Patent ID: 7931750

Claim:
A deposition chamber under vacuum: for deposition of a thin layer on a metal strip in continuous motion having an inlet or outlet sealing lock, comprising: detachable upper and lower covers; a plurality of pairs of metal rollers between which the metal strip passes and held in cradles fixed to the cover facing the strip with a gap defining a first leak, two successive pairs of rollers delimiting a sub-chamber maintained at a set pressure, lower than atmospheric pressure, by a pumping unit connected to said chamber, wherein: the rollers are mounted on bearings fastened to said covers and are configured to be detachable; the rollers of a same pair have their axes arranged in the same vertical plane and have different diameters, the position of the roller with the smaller diameter being alternately high and low when one passes from a given pair of rollers to the subsequent pair; the rollers with the smaller diameter are coated with a set thickness of rubber or elastomer; the rollers with the larger diameter are rollers whose contact surfaces with the metal strip are metal and define the passage line of the metal strip; two rollers of a same pair are offset in a transverse direction relative to motion of the metal strip so that on each lateral side of the lock, one of the rollers protrudes relative to the other roller; the cradles holding the two rollers of a same pair comprising an upper modified cradle holding the upper roller and a lower modified cradle holding the lower roller, each of said upper and lower modified cradles being configured as a cover of a corresponding roller base and fitting the bearings of the corresponding roller base, said two corresponding bases being opposite on the upper and lower rollers, respectively; each of said modified cradles having a transverse protrusion extending as a collar enclosing a portion of the axial cylindrical surface of the corresponding roller towards a center of the strip, said portion comprising a protruding part of the roller corresponding to an offset between the rollers in the transverse direction, the gap between the transverse protrusion and the axial cylindrical surface of the corresponding roller defining a second leak; wherein the transverse protrusions on the cradles extending towards the center of the strip are located on opposite sides of the respective rollers of a same pair.