Ring & Pinion Service Inc. v. ARB Corporation Ltd. (Fed. Cir. 2014) Opinion
Panel: Moore (author), Clevenger, Reyna
One of the main justifications for the doctrine of equivalents is that it prevents patents from becoming worthless as a result of unforeseeable changes in technology. As Judge Rader observed in his concurrence in Festo:
A primary justification for the doctrine of equivalents is to accommodate after-arising technology. Without a doctrine of equivalents, any claim drafted in current technological terms could be easily circumvented after the advent of an advance in technology. A claim using the terms “anode” and “cathode” from tube technology would lack the “collectors” and “emitters” of transistor technology that emerged in 1948. Thus, without a doctrine of equivalents, infringers in 1949 would have unfettered license to appropriate all patented technology using the out-dated terms “cathode” and “anode”.
This case deals with the inverse: whether the doctrine of equivalents can apply when a technology was foreseeable at the time of patenting.
R&P sought a declaratory judgment that its product did not infringe ARB’s patent. The parties agreed that R&P’s product literally met all of the limitations of claim 1 of the patent except for one, which they agreed was present as an equivalent in R&P’s product. However, they disagreed over whether the doctrine of equivalents could apply since the equivalent would have been foreseeable to a person having ordinary skill in the art at the time the application was filed. The parties thus stipulated that infringement in this case turned on the legal question of whether “foreseeability of an equivalent at the time of application prevents use of the doctrine of equivalents.” The district court ruled that foreseeability did not preclude application of the doctrine of equivalents, but granted summary judgment to R&P on a vitiation theory.
On appeal, the Federal Circuit agreed with the district court that forseeability is not a limitation on the DOE:
There is not, nor has there ever been, a foreseeability limitation on the application of the doctrine of equivalents. It has long been clear that known interchangeability weighs in favor of finding infringement under the doctrine of equivalents. [the CAFC cites a number of cases discussing interchangeability, including Warner-Jenkinson and Graver Tank]. Excluding equivalents that were foreseeable at the time of patenting would directly conflict with these holdings that “known interchangeability” supports infringement under the doctrine of equivalents. We conclude that the foreseeability of an equivalent at the time of patenting is not a bar to a finding of infringement under the doctrine of equivalents.
Slip Op. at 4-5.
Nor did it matter that the claim element involved was drafted in means-plus-function terms. The doctrine of equivalents applies equally to these types of claim terms, and there is no “partial” foreseeability limitation here. “Nothing in Chiuminatta or in any other case cited by R&P supports its assertion that there exists a foreseeability exception to the doctrine of equivalents that applies to means-plus-function or any other claim terms.” Slip Op. at 7.
The defendant here thus lost on infringement because there is no foreseeability limitation on the use of the doctrine of equivalents. Furthermore, the stipulation that the parties entered into precluded consideration of other potential issues: the district court erred by not enforcing that stipulation.
Policy rationale: Given that a primary rationale for the doctrine of equivalents is to address the problem of after-arising technology, what is the basis for concluding that the DOE also extends to foreseeable technologies, i.e.: those that the patent drafter could have included in the patent. While Ring & Pinion v. ARB does not offer an explanation, the Supreme Court’s opinion in Festo does:
In other words, patent drafters are not omniscient; they are human beings who are using an imperfect tool (language) to describe an intangible concept. In addition, patent drafters are only one person or a few people, whereas competitors seeking to design around the patent may be numerous (the game show 1 vs. 100 was premised on a concept like this). Under this view, the doctrine of equivalents tries to level the playing field.
Furthermore, although not discussed by the court, foreseeability remains an important component of the prosecution history estoppel analysis. Under Festo, the presumption arising from a narrowing amendment can be rebutted if the patentee can show that the equivalent was unforeseeable at the time of amendment. 535 U.S. at 741. But Ring & Pinion did not assert that there was a narrowing amendment, so this application of foreseeability was irrelevant.