?Cladding and glazing jobs pose particular challenges for lifting firms. Often, cladding sections may need to be installed under roof overhangs; on shopfronts, glazing may need to extend from floor to ceiling. In both cases, that means there is no space above the load for a hook and sling. In glazing, in particular, the load must fit exactly into a prepared space, leaving no space for straps around the load. As the load may be fragile, but its appearance is vital to the success of the job, it must be held securely with as little risk of damage to its finish as possible. All of these challenges prevent the use of traditional slings and hooks.
Vacuum attachments hold a panel from the front, meaning that no space is needed above or around the load for hooks, slings, or boom. Suction pads do not move across the surface of the pane or panel, and are designed so as not to scratch or damage its finish. The frames on which they are mounted can be tilted and revolved, allowing window panes to be positioned with minimal clearance on all sides.
The manufacture of the attachments is dominated by specialists, often with roots in the glazing industry, who supply them both to end users and to crane builders for use in specialised machines, either directly or through distributors.
All of the manufacturers offer vacuum lifters for a wide range of applications. Cully Murphy, manager of online marketing for Anver, says, “Glazing would be the most obvious application. Other areas are decorative and structural architectural panels, including stone, concrete, steel, aluminium; steel fabrications, including vessels, such as large water tanks. We have sold a lifter used to handle large steel structures used in the fabrication of railroad cars.” Pannkoke managing director Bernd Pannkoke adds that the lifters can also be used for stairs, complete window elements and steel plates.
UK Unic minicrane dealer and glazing specialist GGR offers a range of vacuum lifting equipment suitable for all sizes and weights of glass up to 2,500kg. The company uses vacuum lifters from manufacturers including Pannkoke, Woods PowrGrip and Kappel. Managing director Gill Riley owns the company with her brother, Graeme Riley, GGR’s CEO. She says, “GGR UNIC was the first company to offer the package of minicranes and vacuum lifters together. Since then other companies have seen the benefits and tried to duplicate the GGR business model.”
GGR marketing manager Matthew Deasey says, “The specification a customer looks for depends on its lifting scenario. The type of material (glass, metal, stone, plastic, etc.) dictates the type of lifter in terms of vacuum pad, vacuum pump and construction. The weight and dimensions of the load determine lifter capacity and pad spread. The mechanics of the lift (i.e. whether the load needs to be tilted and/or rotated) determine the load manipulation capabilities of the lifter. The lifting environment determines operating power: outdoor applications generally require battery power while indoor applications may use mains.”
Unlike hooks and slings, vacuum lifters are not a commodity component. Each company offers a range of power packs, suction cups and frames. Anver’s Murphy says, “We are able to handle a wide range of materials for a wide range of applications, but our experienced application engineers need application details to find the best solution including dimensions (width, length, and thickness), weight, surface, material of load, etc. The features offered by Anver for glass applications include lifting, tilting and rotating capabilities allowing attach and release in various load orientations. Fully adjustable cross beams and spring suspended vacuum cups allow handling of delicate glass sheets in numerous sizes. Other features include remote controls, vacuum gauges, audio/visual alarms and parking stands.”
Using the lifters for cladding, rather than glazing, poses new challenges. GGR managing director Gill Riley says, “Cladding panels are mainly quite long and thin, sometimes up to 20m in length, and a cladding lifter needs to be able to rigidly support this load. Glass is normally flat, whereas cladding panels can have grooves of various depths. This requires a specially-designed flexible vacuum pad that can still seal on difficult surfaces to maintain the vacuum at all times.”
GGR worked with Wood’s PowrGrip to develop a new vacuum attachment for cladding, the Clad King. Gill Riley says, “The GGR Clad King took about two years to develop, with the first prototype coming 12 months ago. This was given to a customer for field trials and after some small refinements sits in the GGR range of lifting solutions that have been sold in the UK and exported throughout Europe.”
Wood’s PowrGrip’s new product development engineer Bryan Strobel explains some of the issues involved in designing a new vacuum lifter, like the Clad King: “The vacuum pad style needs to as universal as possible to minimise the need to change vacuum pads for each type of cladding surface. A closed cell foam sealing edge accommodates a wide variety of surfaces by conforming to the surface irregularities. The pad dimensions were selected to fit between the large ribs present on the profile of popular cladding panels. A replaceable foam insert keeps the cost of maintenance low.”
Strobel says the lifter was designed to accommodate wall installations where the axis of the panels can be either horizontal or vertical, as well as roof installations. He says, “Vertical wall installations are performed by attaching to the top of the panels that are delivered flat (with respect to the ground) and allowing them to tilt as the panel is lifted. Pad frame extensions can be installed for large horizontal wall installations to support the panel as it is lifted and tilted. Individual pads can be rotated as needed to accommodate the cladding profiles. Pad frame extensions are available to support cladding during large roofing installs.”
