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Automatic Door

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.[1]

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.[2][3]

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.[4]

​Leicestershire (/ˈlɛstərʃər, -ʃɪər/ (About this soundlisten); postal abbreviation Leics.) is a landlocked county in the English Midlands, being within the East Midlands. The county borders Nottinghamshire to the north, Lincolnshire to the north-east, Rutland to the east, Northamptonshire to the south-east, Warwickshire to the south-west, Staffordshire to the west, and Derbyshire to the north-west. The border with most of Warwickshire is Watling Street, the modern A5 road.

Leicestershire takes its name from the city of Leicester located at its centre and administered separately from the rest of the county. The ceremonial county – the non-metropolitan county plus the city of Leicester – has a total population of just over 1 million (2016 estimate), more than half of which lives in the Leicester Urban Area.

Leicestershire remains the only county in England other than Greater London that has yet to adopt an official county flag.