When a patent talks about a ‘preferred embodiment’ but goes onto to describe other particular details of a product am I right in thinking that none of those additional details are protected?

The patent is EP1301412B1

  • thanks for responses so far, the patent is EP1301412B1. The patent is against the locking mechanism and not the box, but describes the box in so much detail in the preferred embodiment when it is nothing to do with the claims Aug 6, 2020 at 19:51
  • Most of the claims are, in fact, to a box with a lid, with a tamper-evident lock having certain physical characteristics. No specific box or lid details are part of those claims. One claim is to the tamper-evident lock that is suitable to be attached to a box with a lid. If not for that claim, a lock mechanism, sitting on a shelf on its own, would not directly infringe.
    – George White
    Aug 7, 2020 at 3:23
  • I added a bit to my answer based on the link to the patent.
    – Eric S
    Aug 7, 2020 at 22:42

1 Answer 1


What is protected is what is described in the claims. Nothing more, nothing less. While the rest of the patent describes the background, the invention and how it works, only what is in the claims matters with respect to what is protected. It is very important to make sure you are assessing the claims of an actual patent and not an application. Claims in applications are almost always broader than what ends up in the granted patent.

Looking at the linked patent, the invention is a tamper evident closure for a box. While the box and lid are described and part of the device, it is the tamper evident closure itself that is the actual invention. The addition of the box and lid are necessary to describe how the invention works. Again, what is patented is limited to the claims.

With respect to your question, in no way should you assume only the preferred embodiment is protected. In my experience patent attorneys only describe embodiments they plan on protecting. They may not get all those protections based on how the claims work out, but they surely want to protect them.

  • An aside - US rules require a patent application to enable the claims with sufficient detail for at least one embodiment. It also requires the applicant to show the "best mode" - the best way known to the applicant at the time of filing . It does not require that mode be labeled as such. If four embodiments are described, there is no need to point out which is the best mode. It is no longer considered a good idea to label something a preferred embodiment/best mode. It is feared that a judge will read the details of that embodment in to the claims, narrowing the claim interpretation.
    – George White
    Aug 6, 2020 at 3:38
  • @GeorgeWhite As usual, your comments add a lot of insight. I'd encourage your posting the comment as an answer as I think it complements mine.
    – Eric S
    Aug 6, 2020 at 14:11
  • thanks for responses, the patent is EP1301412B1. Its just that it describes in detail the box, its construction and features, which really has little to do with the claim. Aug 6, 2020 at 16:06
  • @EricShain - thanks, re-reading the question, I don't see that my comment addresses the question.
    – George White
    Aug 6, 2020 at 16:20
  • @JonnySegway You should consider adding the patent number (and a link) to your question. If there is a particular embodiment you want to know is protected, you can ask that and we can attempt to interpret the claims.
    – Eric S
    Aug 6, 2020 at 18:24

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