Breast roller pivoting

Claim 1

A web coating assembly comprising a source of heated high viscosity liquid coating material for coating a web; an extrusion head for applying the material onto a web, the extrusion head comprising an upper flat substantially horizontal surface having a narrow elongated opening formed therein of substantially the same length as the width of the extrusion head, said opening having a vertical centerline, said head having a forming lip and a coating thickness determination portion; means for supplying the material under pressure from said source to said extrusion head opening; a breast roller of hard material for contacting a web to be coated, said breast roller rotatable about a generally horizontal axis and positioned above said extrusion head opening for cooperation therewith, said breast roller being mounted with respect to said extrusion head so that no radius of said breast roller is coextensive with said extrusion head opening centerline and a lead-in wedge being formed by said roller and head forming lip; means for maintaining during coating the relative positions of said breast roller and said extrusion head; and means for feeding a web in contact with said breast roller past the lead-in wedge and then past said coating thickness determination portion, between said roller and said head forming lip; wherein the improvement comprises means for mounting said breast roller for pivotal movement with respect to said extrusion head, to control coating thickness, so that the size of said lead-in wedge increases at a greater rate during relative movement between said head and roller than the distance of said coating thickness determination portion of said head from said roller, so that web breakage at said extrusion head opening is minimized, said means including a lever arm operatively connected to said breast roller substantially at the center thereof, and a stationary pivot point for said lever arm located on the same side of said vertical centerline of said extrusion head opening as said lead-in wedge formed by said roller and said head forming lip, and located vertically above a horizontal plane passing through the center of said breast roller.