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A metal gear with cylindrical teeth was found in a ship wreck. It looked like it had been in a wooden frame. X-ray was used to date it to 100 BCE. This gear used a hand crank. -
This clock was made to calculate the date, solar eclipses, the position of the sun, moon, stars, and planets.
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Leonardo da Vinci used interconnected gears to make weaponry. -
At this point, the involute gear was invented. It was spiral shaped. This way, the gear could handle more complex tasks. -
Eli Whitney invented a machine that separated cottonseed from cotton fiber. This was one of the first steps that started the American Civil War. -
The industrial revolution, allowed gears to be made in mass production, using form cutters, and hobbing. They could make more complex gears faster and cheaper. So gears started to be used in more machines.
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Joseph Whitworth invented spiral gears.
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Mr. Christian Schiele, a British inventor, was the first to patent the gear hobbing machine. This machine made gears quicker, cheaper, and more accurately. -
Leonardo da Vinci started the gear chains, but it wasn't until 1885 when John Kemp Starley invented a bicycle with two wheels of the same size driven by a chain and gears. -
Robert Hermann Pfauter invented the spur and helical gears. The company Robert started, now called Gleason, is still making gears.
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The jet engine uses a epicyclic gear train, it was made by Pratt and Whitney. This engine now powers more than 1,000 planes.