Southwire Company v. Cerro Wire LLC
870 F.3d 1306
| Fed. Cir. | 2017Background
- Southwire owns U.S. Patent No. 7,557,301 directed to a method of manufacturing electrical cable jackets by incorporating a lubricant into the sheath so the lubricant migrates to the surface and reduces pulling force during installation.
- Cerro Wire requested inter partes reexamination of the ’301 patent; the PTO Examiner and the Patent Trial and Appeal Board (PTAB) held claims 1–42 obvious over Summers in view of Dow and UL-719.
- Summers discloses extruding a cable jacket from plastic containing a friction-reducing additive that migrates to the surface (examples: fatty acids, silicone oils) to reduce pulling resistance; it does not quantify a 30% reduction.
- Claim 1 requires that the finished cable exhibit at least about a 30% reduction in installation force (measured by a specified wood-block test) relative to a non-lubricated cable.
- The Board found Summers (with Dow) discloses substantially identical manufacturing steps and that it would have been obvious to select lubricant amounts achieving the claimed reduction; the Board rejected Southwire’s experimental/declaration evidence as lacking sufficient support or nexus to the claim.
- The Federal Circuit affirmed: it held the Board erred in invoking inherency as its primary rationale but that error was harmless because substantial evidence supports a prima facie obviousness rejection and the Board’s other factual findings.
Issues
| Issue | Southwire's Argument | Cerro's Argument | Held |
|---|---|---|---|
| Whether the 30% reduction limitation is inherent in Summers | Inherency requires necessity; Summers does not necessarily always produce ≥30% reduction, so inherency cannot supply the limitation | Summers discloses the same process and purpose; the 30% reduction is a predictable/resultant property of that process | The Board erred to rely on inherency alone, but the error was harmless because substantial evidence supports obviousness without inherency |
| Whether the claimed process is obvious over Summers (with Dow, UL-719) | The claimed quantified result is not taught by Summers; Southwire’s evidence shows the quantification was not obvious | The process and purpose are the same; it would have been obvious to select lubricant types/amounts to achieve the reduction; applicant bears burden to show prior-art product lacks claimed characteristic | Affirmed: claims obvious — Board’s findings that Summers discloses identical/substantially identical process and that no evidence showed the 30% result was unexpected are supported by substantial evidence |
| Whether Southwire’s objective (secondary) evidence rebuts obviousness | Experimental declarations and long-felt need evidence show nonobviousness and nexus to the claimed limitation | Declarations lack detail/statistics/nexus; Summers already addressed the problem, so long-felt need without solution not established | Board correctly discounted Southwire’s evidence for lack of factual support and nexus; long-felt need was not established against Summers |
Key Cases Cited
- In re Elsner, 381 F.3d 1125 (Fed. Cir.) (standard of review: legal determinations de novo; Board factual findings for substantial evidence)
- In re Gartside, 203 F.3d 1305 (Fed. Cir.) (substantial evidence standard for factual findings)
- Apple Inc. v. Samsung Elecs. Co., 839 F.3d 1034 (Fed. Cir.) (obviousness involves what a reference teaches, motivation to combine, and objective indicia)
- In re Rijckaert, 9 F.3d 1531 (Fed. Cir.) (inherency may not be used to supply unknowns; inherency requires necessity)
- PAR Pharm., Inc. v. TWI Pharm., Inc., 773 F.3d 1186 (Fed. Cir.) (inherency can supply a missing limitation if it necessarily is present)
- In re Best, 562 F.2d 1252 (CCPA) (applicant may be required to prove that a prior-art product does not possess a claimed characteristic; burden of proof same for inherency and obviousness)
- Consol. Edison Co. v. NLRB, 305 U.S. 197 (U.S.) (definition of substantial evidence)