The U.S. Supreme Court case Cuno Engineering Corp. v. Automatic Devices Corp., 1941, revolved around the issue of patent validity and infringement related to a coin-operated device that could select, display and vend merchandise articles like candy bars or cigarettes from a vending machine. The plaintiff, Cuno Engineering Corporation claimed that Automatic Devices Corporation had infringed on their patent rights by using similar technology in their own devices without permission or licensing agreements. However, the court ruled in favor of Automatic Devices Corporation stating that the alleged invention did not meet the requirement for patentability as it lacked novelty and inventiveness - two key criteria for granting patents under U.S law at that time (and still today). The court held that merely bringing together old elements with no change in their respective functions was not enough to qualify for a patent; there must be an element of ingenuity involved which results in greater efficiency or economy of operation. This ruling set important precedents regarding what constitutes 'invention' within US Patent Law context and has been cited numerous times since then.

In the dissenting opinion for CUNO ENGINEERING CORP. v. AUTOMATIC DEVICES CORP., Justice Frankfurter argued that the majority's decision to invalidate Automatic Devices Corp.'s patent was based on an overly narrow interpretation of what constitutes a "new and useful process, machine, manufacture, or composition of matter." He believed that this restrictive view could stifle innovation by discouraging inventors from seeking patents for their creations. Furthermore, he disagreed with the majority's assertion that Automatic Devices' invention was merely an obvious improvement upon existing technology rather than a novel creation in its own right. According to Justice Frankfurter, such judgments should be left up to experts in the field rather than decided by courts without technical expertise.