Valentine’s Day brings out all kinds of creativity—and some people even turn romance into patented inventions! Let’s look at some of the strangest love-related patents ever filed. I’ve kept these suitable for all ages so any little ones overhearing this won’t learn new and exciting inappropriate things to say at school.

This Valentine’s Day week I’m talking about the intellectual property of love, but what I’m saying applies year-round.

Ok, here we go:

💡 Patent US5727565A is for a “Kissing Shield,”—a plastic barrier for germ-free smooching. This invention from 1995 is a thin, flexible yet impervious membrane you can slide over a frame on a stick and place over your mouth. It was created to help prevent the spread of HIV, herpes, and other viruses that can be transmitted through a kiss. The inventor notes it’s also good for preventing getting lipstick on someone’s face with a kiss to the cheek. As a nice touch, in the drawings, the frame is heart-shaped. I don’t recall this ever becoming popular, so this is a good example to show that getting a patent is no guarantee of financial success. This patent has expired, so you can make and sell this if that tickles your fancy!

💡 Patent CN202444846U is for a mold that guides growth of fruits into a heart shape. The illustration shows a melon, and the translated claim says “melon and fruit.” Whether this is meant to cover all fruits is probably clear in the original Chinese version, but even if it doesn’t,it would probably make any later application in any country for a similar method of growing any kind of fruit (including fruits we think of as vegetables, like zucchini) into a heart shape rejected for being too obvious, because even a non-gardener like me instantly thought, “hey, I bet you could do that with an apple, a tomato, or a bell pepper, too.” Obviousness is a common reason for patent applications being rejected. It can be a subjective call, too, so it’s a rejection a patent attorney may be able to help you overcome with a good argument as to why your invention isn’t obvious. Sometimes, though, it really is obvious, and a patentability search can help you know whether that’s the case before you spend money on filing a patent application that will be rejected like a bad date.

💡 For the dates that lead to marriage, Patent US6434805B2 is for a method of making a heart-shaped diamond out of two pear-shaped diamonds. The inventor said this solved the problem of creating a heart shape from diamonds and other gemstones that don’t lend themselves well to being ground into a heart shape, like some softer gemstones do, and the problem of cutting a diamond into a heart shape being more difficult than more common shapes. This patent expired a mere four years after it was granted, when the first maintenance fees due weren’t paid. That usually happens when the owner isn’t making enough money from the patent to warrant paying those fees. That suggests these weren’t such big problems after all, that someone else had a better solution, that people didn’t want two diamonds stuck together, or that the inventor didn’t have a good way to get the invention in front of the right manufacturers, marketers, or retailers. If you want to make money from an invention, you need more than just a patent. You need people or businesses who would want to buy it or license it and an effective way to get their attention.

So, what do these patents tell us? Patents are yet another legal tool that can take all the joy out of love and reduce romantic things to technical mechanics. No. Well, yes, but they can also protect inventions you have poured your heart into and protect inventions that can enhance your expressions of love.

If you have an invention you think others will love, it may be worth applying for a patent to protect your rights to your idea. You can talk with a patent attorney about whether applying for a patent is right for you and what the process of getting a patent involves.