Tesla Files Lawsuit Against Guglielmo Marconi
Tesla was embroiled in other problems at the time, but when Marconi won the Nobel Prize in 1911, Tesla was furious.
He sued the Marconi Company for infringement in 1915, but was in no financial condition to litigate a case against a major corporation. It wasn't until 1943—a few months after Tesla's death— that the U.S. Supreme Court upheld Tesla's radio patent number 645,576. The Court had a selfish reason for doing so. The Marconi Company was suing the United States Government for use of its patents in World War I. The Court simply avoided the action by restoring the priority of Tesla's patent over Marconi.
In 1943 a lawsuit regarding Marconi's US radio patents was resolved by the United States Supreme Court, who overturned most of these. The Marconi Company brought this suit in the Court of Claims to recover damages for infringement of four United States patents. Two, U.S. Patent 763,772 and U.S. Patent RE11,913, were issued to Marconi, a third, U.S. Patent 609,154, to Lodge, and a fourth, U.S. Patent 803,684, to Fleming. The court held that the Marconi reissue patent was not infringed. In its consideration of radio communication systems, the United States courts accepted a "definition evolved out of the exhaustive depositions taken from many technical experts..." as requiring "two tuned circuits each at the transmitter and receiver, all four tuned to the same frequency.
The court found Marconi showed no invention over Stone (U.S. Patent 714,756) by making the tuning of his antenna circuit adjustable, or by using Lodge's variable inductance for that purpose. The court decision was based on the proven prior work conducted by others, such as by Nikola Tesla, Oliver Lodge, and John Stone Stone, from which some of Marconi patents stemmed. At the time, the United States Army was involved in a patent infringement lawsuit with Marconi's company regarding radio, leading various observers to posit that the government nullified Marconi's other patents in order to moot any claims for compensation (as, it is speculated, the government's initial reversal to grant Marconi the patent right in order to nullify any claims Tesla had for compensation).
The U. S. Supreme Court stated that,
"The Tesla patent No. 645,576, applied for September 2, 1897 and allowed March 20, 1900, disclosed a four-circuit system, having two circuits each at transmitter and receiver, and recommended that all four circuits be tuned to the same frequency. [... He] recognized that his apparatus could, without change, be used for wireless communication, which is dependent upon the transmission of electrical energy."
In making their decision, the court noted,
"Marconi's reputation as the man who first achieved successful radio transmission rests on his original patent, which became reissue No. 11,913, and which is not here [320 U.S. 1, 38] in question. That reputation, however well-deserved, does not entitle him to a patent for every later improvement which he claims in the radio field. Patent cases, like others, must be decided not by weighing the reputations of the litigations, but by careful study of the merits of their respective contentions and proofs." The court, therefore, did not consider the issue of whether Marconi was the inventor of radio, since his original patent was not at issue nor, as they stated, being disputed in this particular proceeding. This is because Marconi's original patent was filed with the British Patent Office on June 2, 1896 and therefore pre-dated Tesla's Patent No. 645,576, applied for September 2, 1897 by more than one year.
The court also stated that,
"It is well established that as between two inventors priority of invention will be awarded to the one who by satisfying proof can show that he first conceived of the invention.