical opening through which said fluid passes and said members being adjustably connected to each other for axial movement in respect to each other to change the width of said opening; 2. means for introducing said fluid into said opening; and 3. impeding means in said opening for creating a back pressure on said fluid; said first member comprising: a. a first body portion secured to the die in axial alignment with and adjacent said annular orifice and having an external frusto-conical surface starting at a diameter that is substantially equal to the diameter of said die orifice and terminating at a smaller diameter; and b. a sleeve portion integral with said first body portion that extends axially away from said first body portion at the smaller diameter of said frusto-conical surface; and said second member comprising: a. a second body portion having an internal frusto-conical surface matching the frusto-conical surface of said first body portion; and b. a collar mounting said second member to said sleeve portion of said first member.