
Sometimes a patent provisional can be useful to an inventor. The drug maker of the popular cholesterol medicine got a patent provisional this past year after changing wording about the medicine’s key ingredient. The patent was extended until 2011. But inventors have to be careful because a patent provisional can also be a double-edged sword.

A patent provisional can be filed and obtained when a patent is about to expire and there is insufficient time to complete a patent application. A patent is generally good for 20 years after its issue date, while a patent provisional expires a year from the date of its issuance.
A patent provisional can be useful to an inventor when they are in the process of applying for a non-provisional patent, known also simply as a patent. This will give an inventor time to file the sufficient paperwork and pay fees to government to file a patent.
Any inventor wanting a patent provisional must file an application with the U.S. Trade and Patent Office. The cost to file a patent provisional is generally less than applying for a regular patent. For $110, an inventor may apply for a patent provisional. They are not required to disclose financial information. However, they must have 100 pages or less on the specifics of their product before a patent provisional is issued.
A patent provisional only costs $110 to file an application, while a non-provisional patent can cost more than $1,000 to file an application. There is also less preparation needed to file a patent provisional. A inventor can file a patent provisional without hiring a lawyer.
A patent provisional may not always cover a product awaiting patent approval if information is considered to be not adequately disclosed. For instance, the inventor of an angled drill bit body lost a lawsuit involving his drill bit after the courts found his invention was for sale a year before a patent was issued. The invention was not covered under a patent provisional because the inventor failed to mention his angled drill bit body in the patent provisional, even though he had included information about the angled drill bit body on his patent application.