Despite their small package size and high force capability, one common fault with conventional pneumatic or gas (nitrogen-filled) struts is that they are susceptible to slow leaks or punctures during operation
Problem: , resulting in a load loss over time. And they are not designed to withstand harsh environments such as dust and high temperature applications.
Most gas strut manufacturers offer various pressure ratings, forces, strokes and end fittings to meet certain applications within a small package design. The automotive industry is a keen user of gas struts, so too are medical lid, tanning bed and machine door manufacturers.
Solution: Worcestershire-based Associated Spring has developed a new range of mechanical spring struts that solve many of the problems associated with gas equivalents (the struts have actually been designed and patented by US manufacturer, Raymond). They are designed to yield long life with repeatable loads and are even interchangeable with customer's existing gas springs.
The purely mechanical features of the units use advanced coiled spring technology along with engineered components to provide a low-friction, high reliability unit. The springs are made from either stainless steel (for corrosion-resistant applications) or carbon steel for high loads. One advantage of going mechanical rather than gas is that there are no hazardous material concerns with mechanical designs. Also, the strut has a longer life since there are no load losses over time. The units require no internal gases and therefore require no seals, therefore are more robust and are not sensitive to side loading. The units can operate in temperatures up to 400 deg F and are FDA approved.
Applications: Because the struts are available in both low and high loads and come with a range of different end mountings, the potential applications are enormous. They can be speed controlled and an index-lock function is also available. The struts can be used as self-centring devices, dampening units, compression or extension force units.
There are obvious benefits of using mechanical struts in the medical industry where product reliability and robustness are key. The units could also be used in earth moving equipment, furnace doors, military lids, heat shields, industrial lids, medical devices, food preparation and processing, motion control and heating, ventilation and aeration equipment.DP