The task was to find a way of destacking stacks of totes from dollies, conveying the totes away separately, and then stacking the loaded shipping totes back on the dollies.
The target was to be able to stack and unstack more than 600 totes/hour onto and from dollies, and to feed these totes to the tote conveying system.
Stacks also had to be able to be fed from the dollies into the system, temporarily stored, unstacked and fed separately to the loading station.
To allow the dollies to be coupled to tugger trains, they have a spring-loaded drawbar. This was to be handled using a special gripper when the totes are being stacked/unstacked and loaded/unloaded.
An additional challenge was to find a way of feeding the dollies into the conveying system manually and at floor level, and of removing the dollies from the conveying system once they have been loaded.
Conventional chain conveyors are not suitable for transporting the dollies used there.
A special new design of chain conveyor, called a “gripper chain conveyor”, has allowed for a reduction in the upper conveying edge to 200 mm.
This enables loaded or empty dollies to be fed in or removed easily, without the need for stackers such as fork lift trucks or floor lifting stations.
These technical challenges had to be overcome in the smallest amount of space possible.
The compact design of the conveying equipment and the loading/unloading stacker means that the entire conveying system covers an area of just 130 m2
Up to 110 dollies can be conveyed in the system at a time.