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.
Lincoln (/ˈlɪŋkən/) is a cathedral city and county town of Lincolnshire in the East Midlands of England. The non-metropolitan district of Lincoln had a 2012 population of 94,600. The 2011 census gave the urban area of Lincoln, which includes North Hykeham and Waddington, a population of 130,200.
Roman Lindum Colonia developed from an Iron Age settlement on the River Witham. The city's landmarks include Lincoln Cathedral, an example of English Gothic architecture and the tallest building in the world for over 200 years, and the 11th-century Norman Lincoln Castle. The city is home to the University of Lincoln and Bishop Grosseteste University, and to Lincoln City FC and Lincoln United FC.