## Facts

- Carl Schenck, A.G. owned U.S. Patent No. 3,182,511, directed to a hard-bearing vibratory testing (wheel-balancing) machine that senses imbalance-induced vibration in rotating elements.
- The claimed machine used a rigid base and a vibratory workpiece-holding structure connected by supporting rod members forming a parallelogram linkage yieldable in the measuring direction and stiff transversely, with the structures jointly forming a “single integral and gaplessly continuous piece.”
- Evidence at trial indicated that, before the invention, skilled practitioners believed hard-bearing balancers required damping to control resonance; the patent taught avoiding damping and operating with a rigid, integral support configuration.
- Nortron competed in the wheel-balancer market and sold a noninfringing product earlier, but in 1979 introduced its Model 7402 balancer, which Schenck alleged infringed claims 1, 2, and 5.
- The district court held claims 1, 2, and 5 valid and infringed and entered judgment for Schenck; proceedings on damages were stayed pending appeal.
- Nortron appealed, challenging nonobviousness, raising disclosure/fraud-type defenses (including an asserted prior Federn patent), and disputing infringement.

## Issues

1. Whether the district court clearly erred in finding claims 1, 2, and 5 nonobvious under the Graham framework in view of the prior art and industry practices.
2. Whether the claims were unpatentable as a matter of law because they allegedly amounted to a “mere consolidation” into a one-piece, integral support structure.
3. Whether alleged deficiencies in drawings/disclosure or asserted prior art supported a fraud/invalidity defense.
4. Whether Nortron’s Model 7402 infringed claims 1, 2, and 5 under the proper interpretation of the claim limitations.

## Decision

- The Federal Circuit affirmed the judgment that the ‘511 patent was valid and that claims 1, 2, and 5 were infringed by Nortron’s Model 7402.
- The court upheld the district court’s factual findings and found no clear error supporting reversal on nonobviousness or infringement.
- The court rejected Nortron’s categorical argument that consolidating components into a one-piece structure cannot be patentable.
- The court rejected Nortron’s fraud/disclosure defenses and the contention that the asserted Federn patent qualified as prior art invalidating the claims.

## Legal Principles

- Patentability is governed by statutory nonobviousness analyzed under Graham v. John Deere Co., not by older, generalized “invention” rhetoric.
- There is no per se rule that a change from a multi-part assembly to an integral, one-piece structure is unpatentable; obviousness must be determined from the full prior-art record and the claimed combination.
- Industry change and related objective evidence (e.g., abandonment of prior approaches and widespread adoption tied to the claimed advance) can support a nonobviousness finding when linked to the claimed features.
- Appellate review defers to district-court fact-finding on technical matters and comparisons relevant to validity and infringement; reversal requires clear error.
- Inequitable conduct/fraud-type and prior-art defenses require evidentiary support; unsupported challenges to disclosure and asserted references do not defeat validity.

## Conclusion

The Federal Circuit affirmed that the wheel-balancing claims were nonobvious and infringed, holding that an integral “one-piece” structural configuration is not categorically unpatentable and that the district court’s fact-based validity and infringement determinations were not clearly erroneous.


Carl Schenck, A.G. v. Nortron Corp., 713 F.2d 782 (Fed. Cir. 1983)