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Four months after being filed, Strike Tool, Inc. v. Ess Brothers and Sons, Inc. is set to move into the discovery phase. Based in Hampton, Minnesota, Strike Tool makes and sells products for the precast concrete industry. Ess Brothers and Sons, based in Loretto, Minnesota, operates in the same market, distributing and manufacturing custom and standard products including manholes and catch basins.

Strike Tool filed its original complaint back in April, alleging that Ess Brothers and Sons’ “Infi-Shield Uni-Band” products and systems infringe U.S. Patent No. 6,986,226, entitled Manhole Water Seal-Cap/Diverter. The complaint was amended in June to add allegations that the Ess Brothers’ “Alignment Barrier” products and systems also infringe the ‘226 patent. Ess Brothers and Sons denies infringement and has counterclaimed for declaratory judgments of noninfringement and invalidity.

The ‘226 patent issued in 2006. It is directed to an apparatus that can be inserted into a manhole to prevent water from leaking into the basin below, and the method of constructing such an apparatus. This is the first time Strike Tool has asserted the patent in litigation.