This is how the battery-operated 7411-VT6-SO vacuum lifter was tested for a load of 2500 kg

For a task as particular as this one, something rather special was needed. Our customer had until now failed to find a solution for installing a glazing unit measuring 9 metres in length and 2 metres in height in a single operation. This small pane of glass weighs no less than 4500 kg. As well as this large pane of glass, a couple of smaller glazing units weighing between 2000 and 2500 kg needed to be installed. Our customer considered accomplishing this with two vacuum lifting devices which he was going to attach himself to a cross-beam on his premises.

Consequently, he requested two vacuum lifters, each rated for loads of 2500 kg. They should be as flat as possible. Since there is only a gap of 300 mm between the wall and the scaffolding, and since the glass pane itself measures 70 mm in thickness, this only leaves 230 mm. To enable this project to work, the load needed to be suspended as perpendicularly as possible to the crane hook.

Here is a brief summary of the required properties:
carrying capacity 2500 kg
battery vacuum lifter
adjustable carrying frame to enable smaller panes of glass to be moved too
total width of less than 4 metres
flat device with a thickness of less than 200 mm
the load should be suspended as close to perpendicular as possible
very short delivery time

From these requirements, we developed the 7411-VT6-SO vacuum lifter. With two extension kits with an approximate width of 2140 mm this unit can be upgraded to a width of approx. 3580 mm. The vacuum lifting device attached by suction has a thickness of approx. 190 mm.

The load test is performed once the two devices have been constructed. As stipulated in EU standard EN 13155 for operation on construction sites, every fully-configured device must be able to support loads of 5000 kg for at least 5 minutes. Our gantry crane is not designed for operations of this nature, so we always bring a mobile crane into our production facility for this kind of test. Admittedly, we incur a big expense in the process. However, it does mean that we can be certain that we genuinely can satisfy these demanding requirements, preferring to actually do it rather than simply claim to be able to do so theoretically. This is something upon which our customers can depend.

After all, theory is one thing, and practice is a quite different thing. And from time to time, we too have experienced some unpleasant surprises. This time, we were pleasantly surprised because our 6 x 2.5 m steel package weighing 5000 kg hung in a remarkably perpendicular position. Well, not entirely, but 88.75° is pretty close to 90°.

Both vacuum lifters passed this test using just three of their four vacuum circuits and a load of 5000 kg without any obvious effort. Which meant that nothing stood in the way of delivery to our customers any more. And once again, the mobile crane managed to reverse out of our little building. Mind you, our professional crane driver has clocked up a lot of experience of doing so over the years.

We recorded that for you in this short video.