Patent drawing - for F. Shaw's Head Telephone Public domain image

Famous patent drawings from The National Archives, Washington DC There are many famous patent drawings from a wide range of inventors and inventions. Some notable examples include: The light bulb: Thomas Edison's patent for the light bulb, which was filed in 1879, included detailed drawings of the bulb's design and construction. The phonograph: Edison's patent for the phonograph, which was filed in 1877, included drawings of the device's components, including the cylinder and the needle. The motion picture camera: Edison's patent for the kinetograph, which was filed in 1891, included drawings of the camera's mechanisms and components, such as the rotating lenses and the film roll. The airplane: The Wright brothers' patent for their airplane, which was filed in 1906, included detailed drawings of the aircraft's design and construction, including its wings, fuselage, and propeller. The telephone: Alexander Graham Bell's patent for the telephone, which was filed in 1876, included drawings of the device's components, such as the transmitter and receiver, as well as a diagram of the electrical circuit. These are just a few examples of famous patent drawings. Many other inventors and inventions have also been represented in detailed drawings in their patent applications.

The invention of the telephone still remains a confusing morass of claims and counterclaims, which were not clarified by the huge mass of lawsuits to resolve the patent claims of commercial competitors. The Bell and Edison patents, however, dominated telephone technology and were upheld by court decisions in the United States. Bell has most often been credited as the inventor of the first practical telephone. Alexander Graham Bell was the first to patent the telephone as an "apparatus for transmitting vocal or other sounds telegraphically". The telephone exchange was an idea of the Hungarian engineer Tivadar Puskás (1844 - 1893) in 1876, while he was working for Thomas Edison on a telegraph exchange. Before the invention of the telephone switchboard, pairs of telephones were connected directly with each other, practically functioned as an intercom. Although telephones devices were in use before the invention of the telephone exchange, their success and economical operation would have been impossible with the schema and structure of the contemporary telegraph systems. A telephone exchange was operated manually by operators, or automatically by machine switching. It interconnects individual phone lines to make calls between them. The first commercial telephone exchange was opened at New Haven, Connecticut, with 21 subscribers on 28 January 1878, in a storefront of the Boardman Building in New Haven, Connecticut. George W. Coy designed and built the world's first switchboard for commercial use. The District Telephone Company of New Haven went into operation with only twenty-one subscribers, who paid $1.50 per month, a one-night price for a room in a city-center hotel. Coy was inspired by Alexander Graham Bell's lecture at the Skiff Opera House in New Haven on 27 April 1877. In Bell's lecture, during which a three-way telephone connection with Hartford and Middletown, Connecticut, was demonstrated, he first discussed the idea of a telephone exchange for the conduct of business and trade.