SOUTHWIRE V. CERRO WIRE: Sep. 8, 2017. Before Lourie, Moore, and Hughes.
- The Federal Circuit held that the Patent Trial and Appeal Board erred in relying on inherency in making a determination of obviousness, because PTAB did not find that the Summers reference necessarily would achieve a 30% reduction in pulling force, but rather finding that it merely renders that limitation obvious.
- The Federal Circuit concluded that, while PTAB erred in relying on inherency, the error was harmless because PTAB made the necessary underlying factual findings to support its determination of obviousness. Specifically, the CAFC held that the claimed method simply applies the same process for the same purpose as discussed in Summers.
Southwire appealed the Patent Trial and Appeal Board’s decision in an inter partes reexamination that claims 1–42 of U.S. Patent No. 7,557,301 are unpatentable under 35 U.S.C. § 103. CAFC affirmed.
- Obviousness—Inherency: The Federal Circuit noted that the use of inherency in the context of obviousness must be carefully circumscribed because that which may be inherent is not necessarily known, and that which is unknown cannot be obvious. The CAFC further explained that while inherency may supply a missing claim limitation in an obviousness analysis, the limitation at issue necessarily must be present in order to be inherently disclosed by the reference.
- Obviousness—Inherency: The CAFC agreed with Southwire that PTAB erred in relying on inherency in making its obviousness determination. The ’301 patent is directed to manufacturing an electric cable, and involves a lubricant that is used to reduce the pulling force required to install the cable. PTAB found that because the claims recite “a preselected lubricant” chosen to “provide a reduced coefficient of friction,” they “require an amount of lubricant which meets the stated reduction in [coefficient of friction].” PTAB also found that because Summers teaches reducing the coefficient of friction using a lubricant, Summers inherently teaches the 30% reduction limitation because Summers renders it “obvious to have selected [lubricant] amounts” that achieve that result. The CAFC concluded that PTAB erred in relying on inherency without finding that Summers necessarily would achieve a 30% reduction in pulling force, but rather finding that it merely renders that limitation obvious. However, the CAFC further concluded that PTAB’s error was harmless because, although it improperly invoked inherency, it need not have because PTAB made the necessary underlying factual findings to support its obviousness determination.
- Obviousness: The CAFC held that PTAB made the necessary underlying factual findings to support its determination of obviousness. Specifically, the CAFC agreed with PTAB that the claimed method simply applies the same process for the same purpose as discussed in Summers—i.e., to reduce the pulling force on a cable for ease of installation. Further, the CAFC noted that there is no evidence that the claimed 30% reduction in pulling force would have been unexpected or unattainable from the process disclosed in Summers. The CAFC also noted that because Summers never quantified the reduction in pulling force, this does not preclude the possibility, or even the likelihood, that its process achieved at least a 30% reduction, especially since its stated purpose was the same as that of the ’301 patent. Finally, the CAFC stated that neither the patent itself nor any evidence proffered by Southwire during the reexamination provides any indication that the 30% reduction limitation was something other than an observed result of an old process, written into the claim in an attempt to avoid the prior art process.