Conducting a Preliminary Patent Search

You’re feeling ready to start the patent application process for your invention, but aren’t really sure how to proceed. You have your inventor’s notebook; you’ve done some online and in-store product research and have not found a product like yours in the market. Before you move on to applying for patent for your invention, it’s necessary to conduct a preliminary patent search.

A preliminary patent search will help you discover whether or not there is a patent already in existence for your invention. The importance of this step should be stressed. You wouldn’t want to work on developing a product that already has a patent on file with the United States Patent and trademark office (USPTO). Failure to do a good search puts you are risk of infringing on another person’s intellectual property and worst yet, you could hit a major legal and financial wall head on.

Now let me warn you, during your preliminary patent search it is very likely that you will find a similar patent. Even though the feeling is similar to going to a party and seeing someone wearing your exact same dress; don’t be discouraged, this doesn’t necessarily put the break on your invention. Your invention could have enough unique features and benefits, which set it apart from existing patents, allowing you to continue developing your idea.

When performing your preliminary patent search, there is something called, “Prior Art” you should know about. Prior art is any body of knowledge as related to your invention. These can be previous patents, journals, articles, any type of data book, catalogs, public discussions and more. When conducting your preliminary patent search you are in essence looking for prior art, this helps build a case showing that your invention is novel and proves non-obvious legal conditions that you will need to be granted a patent.

You can conduct your own preliminary patent search and save yourself some of your hard earned equity. Because as we know during the beginning stages of an invention, most inventors self-fund their projects. All you need to start your search is a computer with internet access and a printer. The USPTO has libraries called the Patent and Trademark Depository Library (PTDL). These libraries allow the USPTO to receive information from inventors and publish patent and trademark information to the general public.

You can search the USPTO library collections online free at There you will be able to search patents which were issued after 1976. You can also search patents issued between 1970 & 1975, granted you know the patent number and the patent classification. Again, don’t be discouraged if you find similar patents. Patents contain lots of wordy legal jargon which can leave you scratching your head; so it is suggested you go straight to the diagrams and drawings when researching patents. According to an article in, “only 2 to 3 percent of products with granted patents ever make it to the market.” Finding a patent which relates to you invention could turn into a new opportunity; if the product for which there is a patent already on file is not in the market you may consider contacting the patent owner and cutting a deal. Many times, patent owners which products they have not fully developed and taken to the market will accept money to transfer the patent or you could work out a partnership deal. Either way, you’d be one step ahead because you just cut out the patent process from your steps.

In your search on, you will be using the advanced search feature. There are a few guidelines to help you conduct a successful search. It’s important you use parenthesis and the use of booleans, AND, OR, & AND NOT can help you narrow down your search to specific items. Without parenthesis, your booleans will associate from left to right. For more information, visit the the United States Patent and Trademark Office Help pages.

To get started with your research, you should follow these steps:

Open you web browser and on the address line type This will bring you to the main page of the United States Patent and Trademark Office website. The page can look extremely overwhelming at first sight, but don’t fret. Just following the steps.

On the left hand side there is a menu bar, click on “Patents”, this will expand the caterogy. There you can then select “Search Patents”. This will bring you to a page that has a box titled “Query”. There you will enter your keywords, similar to the keywords you would use when conducting online research.

Here’s a little example of a keyword search. Let’s say your product is a baby temperature blanket that takes a babies temperature just by placing it over the baby. You might want to search the words baby, blanket, thermometer, among your word. So you could use of the of the following expressions:

Baby AND (blanket OR thermometer) – this search will find all patents containing to Baby Blanket AND Baby thermometer
Baby OR (infant AND newborn) – this search will find all patents containing the words baby, infant and newborn

Don’t stop on your first search, use as many keywords as possible. When you find similar patents, print them out and keep these in a folder; when you are ready to apply for your patent you can bring these documents to your patent attorney and you could save yourself a couple hundred dollars. As an endnote, patents do expire. Patent applications filed before November 1999 expire 17 years from the date issued. Patent applications filed after November 1999 will expire in 20 years from the issue date. When a patent is issued, the patent owner must pay maintenance fee on their patent three times during the life of their patent; failure to pay the maintenance fee will result in the patent becoming “abandoned” making the patent unenforceable.

So roll-up your sleeves turn on that computer and let the search begin.