One for all – ideally this would be the motto for industrial users when handling sheet-metal workpieces in automated production systems. Although the raw and machined metal sheets are today handled almost everywhere with vacuum gripper systems, the handling of sheets with many holes still causes problems. For such workpieces, it is then necessary to change the gripper, but this costs time and productivity and also involves the investment in a further gripper. Another possible solution would be to have the sheets handled manually by two persons, but this negates the advantages of automation and reduces the performance of the machines. It also has a negative effect on the economics of the production process. For this reason, the vacuum specialist J. Schmalz GmbH in 72293 Glatten has developed a clever solution, namely the new, specially designed magnetic gripper SGM.

Magnetic grippers from a vacuum specialist? This seems strange, but it is a sensible move which helps the users of vacuum gripper systems for sheet metal to increase productivity and save costs. The solution to this apparent paradox is that the new magnetic grippers SGM provide the necessary holding force with the aid of a magnetic field generated by a permanent magnet, but the field can be switched on and off with the aid of a compact ejector or with pneumatic valves. The pulses of vacuum or compressed air used to control the magnetic gripper consume very little energy. The magnetic grippers are bistable, which means that they remain in the state "grip" or "release" even in the case of a power failure.

The design of the magnetic grippers SGM is simple and robust. They consist of an aluminium housing with an integrated permanent magnet and a hose connector for the vacuum or compressed-air supply.

The magnetic grippers SGM are mounted on a vacuum griper system and connected to the vacuum or compressed air. Depending on how the vacuum gripper system is designed, the vacuum grippers and the magnetic grippers can then be used either separately or together. This makes it possible to handle complex laser-cut sheets, sheets with many holes and narrow webs and, above all, perforated plates reliably, precisely and safely. The use of both types of gripper together is also ideal for handling very heavy metal sheets, since the magnetic grippers assist the vacuum grippers in this task. At the moment, the magnetic grippers are available in three different sizes, with diameters of 80 mm, 47 mm and 20 mm.