Here is a mistake we see time and time again. Many inventors fall into the trap of describing their invention with language that discloses only one way of making their invention. They become so focused on their specific way they are making and building their product they often forget there could be alternatives they have not yet considered. Future experimentation and fabrication may result in one or more changes or departures from the invention (which is good), however, while these changes may be in the spirit of the invention, if they were not described in the provisional application then they will not serve as “priority” for later filed patents. This is just a fancy way of saying you will not get credit for something at the time you filed your provisional if that something was never included at the time of filing the provisional.
This scenario can have consequences as shown in the May 2018 case of Three Enterprises, LLC v. SunModo Corp., in which Three Enterprises sued SunModo for infringing its patents on roof mounted sealing assemblies. Since the sealing assemblies were available to the public before the filing date of the non-provisional patents these patents really needed the benefit of the priority claim back to the filing date of an earlier filed provisional application. Why you may ask? Because remember selling a product more than 1-year before your patent is filed is grounds to have your patent rejected in the US (in most countries you do not even get this 1-year window). So here, the inventor really needed his provisional application in order to prove he filed a patent application prior to his first sale. (for more information on this topic read our post on 102 dates)
The inventor’s patent claimed washerless assemblies using a wide range of attachment brackets. However, the provisional application only disclosed one washerless assembly, and it was always described as having one very specific type of attachment bracket. Even though there was boilerplate language in the specification providing that the patent covers all “modifications, permutations, additions and sub-combinations” the court concluded that this was not sufficient to show written description support for the use of all attachment brackets. Regarding the assemblies having a washer, the court concluded that the provisional application only disclosed the washer being positioned above the roof flashing and did not show an adequate written description of what the inventor claimed, a washer above or below the flashing. Because these important features were not included in the provisional application, the claims of the patents-in-suit where deemed invalid.
While this is no doubt a sobering example, it also provides good guidance on how to draft a proper provisional patent application. Below is a checklist for writing a good provisional application.
- Have drawings that show all the elements of the invention in detail.
- Make sure all the important elements are labeled in at least one drawing with a number that is unique to that element.
- Describe (don’t just name) each element in the detailed description.
- Use language that doesn’t lead one to believe that there is only one way to make the invention. Give alternatives for each element and alternative ways of assembling the invention even if you don’t think that they are the best way, you may change your mind later.
- Go back and double check numbers 1 – 4.
This post is not meant to scare anyone and it’s rather rare to see a provisional application be used to invalidate a whole suite of patents. Bottom line, if you are going to spend the time and money to file a provisional application, you might as well put in the extra effort to make sure it will hold up if ever challenged.