Vacuum roll

Claim 1

A VARIABLE SPEED WEB FEEDING DEVICE COMPRISING: (A) A HOLLOW, PERFORATED CYLINDRICAL SHELL ROTATABLE ABOUT ITS AXIS, (B) VARIABLE SPEED DRIVE MEANS FOR ROTATING THE SHELL, (C) A STATIONARY HOUSING MAINTAINED WITHIN THE SHELL FORMED WITH WALLS THAT APPROACH THE INNER SURFACE OF THE SHELL, (D) OVERLAPPING SEALING MEMBERS CARRIED BY SAID WALLS THAT ARE ADAPTED SLIDINGLY TO ENGAGE THE INNER SURFACE OF THE SHELL ALONG ONE EDGE OF SAID SEALING MEMBERS ADJACENT SAID INNER SURFACE TO PRODUCE AN AIR-TIGHT SEAL THEREWITH SO THAT THE DIFFERENTIAL PRESSURE MAY BE MAINTAINED IN SAID HOUSING, (E) A RESILIENT COMPRESSIBLE TUBE CARRIED BY THE HOUSING AND IN CONTACT WITH AT LEAST A PORTION OF THE EDGE OF THE SEALING MEMBER REMOTE FROM THE INNER SURFACE OF THE SEAL SO AS TO PRESS THE SEALING MEMBER AGAINST THE INNER SURFACE, THE PERFORATIONS IN SAID SHELL BEING AXIALLY DISPOSED NARROW SLOTS ARRANGED IN AXIAL ROWS AND THE SLOTS IN ADJACENT ROWS BEING OFFSET FROM EACH OTHER IN STAGGERED RELATIONSHIP.