Intirtool, Ltd. (MASS-TEX) v. Texar Corp. (ToolPro) (Fed. Cir. May 10, 2004).
In this patent infringement case, the district court found that Intirtool’s patent was invalid for failure to satisfy the written description requirement. (U.S. Patent 5,022,253) Additionally, the district court concluded that damages accrued prior filing the lawsuit were barred by laches. The Federal Circuit reversed these rulings for either clear error or abuse of discretion.
The first dispute revolved around whether the preamble:
hand-held punch pliers for simultaneously punching and connecting overlapping sheet metal
restricted the claims to pliers that have a connecting functionality.
The Federal Circuit held that the preamble was not limiting in this case because the body of the claim was described in such exacting structural detail that deletion of the preamble would not affect the claim. (NOTE: The body of claim 1 is quite large for this type of technology, listing 60+ lines in the patent).
In terms of inequitable conduct and laches,
the district court based its conclusion that Intirtool had engaged in inequitable conduct on its view that Intirtool had, during the prosecution of the ’253 patent, “repeatedly stated, and indeed stressed, that the described tool simultaneously punched holes and connected ceiling grids, knowing that this assertion was false.”
The Federal Circuit again disagreed with the district court – finding that the “connecting” references made by the patentee were “merely preamble features of the invention.”