Handling systems

A single device rarely solves a handling task. A balancer lifts but does not grip; a gripper holds but does not carry; a rail guides but does not lift. Only together do they form a solution. The term handling system means precisely this interplay: several assemblies designed as a whole for one task.

Almost any handling system can be broken down into five building blocks.

In practice handling systems appear in three basic forms. Stationary, the device stands on a pillar and serves one workstation. Area-wide, it hangs from a rail system and reaches several stations or an entire production cell. Mobile, it stands on a movable base plate and is taken to where it is needed.

The layout follows not the device but the workflow: where is the part picked up, where is it set down, and what stands in between?

Systems rarely fail at a building block and almost always at an interface. The gripper weighs more than assumed and eats up the capacity. The centre of gravity of the component lies beside the suspension and the load hangs crooked. The hose routing limits rotation. The supporting structure yields and positioning accuracy is lost.

A handling system is therefore designed from the load, not from the device: first the component and the motion sequence, then the gripper, then lifting unit and kinematics, finally structure and fixing.

If a system is supplied from one source, the manufacturer declares the conformity of the complete machine. If devices, grippers and structures of different origin are combined, it must be settled before commissioning who issues this declaration for the whole – a safe individual component does not make a safe system.

In every case the operator retains the risk assessment of the workstation, the instruction of employees and the periodic inspection.