Drying arrangement on machines for coating supporting webs, more especially with photographic emulsions

Claim 1

In a drying arrangement for coated webs being transported in a substantially linear path more especially coated with photographic emulsions, the arrangement comprising means for guiding and retaining the web upon rotatable rollers, wherein at predetermined spaced intervals two-roll hollow suction devices are disposed in contact with said web for guiding and retaining it, said two-roll hollow suction devices each comprising a pair of freely rotatable cylindrical rollers having parallel axes and peripheries disposed closely adjacent each other, a suction box disposed closely adjacent and between the peripheries of said rollers on the side opposite said web and having an arcuately pointed section disposed centrally between and closely adjacent said peripheries of said rollers whereby the static air pressure between said peripheries is reduced below atmospheric pressure and the area of forceful contact of said web with said rollers is increased by the suction effect resulting from the differential between atmospheric pressure on the portion of said web remote from said rollers and the reduced pressure on the portion of said web between the peripheries of said rollers to pull said webs in firm rotation-inducing contact with said rollers irrespective of the weight of the web in a shallow curved indentation from said substantially linear path into the space between said rollers whereby said web is firmly guided and retained in said substantially linear path irregardless of its orientation.