Legal Definitions - accelerated-reentry theory

The term accelerated-reentry theory is another name for the post-expiration-sales theory. This legal concept primarily arises in patent law and addresses situations where a party sells components or materials for a patented invention *before* the patent expires, with the understanding or intent that these components will be assembled or used to reconstruct the patented invention *after* the patent has expired.

The core idea is to prevent circumvention of patent rights. If a competitor can sell all the necessary parts for a patented invention just before the patent expires, allowing customers to immediately assemble and use the invention the moment the patent lapses, it effectively undermines the patent holder's exclusive rights during the final period of the patent term. The theory suggests that such pre-expiration sales can constitute patent infringement because they enable a premature "re-entry" into the market for the patented invention, rather than allowing for a natural market development post-expiration.

• Example 1: Specialized Machine Parts

  Imagine "RoboTech Inc." holds a patent on a highly specialized industrial robot. Three months before RoboTech's patent is set to expire, a competitor, "GearWorks Co.," begins manufacturing and selling a unique, custom-designed gear assembly that is a critical, non-standard component exclusively used in RoboTech's patented robot. GearWorks sells these assemblies in large quantities to various manufacturing plants, knowing that these plants intend to stockpile them and then assemble complete, non-RoboTech robots using these parts immediately after the patent expires.

  This illustrates accelerated-reentry theory because GearWorks is selling essential components of a patented invention *before* the patent expires. By doing so, they are enabling other manufacturers to quickly "re-enter" the market for the patented robot design the moment the patent lapses, effectively diminishing RoboTech's exclusive market position during the final months of its patent term and allowing competitors to hit the ground running post-expiration.

• Example 2: Medical Device Kits

  "BioMed Solutions" holds a patent on an innovative portable diagnostic device. A rival company, "HealthKit Innovations," starts selling "assembly kits" containing all the necessary parts to build BioMed Solutions' patented device, two months before BioMed Solutions' patent expires. HealthKit Innovations explicitly markets these kits as "ready for assembly post-patent expiration," and customers are advised not to assemble them until after the patent lapses.

  Here, HealthKit Innovations is selling the *means* to create the patented device *before* the patent expires. Even though the actual assembly and use are intended for *after* expiration, the pre-expiration sale of the complete kit allows HealthKit Innovations and its customers to bypass the natural market entry period that would typically follow a patent's expiration. This premature provisioning of the invention's components constitutes an "accelerated reentry" into the market for the patented device.

• Example 3: Patented Chemical Process Ingredient

  "PureChem Corp." holds a patent on a unique chemical purification process that relies on a specific, patented catalyst. The patent for the *process* is expiring in five months. A rival company, "CatalystPro Ltd.," begins manufacturing and selling large quantities of this specific catalyst to various chemical producers, knowing that these producers intend to use it to perform PureChem Corp.'s patented purification process as soon as the process patent expires.

  This scenario demonstrates accelerated-reentry theory because CatalystPro Ltd. is selling a critical, patented component (the catalyst) that is essential for performing PureChem Corp.'s patented *process* while the process patent is still active. By supplying this key ingredient in advance, CatalystPro Ltd. facilitates the rapid adoption and use of the patented process by others immediately upon patent expiration, effectively allowing them to "re-enter" the market for the purified chemical product without the usual delay.