Constant force springs are ideal for many uses and are especially useful where constant force is required. For any application which needs a smooth return and retrieve, counterbalance applications, tensioning and loading applications, constant force springs are a perfect choice. Industries which make use of the constant force spring include healthcare and automotive; however, the space industry also uses these specialist springs, mainly to work with the changes of force within the atmosphere. So, what exactly does this industry use constant force springs for and how does it benefit them?
Constant force springs offer:
- High force output with very small space requirements
- Long linear reach with minimal force build-up
- Storage of indefinite power when extended
An extension type of constant force spring could be seen as the most basic, as it is the most versatile.
It is usually a pre-stressed flat strip of spring material formed into a constant radius which coils around itself or on a drum. When the strip is extended or deflected, the stress resists the loading force, though at a nearly constant (zero) rate. A constant force is obtained when the outer end of the spring is attached to another spool and caused to retract in the reverse or same direction as originally wound. Due to the full load being reached after being deflected to a length equal to 1.25 its diameter, it maintains a constant force no matter the length of the extension.
Much flexibility is available with constant force springs, as the load capacity can be varied by factors and configurations such as cavity mounts, multiple spring mounts, sizes and various design specifications.
Wherever constant load is required, a constant force spring is perfect for it, whether this be a hair dryer, gym equipment or a space shuttle.
Why are constant force springs used in space?
Most springs are bound by the principles of Hooke’s Law (F=Kx); however, there is usually an exception to this rule, which is what constant force springs represent. The spring itself takes its name from the fact that their force of motion is always at a consistent point of exertion.
Resembling a wound coil, their independence from Hooke’s Law allows them to produce perpetual force through their deflection and gives them little to no restriction on the speed of extension or acceleration.
Constant force springs offer an excellent mechanism where a constant load is required. The force, due to gravitational acceleration, causes massive bodies to exert a downward force on the earth. This may also be referred to as microgravity. Unlike the springs present on earth, there are varying factors and forces working against the products which are using the springs.
Any springs and components used need to be adapted to sustain the effects of the environment, especially as gravity is not the same.
Constant force springs work best when in static or more dynamic applications where space is critical, or where other circumstances such as radial or axial tolerances are tight.
Constant Force Springs from European Springs
Here at European Springs Ireland, we design and manufacture constant force springs for many industries, one being the aerospace industry. We can fit the components in numerous fashions to ensure the widest possible range of uses, and we are well aware of the requirements and tolerances of this industry.
Our bespoke approach to our products, including our constant force springs, makes sure your project only has the highest quality of springs. Whatever your needs, European Springs and Pressings Ltd can efficiently manufacture constant force springs for you.
Simply get in touch for further information.