The Telephone Cases The Telephone Cases The Telephone Cases, 126 U.S. 1 (1888), were a series of U.S. court cases in the 1870s and 1880s related to the invention of the telephone, which culminated in the 1888 decision of the United States Supreme Court upholding the priority of the patents belonging to Alexander Graham Bell. Those telephone patents were relied on by the American Bell Telephone Company and the Bell System—although they had also acquired critical microphone patents from Emile Berliner. The objector (or plaintiff) in the notable Supreme Court case was initially the Western Union telegraph company, which was at the time
Invention of the telephone receiver. Gray did not convert his caveat into a patent application until after the caveat had expired and hence left the field open to Bell. When Gray applied for a patent for the variable resistance telephone transmitter, the Patent Office determined "while Gray was undoubtedly the first to conceive of and disclose the (variable resistance) invention, as in his caveat of 14 February 1876, his failure to take any action amounting to completion until others had demonstrated the utility of the invention deprives him of the right to have it considered." The carbon microphone was independently developed around 1878 by