Revolving doors are a common sight in offices around the world. These double doors allow personnel to enter and exit with ease so they can be present when important meetings or conversations take place. They may seem like a fairly simple piece of office technology, but the history behind revolving doors is surprisingly deep. From horse stables to railway carriages, and even lighthouses, revolving doors have taken many forms over the years. Here’s everything you need to know about revolving doors
How Does a Revolving Door Work?
The mechanism that makes up a revolving door is fairly simple. First, a pair of rollers, or “rotors”, sit on either side of a central shaft. The rollers are connected to a gearbox, which sits inside a door frame. The shaft is connected to a pair of hydraulic pistons that sit in either side of the frame. The pistons are connected to a pair of shear pins, which can be set to retract or extend into the frame. When the door is in a closed position, the pistons sit inside the frame. As the door opens, the pistons are forced to extend, which pushes the rollers out and allow the door to rotate. The door will then retract into the frame, allowing the pistons to move back inside the frame and retract, returning the rollers back to their original position.
Connected: How Horse Stables Led to Revolving Doors
The earliest revolving doors probably evolved from horse stables. In the early 19th century, carriages began to become more common, and people wanted a way to safely and quickly enter and exit their vehicles. Horse stables were adapted as the first revolving doors, but with a few major differences. Firstly, the shafts in these early revolving doors were much smaller than the shafts in modern revolving doors. Instead of being around 2.5 metres tall (approximately 9 feet), horse stables were about 0.4 metres tall (around 13 inches). This made them significantly smaller, and therefore cheaper to build. Horse stables were also usually open-sided rather than enclosed, meaning the shafts instead led to a pair of doors set perpendicular to each other. Horse stables were still very useful though, and in the early 20th century they evolved once more. The shafts in these doors also shrank, allowing them to be placed inside a much smaller space.
More Connected: The Invention of the Automatic Door
A few years after rotating carriage doors were invented, architects began to experiment with the idea of a revolving door that would automatically open when a person approached. The first automatic revolving door was created by William Gibb & Co in Germany in 1904, and they quickly became popular. Automatic revolving doors appeared in a variety of forms, from the Gibb model that used hydraulics to the emergency exit doors found in some offices. Automatic revolving doors were introduced when offices were becoming larger, as a way to lighten the load on maintenance teams. Modern automatic revolving doors usually feature a sensor that detects movement and activates the door. They can often be programmed to automatically open at certain times, or open and close using a remote control.
Companies who make them
There are many companies that manufacture revolving doors, such as Protogetic, C&M and one of our favourite door brands, KORB. These companies design, manufacture and supply revolving doors for various commercial uses, such as offices and hospitals. There are also companies that supply revolving doors as an afterthought, such as door closers and furniture. Revolving doors are not just for big businesses that need a lot of custom-built doors – they are a cost-effective way to create an entrance in any small to a medium-sized building.
The history of revolving doors is fascinating and shows just how many different forms they have taken in their nearly 200-year history. Today, revolving doors are ubiquitous in offices and can be found in almost any building. They are a useful way to safely and quickly enter and exit buildings and are usually operated by a push or pull device. However, in order to use them correctly and safely, it is important to know how they work.