An automatic door, also known as an auto door, is a door that opens automatically, usually on sensing the approach of a person.
In the 1st century AD, mathematician Heron of Alexandria in Roman Egypt invented the first known automatic door. He described two different automatic door applications. The first application used heat from a fire lit by the city's temple priest. After a few hours atmospheric pressure built up in a brass vessel causing it to pump water into adjacent containers. These containers acted as weights that – through a series of ropes and pulleys – would open the temple's doors at about the time people were to arrive for prayer. Heron used a similar application to open the gates to the city.
In 1931, engineers Horace H. Raymond and Sheldon S. Roby of the tool and hardware manufacturer Stanley Works designed the first model of an optical device triggering the opening of an automatic door. The invention was patented and installed in Wilcox's Pier Restaurant in West Haven, Connecticut for the benefit of waiters carrying plates of food and drink. The entire system plus installation was sold for $100.
In 1954, Dee Horton and Lew Hewitt invented the first sliding automatic door. The automatic door used a mat actuator. In 1960, they co-founded Horton Automatics Inc and placed the first commercial automatic sliding door on the market.
Dereham (/ˈdɪərəm/), also known as East Dereham, is a town and civil parish in the Breckland District of the English county of Norfolk. It is situated on the A47 road, about 15 miles (25 km) west of the city of Norwich and 25 miles (40 km) east of King's Lynn.
The civil parish has an area of 21.51 km2 (8.31 sq mi) and, in the 2001 census, had a population of 15,659 in 6,941 households; the population at the 2011 census increased to 18,609. Dereham falls within, and is the centre of administration for, Breckland District Council. The town should not be confused with the Norfolk village of West Dereham, which lies about 25 miles (40 km) away.
Since 1983, Dereham has been twinned with the town of Rüthen in North Rhine-Westphalia, Germany. It is also twinned with Caudebec-lès-Elbeuf, France. In spite of the reunification of Germany in 1990, the sign on the A47 at the entrance to Dereham from the Swaffham direction still refers to Rüthen being in West Germany; this sparks periodic comment in the local press.