Top of the range are the triple-convoluted model 348-3s, which can lift more than 40,000 kg each using normal industrial compressed air at 7 bar (100 psi) to provide strokes of up to 350mm from a compact starting height of just 140mm.

Complementing the big triple and double-convoluted Airstrokes are new single-convoluted models with between 25-60mm greater stroke than standard models, permitting them to be used in applications that might otherwise require more complex lifting and actuation alternatives.

The rugged, fabric-reinforced rubber bellows – identical in construction to the airbags used in the suspensions of semi-trailers and express trains – are used singly or in multiple sets for tasks such as hoisting heavy machinery for inspections and maintenance, lifting drive tables and conveyor transfer sections and actuating powerful scissors lifts.

“Advantages of the Airstrokes for lifting tasks include easy installation in confined spaces beneath heavy equipment, or where overhead space for lifting is restricted. They can also be simply engineered for multiple repetition tasks, where their advantage of not having any internal moving parts to break or wear means they offer high reliability in industrial environments,” said Air Springs Supply national sales manager Simon Agar.

“Compared with alternatives, such as hydraulics, they can offer considerable savings in set up costs. Rather than dedicated pumps and sophisticated lifting infrastructure usually required for precision heavy lifts, Airstrokes connect to less costly general purpose compressors. Fine control of the lift can be obtained through valving and mechanical means, making the lift less of an engineering task then it might be otherwise,” Agar said.

Because of the comparatively low cost of Airstroke installations, they can be used either as mobile jacks or built into equipment for swift, trouble-free use when inspection and maintenance periods come around, he says. This helps operations staff to conduct periodic inspections and maintenance with minimum downtime – an important consideration when individual items of equipment and production savings can be worth huge amounts.

“The versatile new longwall actuators share the simplicity which is the beauty of all Air Springs used in demanding processing applications such as conveying, metal processing, vibrating screens, manipulation and actuation. They are fundamentally rugged fabric-reinforced bags of air, the shapes of which have been engineered for specific tasks and which have been demonstrated in Australian service to go through millions of actuation cycles without needing maintenance.

The company said the longwall Airstrokes extend these benefits by permitting more compact, single-convoluted actuators to be used in applications where, compared with equivalent double convoluted bags, they offer 30% better lateral stability and 25% better air volume.

The extended Airstrokes also offer a flatter performance curve, with a more even load carrying capacity throughout the cylinder’s stroke and, in particular, a higher performance at the end of the stroke.

Inflated at between 3-7 bar (within the range of pressures produced by standard industrial plant compressors), the extended stroke Airstrokes are part of a family of actuators offering from 40 to 40,000kg capacity.