Non-contact floating device for turning a floating web

Web support apparatus comprising a plurality of contactless web supports, each comprising a perforated arcuate surface, said arcuate surface having a plurality of rectangular perforations, spaced from one another in the web width direction and in the direction of web travel, and discontinuous with respect to each other at said arcuate surface, said arcuate surface having a first maximum diameter, and a bottom arcuate portion having a second maximum diameter less than said first maximum diameter, said perforated arcuate surface and said bottom arcuate portion defining a plenum, whereby pressurized gas in said plenum is discharged through the perforations to float said web about said perforated arcuate surface, each said plenum being in independent fluid communication with a source of said pressurized gas.

A contactless web support comprising a perforated arcuate surface and over which a running web is floatingly supported, said arcuate surface having a plurality of discontinuous perforations with respect to each other at said arcuate surface, said arcuate surface having a first maximum diameter, and a bottom arcuate portion having a second maximum diameter less than said first maximum diameter, said perforated arcuate surface and said bottom arcuate portion defining a plenum, whereby pressurized gas in said plenum is discharged through the perforations to float said web about said perforated arcuate surface, said perforated arcuate surface having a web entry point and a web exit point, and wherein said perforations are arranged in parallel rows along said perforated arcuate surface such that the cross-sectional area of each of said perforations in the first two rows from said web entry point and of each of said perforations in the first two rows from said web exit point is larger than the cross-sectional area of each of the remaining perforations in said perforated arcuate surface.