Floating roller seal

Claim 1

IN COMBINATION WITH A CHAMBER STRUCTURE HAVING AN OPENING FOR RECEIVING SHEET MATERIAL IN ELONGATED STRIP FORM AND INCLUDING SHEET MATERIAL GUIDE MEANS FOR REVERSING THE DIRECTION OF MOVEMENT OF THE SHEET MATERIAL AND RETURNING THE SHEET MATERIAL OUT OF THE CHAMBER STRUCTURE THROUGH THE SAME OPENING, MEANS FOR REDUCING THE PRESSURE WITHIN THE CHAMBER BELOW ATMOSPHERIC PRESSURE, A DEVICE WITHIN THE CHAMBER FOR TREATING THE MATERIAL, A SEAL COMPRISING FIRST AND SECOND SEALING GUIDE ROLLS MOUNTED IN THE OPENING AND SPACED APART ON PARALLEL AXES WITH THE PERIPHERIES THEREOF SPACED AT A DISTANCE GREATER THAN TWICE THE MAXIMUM THICKNESS OF THE SHEET MATERIAL, A THIRD SEALING ROLLER LOOSELY POSITIONED ADJACENT SAID FIRST AND SECOND SEALING ROLLS AND HAVING A DIAMETER GREATER THAN THE DISTANCE BETWEEN THE PERIPHERIES OF SAID FIRST AND SECOND ROLLS, SAID THIRD ROLLER HAVING ITS AXIS LOCATED OUTSIDE THE PLANE THROUGH THE SAID FIRST AND SECOND ROLLS WHEREBY THE PRESSURE DIFFERENTIAL URGES THE THIRD ROLLER TOWARD THE NIP OF SAID FIRST AND SECOND ROLLS WITH SAID FIRST SEALING ROLL TO DEFINE A FIRST SHEET MATERIAL PASSAGE, SAID