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.
Arnold (/ˈɑːr.nəld/) is a market town and unparished area in the ceremonial county of Nottinghamshire in the East Midlands of England. It is situated to the north-east of Nottingham's city boundary. Arnold's town centre is the largest in the Borough of Gedling and the most important in the northeastern part of the Greater Nottingham conurbation. Gedling Borough Council is headquartered in Arnold. Since 1968 Arnold has had a market, and the town used to have numerous factories associated with the hosiery industry. Nottinghamshire Police have been headquartered in Arnold since 1979. At the time of the 2011 census, Arnold had a population of 37,768.
Areas within Arnold include Daybrook, Woodthorpe, Redhill, Warren Hill, Killisick and Dorket Head.