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.
Leicester (About this soundlisten) LEH-ster) is a city and unitary authority area in the East Midlands of England, and the county town of Leicestershire. The city lies on the River Soar and close to the eastern end of the National Forest. It is to the north-east of Birmingham and Coventry, south of Nottingham, and west of Peterborough.
The 2016 mid year estimate of the population of the City of Leicester unitary authority was 348,300, an increase of approximately 18,500 (Increase 5.6%) from the 2011 census figure of 329,839, making it the most populous municipality in the East Midlands region. The associated urban area is also the 11th most populous in England and the 13th most populous in the United Kingdom.
Leicester is at the intersection of two major railway lines—the north–south Midland Main Line and the east/west Birmingham to London Stansted CrossCountry line; as well as the confluence of the M1/M69 motorways and the A6/A46 trunk routes. Leicester is the home to football club Leicester City and rugby club Leicester Tigers.