## Facts

- Steven G. Lough developed an improved upper seal assembly for marine stern drives to reduce corrosion in Brunswick’s prior design.
- In spring 1986, after experimentation, Lough made six usable prototypes.
- Lough installed one prototype in his own boat, installed another in a customer’s boat, and gave the remaining prototypes to friends and acquaintances.
- The recipients paid nothing and were not bound by confidentiality, restrictions on use, or obligations to report performance.
- Lough did not maintain records of the installations, did not supervise users, and did not regularly inspect, retrieve, or follow up on the prototypes.
- Lough filed a patent application on June 6, 1988; the patent issued in 1989 as U.S. Patent No. 4,848,775.
- Brunswick later marketed a redesigned seal assembly, and Lough sued for infringement in the Middle District of Florida.
- A jury found infringement and awarded $1.5 million in lost profits; the district court entered judgment and a permanent injunction and denied Brunswick’s JMOL motions.
- Brunswick appealed, asserting invalidity under the § 102(b) public-use bar based on Lough’s 1986 prototype uses.

## Issues

1. Whether the 1986 installation and distribution of Lough’s prototypes, more than one year before the June 6, 1988 filing date, constituted “public use” under 35 U.S.C. § 102(b).
2. Whether those pre-filing uses qualified as experimental use sufficient to avoid the § 102(b) bar, given the inventor’s lack of control, supervision, recordkeeping, and feedback collection.

## Decision

- The Federal Circuit reversed in part and vacated in part the district court’s judgment.
- The court held that Lough’s pre-critical-date uses were not experimental and constituted public use under § 102(b).
- Because the patent was invalid, the court concluded the district court erred in denying Brunswick’s JMOL motion on the public-use defense and set aside relief dependent on validity (including infringement-based relief).

## Legal Principles

- Under 35 U.S.C. § 102(b), an invention is barred from patenting if it was in public use more than one year before the application filing date.
- Use by others without limitation, restriction, or an obligation of secrecy can constitute public use even if the public does not understand the invention’s internal details.
- The experimental-use doctrine is a narrow exception; it applies only where pre-filing use is reasonably necessary to test and perfect the invention.
- To establish experimental use, the inventor must generally retain control over testing (e.g., supervision, restrictions, inspection, retrieval, records, and performance feedback).
- Unrestricted distribution of prototypes to friends or customers for ordinary use, without a structured testing program or inventor oversight, is inconsistent with experimental use and supports a finding of public use as a matter of law.

## Conclusion

The court held the patent invalid under § 102(b) because Lough’s 1986 prototype installations and giveaways were uncontrolled, unrestricted uses by others in ordinary conditions, and therefore were public use rather than protected experimental testing.


Lough v. Brunswick Corp., 86 F.3d 1113 (Fed. Cir. 1996)