There are a number of different places where you can do that, most notably including the US Patent and Trademark Office [look for its PATFT system], but instead I want to write about a little-known product (service?) from Google called Google Patent Search. Why? Because I find it far easier to dig around in the Google system than the USPTO system.

For example, if you've ever been to a café and gotten a hot cup of coffee, you've probably also gotten a cardboard hot cup holder. I'm in a coffee shop as I type this and this particular place uses "EcoGrip" holders, with a patent number conveniently printed on the holder itself: 5425497.

Armed with that, we can easily search the Google patent database and find out that this particular product is patented by someone called Jay Sorensen and that it's described as

"A cup holder is disclosed in the form of a sheet with distal ends. A web is formed in one of the ends, and a corresponding slot is formed in the other end such that the ends interlock. Thus the cup holder is assembled by rolling the sheet and interlocking the ends. The sheet can be an elongate band of pressed material, preferably pressed paper pulp, and is preferably formed with multiple nubbins and depressions. In one embodiment, the sheet has a top and bottom that are arcuate and concentric, and matching webs and cuts are formed in each end of the sheet, with the cuts being perpendicular to the top of the sheet."

Very interesting (or, alternatively, far more than you ever wanted to know about these cup holder devices) but where this gets interesting is when you start to actually search for synonyms or competing products. Search for paper cup holder and there are now many dozens of matching patents, which means if you want to invent something in this area, you will have to careful wind your way around what patent lawyers love to call "prior art".

You might want to compare these results with those that you would get on the USPTO, even though I'm demonstrating Google's solution here. One big problem is highlighted in the FAQ for Google Patent Search: "We don’t currently include patent applications, international patents, or U.S. patents issued over the last few months, but we look forward to expanding our coverage in the future." That could be a big issue, and it's rather surprising, really, given that Google can clearly manage zillions of records. By comparison, the seven million patents awarded to-date are a tiny, tiny subset of the pages indexed in the main Google engine!

Anyway, good luck with your patent search!