I have absolutely zero understanding of patent law, and have only just discovered that it's illegal for me to reproduce a game called "9 Square in the Air" for personal use due to two "ornamental design" patents they were able to secure, and because of their price purchasing is out of the question as a college student. It may sound ridiculous, since I'm well aware no one is going to "come after me" over something I build for my backyard, but I'd like to obey the law.

My friend has argued that all I have to do is modify the design in some manner in order to achieve enough of a change for it to be legal. My question then stands, what is enough of a change for a patent to no longer apply?

For example, if the result is still 9 squares in the air using PVC piping, does it really matter what else I change since it will perform the same function?

The two design patents: US D650,445 and US D656,995. Also, US 7,608,000 is a patent created by some prior to them for the game idea itself (no idea how they got away with that).

  • I have had the same problem of wanting to build one myself. Would you be able to build it out of wood instead? would that bypass the patent restrictions, if it wasn't pvc pipe?
    – user3735
    May 6, 2013 at 22:46
  • 2
    The materials are not indicated in the patent, so I'm going to give an (un)educated answer that no, that probably wouldn't make a difference.
    – xtraorange
    May 7, 2013 at 2:41

3 Answers 3


USD656995 is an "ornamental design" for a 9-square game that includes telescoping legs. The test of another design is that it won't be mistaken for the patented design. Nine circles or hexagons would clearly qualify. If squares are required, then have the legs mid-span instead of at the corners, or make them wider flat plates at the top instead of the same size as the legs, etc.

  • Thank you for your response! Unfortunately none of the above suggestions are possible with PVC piping, though I greatly appreciate the input. If it has the same base design, but adds more to it (i.e. if I ran a PVC pipe around the perimeter at mid-height), would that be enough, or does it need to modify the base design rather than add to it?
    – xtraorange
    Mar 13, 2013 at 17:59

Any improvement that you make to the product or item.

  • 2
    No - it needs to be a change in the external look. Improvement implies functionality.
    – George White
    Mar 13, 2013 at 8:24
  • 2
    Paul, no offense, but you are way off. Search design-around strategies.
    – Yorick
    Mar 16, 2013 at 14:43

Removal of the telescoping legs is enough to differentiate from the patented designs.

Design Patents US D656,995 and US D650,445 should not have issued based on Prior Art, obviousness, and a lack of an "ornamental design". This 3x3 grid is purely utilitarian and lacks any ornamental features. These Design Patents both have Priority Dates of July 7, 2010.

Prior Art

12/5/2006 12:59:07 AM EDT Studio Gear - Build a custom studio shooting table for under $80.00 Building a Custom Studio Table for under $80

Two more examples that this is a non-ornamental design:

Grid Garden Watering System


More obviousness:

Does this double as a jungle gym?

Where Have You Gone, Monkey Bars?

Obviousness: telescoping PVC can be found in many DIY projects.

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