Two prominent law professors have called for major reforms in the practice of filing continuation patent applications. In a recent paper, Professors Mark Lemley and Kimberly Moore outlined their view that continuation applications "have led to abuse of the patent prosecution process." According to Lemley and Moore, "they serve very little useful purpose, and what benefits they confer may be outweighed by their potential for mischief. The world would probably be a better place if continuation applications were abolished."
Specifically, the professors propose to limit each application to only one continuation application. "Allowing even one continuation application will give the applicant five or six bites at the apple. Surely that is enough." In addition, the professors would create "intervening rights" for competitors who begin making a patented invention prior to a broadening continuation.
Article: Ending Abuse of Patent Continuations, 84 B. U. L. Rev. 63 (2004).
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Comment: Lemley and Moore are formally correct that an applicant always has an opportunity to keep an application alive by filing a continuation. However, as each day passes, the eventual resulting patent becomes less and less valuable because the patent term will be calculated from the filing date of the original parent application. At the limit, a continuation that issues 20 or more years after the original parent was filed is completely unenforceable. Thus, there is a practical 20-year limit on the filing of continuations.