Differences

When Congress contemplated changing the patent term from 17 years after issuance to 20 years from earliest claimed U.S. priority, there was an uproar among individual patentees (as opposed to corporate patentees) that such a change would impact them in an unduly harsh manner. One compromise was to allow the filing of "provisional patent applications" that would eliminate most of the drafting formalities, and would therefore be relatively simple and inexpensive to get on file.

The Patent Office currently charges only about $100 filing fee for provisional patent applications (referred to as "provisionals" in ordinary speech) . They can be extremely short, and sometimes run only one or two paragraphs. It is certainly not necessary to include the usual sections such as Background, Brief Description of the Drawings, and so forth. The only requirements are that one skilled in the art would understand how to make and use the invention (enablement), that the attorney include the best way that he knows how to practice the invention (best mode), and that a reader would appreciate that the inventor was in possession of the invention (written description). I once filed a provisional without any words at all, only a drawing. The patent office rejected the application on the grounds that the disclosure failed to adequately characterize the invention, but I finally prevailed by demonstrating that the drawing satisfied enablement, best mode, and written description.

The patent office never substantively examines provisional patent applications. They last only one year, after which they are microfilmed and shredded - unless a formal utility or PCT application is filed during that one-year period that claims priority back to the provisional. In that latter case, the provisional escapes from the terrible fate of shredding, and is instead placed in the file of the formal application. A formal application (utility or PCT) can claim priority to any number of provisionals. I once filed a PCT application claiming priority to 12 provisionals. Every time the inventor devised an improvement to his idea, I filed a new provisional. Within one year of the earliest provisional I filed a PCT application that included all of the various improvements.

The U.S. patent office allows filing of provisionals without claims. Indeed many or possibly even most provisionals are filed without claims. The ability to file without claims reduces the cost of the application considerably, and may be advantageous when the attorney really doesn't know what is inventive. There is a danger, however, that in failing to include or at least write claims for a provisional, the attorney doesn't go through the difficult work of figuring out what is inventive. Without understanding what is inventive, it is exceedingly difficult to know what to focus upon in drafting the disclosure and distinguishing other art. I often draft a tentative set of claims, and use those claims as a guide in drafting the disclosure, even if I never include the claims in the provisional application. If I do include draft claims, I preface them with the following caveats:

The following claims are provided to add additional clarity to this disclosure. Future applications claiming priority to this application may or may not include the following claims, and may include claims broader, narrower, or entirely different from the following claims.

As discussed above, provisional applications cannot claim priority to any other applications. This limitation becomes important when an applicant has already filed a utility or PCT application, and is subsequently filing a short provisional identifying some new twist on the invention. A patent attorney typically doesn't want to waste time or money reiterating all the supporting detail that was set forth in the previous application. The solution is to simply draft the one or two page description of the new material, and then attach a photocopy of the previously filed application. The disclosure will then include both the new material as well as the old material.