Are patents the only type of IP right that applies to physical, functional things, or can copyright and trademark also apply?

For example, say a third party wants to manufacture and sell a purely functional part of a car, like part of the engine, not something like a badge or hood ornament that's likely trademarked. If the part is not covered by a patent, are they in the clear? Or could some other type of IP right apply to, say, a bolt hole pattern?

3 Answers 3


Copyright and trademark are limited by the functionality doctrine which is the legal principle that denies trademark and copyright the ability to restrict the reproduction of purely functional features.

17 U.S.C. §101 defines the notion of a "useful article":

A "useful article" is an article having an intrinsic utilitarian function that is not merely to portray the appearance of the article or to convey information.

17 U.S.C §103(b) limits the applicability of copyright on useful articles:

This title does not afford, to the owner of copyright in a work that portrays a useful article as such, any greater or lesser rights with respect to the making, distribution, or display of the useful article so portrayed than those afforded to such works under the law...

In other words, you cannot stop someone from making and distributing a useful article merely because you have previously expressed the useful article in a copyrighted work.

For trademark, the most significant court case is TrafFix Devices, Inc. v. Marketing Displays, Inc., which held that trademark cannot restrict distribution of functional components. The plaintiff in that case claimed that their product's spring mechanism was legally protected as a visually distinctive part of their product's trade dress, but the Supreme Court held that the spring mechanism was ineligible for trademark protection insofar as it was a functional component of the product.

  • Good answer. Without checking in detail, I think the trademark and "trade dress" restrictions on any functional feature are somewhere in 15 U.S.C., from the Lanham Act.
    – feetwet
    May 4, 2016 at 21:22

"Trade secret" is one other common protection for functional IP. Although defined and protected in statute (e.g., 18 U.S.C. §1839(3)), it depends primarily on contractual protections like confidentiality agreements rather than statutory protection. However, if the owner of IP takes sufficient care to protect it from disclosure, competitors can be enjoined from its use if they were found to have "misappropriated" the IP, which has a lower threshold than "stolen."



Registers design is a type of IP that relates to the form of an object i.e. the way it looks.

Also, if the work is an artistic expression, like a sculpture, then copyright applies.

Absent these you can make whatever you like.

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