The reliability of pedestrian turnstiles is critical to public safety. To keep them running smoothly, manufacturers use customised shock absorbers.

In a turnstile application, one of the biggest issues is user safety. With no shock absorber, the turnstile bars can bounce back and cause injury, which is a large concern when millions of people use turnstiles every day for business, travel and recreational purposes. 

In tripod turnstiles, shock absorbers provide smooth and consistent dampening for the rotational movement, preventing the tri-arm bars from swinging too quickly or banging at the end of the rotation. These units protect the turnstile and are tuned specifically to withstand the energy delivered by the rotational movement of each turnstile application. Once a person enters the turnstile, he or she exerts force on the arm until a certain point in its rotation, and then the arm drops automatically to the next position. The shock absorbers are mounted so that they absorb the energy of the arm when it drops back to the rest position.

“In tripod turnstiles, shock absorbers provide smooth and consistent dampening for the rotational movement, preventing the tri-arm bars from swinging too quickly or banging at the end of the rotation.

The benefits of custom-engineered shock absorption

In some applications, shock absorbers do not provide enough resistance to the increased mass and force applied during operation, but redesigning the unit for a larger type of shock absorber would be very costly and time consuming to the manufacturer. A custom-designed shock absorber can meet these larger mass and drive force requirements, providing significant savings to the customer for a modest investment. By designing and developing a modified standard shock absorber into a specific application, manufacturers save time and cost associated with redesigning a turnstile unit to fit a standard motion control product. 

“Shock absorbers protect turnstile machinery eliminating machinery damage, reducing downtime and maintenance costs, and increasing lifespan and reliability.

Adjustable shock absorbers are another type of custom shock-absorber product that should be considered for industries where the turnstiles will experience increasing and decreasing flow demand. By allowing for adjustments to the rate and energy absorption, adjustable shock absorbers offer manufacturers the ability to protect equipment and extend machine life, while maintaining or expanding output. In amusement park applications for example, the ability to enter the park and ride waiting areas smoothly are as critical to the experience as the ride itself. The turnstiles in these applications experience increasing and decreasing rates of use by hour and season, but remain critical to ensuring customers are safe. Shock absorbers are key to serving industries around the world and providing rate control and energy absorption solutions for lasting operation of turnstiles and gates.

When designing a shock absorber for a turnstile application, manufacturers should consider the size, force capacity and stroke needed for their specific function. The shock absorber may be handling children, adults, or even cattle and the turnstile application, from a business entrance to a busy sports arena, could vary greatly. Think about public transportation. You have people crossing through turnstiles, from small kids to adults, which means you have different weights and different speeds, which creates different forces. These varying weights, speeds and forces that have to be absorbed need to be considered when choosing an off-the-shelf or designing a custom-engineered shock absorber for a turnstile. To have the best design for these turnstile applications, manufacturers should look to experienced engineers to design a shock absorber to meet all of those requirements and conditions.

20 years and 25 million cycles: Automatic Systems’ tripod turnstiles built to last with Enidine shock absorption

Automatic Systems is a world leader in the automation of secure entrance control, with more than 19 million people in 25 different countries using their equipment daily. Automatic Systems designs and manufactures vehicle, pedestrian and passenger-access control equipment, including public transport, security entrance lanes, tripod turnstiles and full-height turnstiles. 

For more than 20 years, Enidine has worked closely with Automatic Systems to supply shock absorption solutions for their tripod turnstile applications. Enidine’s shock absorbers protect turnstile equipment at an extremely high cycle rate for robust and reliable performance, perfectly suiting them for typical heavy-use tripod turnstile sites, such as leisure centres, stadiums and factories.  

Installed over 20 years ago and surpassing 25 million cycles, Automatic Systems’ oldest tripod turnstiles, featuring Enidine shock absorbers, are still in place and working today. Over the course of the past 20 years, some Automatic System customers have needed to replace the stainless steel casing of the turnstiles due to typical wear-and-tear damage after years of use, but the installed Enidine shock absorber system is still meeting cycle rate and safety standards, with no need for replacement.

In keeping with their reputation for service and support, approximately five years ago, Enidine was required to adjust their shock absorber design to meet new regulations. Automatic Systems received outstanding support from the Enidine engineers, as they were required to perform extensive testing over the course of several months and several million cycles. As their clients depend on reliable turnstiles, Automatic Systems did not want to take any risks. Ultimately, Enidine provided a modified shock absorber design that withstood the extensive testing and met global regulations in a fast turnaround time. Automatic Systems was fully satisfied and maintained their longstanding relationship with Enidine. Automatic Systems is extremely pleased with the reliable, attentive service provided by Enidine engineers. 

Protect equipment; reduce cost and downtime; increase reliability and lifespan

Shock absorbers protect turnstile machinery by offering predictable, reliable and controlled deceleration. In addition to the human safety aspect, harmful side effects of motion, such as noise, vibration and damaging impacts, are moderated or eliminated. This eliminates machinery damage, reduces downtime and maintenance costs, and increases turnstile lifespan and reliability. Additionally, the flexibility provided by some shock absorbers means turnstiles can operate at higher cycle rates and, if required, can be designed to meet specified safety standards.

The customizable design and development of shock absorbers in turnstile applications is critical to increasing safety and prolonging machinery lifespan. With so many variations in weight, speed, energy and environments, turnstile manufacturers need highly engineered parts to ensure people around the world continue to stay safe and secure.  

Text: Dieter Klaiber, Project & Application Manager, ITT Enidine , dieter.klaiber(at)itt.com