Great Invention: Light Bulb

Light Bulb by Thomas Alva Edison in 1879:



Milestones:


1850 Joseph W. Swan began working on a light bulb using carbonized paper filaments
1860 Swan obtained a UK patent covering a partial vacuum, carbon filament incandescent lamp
1877 Edward Weston forms Weston Dynamo Machine Company, in Newark, New Jersey.
1878 Thomas Edison founded the Edison Electric Light Company
1878 Hiram Maxim founded the United States Electric Lighting Company
1878 205,144 William Sawyer and Albon Man 6/18 for Improvements in Electric Lamps
1878 Swan receives a UK patent for an improved incandescent lamp in a vacuum tube
1879 Swan began installing light bulbs in homes and landmarks in England.
1880 223,898 Thomas Edison 1/27 for Electric Lamp and Manufacturing Process
1880 230,309 Hiram Maxim 7/20 for Process of Manufacturing Carbon Conductors
1880 230,310 Hiram Maxim 7/20 for Electrical Lamp
1880 230,953 Hiram Maxim 7/20 for Electrical Lamp
1880 233,445 Joseph Swan 10/19 for Electric Lamp
1880 234,345 Joseph Swan 11/9 for Electric Lamp
1880 Weston Dynamo Machine Company renamed Weston Electric Lighting Company
1880 Elihu Thomson and Edwin Houston form American Electric Company
1880 Charles F. Brush forms the Brush Electric Company
1881 Joseph W. Swan founded the Swan Electric Light Company
1881 237,198 Hiram Maxim 2/1 for Electrical Lamp assigned to U.S. Electric Lighting Company
1881 238,868 Thomas Edison 3/15 for Manufacture of Carbons for Incandescent Lamps
1881 247,097 Joseph Nichols and Lewis Latimer 9/13 for Electric Lamp
1881 251, 540 Thomas Edison 12/27 for Bamboo Carbons Filament for Incandescent Lamps
1882 252,386 Lewis Latimer 1/17 for Process of Manufacturing Carbons assigned to U.S. E. L. Co.
1882 Edison's UK operation merged with Swan to form the Edison & Swan United Co. or "Edi-swan"
1882 Joesph Swan sold his United States patent rights to the Brush Electric Company
1883 American Electric Company renamed Thomson-Houston Electric Company
1884 Sawyer & Man Electric Co formed by Albon Man a year after William Edward Sawyer death
1886 George Westinghouse formed the Westinghouse Electric Company
1886 The National Carbon Co. was founded by the then Brush Electric Co. executive W. H. Lawrence
1888 United States Electric Lighting Co. was purchased by Westinghouse Electric Company
1886 Sawyer & Man Electric Co. was purchased by Thomson-Houston Electric Company
1889 Brush Electric Company merged into the Thomson-Houston Electric Company
1889 Edison Electric Light Company consolidated and renamed Edison General Electric Company.
1890 Edison, Thomson-Houston, and Westinghouse, the "Big 3" of the American lighting industry.
1892 Edison Electric Light Co. and Thomson-Houston Electric Co. created General Electric Co.
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Construction:



Incandescent light bulbs consist of a glass enclosure (the envelope, or bulb) with a filament of tungsten wire inside the bulb, through which an electric current is passed. Contact wires and a base with two (or more) conductors provide electrical connections to the filament. Incandescent light bulbs usually contain a stem or glass mount anchored to the bulb's base that allows the electrical contacts to run through the envelope without gas/air leaks. Small wires embedded in the stem in turn support the filament and/or its lead wires. The bulb is filled with an inert gas such as argon to reduce evaporation and prevent oxidation of the filament.
An electric current heats the filament to typically 2,000 to 3,300 K (3,140 to 5,480 °F)), well below tungsten's melting point of 3,695 K (6,191 °F). Filament temperatures depend on the filament type, shape, size, and amount of current drawn. The heated filament emits light that approximates a continuous spectrum. The useful part of the emitted energy is visible light, but most energy is given off as heat in the near-infrared wavelengths.
Three-way light bulbs have two filaments and three conducting contacts in their bases. The filaments share a common ground, and can be lit separately or together. Common wattages include 30–70–100, 50–100–150, and 100–200–300, with the first two numbers referring to the individual filaments, and the third giving the combined wattage.
While most light bulbs have clear or frosted glass, other kinds are also produced, including the various colors used for Christmas tree lights and other decorative lighting. Neodymium-containing glass is sometimes used to provide a more natural-appearing light.

Many arrangements of electrical contacts are used. Large lamps may have a screw base (one or more contacts at the tip, one at the shell) or a bayonet base (one or more contacts on the base, shell used as a contact or used only as a mechanical support). Some tubular lamps have an electrical contact at either end. Miniature lamps may have a wedge base and wire contacts, and some automotive and special purpose lamps have screw terminals for connection to wires. Contacts in the lamp socket allow the electric current to pass through the base to the filament. Power ratings for incandescent light bulbs range from about 0.1 watt to about 10,000 watts.
The glass bulb of a general service lamp can reach temperatures between 200 and 260 °C (392 and 500 °F). Lamps intended for high power operation or used for heating purposes will have envelopes made of hard glass or fused quartz.

http://en.wikipedia.org/wiki/Incandescent_light_bulb
http://www.ideafinder.com/history/inventions/lightbulb.htm