Description

New logistics and production concepts (lean production) are presently seeing a trend not only to increase efficiency and to reduce costs (operational expenses and human resource costs) but also to prevent any kind of waste. Waiting times, transports, moving materials and retrofitting work is to be limited to a minimum. Such requirements triggered the idea of the future factory with few trucks in which virtually all transports of materials are handled by tugger trains.
For this trend, STILL has developed a new version of the tugger train which does not only increase efficiency but also improves occupational safety and eco-friendliness. The new tugger trains make material handling more comfortable for the user, the turnaround will speed up and there are more possible applications.

Innovations

Up to now the STILL tugger train was available with a tractor and pneumatically or hydraulically operated C-type or E-type frames. In the newly developed version of the E-type frame, the generator producing the pressure needed for lifting was integrated into the frame so that the new frame now operates independently of the power supply by the tractor. This way hydraulic or pneumatic connections from the tractor to the trailers/load carriers with the trolleys are not needed anymore. This does not only save time but also electric energy. The pressure must not be generated to lift all the trailers but only for the one that is actually being loaded. When the new trolley is pushed completely into the frame, it will automatically lift. The autonomous trailers allow combining the tugger trains even more flexibly, e.g. when operating several trains with one tractor.
The staff in production often have to push or pull heavy trolleys. To facilitate handling, it is therefore necessary to minimise the tare weight of the trolley as much as possible. The innovative series of resilient plastic trolleys it ideally suitable for this. It is designed as a modular system for load weights up to 1 000 kg and makes load handling in production, warehouse and workshop much easier.

Market relevance

The target for STILL in developing the autonomous frame and the respective trolleys was not only to substantially facilitate handling but also to improve the efficiency and the functional safety in case of a failure of the tractor.
Goal for the development was to improve the hydraulically or pneumatically operated C-type and E-type frame of the conventional tugger train. Especially the time needed to change the tractors or individual trailing frame had to be reduced. In case of failure or defect of a tractor there is often no replacement truck to move the train. In this case the replacement truck is often only connected provisionally to the train, i.e. without the hydraulic/pneumatic connection. This impairs operational safety. A solution cost-efficient, universally applicable and functional solution was needed to solve this problem. Another goal was to optimise handling of the tugger train. On one hand physical effort for the worker had to be minimised and on the other hand the tugger trains as such were to be made more flexible. Requirements for this were the capability to load the trains from both sides, a lean design and easy loading and unloading the frames with the trolleys.

Customer benefits

Discarding of the hydraulic/pneumatic connections in-between the trainers saves work time and electric energy. Each load carrier can be lifted and lowered individually, so that only the energy to lift one trailer is needed opposed to the energy to lift each trailer in the train. The more trailers the train has, the more energy is saved. When travelling a pump reloads the pressure vessel mounted beneath the chassis of the trailer. The autonomous trailers allow to combine the trains more flexibly and the time needed to modify the trains is shortened. The autonomous pressure generation does not only save space and reduces the risk of oil spillages, it also increases safety. The trailers can operate autonomously so that they are independent from the tractor used. This means that when changing the tractor, it is not necessary to match the correct pneumatic or hydraulic combination of tractor and trailers. The innovative product series of plastic trolleys is ideally suited for operation with the STILL tugger train. The series is designed as a modular system, rated to carry load up to 1 000 kg to facilitate load handling in production, warehouse and workshop. The low weight of the trolleys substantially reduces the weight of the whole train cutting the power consumption, floor loads and physical effort staff need to make when moving the trolleys. During an eight-hour shift clocked in 10-minute cycles with four E-type frames, the moved weight can be reduced by as much as 1 152 kg.