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Alastair Pilkington of Pilkington Bros. has been identified as the inventor of the float glass process even though it was first patented in 1848 by Henry Bessemer, an English engineer. The float glass process was also patented in the United States in 1902 by W. E. Heal and again in 1925 by Hitchcock (a revised version of Heal's patent). What Pilkington Bros. should be recognized for is their success in commercializing the float glass process, obtaining "Original License Patents", restricting its use through licenses and by defining it as "Confidential Information" in their confidentiality agreements.

"Original Licensed Patents" registered to Pilkington's in the U. S. relating to the manufacturing of float glass have expired making the technology and know-how contained within them public domain information.  In addition to the expiration of the "Original Licensed Patents", in 1986, a U. S. Federal Court published a slip decision at the request of Pilkington in an attempt to win a law suit they had filed against Guardian Industries. In the 1986 slip decision, the court declared that Guardian breached Pilkington's "Original License Patents" and "Confidential Information" by constructing their first float glass plant in 1970. Guardian also breached Pilkington's "Confidential Information" licensed to Ford Motor Company's glass division.  Because both Pilkington and Ford were aware of the breach and did nothing about it, their rights expired in 1974 to the float glass manufacturing technology and know-how.  In summary, the court declared that Pilkington's float glass manufacturing technology and know-how was public domain information (see Note).

In addition to the 1986 U. S. Federal Court slip decision, in 1994 the U. S. Justice Department obtained and published a consent decree reached with Pilkington Bros. as the final resolution to an anti trust law suit they filed against them in Tucson, AZ.  The consent decree (U. S. Justice Department, case # CIV94-345TUCWDB Final Judgment dated May 24, 1995 allows AJZ to use the information contained with the "Original Licensed Patent" and "Confidential Information" without having to obtain permission or license from Pilkington Bros. or any other float glass manufacturer.

Note: Public domain is what becomes of the data/information contained within patents that expire. This means that all of the patents claims can be used by anyone to design and build a float bath for a glass manufacturing plant. It also applies to confidential and proprietary relating to the design, construction and operation of a float bath (tin bath/float furnace) information that has been used without permission (breached) and no legal action was taken before the statue of limitations expired (the number of years after a breech was identified and known to have occurred by the breached party).

Rev. 1 - 2006