The new generation of vacuum lifting devices of the series VacuMaster Basic/Comfort are worthy successors to their predecessors, which have proved their value in thousands of applications. This is due, above all, to the innovative and functional design, which is based on so-called longitudinal beams. These beams, made of anodised, extruded aluminium sections, act as load carriers, vacuum reservoirs and vacuum distributors. This does away with the need for many hoses, which tend to get in the way, and also saves weight. The modular system, which consists of only a few components, makes it easy to construct vacuum lifting devices for almost any application.

There are three basic version of the lifting devices (for horizontal handling and for turning the workpiece by 90° or 180°). The horizontal versions can lift loads between 75 and 750 kg, while the versions for turning the workpiece can handle loads of up to 500 (90° turning) or 250 kg (180° turning). The workpieces are turned with the aid of an electric linear drive. The operator controls all functions of the lifting device with push buttons on the operator handle. This principle is particularly advantageous when handling unwieldy workpieces, since it permits the operator to move and position the load (suspended on a crane and the lifting device) quickly, safely and precisely. The low overall height of the lifting devices with the turning option means that the turning of workpieces can be mechanised even in restricted spaces or in rooms with low ceilings.

Workpiece handling with vacuum for
more productivity and quality

The technical benefits and the simple handling also convinced a well-known manufacturer of workbenches and tool trolleys located in South Germany, who was looking for a way of rationalising the machining of the edges of workbench tops. These tops are made of solid wood, with dimensions up to 2,000 x 1,000 mm and thicknesses of 25, 40 or 50 mm. The workbench tops thus weigh up to 100 kg each, and manual handling is possible only with at least two persons. Although the sawing and surface machining were already executed semi-automatically or fully automatically, the machining of the edges was still being done with hand-held machines. A further problem was that the workbench tops had to be turned over to permit the machining of the top and bottom edges, which meant that the machining and handling was relatively time-consuming.

For this reason, the responsible persons at the company started a rationalisation project which included the investment in a new CNC machining centre. In order to make best use of the capacity of this machining centre, the company also invested in a vacuum handling system for loading the machine, turning the workpieces and removing the finished workbench tops. The handling system selected for this task was a crane-mounted vacuum lifting device VacuMaster Comfort 125-180°-2 made by the vacuum specialist J. Schmalz GmbH in D-72293 Glatten. The VacuMaster was mounted on an existing double-beam crane system.

More efficiency thanks to a 50% reduction in personnel,
shorter idle times and better utilisation of the machine

After an analysis of the task, the company selected the above-mentioned VacuMaster Comfort 125-180°-2. This device is designed for a maximum load of 125 kg and is equipped with the 180° turning option. It has two vacuum plates, each with a diameter of 360 mm, which more than meet the requirements of the applicable safety regulations and make the work of the operator even safer.
The vacuum lifting device is used to place the workbench tops on the CNC machine, where they are machined, and to remove the finished workpieces. Depending on the type of workbench top, the workpiece has to be turned over after the upper edge has been machined in order to permit machining of the other edge. Since installation of the CNC machining centre, the company ensures that as many workbench tops as possible are designed such that no manual machining of the edges is necessary.

Not only the edge machining, but also the complete handling of the workpieces, is now much more rational and efficient, since the vacuum handling also avoids damage (scratches) to the surfaces of the workbench tops which, in turn, means that almost no reworking is necessary. Another ideal feature of the vacuum lifting device is its low overall height, including the turning mechanism. Although the machine table is equipped with a console clamping system with Schmalz suction blocks to hold the workpieces during machining, the workbench tops can still be turned through 180° in the space above the machine. This saves the time-consuming operations of withdrawing the workpiece from the machine and inserting it again after it has been tuned over, thus reducing the idle times of the machine to a minimum.

The handling of the workbench tops with a vacuum lifting device with a 180° turning mechanism was thus the answer to several of the specified tasks and provides more productivity, quality and safety, and also improves the motivation of the machine operators.