Epcon Gas Systems Inc.'s 3-year-old battle against Bauer Compressors Inc. over gas-assisted molding technology appears headed for a trial, as an appeals court has sent the case back to U.S. District Court.
A trial date has not been scheduled, according to officials from both companies.
The patent fight began in late 1998 when Epcon of Rochester, Mich., filed a lawsuit against Bauer in U.S. District Court in Detroit. Both firms make equipment for gas-assisted injection molding. The process pushes the melted plastic out against the walls of a mold, creating hollow parts.
Epcon claims Bauer's nitrogen gas controller violates a patent Epcon licensed from inventor Norman Loren of Warren, Mich. The Loren patent involves pressure profiling during injection molding - the ability to step gas pressure up or down, or keep it the same. The patent says the gas is injected at a pressure lower than that of the supply of stored gas.
Last year Judge Arthur Tarnow handed Norfolk, Va.-based Bauer a victory by granting Bauer's motion for summary judgment, on the grounds that the company's gas-control unit does not infringe on the Epcon patent.
In a Feb. 1 ruling, the U.S. Court of Appeals for the District of Columbia reversed the summary judgment and sent the case back for trial. Both companies issued news releases claiming victory.
The three-judge panel upheld parts of Tarnow's ruling and reversed other parts. Much of the argument centers on patent language, including the terms ``supply of stored gas,'' ``substantially,'' ``venting'' and ``control means.''
The Loren patent was issued in 1992. Bauer began making its nitrogen control unit in 1998, and a company official testified that Bauer has sold about 100 of them to injection molding businesses, according to court documents.
Bauer markets the control unit through its Plastics Technology Group in Clinton Township, Mich., near Detroit.