Most countries require that patent applications be filed before public disclosure of an invention: does it include US provisional patent applications?

Question

I read on techtransfer.harvard.edu:

In the United States, patent applications may be filed up to one year after an invention's first public disclosure. In contrast, most foreign countries require that patent applications be filed before any public disclosure of an invention. Despite these strict rules, if a U.S. patent application is filed before any public disclosure, most foreign countries permit filing of corresponding applications for up to one year after the U.S. filing date, even if a disclosure of the invention was made after the U.S. filing. Therefore, a U.S. patent application filing prior to any publication or oral disclosure preserves both U.S. and foreign patent rights.

When they write "if a U.S. patent application is filed before any public disclosure", can it be either U.S. patent application or a U.S. provisional patent application?

Answer 1

Absolutely - that is the main reason provisional applications were created. When the US signed the treaty that changed term from 17 years after grant to 20 years after filing the US saw that a person filing in another Paris county getting priority to a US filing would have a “free” year that a U.S. application did not afford.

From the Paris Convention

(2) Any filing that is equivalent to a regular national filing under the domestic legislation of any country of the Union or under bilateral or multilateral treaties concluded between countries of the Union shall be recognized as giving rise to the right of priority.

(3) By a regular national filing is meant any filing that is adequate to establish the date on which the application was filed in the country concerned, whatever may be the subsequent fate of the application.

Not well known is the option to actually literally convert a provisional application to a non-provisional application. See MPEP 601.01(c) This is in contrast to the normal process of filing a second non-provisional application that claims the benefit of a provisional. Since a provisional filing can, itself, lead to a granted patent it is even more clear that it qualifies as a Paris filing.

Note that in practice it is rare to convert vs file a new application.