Automatic Doors – from Lever to Software

Greek mathematician Heron of Alexandria created a system that opened the gates of a temple. He used the heat from a fire lit by the city’s temple priest. After a few hours, atmospheric pressure, captured in a brass vessel, was sufficient to pump water into adjacent containers. These containers acted as weights that, through a series of ropes and pulleys, opened the temple doors when people were about to arrive for prayer. A similar system was later applied to open the city gates.

It is assumed that the pharaohs also created for their pyramids and tombs a type of automatic door systems that opened through a lever system triggered when someone pressed a specific area or stepped on a portion of the floor. The first documented reference, however, dates back to the year 600, when the Chinese invented the first foot sensor: specifically, when a person stepped on the threshold, the door opened automatically.

But automatic doors as we know them appeared much later. For a long time, they were just a subject for science fiction writers. H.G. Wells talks about a door that opens by itself in the book “When the Sleeper Wakes,” a science fiction series published in 1899.

In 1931, engineers Horace H. Raymond and Sheldon S. Roby from the tool and hardware manufacturer Stanley Works designed the first model of an optical device that triggers the opening of an automatic door. The invention was patented and installed in the Pier Wilcox restaurant in West Haven, Connecticut, for the benefit of waiters carrying trays of food and drink. The entire system plus installation was sold for $100.

In 1954, Dee Horton and Lew Hewitt invented the first automatic sliding door. In 1960, they founded the company Horton Automation Inc. and launched the first automatic sliding doors for shopping centers on the market. Agta Record is one of the first companies to adopt and perfect the concept of automatic doors. Founded in 1953, Agta Record initially produced swinging doors. Five years later, the first Record automatic doors appeared on the market. Today, the company has over 2500 employees, subsidiaries, and collaborators in 50 countries. One of these collaborators is KADRA. As in any other field, technology has evolved, and safety and reliability have become key words, perfectly visible in all KADRA products.