In the case of Aircraft & Diesel Equipment Corp. v. Hirsch et al., 1946, the United States Supreme Court was asked to determine whether or not a patent for an invention could be invalidated due to public use prior to its application date. The court ruled that if an invention is used publicly and without restriction more than one year before a patent application is filed, it becomes part of the public domain and cannot be patented by anyone. This ruling upheld Section 102(b) of the Patent Act which states that "A person shall be entitled to a patent unless...the invention was...in public use or on sale in this country, more than one year prior to the date of application for patent." In this particular case, Aircraft & Diesel Equipment Corporation had attempted to secure patents for certain aircraft parts but were denied because their inventions had been in unrestricted public use over a year before they applied for patents.

The dissenting opinion in the Aircraft & Diesel Equipment Corp. v. Hirsch case argued that the majority's decision to uphold a price control order issued by the Office of Price Administration (OPA) was incorrect because it violated due process rights under the Fifth Amendment. The dissenters believed that, while Congress has broad powers during wartime, these powers do not extend to authorizing an administrative agency like OPA to issue orders without providing affected parties with notice and an opportunity for hearing before their property is taken or their business operations are significantly impacted. They contended that such procedural safeguards were fundamental aspects of due process and could not be bypassed even in times of war or national emergency.