A retractable roll-stop bar is built into the lift table platform, which extends when the table is raised. This is to prevent the rolling load from inadvertently rolling up to the edge of the scissor lift.
We use hydraulic cylinders to extend and retract the roll-stop bar. These hydraulic cylinders were connected to the circuit of the lifting system to keep the number of hydraulic valves required as low as possible. The advantage is not only the lower price, but the subsequent extent of maintenance is also reduced. The video below shows how the active roll-stop bar works.
A bellows secures the hazard area underneath the scissor lift. The bellows is a plastic cover that folds together or apart like an accordion. The platform also has a foot protection safety edge. If the bellows is pressed in by one of the employee's feet, the safety edge prevents the feet from being crushed when activated by immediately stopping the lowering movement of the scissors.
We design our lift tables with a high safety factor in mind. Nevertheless, a load that is too heavy destroys any mechanical system. To prevent this from happening, we monitor the pressure in the hydraulic system and so prevent the transportation loads that are too heavy.
In the lowered position, a pressure relief valve, which transports the hydraulic oil back into the tank if the pressure is too high, making it impossible to lift the platform, is sufficient for this purpose. In the raised position, pressure monitoring is more complex. For this purpose we install a pressure switch which continuously compares the actual pressure with the permissible maximum pressure. If the permissible pressure is exceeded, the pressure switch reports this to the higher-level control system. A warning message is then issued to the operator and the lift table can no longer be moved.
In contrast to the above points, the surrounding platform edge is not a safety device. The edge was requested for visual reasons, as the lift table should get the same floor covering as the on-site floor at the customer’s.