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 rapidly improved. The double electromagnet was replaced by a single permanently magnetized bar magnet having a small coil or bobbin of fine wire surrounding one pole, in front of which a thin disc of iron was fixed in a circular mouthpiece. The disc served as a combined diaphragm and armature. On speaking into the mouthpiece, the iron diaphragm vibrated with the voice in the magnetic field of the bar-magnet pole, and thereby caused undulatory currents in the coil. These currents, after traveling through the wire to the distant receiver, were received in an identical apparatus. This design was patented by