Exhausted Combination Doctrine - The Lincoln Engineering Decision

The Lincoln Engineering Decision

In Lincoln Engineering, the inventor invented a new and improved coupling device to attach a nozzle to a grease gun. The patent, however, claimed the whole combination of grease gun, nozzle, and coupling. The Supreme Court stated that "the improvement of one part of an old combination gives no right to claim that improvement in combination with other old parts which perform no new function in the combination". It then concluded that the inventor's "effort, by the use of a combination claim, to extend the monopoly of his invention of an improved form of chuck or coupler to old parts or elements having no new function when operated in connection with the coupler renders the claim void."

This way of claiming an invention was termed “overclaiming,” because it inflated the royalty base for licensing and potentially effectuated a tie-in by means of which the patentee required users, for example, to purchase not only the couplings but the whole grease gun as well in order to use the invention.