Method and apparatus for vacuum coating metallic substrates

Claim 1

THE PROCESS OF COATING A METALLIC SUBSTRATE WITH ANOTHER METAL WHICH COMPRISES THE STEPS OF PASSING THE SUBSTRATE INTO A VACUUM CHAMBER MAINTAINED AT A PRESSURE BELOW ABOUT 10 MICRONS HG ABS., HEATING THE SUBSTRATE DURING ITS PASSAGE INTO SAID CHAMBER, PROVIDING A STREAM OF VAPORS OF SAID OTHER METAL IN SAID VACUUM CHAMBER, PASSSING SAID METALLIC SUBSTRATE THROUGH SAID STREAM OF METAL VAPORS, CONDENSING VAPORS OF SAID OTHER METAL ON THE HOT SUBSTRATE, PASSING THE THUS COATED SUBSTRATE INTO A SECOND CHAMBER, MAINTAINING THE SECOND CHAMBER AT A PRESSURE LOWER THAN THE PRESSURE IN THE COATING CHAMBER, IMMERSING THE HOT COATED SUBSTRATE IN A LIQUID BATH IN THE SECOND CHAMBER TO COOL THE SUBSTRATE, CONDENSING VAPORS OF THE LIQUID BATH IMMEDIATELY ADJACENT THE SURFACE THEREOF, AND PASSING THE SUBSTRATE THROUGH A BAROMETRIC SEAL COMPRISING SAID LIQUID.