Lifting aids in production: the load where the machine needs it.

When loading a machine, the movement does not end on a shelf but at a precise point: in the chuck of a lathe, on the locators of a fixture, against the stop of a saw. The operator has to do more than lift – the load must be aligned, rotated and set down gently.

A rope can only do that while the load hangs straight below it. As soon as it is guided into a working area, it is off-centre – and then a lifting aid with a rigid arm is needed to take up the resulting moment.

The moment is load multiplied by distance. A part held half a metre in front of the gripping point creates a moment that a device with the same rated capacity cannot necessarily take. Every serious design therefore states the permissible load moment alongside the capacity.

Articulated-arm manipulators such as the Elbow, with a radius of around 2.4 metres, are built for such tasks. For screwdrivers whose reaction torque the operator would otherwise absorb with the wrist, there are torque arms. Our calculator gives a first estimate of capacity and load moment; it does not replace the verification.

Flat workpieces are usually gripped by vacuum. With large formats, deflection comes into play: a thin panel held only in the middle sags at the edges and can come away from the pad. A spreader beam with several pads distributed over the surface solves this.

At a press brake, the sheet also has to be turned over, often several times per part. The gripper then needs a rotating or turning unit that holds the sheet while it goes from underside to top. Our applications on turning sheets and loading a CNC with panels show the details.

Some lifts are rare but heavy: an injection mould, a roll, a coil. Production often waits for the overhead crane, which is needed elsewhere at that moment. Every minute of waiting lengthens set-up time.

A dedicated lifting aid at the machine makes the change independent of the crane. Whether that pays off depends on how often set-ups happen and what an hour of downtime costs – our guide “Overhead crane or own device?” works through the trade-off.

Parts removed from a press, an injection moulding machine or a machining centre are rarely clean and dry. They may be warm, wet with coolant or sharp-edged. This mainly affects the gripper: vacuum holds less well on oily surfaces, pads of an unsuitable material age faster on warm parts, and edges can damage suction plates. A mechanical gripper is often the more robust choice here.

Where a lifting aid reaches into a machine’s working area, it touches that machine’s safety concept. Guard doors, light curtains and enabling signals have to work together so that nobody reaches into a running movement. If the lifting aid is fixed to the machine frame, the frame has to take the additional forces.

Both belong in the risk assessment. We therefore plan the lifting aid with the machine it serves in view, and clarify with the operator whether the combination amounts to a substantial modification.