Why are custom springs here to stay? It’s because of their major benefits and use for everyday applications. Read further on now.
Springs are used in various devices, tools, or machinery in general. This shows that these mechanical components are of immense importance as they help effect motion, improve shock-absorbing capabilities, etc., in many machines, including heavy industrial equipment.
Springs are analogous to dry cell batteries as they work by storing mechanical energy. The first set of springs to gain worldwide attention appeared in the 15th century, i.e., the 1400s.
But fast-forward up to 600 years or more, springs are still heavily used today. This shows how important and valuable they are in everyday applications.
Several widely-used products nowadays incorporate springs in their design. This is why it is necessary to learn more about springs. Understanding springs and their numerous application makes it easy to make the proper selection whenever you want to use a spring in a given application.
Let’s start with the types of springs as well as their applications.
Types of Springs and Their Distinct Applications
The best – and most common – way to classify springs is how the load is applied to them. Check out the following types of springs to see if you are familiar with them:
Compression Spring
Compression springs are primarily designed to function with compressive loads. This open-coil helix is the most common type of spring. They are often used heavily in spring mattresses, shock absorbers, retractable pens, and mechanical pencils.
This type of spring offers resistance when compressed along its central axis or axially. Compression springs follow Robert Hooke’s – a British physicist – law, known as Hooke’s Law, i.e., F = k*x, where ‘x‘ is the distance, and ‘k‘ is the spring rate. The law states that the force needed to compress or stretch a spring by a specific distance is directly proportional to that distance, provided the said force does not exceed the spring’s elastic limit.
Extension Spring
Extension springs – otherwise referred to as ‘Tension Springs’ – are primarily designed to function with tensile loads. They share remarkable similarities with compression springs, though extension springs are wound so tight in order to oppose that extension.
Extension springs are found in garage door mechanisms and luggage scales. They are also used extensively in trampolines.
Torsion Springs
Torsion springs are primarily designed to function with twisting forces or torque. This type of spring is somewhat different from extension and compression springs. The load on torsion springs is not applied axially but as a twisting motion or torque.
This means that when a torsion spring is twisted, it offers some resistance, causing the spring to return almost immediately to its original position. This type of spring often powers mouse traps and all clothespins.
Torsion springs also obey Hooke’s Law, but an analogous version of it. Hooke’s Law: F = K*x is transformed to F = k*θ where ‘θ’ in this case refers to an angle and ‘k’ is the spring rate, which stays constant irrespective of the spring’s deflection.
These springs can be further categorized, especially when considering the relationship between the force applied directly to the spring and the ensuing displacement.
In view of this, 3 classes of springs come to mind:
- Linear – or constant rate – springs
- Constant force springs
- Variable-rate springs.
Let’s check them out one after the other.
1. Linear Springs
Linear springs or constant rate springs strictly obey Hooke’s Law. The force required to compress or extend this spring by a specific distance is directly proportional to this distance, provided the force does not exceed the spring’s elastic limit.
2. Constant Force Spring
A constant force spring – as the name implies – requires almost the same force, regardless of how long the extension. This type of spring is sometimes referred to as a ‘clock spring.’
Constant force springs are usually coiled ribbons of spring steel used in counterbalancing applications such as clocks, height adjustment for monitors, etc.
3. Variable Rate Spring
Variable-rate springs do not have the same spring rate throughout their axial length. This type of spring can have more abrupt changes or progressive changes in the spring rates.
The cone-shaped compression spring, commonly found in battery boxes, is a familiar and excellent example of a variable rate spring. When fully compressed, the height of the spring can be as low as one wire diameter.
Variable-rate springs have one additional benefit: they are far less prone to buckling than many other springs and are also laterally stable.
Fabricating Springs
At times, springs are classified via how they are manufactured. The helical spring – metal coil spring – is often the first thing that jumps into one’s mind when the word ‘springs’ is mentioned.
But then, there are several other types of springs. Here are a few more to help your quest for custom springs easier and smoother:
Flat Springs
Flat springs are available in a wide range of shapes and sizes. They are basically sheet metal parts made by stamping. Examples of flat springs include retainer clips, PCB spring contacts, spring washers, etc.
Coiled flat springs also exist, e.g., volute springs, clock springs, etc. Flat springs are mostly heat-treated for shape memory.
Coil Springs
Coil springs are primarily lightweight and created by forming metal wires on CNC coiling equipment.
The multi-axis CNC control allows the manufacturer to create varying pitches as well as end conditions according to the multitude of the manufacturer’s imagination.
Springs manufactured by coiling machines are devoid of springy characteristics. They require heat treatment and exposure to a temperature as high as 500 degrees Fahrenheit – or more – in order to alleviate stress. Then quenched suddenly in order to formulate shape memory. This is the treatment for creating lightweight coil springs.
But when creating heavy-duty coil springs, the metal wires will, first of all, undergo heat treatment before coiling.
Molded Springs
Composite or plastic springs are generally used extensively in highly corrosive environments. This includes marine, medical, and food production applications. This type of spring is a relatively newcomer in this space, so supply is not all that abundant.
Taking creep into consideration, molded springs should only be used intermittently.
Do You Need Custom Springs?
Springs are vital parts of many products that undergo motion. They can store and release energy rapidly when expanded and compressed.
Knowing the kinds of springs available these days is crucial to choosing the correct spring for a specific purpose. This is because every spring has its own characteristics and features, depending significantly on the design, the material used, as well as the manufacturing process. These are the factors you should consider whenever you need custom springs.