Model Builders Inc Blog

Is a product model or prototype required with a patent application?

Posted by Hal Chaffee on Mon, Oct 01, 2012 @ 11:48 AM

"Is a product model or prototype required with a patent application?" is a question we often hear. The answer today is no. The US Patent of Act of April 10, 1790 required a patent model. if possible. The  US Patent Act of July 4, 1836 required a patent model until 1880. Each inventor submitted a model "not more than 12 inches square" along with the patent application as an aid to the patent examiner to determine the originality of the invention. 

Prototypes, although not ever required, are usually advisable because they help others visualize the idea and prove that it works. Prototypes help a lot when you are trying to sell or license your patent idea to others. They also help when you go to a manufacturer so they can determine what the parts might cost.

Rarely can you build a prototype straight from the patent drawing(s). Here are some important points to keep in mind when having a prototype built of your patent idea.

  • Patent drawings illustrate the concept and are not meant to be engineering drawings. Measurements when shown in a patent are often a range within which the concept can work. However, many inventors we talk with think all they need to give us is the patent illustrations to have us build a prototype.

Sawhorse Patent

  • To build or hire someone else to build a prototype requires that you provide or they create detailed drawings with measurements. If you go to a model shop, an industrial design firm or engineering firm with just your patent they will have to first create drawings with measurements that they can build from.
  • First you may want to do a series of rough prototypes and have people test them until you determine potential problems and what variation of your idea has the best chance of being sucessful.
  • Inventors sometimes want to build a final product model of their patent idea and then go out and market it to others.  It is probably a waste of money to try to build the final product in the beginning. If the idea is licensed to others they may want to modify your patent idea or use different production equipment which can't make the product exactly like yours.  So the money you spent to make your idea exactly like you wanted may be wasted. Furthermore you should probably use a rough prototype with people to test and see if it works well or needs improvement before it goes into production.
  • We sometimes see inventors whose ideas when built as they describe, don't work. One patent was for something that worked in more than one direction.  The product as shown in the patent illustrations looked to the inventor and the patent examiner like a product that would work.  The inventor even had a series of drawings showing step by step how it worked.  However as we started to build the prototype it didn't work as drawn.  Fortunately we were able to change the design to make it work. Until you build a prototype and test it you may not know for sure if the idea works at all. 


If you are interested in the history of patents to gain a perspective on what works you may want to read "The Patent Book An Illustrated Guide and History for Inventors, Designers and Dreamers" by James Gregory and Kevin Mulligan. A&W Publishers, Inc. New York, New York. 1979. ISBN: 0-89479-037-4. Hardcover: 126 pages. This book covers the history of patents, who needs a patent, how a patent is obtained, the proper selling strategy behind the invention, and a list of common mistakes made by new inventors and how to avoid them. Along with an illustrated review of 50 famous patents – some of which changed the course of American history – are actual drawings from the patents. Hopefully this book enables you to see why some ideas succeeded and others failed.

If you have any questions or would like to discuss a patent model, prototype or other projects contact us at Model Builders, Inc. 773-586-6500 or .



Tags: product model, prototype, product models, prototype model