## Facts

- Evans Cooling Systems, Inc. owned U.S. Patent No. 5,255,636, claiming an aqueous reverse-flow cooling system for internal combustion engines.
- The inventor, John Evans, admitted he conceived the invention in 1984 and reduced it to practice in 1986, but did not file a patent application until July 1, 1992.
- Evans alleged GM learned of the invention through a 1989 demonstration at a GM test facility and misappropriated it.
- Evans sued GM in early 1994 for infringement based on GM’s manufacture and sale of vehicles using LT1 and L99 engines.
- Evans admitted the LT1 engine infringed and did not dispute that the LT1 engine as installed in the 1992 Corvette practiced each limitation of at least claim 1.
- The § 102(b) critical date was July 1, 1991 (one year before the July 1, 1992 filing date).
- In late April or early May 1991, GM sent independent dealers an “Order Guide” for the 1992 Corvette intended for ordering vehicles, and a supplemental brochure stating the vehicle had reverse-flow engine cooling.
- Evidence showed dealers entered into binding sales contracts with retail customers for 1992 Corvettes before the critical date.

## Issues

1. Whether the claimed invention was “on sale” in the United States more than one year before July 1, 1992, rendering the patent invalid under 35 U.S.C. § 102(b).
2. Whether § 102(b) should include an exception when the pre-critical-date sales resulted from a third party’s alleged misappropriation of the invention.

## Decision

- The Federal Circuit affirmed summary judgment that the ’636 patent was invalid under the § 102(b) on-sale bar.
- The court held there was no genuine dispute that, before July 1, 1991, the 1992 Corvette embodying the claimed invention was the subject of commercial offers for sale through dealer ordering and consumer contracts.
- The court held the invention was ready for patenting before the critical date, based on the inventor’s admitted reduction to practice years earlier and implementation in GM’s engine.
- The court declined to recognize any misappropriation-based exception to the on-sale bar, including where sales involved innocent third parties.

## Legal Principles

- A patent is barred under pre-AIA 35 U.S.C. § 102(b) if the invention was on sale in the United States more than one year before the patent application filing date.
- The on-sale bar applies when (1) there is a commercial offer for sale of a product embodying the invention and (2) the invention is ready for patenting at the time of the offer.
- The on-sale bar may be triggered by commercial sales activity of third parties, not only by the inventor or parties under the inventor’s control.
- Courts will not add extra-statutory exceptions to § 102(b) based on alleged misappropriation; the relevant trigger is the objective fact of pre-critical-date commercial sales activity involving the invention.

## Conclusion

The Federal Circuit held the patent invalid because GM’s pre-critical-date dealer ordering materials and resulting retail sales contracts placed a product embodying the claimed reverse-flow cooling system on sale when the invention was already ready for patenting, and the court refused to create a misappropriation exception to § 102(b).


Evans Cooling Sys., Inc. v. Gen. Motors Corp., 125 F.3d 1448 (Fed. Cir. 1997)