Next in this series of Spring Construction is the Torsion Spring, a type of spring that gives back what you put in, so to speak.
Torsion springs work by storing energy through being twisted which creates torque. This mechanical energy can be stored and then released on demand. The really impressive part about torsion springs is that they release the same amount of energy that was put in. The formula goes: 'Torque = Force x Leg Length' and can be applied to torsion springs of any size.
Leonardo Da Vinci was famous for his hidden inventions, and in 1478 at the age of 26, he practically created the first automobile using a combination of torsion springs: you can see his designs in the featured image. Even more impressive is the fact that Da Vinci's mini-car did not simply move forward on its own, it also had steering capabilities. You can read more about Da Vinci's automobile on How Stuff Works here which explains how the model works 'by rotating the wheels opposite of their intended direction'.
What Are They Used For?
You can find torsion springs in a whole world of useful items and mechanisms. The standard model for a torsion spring is the common mousetrap.
With the exception of electronic doors, the counter-balance feature in most garage doors relies on the backwards pull of the torsion springs in the hinges.
From mousetraps and garage doors to siege weapons: the Mangonel was an ancient Greek catapult that used great torsion springs in a wooden frame to fling huge missiles at their enemies. In order to achieve a torque strong enough to hurl giant rocks, the ancient Greeks would have had to calculate things like wiring, length, and pitch etc, all proportional to the weight of their ammunition.
Do you know what the time is? You do thanks to the hairspring in your watch: a tiny spiral-shaped torsion spring.
At European Springs, we take great pride in our manufacturing processes. As you can see, things have come a long way since Da Vinci's time, and yet the fundamental force behind torsion springs has a timeless energy.