Underrun protection for scissor lift tables: Which one is right for you?

Corrugated wire mesh is the simplest and most cost-effective solution to protect the hazardous area beneath a scissor lift table. It consists of a curtain made of interwoven metal elements, attached to the underside of the platform. Apart from the upper mounting, no additional components need to be installed on the lift table for the wire mesh.

A key advantage of the corrugated wire mesh is its design: The numerous small openings and the weight of the metal curtain provide minimal wind resistance. This makes it particularly well-suited for outdoor use. The risk of the mesh being pushed into the moving parts of the scissor lift table is virtually eliminated.

However, if the lift table needs to be moved frequently, the corrugated wire mesh is less ideal. Without a specialized collection tray, the chain curtain rests on the ground and can complicate transportation. In such cases, a PVC roller shutter is a better option.

The PVC roller shutter is a tarpaulin fixed onto a spring-loaded roller. During the lifting motion, the spring roller tightens, causing the tarpaulin to roll up as the lift table is lowered. To install the PVC roller shutter, a bracket for the spring roller and a counter bearing on the base frame of the lift table are required. Compared to a simple wire mesh, the PVC roller shutter is a somewhat more expensive solution, but it is priced below the bellows system.

The PVC roller shutter offers two advantages over wire mesh:

• Fixed connection to the base frame: By being attached to the base frame, the PVC roller shutter does not rest on the floor. This makes it suitable for lift tables that are frequently relocated.
• Easy access for maintenance work: For maintenance and repair tasks, the PVC roller shutter provides quick access to the hazardous area beneath the lift table. By simply loosening the lower fastening screws, the spring roller automatically rolls up, and the sheet exposes the area below.

The bellows, often referred to as a box bellows, is a widely recognized solution for preventing reach-in accidents. It provides an effective barrier, ensuring safety and enhancing the functionality of machinery where hazardous areas need to be shielded.

Thanks to its accordion-like design, the bellows is made up of multiple small plastic folds securely bonded together. These folds compress tightly in the retracted state and expand when extended, making it a flexible yet robust protective covering. Typically, the bellows is mounted to the lift table platform using specialized clamps, requiring additional support on the base frame for proper installation.

Unlike wire mesh or PVC roller shutters, which may leave corners exposed, the bellows offers full coverage of the area beneath the lift table. Beyond injury prevention, it also serves as a protective barrier against dust, debris and other contaminants, safeguarding the lift mechanism.

The sheet metal apron is a specialized solution for underrun protection, used almost exclusively on scissor lift tables with low effective stroke. Installing a sheet metal apron is often more cost-effective than other underrun protection options, such as wire mesh or PVC roller shutters.

The protective function of the sheet metal apron is based on its length: It is designed to cover the entire hazardous area beneath the platform. When the lift table is installed in a pit, the lower edge of the apron remains below floor level even when the table is raised. This prevents individuals from accessing the hazardous area under the platform. Additionally, this design eliminates the need for a foot protection safety strip, reducing costs further.

As the effective stroke of the scissor lift increases, the length required for the sheet metal apron also grows. Beyond a certain height, a single-piece apron becomes impractical. In such cases, a telescopic apron is used. While offering comprehensive protection and remaining wind-resistant, telescopic aprons are significantly more expensive due to their complex design and manufacturing. For scissor lift tables with a effective stroke exceeding their built height, sheet metal aprons are rarely used. In these scenarios, users often opt for alternative underrun protection solutions, such as bellows.