A socialite tired of chipped china built the first dishwasher that caught on
Josephine Cochrane was wealthy enough to have servants, and that was her problem: they kept damaging her good china while washing it. In 1886, working with a mechanic in her tool shed in Shelbyville, Illinois, she built the hand-powered machine that outperformed every earlier attempt and later starred at the 1893 Chicago fair.
Earlier inventors had tried and flopped. Joel Houghton filed an American patent in 1850 for a wooden, hand-cranked contraption that sprayed water at plates, but it was slow and unreliable. L.A. Alexander's 1865 version added a cranked rack and fared no better. Some historians blame attitudes as much as engineering: housework was valued for the effort women put in rather than the outcome, so a labour-saving gadget could seem to cheapen that work.
Cochrane built her machine with the mechanic George Butters. It was unveiled at the World's Fair in Chicago as the Lavadora, then renamed Lavaplatos because a machine from 1858 already used the first name. In Britain, William Howard Livens produced a small non-electric home model in 1924 that already had a loading door, a wire rack and a rotating sprayer, the layout still used now; drying elements came in 1940. Miele made Europe's first electric-motor domestic dishwasher in 1929. None of these sold widely, and household sales only took off in the 1950s postwar boom, at first among the rich.
Standard kitchen cabinets changed the shape of the product. Once counters ran wall to wall at fixed heights, dishwashers shrank into modular units slotted underneath, 60 centimetres wide in Europe and 24 inches in the United States. By the 1970s they were common in North American and Western European homes, and by 2012 more than three quarters of households in the United States and Germany owned one. Older 1950s American models had a whole tub that rolled out for loading from above, and Fisher and Paykel introduced the drawer-style dishwasher in 1997.
Inside, a pump sends water and detergent to rotating arms at roughly 45 to 75 degrees Celsius, recycling the mixture to save water and power. Since the late 1990s soil sensors have measured food particles in the water and stretched or shortened the cycle accordingly. Restaurant machines sanitise with an 82 degree final rinse or a chemical agent.
Source: Dishwasher
