Thermoforming machine tooling assembly with plug assist tooling

A plug assist tooling assembly in combination with a thermoforming apparatus having roll feed of sheet plastic material, a heater station for preheating said sheet material advanced from said roll feed, a press in a forming station having main platens for bringing tooling assemblies including said plug assist tooling assembly and a mold cavity tooling assembly together with a section of preheated sheet material disposed therebetween to form products in said sheet material, and a post trim apparatus separate from said press receiving said sheet material with product formed therein, and cutting said products free from said sheet material, said plug assist tooling assembly installed on one of said press platens, a third platen independently stroked from said one platen for advancing and retracting said plug assists in said plug assist tooling assembly, the improvement wherein said plug assist tooling assembly includes a plurality of plug assists each having an elongated rod attached thereto, a spider plate connecting said rods together at ends opposite said plug assists, said spider plate disposed adjacent said one platen and connected to said third platen through one or more connecting members extending through said one platen;

• at least one support plate disposed between said plug assists and said spider plate, said plug assist rods sealed to openings in said support plate through which said rods pass in extending to a respective one of said plug assists;
• a series of standoffs fixing said main platen relative said support plate;
• a clamping plate fixed relative said at least one support plate and having a series of cylindrical holes defining sealed chambers, which each receive a plug assist;
• and, a series of clamping rings fixed relative said clamping plate, each clamping rings encircling a hole in said clamping plate and adapted to clamp said sheet material when said main platen is stroked during a thermoforming cycle, said plug assists thereafter stroked by said third platen to engage said sheet material and air pressure is applied in said chambers to cause forming of said sheet material into cavities in said mold cavity tooling assembly.