Metering system for an apparatus for coating webs of material such as paper, paperboard or cardboard webs

Our present invention relates to a metering system for a coating apparatus and, more particularly, to an apparatus for coating webs of a material such as paper, or cardboard. The invention, more particularly, relates to a metering system of the type in which a doctor bar is received in an elastic bed which is pressed toward a surface to be coated, i.e. the surface of the web as it is passed along a drum or roller surface, or the surface of a transfer roller from which the coating is applied to the web, and wherein the doctor bar is pressed toward that surface by a bladder, hose or tubular element extending along the width of the web and subdivided along the web into individually pressurizable compartments. A metering system for the coating of webs of paper and cardboard uses a doctor bar received in an elastic bed which is urged toward the surface to be coated by a pressurizable bladder subdivided into compartments. An elastic continuous member between the diaphragm and the bed equalizes the pressure so that sudden changes in pressure in the regions between the compartments are eliminated.