Firestone Marsh Mellow rubber-and-fabric springs

Rubber-and-fabric Marsh Mellow springs from Firestone are distributed throughout Australia by actuation and isolation specialist Air Springs Supply. They are designed to alleviate excessive spring set and breakages.

Compression set can become a chronic problem with metal coil springs supporting and isolating crushing, shaking and screening equipment. This means that some springs can settle, or set, suffering permanent compression below their original design height, preventing them from performing to their original specifications. One side may become more worn than another, for example, affecting dynamic stability, imposing uneven loads and even leading to breakages and production interruptions. The problem is compounded by the springs often being in the most inaccessible parts of machinery where workers have to crawl around in confined spaces, leading to delays and safety issues.

Marsh Mellows can be used in applications such as shaker screens, crushing equipment, vibrating bins and other vibrating equipment used in manufacturing, materials handling and processing, quarries, mineral processing, food and beverage and primary product processing. They operate silently with more spring travel and greater load capacities than convention coil springs. Marsh Mellows are designed to withstand breakages, splinters or fragmentation and they suffer only 7% compression set over the life of the part. This means they can be changed in and out of different sets of springs without upsetting the dynamic balance of the whole set.

Cylindrical Marsh Mellow springs are constructed of a solid rubber core with a hollow centre and several plies of fabric-reinforced rubber as an outer cover. The plies provide the springs with stability as well as a consistent cylindrical shape. The spring’s components (rubber, bias plies, size of centre) are combined in different ways to meet specific load and performance requirements (such as those of crushing and screening equipment). This gives them flexibility and precision. Marsh Mellows also offer constant vibration isolation with changing loads; their variable spring rate allows for a nearly constant natural frequency under the impact of such loads.