The Spotlight on an Unexpected Star: A Metal Leg
In the glamorous world of intellectual property law—where patents, trademarks, and obscure definitions collide—there comes a moment every so often when something unexpected takes center stage. This time, it wasn’t a tech breakthrough or a fashion logo. It was… a metal leg.
Yes. A leg. A shiny, two-part, cylindrical support leg for restaurant equipment. And not just any leg—Kason Industries’ leg, which dared to dream big and asked the U.S. government, “Can I be a trademark?”
Spoiler alert: the government said no. But the reason why is actually a great crash course in the weird world of design law.
Design Patent vs. Trademark (Trade Dress)
Let’s start with the basics. If you want to protect how your product looks, you have two options: get a design patent, or register it as a trademark (also called trade dress when it involves product shape). Now you may think, “Cool, same thing, right?”
Wrong. These two legal tools look similar—they even use the same words like functional and ornamental—but they mean very different things.
Kason Industries designed a telescoping leg for commercial kitchen equipment—one part slides into another, adjusts the height, and keeps bugs from moving in.
They had already gotten:
• A design patent (yay! It looks cool), and
• A utility patent (yay! It works cool), and now…
• They wanted to register the shape of the leg as a trademark.
Functionality: The Key Legal Question
The Trademark Trial and Appeal Board (TTAB)—a group of very serious people who spend their days judging what can and can’t be a brand—looked at Kason’s leg and asked a simple question: “Is this thing functional?”
Now here’s where the rubber (or metal leg) meets the road.
In design patent law, a design is considered functional if it’s “dictated by function”—in other words, if the product has to look a certain way in order to work. If there are other ways to design it that would work just as well, then the design might be considered ornamental and eligible for a design patent.
In trademark law, however, the test is broader. A feature is functional if it is:
1. Essential to the use or purpose of the product, or
2. Affects the cost or quality of the product.
Even if there are alternative designs out there, a feature can still be functional for trademark purposes if giving one company exclusive rights to it would put competitors at a disadvantage. That’s a stricter test—and it’s what sunk Kason’s ship. Essentially, it’s harder to get three-dimensional products protected under trademark or trade dress because the definition of “functional” is broader.
The TTAB’s Ruling
In Kason’s case, the TTAB said, “Look, your leg is great, but it basically has to look like what you created in order for it to work.” Their own utility patent described the telescoping, cylindrical shape as essential for smooth height adjustment and bug prevention. The Board essentially said: “This isn’t ornamentation—it’s engineering.”
So, Kason’s request for a trademark fell flat. Why? Because trademark law doesn’t like giving permanent monopolies on things that actually work. If they let that happen, you’d end up with a world where one company owns all “wheel-shaped wheels” or “box-shaped boxes.”
A Spoonful of Illustration
Let me give you another example.
Let’s say you design a spoon that has a handle shaped like a twisting vine with delicate leaf patterns. Under design patent law, this vine-shaped handle could be considered non-functional, because the aesthetic flourish isn’t required for the spoon to work. You can still scoop up soup whether the handle looks like a stick or a grapevine. So long as the vine design is not dictated by function—meaning you could have made the handle look like anything else—it qualifies as ornamental and is eligible for a design patent.
Now imagine that years later, you try to register the same handle design as a trademark—arguing that people now associate the vine design with your brand.
Enter trademark law. A trademark examiner might say:
“Sure, it’s pretty. But that twisty shape actually gives users a better grip, or maybe it helps prevent the spoon from slipping into the pot. That’s a functional benefit.”
In trademark law, even aesthetic features can be considered “aesthetically functional” if they give the product a commercial advantage unrelated to brand identity—for example, by improving ergonomics or by being the main reason someone buys the product.
So even if the design is non-functional enough to get a design patent, it might still be too functional to serve as a trademark.
Secondary Meaning (Acquired Distinctiveness)
Going back to the metal leg—even if the design hadn’t been functional, Kason had another hurdle: they had to prove that when people saw this leg, they thought, “Ah yes, that’s a Kason leg!”
This is called acquired distinctiveness, or secondary meaning.
Kason gave the Board some numbers: about 3.2 million legs sold over 19 years, and nearly $11 million in revenue. Not bad! But they spent a total of about $35,000 over all that time on advertising this product, which comes out to a whopping $1,800 a year, which is basically a lemonade stand marketing strategy.
And—most importantly—they didn’t provide any direct evidence. No surveys, no consumer declarations, no glowing Yelp reviews saying, “I knew it was Kason the moment I laid eyes on that cylindrical leg.”
So, the Board wasn’t impressed. “All you’ve shown,” they said, “is that you sell a good product. But that doesn’t mean people recognize your leg the way they recognize the Nike swoosh.”
Key Takeaways from In re Kason
1. Don’t assume a design patent guarantees trademark rights.
2. Functionality in trademark law is the fun police—it ruins everything cool that actually works.
3. If you want to turn your product’s shape into a trademark, make sure it’s doing less and looking more.
4. And finally, if your whole legal strategy relies on people recognizing your leg, maybe spend more than $1,800 a year telling them about it.
Because as the TTAB made clear, just because your leg is pulling its weight doesn’t mean it gets to be a brand. Sometimes, a leg is just a leg—even if it’s really good at standing.
Until next time, I’m Adam Diament, and keep on inventing.