Gunnebo, Crosby Straightpoint, Crosby BlokCam, Crosby Airpes, ACCO, McKissick, Crosby Feubo, Trawlex, Lebus, Speedbinders, and CrosbyIP are just some of the below-the-hook brands of the Crosby Group. Kito brands include Kito itself, plus Harrington, Peerless, Jiangyin, Erikkila Van Leusden, Kito Weissenfels, SCC, and Fall Safe. In the UK, the Crosby Group, as of February this year, relocated to a larger, state-of-the-art facility for the production of its Crosby Straightpoint and Crosby BlokCam products. The production plant in Hampshire made a short trip inland to Waterlooville from Havant on England’s south coast. The expanded space provides additional capacity to meet the increasing demand for Crosby Straightpoint and Crosby BlokCam products as well as allow for future growth.
Elsewhere, Bushman Equipment, based in Menomonee Falls, Wisconsin, US, specialises in the design and manufacture of below-the-hook devices to grip, lift and transport almost any solid product. Its list includes C-hooks, coil grabs, coil lifters, vertical lifting equipment, spreader beams, hook blocks, ladle hooks, load weighing, sheet lifters, plate lifters, bundle lifters, pallet lifters, lifting tongs, roll handling equipment, drum tilters and rotating axis grabs (plus one or two more that we have probably missed). The company claims to maximise crane payloads because its devices are themselves of lower weight.
VACUUM LIFTING
Lifting by vacuum doesn’t sound terribly powerful. Paul Watson is sales director of the Vacuum Lifting Company, of East Kilbride in Scotland. He dispels any suggestion that vacuum lifting is for wimps and light loads only: “The biggest lifter we have done is for 40t capacity. That was for a construction project for Microsoft, lifting concrete segments.
“Vacuum lifting strength is all about area and it is an easy calculation: the greater the weight, the greater the area of suction you need. It can come from one large suction pad or several smaller ones.
“We use vacuums of around 40% [of air removed] for lifting,” he says. “The vacuum pumps are battery-powered, which means they are independent of mains supply and are portable: they can be used on construction sites and the like. It also makes them ideal attachments for forklift trucks; they greatly extend the type of loads they can lift and carry.
“Lifting concrete segments and steel plates are the most common applications. We make standard units, but can do bespoke designs as well. We have provided vacuum lifting for curved nuclear submarine fairings among other things.”
Some recent products include a triple pipe lifter, to lift three pipes at a time with capacities from 3.0t to 30t, which has been custom-designed for a client in the Philippines, who uses it for loading pipes into barges; the SP12KB single pad pipe lifter for stockyard gantry cranes, which can lift pipes up to 100in in diameter and up to 20t; and the TP30KB multi-pipe lifting system, which can lift up to three pipes at once using pads that can be adjusted in position or can be preset in position on a cross beam. They are radio-controlled – to free the load on set-down the appropriate button is pressed on the remote and the vacuum is released, which, of course, releases the load also.
The main requirement for vacuum lifting is that the load does not let air through it.
“Some thin concrete panels can be porous, so you would look at a different method for those,” says Watson. But porous loads in a factory or production-line process can be vacuum-lifted. “There you would use not suction cups but vacuum lifters,” he says. “It is a different technique. They use much more powerful pumps, and basically just keep sucking air in, through the load, all the time.”
In such machines the vacuum principle is cunningly extended. The vacuum keeps the load attached and in place, as with suction cups, but the same vacuum also does the actual lifting to the height that is required – no extra crane or hoist mechanism is needed. They are principally used in manufacturing: a flexible tube, attached to a suction pump, hangs down from some suitable support: think the hose and nozzle of a domestic vacuum cleaner hanging down from the ceiling. When the dangling end is placed on an object the suction pulls the load tightly against it, sealing the load in place. The suction then continues, forcing the tube itself to contract and shorten, pulling its end, and the attached load, into the air. It is a simple process; it requires only a single lever to control the lifting, gripping, lowering and releasing functions, and can typically be operated by just one worker. Loads of 80kg and upwards can be carried, and they need not be impervious to air. Porous surfaces, such as sacks and cardboard cartons, are by no means unusual loads.
H&S Lifting, based in Derbyshire, UK, makes such vacuum lifters. Pallets, reels and drums as well as metal plates and flat panels are all applications it has covered. The ever-increasing distribution and shipping sector, driven by the rise of internet shopping, is hugely dependent on boxes and cartons for transporting items, and poor manual handling can easily damage them. It can also damage the backs of the warehouse staff doing the lifting. There are therefore strong arguments for any such operation to install vacuum lifters.
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