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.
Cromer (/ˈkroʊmər/ KROH-mər) is a coastal town and civil parish on the north coast of the English county of Norfolk. It is approximately 23 miles (37 km) north of the county town of Norwich, 116 miles (187 km) north-northeast of London and 4 miles (6.4 km) east of Sheringham on the North Sea coastline. The local government authorities are North Norfolk District Council, whose headquarters is on Holt Road in the town, and Norfolk County Council, based in Norwich. The civil parish has an area of 4.66 km2 (1.80 sq mi) and at the 2011 census had a population of 7,683.
The town is notable as a traditional tourist resort and for the Cromer crab, which forms the major source of income for local fishermen. The motto Gem of the Norfolk Coast is highlighted on the town's road signs.