Chalk up one gas-assisted injection win to Michael Ladney and Gain Technologies Inc. Ladney is claiming victory from a United Kingdom Patent Office ruling on a patent covering the use of overflow wells, used to catch plastic material forced out during gas-assisted injection molding. The patent office ruled against Cinpres and Tamworth Mouldings Ltd. of Tamworth, England, on May 22 after a six-day hearing. Cinpres has appealed.
Gain Technologies said that, under British patent law, Cinpres may use overflow wells for its own molding, but may not license the overflow invention to other companies. A Gain Technologies press release issued Aug. 15 warns that Cinpres licensees ``are at risk with respect to their unlicensed past and future use'' of the overflow invention.
The central issue: What did gas-assisted molding pioneer Jim Hendry know, and when did he know it?
Cinpres filed the case against Ladney and Hendry in 1991, claiming that Cinpres was entitled to ownership of a European patent for overflow wells. Cinpres claimed that Tamworth Mouldings had used the technique in the early to mid-1980s and that Hendry took knowledge of the invention when he left the company and used the information to file the patent application later.
The patent hearing officer agreed that Cinpres did use overflow wells in 1985, but found that Cinpres did not prove that Hendry learned of the process while working at the company in England.
According to the press release from Gain Technologies, Ladney and Hendry disagree with the decision that Cinpres and Tamworth Mouldings used overflow wells in 1985, but because they won they decided not to appeal.
Cinpres issued its own release
defending its appeal ``because we believe that there is overwhelming circumstantial evidence to show that Jim Hendry must have been aware of our use of overflow wells when he worked for us as a consultant between 1982 and 1985.''
Hendry later worked for Gain Technologies, Ladney's Sterling Heights, Mich., firm. The overflow well patent is now owned by Melea Ltd., a Gibraltar firm that also owns gas-assisted molding patents marketed by Gain.
Gain Technologies said the UK Patents Act of 1977 gives a person in the United Kingdom who used a technology before its priority date the right to continue using the invention after its patent by another person. That right does not extend to licensing the technology to others, however.
In the Cinpres release, Steve Jordan, Cinpres managing director, said: ``We and our licensees will not be hampered by the patent office decision on overflow wells, but naturally we would prefer control of the patents covering this aspect of the process.''
Gas-assisted molding makes hollow parts by injecting gas into the melt stream, which pushes the plastic toward the walls of the mold.
Legal battles and threats of suits, which raged between the two leading suppliers, Cinpres and Gain, in the late 1980s and early 1990s, seemed to die down in recent years.
But that relative tranquility was shattered even before the clash about overflow wells.
In February, Melea filed lawsuits in London against Cinpres and Cinpres licensees, English molders Linpac Mouldings Ltd. of Birmingham and ClearPlas Ltd. of Coventry. The lawsuits alleged the infringement of a Melea patent that covered the concept of ``timely injection'' of gas into the mold.