Patent ID: 6585139
Filing Date: 2003-07-01
Classification: B65H

Abstract:
A draw roller for advancing a web, the roller having:a generally nonrotatable inner part; a cylindrical jacket having a surface centered on an axis, rotatable about the axis on the inner part, and formed over substantially all of the surface with a multiplicity of air holes; drive means for rotating the jacket about the axis in a rotational direction with the web engaging only a portion of the surface; partitions inside the jacket on the inner part forming against an inside face of the jacket an upstream vacuum chamber immediately upstream in the direction from the web-engaging portion of the jacket, a pressure chamber immediately downstream in the direction from the web-engaging portion of the jacket, and a downstream vacuum chamber between the up-stream vacuum chamber and the pressure chamber; and blower means for creating subatmospheric pressures in the vacuum chambers with the pressure in the upstream chamber being substantially less than the pressure in the downstream vacuum chamber and for creating a superatmospheric pressure in the pressure chamber, whereby air is evacuated from under the web as it engages the jacket, the web is solidly held by suction against the jacket where it engages the jacket, and the web is pushed by air off the jacket as it separates from the jacket.