Crown Die & Tool Co. v. Nye Tool & MacHine Works

Background

A company brought a suit based on an agreement it said assigned patent rights to it and asked for an accounting and an injunction (a court order to stop copying). The dispute arose because the instrument left the original patentee with the right to make, use, and sell the invention but appeared to give others the exclusive ability to sue certain alleged infringers. Lower courts disagreed about whether that instrument actually transferred ownership of the patent.

Reasoning

The Court addressed whether simply giving someone the power to exclude particular people or the right to sue amounts to transferring the patent itself. The opinion explains that a patent is a statutory monopoly tied to the inventor’s underlying common-law right to make, use, and sell an invention. The Court held that the exclusionary power is an incident of owning that underlying right and cannot be split off into separate assignable pieces that let third parties sue alone. The Court also relied on the rule that only the person who owned the patent when an infringement occurred can recover past damages, unless the patent and the claim for past damages are both actually assigned to the same person.

Real world impact

The decision means people or companies who buy only a claim to sue, but not the patent title itself, cannot bring solo lawsuits for past infringement or recover prior damages. It also confirms that disputes over whether an agreement transfers patent title are matters arising under patent law and properly addressed in federal courts. The Supreme Court reversed the Circuit Court of Appeals and affirmed the District Court’s dismissal of the plaintiff’s bill.