## Facts

- Heat and Control, Inc. (H&C) owned U.S. patents and corresponding British patents covering steam-cooking apparatus and methods.
- H&C filed a U.S. parent application on February 2, 1973, and filed a British application on May 9, 1973, claiming priority from the U.S. filing.
- Stein Associates, Inc. (Stein) manufactured a “Counterflow Oven” and pursued sales in Great Britain, including installation of a pilot unit at a British poultry company.
- After learning of Stein’s U.K. sales activity, H&C initiated infringement proceedings in British courts to enforce its British patents against Stein and a British distributor.
- Stein filed suit in a U.S. district court seeking declaratory judgments of noninfringement and invalidity of H&C’s U.S. patents and asserting unfair competition and antitrust claims; H&C counterclaimed for U.S. patent infringement.
- Stein claimed H&C’s U.S. patents were invalid under the § 102(b) on-sale bar, alleging the claimed invention was reduced to practice in 1971 and offered for sale on January 2, 1972 (more than one year before February 2, 1973).
- H&C disputed that the 1971–1972 oven embodied the claimed invention, citing testimony that it lacked claimed features for excluding outside air and for measuring/regulating moisture content.
- After the U.S. action was transferred to the Northern District of California, Stein moved for a preliminary injunction to stop H&C from enforcing its British patents in the pending U.K. litigation.
- The district court denied the requested preliminary injunction; Stein appealed that denial.

## Issues

1. Whether a U.S. district court may, consistent with international comity, preliminarily enjoin a party from enforcing foreign patents in foreign courts where the foreign tribunal is competent to adjudicate the dispute.
2. Whether Stein showed a sufficient likelihood of success on its U.S. patent invalidity claim under 35 U.S.C. § 102(b) to justify an injunction interfering with the U.K. infringement actions.

## Decision

- The Federal Circuit affirmed the denial of the preliminary injunction.
- The court held that, on the circumstances presented, the district court lacked discretionary power to enjoin H&C from enforcing its British patents in British courts.
- The court also held Stein failed to establish the necessary likelihood of success on its § 102(b) invalidity theory because the evidentiary record was materially disputed as to whether the alleged pre-critical-date device met the U.S. claim limitations.

## Legal Principles

- U.S. courts’ authority to restrain parties before them is limited by international comity; interference with foreign proceedings enforcing foreign patent rights is strongly disfavored when the foreign court is competent to decide the matter.
- A preliminary injunction is an extraordinary remedy; the movant must show (among other factors) a substantial likelihood of success on the merits, and relief should not issue where entitlement is doubtful or speculative.
- For an on-sale bar under 35 U.S.C. § 102(b), the challenger must prove with clear and convincing evidence that the invention as claimed was the subject of a commercial offer for sale more than one year before the U.S. filing date; an earlier device that omits claimed elements does not establish invalidity.

## Conclusion

The Federal Circuit refused to permit a U.S. preliminary injunction to halt U.K. infringement litigation over British patents, emphasizing comity and the competence of the British courts, and concluding that disputed evidence on whether the earlier oven embodied the U.S. patent claims defeated Stein’s showing of likely success on its § 102(b) invalidity defense.


Stein Assocs., Inc. v. Heat & Control, Inc., 748 F.2d 653 (Fed. Cir. 1984)