Company A obtained a design patent(unpublished)in 1990 which was granted and enforce. Company B during the enforcement period of 1995, decided to apply for a utility patent, using the methods of reconstructing the design, now both A and B designs are for a article of manufacturing and both have similarities in design. Company B after extensive prosecution was able to obtain a utility patent for their invention design in 1998. Company A design patent expired in 2003 (14 years Period), which is now become public domain. Company C wanted to manufacture Company A design, not knowing that Comp B used the design for their invention. Comp. B filed suit against Comp. C in federal court, allegations of infringement. Can B successfully sued C for a design patent which is public domain and why are Patent Designs not Published.

  • This is just a prime examples, don't want a burst anyone bubbles. You know this can and will happen
    – meta9
    Mar 30, 2015 at 22:05
  • If C utilizes the same method/process as claimed by the utility patent, and if B can prove that, B can file a suit against C. C will likely obtain an expert opinion challenging the validity of the utility by arguing that the method/process is obvious in light of the design patent. It's very likely B and C will settle before the case ever goes to the court, or engage in a lengthy litigation before someone calls quit and both parties settle out of court anyway.
    – daniel
    Feb 24, 2016 at 3:00
  • Company B's utility patent filed in 1995 probably expired in 2015. Did company C start manufacturing before then?
    – Eric S
    Feb 18, 2017 at 15:49
  • @daniel Your comment is actually a good answer (better, I think then the only one provided). Perhaps you should submit it as an answer.
    – Eric S
    Feb 18, 2017 at 15:51

2 Answers 2


One, granted design patents are published. Design patents and utility patents cover different aspects of a product. Design patents cover the ornamental features of a product, not the function of a product. For example, the design patent was for an airplane and B made an actual airplane that looked like the drawings in the published design patent. If B gets one or more utility patents on aspects of the plane then C could certainly build an airplane that infringes on B's patents.

It is possible, but unlikely, that A's design patent constituted enabled prior art to the claims B was granted. In that case, C might be able to get the patent invalidated in an IPR proceeding.


In 1990, patent applications were not published until they were granted. If they actually obtained a design patent, it should have been published as a patent grant. Certain granted patents are not published, but that is a very narrow category (basically national security). If you provide some of the patent numbers, you will probably get much better answers.

  • This does little to answer the question which relates to companies B and C not company A.
    – Eric S
    Feb 18, 2017 at 15:51

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .