Roll press comprising two dissimilar rolls with equal deflection characteristics

Claim 2

A roll press comprising two parallel rotary rolls adapted for being pressed against opposite sides of a running web, e.g. of paper, and for providing a pressure evenly distributed over the length of the line of contact with the web, the first one (A) of said rolls having its ends united with bearing journals, whereas the second roll (B) which consists of a tubular shell (21) surrounds a through shaft (21) having bearing journals at its ends and is connected to said shaft merely at a center part and for the rest is free and distant therefrom, the wall thickness of one roll or both rolls varying along the length in such a manner that, starting from the center and progressing towards the ends, the quotient of the wall thickness of the second roll shell (21) and the wall thickness of the first roll shell (11), measured in the same transverse plane, first decreases and then becomes constant or increases; characterized in that said quotient stops decreasing at a distance from the center (23) of the rolls equal to 50 to 90 percent, preferably 60 to 80 percent, of the distance from the center to either end.

Claim 3

A roll press comprising two parallel rotary rolls adapted for being pressed against opposite sides of a running web, e.g. of paper, and for providing a pressure evenly distributed over the length of the line of contact with the web, the first one (A) of said rolls having its ends united with bearing journals, whereas the second roll (B) which consists of a tubular shell (21) surrounds a through shaft (21) having bearing journals at its ends and is connected to said shaft merely at a center part and for the rest is free and distant therefrom, the wall thickness of one roll or both rolls varying along the length in such a manner that, starting from the center and progressing toward the ends, the quotient of the wall thickness of the second roll shell (21) and the wall thickness of the first roll shell (11), measured in the same transverse plane, first decreases and then becomes constant or increases; characterized in that the shell (21) of the second roll is connected with a shrinkage fit to the shaft (31) along two center zones situated symmetrically on opposite sides of the transverse center plane (23) and extending endwardly to a point situated at a distance from the center plane equal to 25 percent at the most, and preferably equal to 10 to 15 percent, of the full distance to either roll end.

Claim 4

A roll press comprising two parallel rotary rolls adapted for being pressed against opposite sides of a running web, e.g. of paper, and for providing a pressure evenly distributed over the length of the line of contact with the web, the first one (A) of said rolls having its ends united with bearing journals, whereas the second roll (B) which consists of a tubular shell (21) surrounds a through shaft (21) having bearing journals at its ends and is connected to said shaft merely at a center part and for the rest is free and distant therefrom, the wall thickness of one roll or both rolls varying along the length in such a manner that, starting from the center and progressing toward the ends, the quotient of the wall thickness of the second roll shell (21) and the wall thickness of the first roll shell (11), measured in the same transverse plane, first decreases and then becomes constant or increases; characterized in that the shell (21) of the second roll is connected with a shrinkage fit to the shaft (31) along two center zones situated symmetrically on opposite sides of the transverse center plane (23) and extending endwardly to a point situated at a distance from the center plane equal to 25 percent at the most, and preferably equal to 10 to 15 percent, of the full distance to either roll end.

Claim 5

In a roLl press for pressing a paper web in a paper making machine, a first roll comprising a hollow cylindrical shell of uniform wall thickness, means connected to either end of said shell for rotatably supporting the same, a second roll comprising a shaft rotatably supported at its ends and a hollow shell having a cylindrical outer face cooperating with the first-mentioned shell to form a pressure nip extending along the lengths of the shells, a shrinkage connection between the center portions of said shaft and of said last-mentioned shell, the inner contour of said last-mentioned shell forming an inwardly concave curve extending from said center connection to either end and defining a shell wall thickness of a maximum value at the center and a minimum value at a point lying between the center and the end; characterized in that said minimum value is 30 to 40 percent of said maximum value and relates to a point of the roll situated at a distance from the center equal to 50 to 90 percent of the distance from the center to the roll end.

Claim 6

In a roLl press for pressing a paper web in a paper making machine, a first roll comprising a hollow cylindrical shell of uniform wall thickness, means connected to either end of said shell for rotatably supporting the same, a second roll comprising a shaft rotatably supported at its ends and a hollow shell having a cylindrical outer face cooperating with the first-mentioned shell to form a pressure nip extending along the lengths of the shells, a shrinkage connection between the center portions of said shaft and of said last-mentioned shell, the inner contour of said last-mentioned shell forming an inwardly concave curve extending from said center connection to either end and defining a shell wall thickness of a maximum value at the center and a minimum value at a point lying between the center and the end; characterized in that said minimum value is 30 to 40 percent of said maximum value and relates to a point of the roll situated at a distance from the center equal to 50 to 90 percent of the distance from the center to the roll end.

Claim 7

A roll press comprising two parallel rotary rolls adapted for being pressed against opposite sides of a running web, e.g. of paper, and for providing a pressure evenly distributed over the length of the line of contact with the web, the first one (A) of said rolls having its ends united with bearing journals, whereas the second roll (B) which consists of a tubular shell (21) surrounds a through shaft (21) having bearing journals at its ends and is connected to said shaft merely at a center part and for the rest is free and distant therefrom, the wall thickness of one roll or both rolls varying along the length in such a manner that, starting from the center and progressing toward the ends, the quotient of the wall thickness of the second roll shell (21) and the wall thickness of the first roll shell (11), measured in the same transverse plane, first decreases and then becomes constant or increases; characterized in that the wall thickness of the first roll shell (11) is substantially constant over the entire effective length, whereas the wall thickness of the second roll shell (21) first decreases from the center outwards and then increases closer to the ends; and in that said quotient stops decreasing at a distance from the center (23) of the rolls equal to 50 to 90 percent, preferably 60 to 80 percent, of the distance from the center to either end.

Claim 8

A roll press comprising two parallel rotary rolls adapted for being pressed against opposite sides of a running web, e.g. of paper, and for providing a pressure evenly distributed over the length of the line of contact with the web, the first one (A) of said rolls having its ends united with bearing journals, whereas the second roll (B) which consists of a tubular shell (21) surrounds a through shaft (21) having bearing journals at its ends and is connected to said shaft merely at a center part and for the rest is free and distant therefrom, the wall thickness of one roll or both rolls varying along the length in such a manner that, starting from the center and progressing toward the ends, the quotient of the wall thickness of the second roll shell (21) and the wall thickness of the first roll shell (11), measured in the same transverse plane, first decreases and then becomes constant or increases; characterized in that the wall thickness of the first roll shell (11) is substantially constant over the entire effective length, whereas the wall thickness of the second roll shell (21) first decreases from the center outwards and then increases closer to the ends; and in that said quotient stops decreasing at a distance from the center (23) of the rolls equal to 50 to 90 percent, preferably 60 to 80 percent, of the distance from the center to either end.