In Formula 1 and touring car racing, changing tires in a matter of seconds is decisive for the win. In most workshops they use pneumatic tools powered by cylinders of compressed air mounted on trollies. If the trolley topples over during use, which is conceivable considering the job it must do, there is a major risk of accidents, especially through damage to the exposed fittings. DK Edelstahldesign, a company specialized in stainless steel design based in Pfullingen, Baden-Württemberg, has been working with the Steinbeis Transfer Center for Process Development in Reutlingen and its director Prof. Karl Schekulin to develop a new type of secure transportation trolley for all kinds of compressed gas cylinders. Not only did their solution withstand the acid test of being used in Formula 1 racing, it also proved absolutely viable for everyday use in standard workshop environments. The project was supported through an innovation voucher offered by the state of Baden- Württemberg.
DK-Edelstahldesign is a medium-sized business that produces small batches of metal and aluminum components based on customer drawings. The designs are laser-cut in house before processing – which primarily involves bending, trimming, and welding parts made of stainless steel. The company’s customers come from the automotive sector, kitchen furnishings, mechanical engineering, and medical technology. The company was already on the lookout for a product it could produce to supplement its portfolio of services, hoping to gain a secondary footing on the market. The opportunity revealed itself when the request came in from the field of motorsports: find a solution to address the constant danger of damage to the exposed fittings of gas cylinders when changing tires.
Working with the Steinbeis Transfer Center for Process Development, the project team at DK Edelstahldesign researched the current state of the technology and the extensive lists of rules and regulations for pressurized containers. Pressurized containers are always a latent source of danger, particularly when it comes to the exposed fittings and connection points like the pressure regulators, manometers, connecting threads, and seals.
For gases like standard air, nitrogen, carbon dioxide, oxygen, hydrogen, helium, argon, or even acetylene, compressed cylinders are generally transported in tubular racks (similar to shopping carts) both in industry and in motorsports. In most cases, valve fixtures aren’t removed and replaced with protective caps because removing them is too time-consuming and wouldn’t make much sense in terms process flow.
This increases the chance of accidents because fittings are left exposed. This became the biggest challenge for the project: The fittings would need to be protected indirectly with a safety engineering solution. This would means developing a mechanical partial housing without affecting the handling of the cylinders, fittings, tubing, and tools.
Systematically working through a variety of design options revealed that conventional designs made of tube-like elements are too instable and too expensive to produce. Instead, the Steinbeis team decided to use beveled sheeting. The trolley components are kept stiff by engineering in sufficient internal strength, with functional surfaces to provide protection to the fittings. The design of the resulting prototype is now based on a partially cut octagonal tube. This delivers ultimate shape retention at low material costs and affordable production costs. The prototype passed hazard testing and even worked in practice during a Formula 1 and touring car race. Nothing stands in the way of using this design in everyday applications in industry and trade, and DK Edelstahldesign now has its own product to add to its portfolio.