Patent Searches and How to Find Similar Inventions. Episode 4

Why Do a Patent Search?

This episode will cover how to conduct a patent search to determine whether similar inventions exist that could prevent you from obtaining your own patent.

First, a disclaimer: There is an entire industry dedicated to patent searching. Many patent attorneys don’t conduct complex searches themselves but instead hire specialized patent search firms. This podcast episode is a brief introduction to the topic and cannot cover everything in depth.

The Main Reason: Cost

There is no legal requirement to conduct a patent search before filing a patent application. However, patenting an invention can cost tens of thousands of dollars—or even hundreds of thousands if you seek patents worldwide. Spending a little time and money on a patent search can save you from investing in an application that is doomed to fail because your invention already exists or is too similar to something else.

What is Prior Art?

In the previous episode, I introduced the concept of prior art—a term used in patent law for anything publicly known before you invented your product. A patent search is just one part of a prior art search, as prior art can include:

• Patents and patent applications

• Product catalogs

• Websites

• Any other publicly available information about similar inventions

How to Start Your Patent Search

The simplest way to begin is with a Google search. Type in a basic description of your invention and see if anything similar already exists. For example, if you invented a pencil with three erasers, you might start by searching “pencil with three erasers.” If nothing relevant appears, you may think you are in the clear—but don’t stop there.

General searches often miss relevant patents. Instead, you should use dedicated patent search databases.

Free Patent Search Databases

There are three websites I recommend for free patent searches:

• United States Patent and Trademark Office (USPTO) – www.uspto.gov

• Google Patents – patents.google.com

• Free Patents Online – www.freepatentsonline.com

The USPTO site is not user-friendly and only includes U.S. patents. For a broader search, Google Patents and Free Patents Online allow you to search international patents from countries such as China, Germany, and those in the European Patent Office.

No patent search is 100% perfect, as some patents may only exist in countries not included in these databases. However, these tools will give you a strong starting point.

How to Conduct a Simple Patent Search

Let’s go through an example. One of my favorite kitchen gadgets is the Oxo Good Grips 3-in-1 Avocado Splitter, Pitter, and Slicer.

Step 1: Keyword Search

• Go to Google Patents and type in “avocado slicer.”

• My search returned 234 results.

• To refine results, you can:

  • Sort by date

  • Filter by issued patents

  • Select specific patent offices

After scrolling, I saw a patent titled “Avocado Pitting Device”, which matched the product on Amazon. The patent application was filed on August 23, 2011. If I were searching back in 2011, I would compare my invention only to patents available at that time.

Step 2: Refining the Search

• If 234 results are too many, add more keywords.

• Searching “avocado slicer pitter” reduced the results to 71 patents.

• Read through patents and examine drawings to compare them to your invention.

Step 3: Comparing Similar Patents

After reviewing patents, I found Patent No. 7,421,786, which includes:

• A handle

• Blades

• A loop-style pitter

However, it lacked a slicing blade and a pitter with jabbed blades like the Oxo splitter. I also found Patent No. 5,115,565, which had slicing blades but a different pitter design.

Since the Oxo avocado tool received a patent, the inventors convinced the examiner that their design was new and non-obvious.

Advanced Patent Search Techniques

Classification Search

Each patent is assigned a classification number based on its technology type. To find the classification manual, search online for “Manual of U.S. Patent Classifications.”

For our example:

• Class 99: Food and beverage apparatus

• Subclass 538: Devices that separate internal portions

• Class 30: Cutlery-related devices

Your invention may belong to multiple classes, so check different classifications.

Forward and Backward Citation Searches

• Backward Citation Search:

  • At the bottom of a Google Patent page, you’ll see a “Patent Citations” section.

  • These references were cited as similar prior art by the inventor.

  • Reviewing these can help you find closely related inventions.

• Forward Citation Search:

  • Below “Patent Citations,” there is a section called “Referenced By.”

  • These patents came after the one you’re looking at and referenced it as prior art.

  • Checking these can help you find newer patents relevant to your invention.

Key Takeaways

• Three search methods:

  • Keyword search (basic search using invention-related terms)

  • Classification search (searching based on patent classification numbers)

  • Forward and backward citation search (examining related patents)

• Patent searches require skill. A poorly conducted search might miss relevant patents, while an overly broad search may overwhelm you with irrelevant results.

• Hiring a professional may be worth the investment, especially for complex inventions.

Important Note: Patentability vs. Infringement

This episode focused on patentability searches—determining if you can get a patent. However, even if you receive a patent, you could still infringe on someone else’s existing patent.

To check whether you can legally sell your product without infringing, you need a freedom-to-operate search, which I’ll cover in a later episode.

Next Episode Preview

In the next episode, I’ll discuss who you should and shouldn’t tell about your invention and the deadlines for filing a patent application if you’ve already shared your idea.

I’m Adam Diament of Diament Patent Law. Until next time—keep on inventing!