In a significant ruling on August 17, 2006, the Federal Circuit decided Conoco, Inc., et al. v. Energy & Environmental International, L.C., et al. (No. 05-1363), addressing patent infringement related to oil and gas pipeline efficiency technology. The patented process involved a stable, non-agglomerating suspension of a drag-reducing agent (DRA) in a suspending material, defined as “selected from the group consisting of water and water-alcohol mixtures.” The case hinged on whether the addition of MIBK (methyl isobutyl ketone), a common impurity in industrial alcohols, could avoid infringement by technically falling outside the defined “consisting of” clause.
Key Issue: The Meaning of “Consisting Of” in Patent Claims
In patent claims, the term “consisting of” is restrictive, typically limiting the scope to only the listed components. Here, Conoco argued that Energy & Environmental’s addition of MIBK, intended to avoid liquor taxes on pure alcohol, did not change the essence of the product and should not preclude infringement.
The court ultimately held that typical impurities, like MIBK in alcohol, do not prevent a finding of infringement if they are commonly associated with the components on the “consisting of” list. For those skilled in the art, MIBK would be seen as a standard impurity in alcohol, which does not significantly alter the nature of the suspension specified in Conoco’s patent.
Relevant Precedent: The Norian Corp. v. Stryker Corp. Case
In its reasoning, the court referenced Norian Corp. v. Stryker Corp., which clarified that added components unrelated to the invention’s purpose—like a spatula in a chemical kit—do not avoid infringement. Similarly, in Conoco, the court reasoned that the presence of a common impurity (MIBK) related to the invention’s purpose did not exempt Energy & Environmental from infringement.
Key Takeaways:
- Unrelated Additions: If an added component is unrelated to the invention’s purpose (e.g., a spatula in a chemical kit), it does not prevent a finding of infringement.
- Related Impurities: If the added component is related to the invention’s function and is a typical impurity associated with a component on the “consisting of” list, infringement is still not avoided.
- Future Considerations: The court left open the question of whether a related component not typically associated with a “consisting of” component might avoid infringement in future cases.
This ruling clarifies how courts interpret “consisting of” in patent claims, particularly when considering typical impurities or elements directly connected to the invention’s function.
If you’re facing questions about claim interpretation or infringement in patent cases, reach out today at (949) 433-0900. I can help you navigate complex claim issues and strengthen your patent protection strategy.