Air shoe with integrated roller

Abstract

A web-guiding system for guiding a web of media along a transport path including a fixed web-guiding structure and a web-guiding roller. The fixed web-guiding structure includes two sections, each having a pattern of air holes formed through a convex exterior surface. The web-guiding roller is located between the first and second fixed web-guiding structure sections. At least one air source provides an air flow through the air holes in the fixed web-guiding structure sections. The web of media travels around the web-guiding roller and the fixed web-guiding structure through a wrap angle of more than 10 degrees, with the web of media contacting an exterior surface of the web-guiding roller. The air flow through the air holes lifts the web of media away from the first and second web-guiding structure sections.

1 . A web-guiding system for guiding a web of media travelling from upstream to downstream along a transport path in an in-track direction, the web of media having a first side and an opposing second side, comprising:
 a fixed web-guiding structure including:
 a first fixed web-guiding structure section having a convex exterior surface, wherein a pattern of air holes are formed through the exterior surface; and 
 a second fixed web-guiding structure section having a convex exterior surface, wherein a pattern of air holes are formed through the exterior surface, wherein the exterior surface of the second fixed web-guiding structure section is aligned with the exterior surface of the first fixed web-guiding structure section; 
   at least one air source for providing an air flow through the air holes in the first and second fixed web-guiding structure sections; and   a web-guiding roller located between the first and second fixed web-guiding structure sections, the web-guiding roller being rotatable around a roller axis;   wherein the web-guiding roller has a width in the direction of the roller axis which is less than 20% of a cross-track width of the web of media;   wherein the web of media travels around the web-guiding roller and the first and second fixed web-guiding structure sections through a wrap angle of more than 10 degrees, with the web of media contacting an exterior surface of the web-guiding roller, and   wherein the air flow through the air holes lifts the web of media away from the first and second web-guiding structure sections such that the first side of the web of media is substantially not in contact with the first and second web-guiding structure sections.   
     
     
         2 . The web-guiding system of  claim 1  wherein the web-guiding roller includes one or more grooves formed around the exterior surface of the web-guiding roller. 
     
     
         3 . The web-guiding system of  claim 1  wherein the web-guiding roller is mounted to the fixed web-guiding structure. 
     
     
         4 . The web-guiding system of  claim 1  further including an air flow control mechanism for controlling which air holes the air flow is provided through in accordance with a width of the web of media. 
     
     
         5 . The web-guiding system of  claim 4  wherein the air flow control mechanism includes one or more fixed walls internal to the fixed web-guiding structure which define a plurality of air chambers with independently controllable air supplies. 
     
     
         6 . The web-guiding system of  claim 4  wherein the air flow control mechanism includes one or more moveable walls internal to the fixed web-guiding structure which define an internal air chamber corresponding to the air holes through which the air flow is provided. 
     
     
         7 . The web-guiding system of  claim 4  wherein the air flow control mechanism includes one or more louvers positioned internal to the fixed web-guiding structure which are repositionable to cover different sets of air holes, thereby blocking air flow through the covered air holes. 
     
     
         8 . The web-guiding system of  claim 1  further including an air conditioning subsystem to condition the air provided by the air source. 
     
     
         9 . The web-guiding system of  claim 1  wherein the exterior surfaces of the first and second fixed web-guiding structure sections have an arc-shaped profile with a first center of curvature and a first radius of curvature, and the web-guiding roller has a second radius of curvature which is larger than the first radius of curvature, the roller axis of the web-guiding roller being aligned with the center of curvature of the first and second fixed web-guiding structure. 
     
     
         10 . The web-guiding system of  claim 9  wherein the second radius of curvature exceeds the first radius of curvature by between 0.1 mm to 4 mm. 
     
     
         11 . The web-guiding system of  claim 1  wherein the exterior surface of the web-guiding roller protrudes above the exterior surface of the first and second fixed web-guiding structure sections by a protrusion height. 
     
     
         12 . The web-guiding system of  claim 11  wherein the protrusion height is between 0.1 mm to 4 mm. 
     
     
         13 . The web-guiding system of  claim 1  wherein cross-track widths of the first and second fixed web-guiding structure sections are substantially equal so that the web-guiding roller is centrally-located in the fixed web-guiding structure in a cross-track direction. 
     
     
         14 . The web-guiding system of  claim 1  further including a tensioning mechanism that provides a force on the web-guiding roller to push it toward the web of media.