Method and apparatus for reliably transporting a web in a paper making machine

Claim 1

Apparatus for reliably transporting a web in a paper making machine from a press section to a drying section and for transporting the web at the initial stage of the drying section, comprising: a group of drying cylinders including a pair of substantially horizontal rows of drying cylinders, said pair of horizontal drying cylinder rows being vertically spaced from each other defining an upper drying cylinder row and a lower drying cylinder row; a web-supporting lower endless drying belt extending alternately between drying cylinders in said upper cylinder row and drying cylinders in said lower cylinder row, such drying belt alternately lapping first sectors of said drying cylinders in said upper row and sectors of said drying cylinders in said lower row, wherein the web is separated from the drying cylinders in said upper cylinder row by said lower drying belt and the web is in contact with the drying cylinders in said lower cylinder row; an upper endless drying belt having a width substantially the same as the width of the web, said upper belt lapping second sectors of said drying cylinders in said upper row such that the web is located between said upper and lower drying belts within said second sectors, said second sectors being smaller than said first sectors of the drying cylinders in said upper row lapped by said lower drying belt; a lead-in drying cylinder located between the press section and said group of drying cylinders; and a selectively adjustable lead-in roller means for directing said upper drying belt into contact with said lead-in drying cylinder at least during the period when the web is directed from the press section to the drying section.

Claim 10

A method for reliably transporting a web in a paper making machine from a press section to a drying section and for transporting the web at the initial stage of the drying section wherein the drying section comprises at least a group of drying cylinders including a pair of substantially horizontal rows of drying cylinders, said pair of horizontal drying cylinder rows being vertically spaced from each other defining an upper drying cylinder row and a lower drying cylinder row and a lead-in drying cylinder located between the press section and said group of drying cylinders, comprising the steps of: directing a web-supporting lower endless drying belt to extend alternately between drying cylinders in said upper cylinder row and drying cylinders in said lower cylinder row such that said drying belt alternately laps first sectors of said drying cylinders in said upper row and sectors of said drying cylinders in said lower row; directing the web from said lead-in drying cylinder onto a first one of said group of drying cylinders such that during drying the web is separated from the drying cylinders in said upper cylinder row by said lower drying belt and is in contact with the drying cylinders in said lower cylinder row; directing an upper endless drying belt having a width substantially the same as the width of the web into engagement with the web over a second sector on each of said drying cylinders in said upper row such that the web is located between said upper and lower drying belts over said second sectors, said second sectors being smaller than said first sectors of said drying cylinders in said upper roll lapped by said lower drying belt; and urging said upper drying belt into contact with said lead-in drying cylinder at least during the period when the web is directed from the press section to the drying section by selectively adjusting the position of a lead-in roller means.

Claim 11

A method for reliably transporting a web in a paper making machine from a press section to a drying section and for transporting the web at the initial stage of the drying section wherein the drying section comprises at least a group of drying cylinders including a pair of substantially horizontal rows of drying cylinders, said pair of horizontal drying cylinder rows being vertically spaced from each other defining an upper drying cylinder row and a lower drying cylinder row and a lead-in drying cylinder located between the press section and said group of drying cylinders, comprising the steps of: directing a web-supporting lower endless drying belt to extend alternately between drying cylinders in said upper cylinder row and drying cylinders in said lower cylinder row such that said drying belt alternately laps first sectors of said drying cylinders in said upper row and sectors of said drying cylinders in said lower row; directing the web from said lead-in drying cylinder onto a first one of said group of drying cylinders such that during drying the web is separated from the drying cylinders in said upper cylinder row by said lower drying belt and is in contact with the drying cylinders in said lower cylinder row; directing an upper endless drying belt having a width substantially the same as the width of the web into engagement with the web over a second sector on each of said drying cylinders in said upper row such that the web is located between said upper and lower drying belts over said second sectors, said second sectors being smaller than said first sectors of said drying cylinders in said upper roll lapped by said lower drying belt; and urging said upper drying belt into contact with said lead-in drying cylinder at least during the period when the web is directed from the press section to the drying section by selectively adjusting the position of a lead-in roller means.