The combination of a vacuum gripper system and a vacuum lifting device has become  very popular as a simple and reliable handling unit in many areas of production, storage, commissioning and distribution activities. As the market leader in this area, the vacuum specialist J. Schmalz GmbH in 72293 Glatten, today offers a wide range of vacuum tube lifters and vacuum lifting devices, together with various vacuum gripper systems which permits individual, customer-specific material-flow solutions to be constructed, in most cases, from the modular system of standard components. So far so good, but even the most flexible vacuum gripper systems have problems in cases where the surface of the product to be handled does not offer the ideal prerequisites for handling with vacuum.

Automated handling devices also have problems with the handling of unstable objects which, for example, can change shape and interfere with safe transport. This was the case at HERMA GmbH in Filderstadt, one of the largest manufacturers and distributors of equipment and products for the labelling of all types of goods and packages. In their new logistics centre, cardboard boxes weighing up to 40 kg are handled and packed with the aid of industrial robots. This involves activities such as lifting the boxes from a roller conveyor and stacking them on pallets. Each day, about 1200 packages are prepared for shipment all over the world, and these quantities can be handled economically only with a relatively high degree of automation.

But what happens if a package cannot be handled and stacked automatically? There packing line backs up and the package(s) which cannot be handled automatically have to be moved manually. In order to avoid this manual work, HERMA installed a vacuum tube lifter with a new multigripper system for handling of cardboard boxes which could not be moved with the industrial robot. This handling system, consisting of a vacuum tube lifter of the type JumboErgo 45, capable of lifting up to 45 kg, a slewing column crane with a 5-metre jib and the new Jumbo Multigripper, is capable of lifting and moving unstable cardboard boxes weighing up to 40 kg safely and reliably.

The Multigripper has a special and extremely flexible set of suction pads: each pad is mounted on a plunger with an internal spring which permits a stroke of 50 mm. This means that even cardboard boxes whose tops bulge considerably outwards can be gripped and transported safely. In addition, the large number of suction pads helps to reduce the deformation of the boxes, which means that there are no visible signs of handling on the dispatched packages. J. Schmalz GmbH was able to offer HERMA a low-cost complete solution for the horizontal handling of cardboard boxes which, in spite of the special requirements, was constructed to a great degree from standard components.

In the meantime, the Jumbo Multigripper is part of the standard product range of vacuum grippers and can be adapted specifically for use in various applications. It weighs only about 6 kg and is relatively compact, measuring only 350 x 280 x 190 mm (L x B x H). The version described above is equipped with 20 separate suction pads of the type FSG 62, but the number and type of suction pads can be varied to meet the specific requirements. However, it is absolutely necessary that lifting tests be carried out before construction of such special systems in order to take all problems which can occur during the handling of unstable loads into account and to ensure the necessary safety in operation.