## Facts

- Seattle Box, a Washington corporation providing oil-pipe bundling services, owned a patent covering a system for shipping bundles of heavy oil-country pipe using longitudinal sleepers and double-concave wooden spacer blocks between tiers.
- The invention addressed damage to pipe during transport by using spacer blocks to keep adjacent pipes separated and to absorb the load of upper tiers.
- The original patent claimed spacer blocks with height “greater than the diameter of the pipe.”
- Within two years of issuance, Seattle Box obtained a reissue patent broadening the spacer-height limitation to “substantially equal to or greater than” the thickness of a tier of pipe lengths.
- Industrial Crating & Packing, Inc., also a Washington pipe-bundling service provider, used double-concave wooden spacer blocks in a tiered stacking configuration that Seattle Box alleged fell within the reissue claims.
- In the district court, Industrial contested validity, noninfringement, and patent misuse; the court held the reissue patent valid and infringed, entered a permanent injunction, and awarded damages.
- Industrial appealed to the Federal Circuit challenging reissue validity, claim construction, and infringement.

## Issues

1. Whether the reissue patent was invalid under 35 U.S.C. § 251 because the reissue claims broadened the original claims.
2. How to construe the reissue limitation requiring spacer blocks of height “substantially equal to or greater than” tier thickness.
3. Whether Industrial’s bundling system infringed under the proper construction of the reissue claims.
4. What level of deference applies on appeal to the district court’s fact findings supporting validity and infringement determinations.

## Decision

- The Federal Circuit affirmed in part, reversed in part, vacated in part, and remanded.
- It upheld the reissue patent’s validity, concluding that a timely sought broadening reissue is permitted under § 251.
- It agreed that “substantially equal to” does not require exact equality and accepted a construction tied to the function of the spacer blocks in bearing the load of upper tiers.
- It declined to disturb the district court’s infringement finding because the underlying factual determinations were not clearly erroneous.
- It remanded for further proceedings consistent with its analysis, including consequences flowing from the broadened reissue claims.

## Legal Principles

- A reissue patent may broaden claim scope if sought within the statutory period allowed by 35 U.S.C. § 251; broadening alone does not invalidate a timely reissue.
- Terms of degree such as “substantially equal to” may be definite when construed in view of the specification, purpose of the invention, and supporting evidence; they need not be read as requiring mathematical precision.
- Appellate review of district-court fact findings underlying patent validity and infringement applies the clearly erroneous standard; an appellate court will not reweigh evidence absent clear error.

## Conclusion

The Federal Circuit largely left liability intact by sustaining the validity of a timely broadened reissue and affirming infringement under a functional construction of “substantially equal to,” while remanding for additional proceedings required by the broadened reissue claims’ effects.


Seattle Box Co. v. Indus. Crating & Packing, Inc., 731 F.2d 818 (Fed. Cir. 1984)