A provisional patent application is a temporary application that provides patent-pending status for one year. The provisional application can be a relatively low-cost way to preserve your patent rights while you develop your invention. The protection offered by a provisional patent application is only as good as the information contained in the application and only addresses the invention as disclosed in the application. The provisional application must include enough information in the specification (the narrative part of the application) and the drawings so that a person who is knowledgeable in the technical field of the invention can make and use the invention.
To have any continuing value, your provisional application must be followed within one year by a full U.S. non-provisional (utility) patent application. If the invention is one for which you will seek international patent protection, your international patent application(s) also must be filed within one year of the provisional filing date.
If you develop improvements to your invention while your provisional application is pending, the improvements are not protected. What to do? File another provisional application addressed to the improvements.
–Robert Yarbrough, Esq.