Tugger trains are often used to transport material to production centres in series production installations. They consist of a tractor and a number of trucks, the design of which differs according to their function and load.
Trolleys are often used to transport large material containers, since they enable the container to be moved by hand. In order for the trolleys to be transported to the production line, they are transported directly on the trailers of the tugger train to overcome the need for the container to be handled. However, this may result in high forces having to be exerted when the trolleys are loaded onto the trailers, particularly when high weights and substantial height differences between the trailer and the ground are involved.
No machinery standards relevant to tugger-train trailers are known.
The Technical Report ISO/TR 22100-3 describes how ergonomic principles can be applied during the risk reduction process according to ISO 12100 and how ergonomics standards can be applied to machinery. It helps designers take decisions with respect to ergonomics during the machine design process and can also be used when no relevant type C standards are available.
Trolleys are often used for the transport of large-volume storage boxes by means of tugger trains. In the store, the storage boxes (e.g. post pallets) are placed on these trolleys, which run on four castors, and the trolleys are inserted into a trailer of the tugger train. The simplest form of trailer has a fold-out loading ramp. However, this trailer design presents the problem that the trolley and its load must overcome the height interval between the floor and the trailer by being pushed up the loading ramp by the worker loading it. An edge or ridge on the loading ramp must often be overcome in addition. This leads to major force exertion (see also EN 1005-3), particularly with heavy loads, and is time-consuming.
- Stress category
The LKE MultiLiner can automatically load different types of trolley weighing up to 500 kg. The design consists of two conveyor belts which are able to move around a central rocker and tilt to the side. The trolley need only be moved to the lowered side of the rocker. The conveyor belts then engage with the trolley between the wheels and draw it onto the trailer truck. When the trolley has reached the mid-point of the truck trailer, the rocker levels the gradient and the load rests safely in the centre of the truck trailer for the purpose of transport. For the trolley to be unloaded, a switch is simply activated and the load is discharged fully automatically. The trolley can be loaded and unloaded onto and from either side of the trailer truck.
- Principle of operation
- Use of driven conveyor belts on handling equipment for the automation of loading processes
- EN 1005-3: Safety of machinery - Human physical performance - Part 3: Recommended force limits for machinery operation