What is the ‘In re Van Esdonk’ case and how does it apply to foreign priority claims?

The ‘In re Van Esdonk’ case (187 USPQ 671, Comm’r Pat. 1975) is an important precedent in patent law regarding the perfection of foreign priority claims. Key points about this case include:

• It involved a situation where a claim to foreign priority benefits had not been filed in the application prior to patent issuance.
• The application was a continuation of an earlier application that had satisfied the requirements of 35 U.S.C. 119(a)-(d) or (f).
• The Commissioner held that perfecting a priority claim in the parent application satisfies the statute for the continuation application.

The MPEP states: In re Van Esdonk, a claim to foreign priority benefits had not been filed in the application prior to issuance of the patent. However, the application was a continuation of an earlier application in which the requirements of 35 U.S.C. 119(a)-(d) or (f) had been satisfied. Accordingly, the Commissioner held that the ‘applicants’ perfection of a priority claim under 35 U.S.C. 119 in the parent application will satisfy the statute with respect to their continuation application.’

This case is significant because it allows for the perfection of foreign priority claims in continuation applications based on the parent application’s compliance, even after patent issuance.