## Facts

- Lisle Corporation owned U.S. Patent No. 5,287,776, directed to an inner tie-rod removal tool for servicing rack-and-pinion steering systems.
- The claimed tool used a hollow tube and an interchangeable C-shaped wrench disc; tabs on the disc engaged openings/slots in the tube and were secured by a retainer ring arrangement.
- A.J. Manufacturing sold an accused inner tie-rod tool (YA3000A) that used the same general tube-and-disc approach but employed non-rotatable T-shaped openings formed in the tube body rather than a separately affixed rotatable ring with L-shaped openings.
- Lisle sued A.J. for infringement in the Northern District of Illinois; the court construed claim 1 and granted summary judgment that the YA3000A infringed, while denying A.J.’s summary-judgment arguments that claim 1 was indefinite or “impossible” to practice.
- Separately, a jury trial addressed A.J.’s defense that the patent was invalid under the § 102(b) public-use bar based on Lisle’s 1989 distribution of prototypes to four repair shops; the jury found no invalidating public use.
- Evidence showed Lisle delivered prototypes without charging money and without written confidentiality agreements, but maintained contact with mechanics to obtain feedback and made design changes based on fit/performance testing across different automobile models.
- Lisle filed its patent application on June 26, 1992; A.J. argued the 1989 distributions were more than one year before filing and therefore invalidating.
- The district court denied A.J.’s JMOL motion challenging the jury’s public-use verdict, and A.J. appealed.

## Issues

1. Whether the district court erred in construing claim 1 and granting summary judgment that A.J.’s YA3000A tool infringed the ’776 patent.
2. Whether claim 1 was invalid for indefiniteness under 35 U.S.C. § 112 or was “impossible” to practice.
3. Whether, as a matter of law, Lisle’s pre-filing prototype distributions constituted invalidating public use under 35 U.S.C. § 102(b), requiring JMOL for A.J.

## Decision

- The Federal Circuit affirmed the district court’s grant of summary judgment of infringement.
- The Federal Circuit affirmed the denial of A.J.’s invalidity challenges based on indefiniteness and “impossibility.”
- The Federal Circuit affirmed the denial of JMOL on the § 102(b) public-use defense, holding substantial evidence supported the jury’s finding that A.J. failed to prove invalidating public use by clear and convincing evidence.

## Legal Principles

- Summary judgment of infringement is proper when, under the correct claim construction, no genuine dispute of material fact exists and the accused device meets the claim limitations as a matter of law.
- Mechanical or design differences in an accused product do not avoid infringement when the properly construed claim language covers the accused structure and its required relationships.
- A patent claim is invalid for indefiniteness only if, viewed in light of the intrinsic record, it is not amenable to construction or is insolubly ambiguous; the challenger bears a clear-and-convincing-evidence burden.
- A pre-critical-date use does not automatically trigger the § 102(b) public-use bar where the evidence permits a finding that the primary purpose of the use was experimental testing and refinement rather than commercial exploitation.
- The absence of payment and the absence of written confidentiality agreements are relevant but not dispositive on public use; the factfinder may consider the parties’ relationship, control/monitoring, and whether feedback-driven changes show experimentation.

## Conclusion

The Federal Circuit upheld judgment for Lisle, concluding that A.J.’s YA3000A infringed under the district court’s claim construction, that A.J. did not prove claim 1 indefinite or impossible to practice, and that substantial evidence supported the jury’s determination that Lisle’s prototype distribution was not shown to be an invalidating public use under § 102(b).


Lisle Corp. v. A.J. Mfg. Co., 398 F.3d 1306 (Fed. Cir. 2005)