Guest Post by Alex Korenberg of Kilburn & Strode (UK)
The Paris Convention (and its implementation by the EPO and UKIPO) requires that the person filing a priority claiming application is the same as the person who has filed an application from which priority is claimed, or his or her successor in title. This has in the past caused problems for US based applicants on several occasions, since a mismatch cannot be fixed retrospectively.
The problematic fact situation was that the chain of title from the inventor(s) on the US priority application to the applicant (e.g. assignee company) on a priority claiming second application (e.g. a PCT application) could not be established at the second (e.g. PCT) filing date. The result in several UK court cases and EPO Board of Appeal decisions was that the claim to priority was found to be invalid, leading to a loss of the patent due to intervening disclosures in the priority year (see here http://www.kilburnstrode.com/resources/news/2011-4-21-ensuring-valid-priority-claims-for-us-originating-applications for a briefing note describing this issue in more detail). The only way to be certain the chain of tile was in place was to have assignments in place from all US applicant/inventors to the applicant on the second application prior to filing it.
The implementation of the provisions of the AIA now provides a convenient way for US patent filing companies to ensure this issue does not affect their foreign filings, making use of the ability to file the US application in the name of the assignee company, rather than the inventors. By filing in the name of the assignee company, there is then no question as to the chain of title in relation to the priority claim for a subsequent PCT or other foreign application filed in the same name. Unlike the entitlement to claim priority, the entitlement to grant of a patent can be settled in Europe after filing and at any time before grant, or even after grant by appropriate assignment. Using the provisions of the AIA to file in the name of the assignee company, the question of assignments from the inventor to the assignee company ceases to be a potentially fatal issue if not settled during the priority year.
The interaction between an invention's chain of title and the ability to claim priority has been a niche pursuit for aficionados of the nether regions of patent law, but this may be one point where the harmonisation of patent law as a result of the AIA can provide readily available benefits for US patent filers. Of course, the complexity of the interaction of earlier inventor filed applications and the Paris Convention will still be around to keep lawyers busy for years to come.