MACHINE ELEMENTS
MACHINE ELEMENTS Powerhouses on tour Technology can be inspired from nature. For example, an elephant weighing 4,000 kgs can carry not more than 500 kgs. That’s merely a 12.5 % of its own body weight. But a tiny ant can lift weights many times its own body weight. Not just that, it can move quickly with this weight on its back and is also able to apply sudden brakes or change direction abruptly. Well just like ants, the dynamic-lift rope winches are a powerhouse. Tours and roadshows demand a maximum flexibility from stage technology. For this purpose, AMW have developed compact and easily transportable rope winches. “At a weight of under 100 kilogrammes, they are able to lift double their own weight”, explains Uwe Schmidt, Head of Design and Development at the AMW Spezialhebezeuge GmbH in Freital near Dresden. “As these winches are relatively compact and lightweight, they are particularly suitable for mobile use, for example whilst on tours or at roadshows”. They can easily be integrated into transportable beam constructions, and provide a viable alternative to permanently installed constructions where only low ceiling loads are permitted. As the rope winches are often used to carry loads over people standing below them, or have to transport people, particular safety requirements must be fulfilled. Being able to carry the weight is one thing, and to provide functional and operational safety is another important aspect. Everyone 28 MDA Technologies 4/2015
must be able to rely 100 % on the safety of stage drives during a performance; any failures would have obvious fatal consequences. This is where the “Roba-stop-silenzio” stage brakes come into play. In the winch drives, these brakes with reliable contactless release monitoring by “Mayr power transmission”, take care of the safety concerns. Safety for people and equipment The function of safety brakes is two-fold. First and foremost they must be able to save lives in emergencies, secondly they provide safety to equipment from any unpermitted operating conditions. During power failure or emergency stop, the brakes bring the loads to a standstill as quickly as possible and thus reliably avoid injury to people or damage to property. This brake system is also equipped with two brake circuits, working independently of each other to ensure maximum operating safety. The brakes in construction size 16 have a braking torque of “two times 19 Nm”. Another important feature of this system is the inductive proximity sensor for function monitoring. This contactless release monitoring system prevents unpermitted operating conditions, such as the motor starting up against closed brakes. In addition, the contactless system is reliable, resistant to magnetic field and it undergoes no “wear and tear”. High-performance, all-round talents Just like the artists on stage, the dynamic-lift rope winches are also multi-talented in event technology due to their flexible rope leadoffs, optional carrying and transportation aids and the fact that they can be installed in any position. In spite of their lightweight and compact construction, they fulfil the strict legal specifications for high levels of safety and resistance strengths for lifting devices MDA Technologies 4/2015 29
