Timing and form of assignments of IP rights from one entity to another has come under increased scrutiny by the UK Courts recently. Decisions have shown that timing in particular is very important and gotten wrong or overlooked, there isn't necessarily a fix.
Under UK law, failure to obtain valid assignment of the priority application from the inventor before a later patent application is filed can result in the loss of priority. This applies when the priority application has been filed in the name of the inventor (as is necessarily the case under US practice) and the later application (such as a PCT application) filed in a different name, such as the name of a corporate entity.
Unless it can be shown that the corporate applicant had obtained the right to the priority application at the date of filing of the later application (for example by way of employment of the inventors or assignment) then the result is that the priority claim is invalid. Furthermore, if the corporate applicant has not obtained the right to the priority application by the time the later application is filed, the priority claim cannot be fixed retrospectively.
This arises from the decision of Mr Justice Kitchin in Edwards Lifesciences AG and Cook Biotech Incorporated (http://alpha.bailii.org/ew/cases/EWHC/Patents/2009/1304.html) in which he said:
“A person who files a patent application for an invention is afforded the privilege of claiming priority only if he himself filed the earlier application from which priority is claimed or if he is the successor in title to the person who filed that earlier application. If he is neither the person who filed the earlier application nor his successor in title then he is denied the privilege. Moreover, his position is not improved if he subsequently acquires title to the invention. It remains the case that he was not entitled to the privilege when he filed the later application and made his claim. Any other interpretation would introduce uncertainty and the risk of unfairness to third parties.”
Practice reminder 1: obtain assignment from inventors before a patent application is filed.
Under US law, an assignment is valid if it is executed by the assignor only, whereas under EPO law, the assignment must be in writing and signed by all parties to the contract (Article 72, EPC 2000). Despite this distinction in national law, the EPO is apparently imposing its rules on the assignment of US priority applications.
Common sense suggests that an assignment of a priority right should be valid if it complies with the law of the country in which the priority right was filed, and this practice was followed for a number of years by the EPO. However, in Decision T62/05 the EPO Board of Appeal suggested that the standard of proof that is required should be the same as that required by the EPO when a European patent application is assigned.
If this policy were adopted by all patent offices then it would impose a substantial burden on the applicant to ensure that overseas formalities were complied with before a decision had been taken as to where to file patent applications. For this reason alone, it seems to us that the policy is contrary to public policy. Nevertheless, in order to be valid as far as the EPO is concerned, it would appear that the assignment of the US priority application should be signed by all parties to the transaction (assignor and assignee).