Patent ID: 6334751
Filing Date: 2002-01-01
Classification: B21B,C21D,C23C,F27B,F27D

Abstract:
An air lock for introducing and continuously passing a strip of substrate, such as a metal sheet, along a travel path and in a direction of travel into and through a vacuum chamber, the strip having a thickness, said air lock comprising:a) an enclosure having a wall; b) a first series of rollers comprising at least two rollers mounted in the enclosure and located on a first side of the travel path, said first series of rollers being mounted to rotate about parallel axes; c) at least one second roller mounted in the enclosure offset from the rollers of the first series and located on a second side of the travel path, said second roller being mounted to rotate about an axis parallel to the axes of the first rollers; d) a passage for travel of the strip along the travel path being provided between each two consecutive rollers for causing the strip to be in contact with each of the rollers over an angle of less than 180 degrees with respect to the axis of each of the rollers, and the passage having a thickness corresponding to the thickness of the strip; e) the rollers being positioned relative to one another such that when the strip is present on the path, the strip, the at least two rollers of the first series and the second roller define an essentially airtight region connected to a vacuum pump; f) means for applying a tension to the strip to create a contact pressure between the strip and the rollers sufficient to absorb a difference in pressure between the essentially airtight region and adjacent regions within said enclosure while ensuring the airtightness of the essentially airtight region; and g) sealing members provided between the wall of the enclosure and the rollers with a minimal clearance between the sealing members and the rollers.