Within the entire history of engineering, the helical spring, also known as the coil spring, is perhaps one of the most classical designs that exist.
Like all great designs, the helical spring combines simplicity and functionality to create a product that offers reliability, durability and even acute precision. The truest testament to a great design though, is in its functionality, and this can easily be highlighted by the sheer number of applications that the spring has in all areas of modern life.
There are of course many other types of spring, such as the pneumatic spring, which uses either a gas or a liquid as the compressor agent. But the classic helical design is what people automatically visualize in association with the word “spring.”
THE ROLE OF THE HELICAL SPRING
The use of springs can be dated as far back as the invention of fire if you consider the use of a supple branch as an early form of the spring. With the invention of the helical spring in 1763, followed by the first steel coil spring in 1857, their range of use has become extensive across almost every industry.
Part of the reason for this is that the coil spring can be used in numerous ways and is available in several forms that can be broadly divided into three main varieties, which are:
- Tension springs – Tight coils used to pull a mechanical movement back to its resting or neutral position
- Compression springs – The stereotypical spring design used as a buffer to absorb the energy of a load. These springs are easily the most common type on the market
- Torsion springs – Are used to control torque or directional forces. Designed to store energy similar to a compression spring. The difference though is in the twisting motion that defines them
As for what the future holds for this industry, they may be a long way off being perfected, but there are already early designs for a new form of energy storage.
FROM THE SMALLEST TO THE STRONGEST
Within the multitude of uses, they offer, springs vary greatly in size from micro designs which are used in electronics or clock springs that are a miniature version of torsion springs, to large industrial sized dampeners used in the foundations of some bridge designs.In addition to using larger springs and stiffer materials, there are also design variations of the spring which allow their use in more demanding applications.
One such design is the Volute spring. A popular variant to the compression spring, which is preferred in heavy duty tasks requiring a much greater load placed upon them. They have a fundamental difference to regular compression springs, in that rather than using wire to form the coil, a strip of plate metal is used and the helical shape is applied across the length of the strip to provide the structure with much more strength. The Volute spring thus has to be formed with a conical shape so that as weight is applied to this spring, the coils can condense and interleave each turn of the coil, allowing for a greater range of movement.
Springs are most commonly manufactured from an alloy metal or a form of plastic, and the composite material is what provides the helical spring with most of its performance characteristics.
Many experienced spring manufacturers will offer an option to produce bespoke designs upon request, often with an advisory service included optimizing the performance of your design. With any spring produced, whether customized or a stock design, the characteristics of the product can be calculated before any practical work is begun by using data sheets and mathematical principles to ascertain the finalized specifications. This can then be used as a parameter guide to evaluating quality control of the finished products.
With a huge array of applications, there is already a large established production industry, which even has a monthly magazine dedicated to it.
There are some different attributes associated with the production of a helical spring and with such a wide range of uses, different attributes are more prevalent than others, according to the purpose that the helical spring is intended. Whether you require something which:
- Can handle a substantial load
- Is engineered to be a precise measuring tool
- Is robust in the integrity of its design, to withstand heavy usage and maintain consistency in performance
- Increased level of Elasticity to provide a greater usable range in movement
Coil springs were traditionally made by winding a piece of wire around a former block. This is a Cylinder shaped rod that has the desired coil shape, etched into its surface as a groove that’s used to guide the wire into the required design.
Some springs are still manufactured by hand, especially when the batch being produced is of a low quantity, but most are now created by machine processing. This allows for not only a quicker production line, but also a more consistent quality of the product due to the mechanical nature of production.
A BUYERS MARKET
With a large number of suppliers now producing springs, there is a wide choice available when it comes to buying replacement machine parts. The materials used to construct the helical spring and the way in which it is manufactured is extremely important and because of this, it is vital that you choose a quality supplier.
As with any other purchase you make, quality is the all important factor, and as such it is worth spending a little time in the beginning to ensure that you are buying from a reputable source. With many manufacturers claiming to have developed new unique techniques that produce enhanced performance or more robust designs, it is worth noting that a testimonial from past client is much more valuable than a sales pitch.
With component manufacturers and specialists alike now selling products directly, it is easy to contact them for advice on general guidelines about their products, as well as specific questions relating to particular model components.