Permissible-Repair Doctrine Law and Legal Definition

Permissible repair doctrine is a principle applicable in Patent law which allows a licensee who is authorized to produce, use, or distribute a patented device to repair and replace unpatented components. The owner of patented property has a lawful right to repair or replace his/her property.

An owner or licensee of a patented machine or combination does not infringe the patent by replacing an unpatented element of the combination which has only a temporary period of usefulness, so that replacement is necessary for continued utilization of the machine or combination as a whole. The patent monopolist cannot prevent those to whom he sells from reconditioning articles worn by use, unless they in fact make a new article. Maintenance of the "use of the whole" of the patented combination through replacement of a spent, unpatented element does not constitute reconstruction.[Aro Mfg. Co. v. Convertible Top Replacement Co., 365 U.S. 336 (U.S. 1961)]