Best Lock Corp. v. Ilco Unican Corp.
94 F.3d 1563 (1996)
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Rule of Law:
A design for an article of manufacture is considered functional, and thus not ornamental and invalid for design patent protection under 35 U.S.C. § 171, if the design is dictated solely by the article's function, such as the need to precisely mate with another part.
Facts:
- Best Lock Corporation manufactures and sells locks and keys for security at various facilities.
- Best Lock is the assignee of U.S. Design Patent 327,636 ('636 patent), which claims the ornamental design for the operative portion of a key blade blank.
- The patent covers only the key blade profile, not the entire key or the lock-and-key assembly.
- The shape of the patented key blade is required to fit into the corresponding lock's keyway for the key to function.
- Best Lock also holds a design patent on the keyway designed to mate with the key blade claimed in the '636 patent.
- Ilco Unican Corp. (Ileo) manufactures and sells replacement key blanks.
- In 1993, Ileo copied the key blade design shown in the '636 patent and distributed key blanks with that shape.
Procedural Posture:
- Best Lock Corporation sued Ilco Unican Corp. in the U.S. District Court for the Southern District of Indiana, alleging infringement of U.S. Design Patent 327,636.
- Ilco Unican counterclaimed, seeking a declaratory judgment that the patent was invalid.
- Following a ten-day bench trial, the district court held that the '636 design patent was invalid because the shape of the key blade was dictated by its function.
- Best Lock Corporation, as appellant, appealed the district court's judgment of invalidity to the U.S. Court of Appeals for the Federal Circuit; Ilco Unican Corp. is the appellee.
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Issue:
Does the specific profile of a key blade, which must match a corresponding keyway to function, constitute a functional design that is not ornamental, thereby rendering its design patent invalid?
Opinions:
Majority - Lourie, Circuit Judge
Yes. The design of the key blade is dictated solely by its function, which is to fit into its corresponding lock's keyway, and is therefore not ornamental and the patent is invalid. The court reasoned that the patent claim is limited to the key blade itself, not the entire key or the key-and-lock system. It is undisputed that the key blade must have the patented shape to perform its intended function. Because no other shape would allow the blade to fit the corresponding lock, the design is dictated solely by function. The availability of other designs for different key-and-lock systems is irrelevant because the patent claims only the key blade, for which there is no alternative functional design. Any aesthetic appeal is merely an inevitable result of its necessary functional shape.
Dissenting - Newman, Circuit Judge
No. The arbitrary design of the key profile is not rendered functional simply because it must mate with a matching keyway. The dissent argues that the existence of thousands of alternative key blade profiles demonstrates that the choice of this particular design was not dictated by function. The majority improperly conflates the functionality of the article (the key) with the functionality of the design itself. That two articles are designed to work together does not deprive the design of its ornamental nature under patent law. The specific design of the key profile is an arbitrary, primarily non-functional choice that should be eligible for design patent protection.
Analysis:
This decision significantly clarifies the functionality doctrine in design patent law, particularly for component parts of a larger system. It establishes that if a component's specific design is dictated by its need to interface with another part, it is legally functional and cannot be protected by a design patent. This ruling narrows the scope of protection for such interlocking designs, even if the overall system could have been designed in many alternative ways. Consequently, it forces manufacturers seeking to protect such designs to rely on utility patents, which protect function, rather than design patents, which protect non-functional ornamentation.
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