The United States Patent and Trademark Office revised the rules of practice relating to PCT applications in view of an amendment to Article 22 of the Patent Cooperation Treaty that changed the time limit for entering the national stage from 20 months to 30 months. The rule changes were effective April 1, 2002.
The rule changes can be found here:
http://www.patentsusa.com/20020104_30_Mo_National_Stage.pdf
The changes in the rules applied to any international PCT application in which the twenty-month period from the priority date expired on or after April 1, 2002 and in which the applicant had not yet entered the national stage. The rule changes were in response to the amendment to PCT Article 22 that changed the time limit for entering the national stage from 20 months from the priority date of the PCT application to 30 month. After the changes to Article 22, a Chapter II Demand for International Preliminary Examination was no longer necessary for entry in the national stage in countries that adopted the changes. After the changes to the U.S. rules, PCT applicants interested in the national stage in the U.S. no longer needed to file a Demand for International Preliminary Examination and pay examination fees in their PCT applications. Not all countries modified their national laws promptly, but the U.S. did modify the patent rules effective April 1, 2002.
