Legal Definitions - permissible-repair doctrine

The permissible-repair doctrine is a principle in patent law that allows an individual or entity who has legitimately purchased a patented product to repair or maintain it without infringing the patent holder's rights. This doctrine distinguishes between actions that merely restore a product to its original functionality (permissible repair) and actions that essentially create a new product (impermissible reconstruction). The core idea is that once a patented item is sold, the buyer has the right to use and maintain it throughout its useful life, even if that involves replacing worn-out components. However, this right does not extend to rebuilding the product to such an extent that it effectively becomes a new item, which would typically require a new license or constitute patent infringement.

Here are some examples to illustrate the permissible-repair doctrine:

• Automobile Maintenance: Imagine a car owner who purchases a vehicle containing several patented components, such as a unique engine design or a specialized transmission system. Over time, parts like brake pads, tires, or even a catalytic converter wear out. When the owner takes the car to a mechanic to replace these worn-out parts, they are engaging in permissible repair. The mechanic is restoring the vehicle to its intended operational state, not creating a new car or a new patented component from scratch. This action does not infringe on the patents held by the car manufacturer or its suppliers because it falls under the right of the owner to maintain their purchased product.

• Industrial Machine Refurbishment: A manufacturing company owns a large industrial machine that incorporates a patented robotic arm for precision assembly. After several years of continuous operation, a specific gear assembly within the robotic arm becomes worn and begins to malfunction. The company orders a replacement gear assembly and has it installed to restore the machine's full functionality. This is a permissible repair. The company is maintaining its existing asset, ensuring its continued operation, rather than manufacturing a new robotic arm or an entirely new machine that would infringe on the original patent for the robotic arm's design.

• Home Appliance Repair: Consider a homeowner who buys a high-tech washing machine with a patented water-saving mechanism. After several years, a specific sensor or pump within that patented mechanism fails, preventing the machine from operating correctly. The homeowner calls a repair technician who replaces the faulty sensor or pump with a new one. This action constitutes permissible repair. The technician is fixing a broken part to allow the washing machine to continue performing its intended function, not reconstructing the entire patented water-saving system or building a new washing machine, which would likely be considered patent infringement.