PRODUCT REPORT | BELOW THE HOOK
surface areas, significant deflections during a single point lift (such as thin sheets), major changes in area from load to load, or large variations in contour of the lifting surface,” says Bradley. Note the ‘thin sheets’ reference: as we saw, such sheets can pose a problem for lifting by edge clamp, but vacuum lifters can handle them with ease. “To meet customer requirements their engineers will often incorporate the ability to telescope (manually or by motor) the frame.” Rotation of the load can also be incorporated – the distinction between vertical and horizontal orientation of the sheet that we laboured so much in the earlier part of this article scarcely applies to vacuum lifts. “Factors that must be considered are temperature, porosity of the material and availability of vacuum or power sources on the crane,” says Bradley. Vacuum lifters of course need to
generate their vacuums. The power source for this can be electricity (mains or battery), or an external source of compressed air or of vacuum. German manufacturers Vaculift have a remarkably simple but ingenious method, used in their Green Line series, in which the load itself generates the vacuum that lifts it. The device is a vertical hollow cylinder with a piston inside it. It sits on a sealing ring on the (horizontal) plate to be lifted; the hoist chain is attached to the piston. When the hook and chain move
upwards, they pull on the piston, which also moves upwards inside the cylinder – generating a vacuum beneath it, which sticks it to the load and lifts it. If it sounds paradoxical – can you really lift yourself up by your bootstraps? – Vaculift points out that they invented the system themselves, some fifty years ago, and it has been in continuous manufacture, and safe use, ever since, and can lift loads of up to 4t. Vaculift also make more conventional, powered, vacuum lifters: its Red Line electric- powered one which can lift up to 1,250kg with between one and eight pads, Gold Line’battery-powered ones, with turning and pivoting abilities if required, and Blue Line’pneumatically powered models. They also make customised solutions. Italian specialists Righetti Sollevamenti, based in Verona, make vacuum lifters for sheet metal, stainless steel, aluminium and non-ferrous materials. Their technology has allowed them to create a system of springy and articulated suction cups for sheet metal, which will also adapt to lift not perfectly flat loads, managing to compensate for corrugated or indented surfaces. So, for example, metal sheeting destined for the floor of a walkway, therefore embossed with raised diamond shapes against slipping, can still be lifted by vacuum, specific suction pads with a special gasket that adapts to the surface unevenness.
Vaculift’s lifter needs no power source.
Righetti make lifters powered by battery, mains electricity, and compressed air. With battery-powered models the client can choose whether he wants to manage suction and release via a manual valve on the handlebar of the lifter, or via a radio remote control. Vacuum monitoring systems ensure safe lifting of the load. Each series of their lifters is available with different lengths of central cross-beams, to accommodate different lengths of load; Righetti also produce customised and tailor-made lifters. So to lift flat sheets or plates, of almost
any material, thickness or size, in whatever orientation you want, you can pick, choose, and consult. You will not be short of options.
The size and number of vacuum pads depends on the weight and dimensions of the load. 28 | April 2024 |
www.hoistmagazine.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77
