Torsion springs are commonly used in mousetraps.
A torsion spring is a device used to support and damp movement in various types of components. There are two different types of torsion springs. The former is not a spring, however it has torsion or spring-like properties and is called a torsion bar. The second is actually a coil spring, like the type of spring used in a normal mousetrap. The torsion bar is commonly used in automobile chassis and trailer suspensions. The long spring, such as those normally found wound tightly around the top shaft of the garage door, is another type of torsion spring.
Torsion springs play a key role in ensuring vehicles offer a smooth ride on rough terrain.
While an ordinary coil spring is designed to operate by compressing against a load or tension, the torsion spring is designed to operate by rotating against itself while placed horizontally. This twist along the axis of the torsion spring causes the coil to coil more tightly, thus providing energy for the spring. As the helix winds, it stores energy in the many small coils that make up the spring. Once released, the spring returns to the original coiled position.
A torsion bar spring consists of a solid bar of steel designed to rotate without breaking. The bar is attached to a moving component at one end and a solid component at the other. As the moving component travels along the projected path of motion, the bar rotates against itself, providing a spring-like response. On a vehicle, the torsion bar is typically attached to the front control arms, while the other end of the bar is attached to a crossmember. As the control arm moves up and down, the torsion bar twists, providing a smoother, more cushioned ride to the vehicle.
When used in a garage door application, the torsion spring provides stored energy to help lift the garage door. The spring wraps tightly around the top shaft of the door. This is a very dangerous operation, as the gate’s pent-up energy is enough to seriously injure and even kill a human if released. The amount of pressure exerted on the torsion spring should be enough for the user to lift the garage door effortlessly. If the garage door torsion spring is coiled so tightly that you attempt to lift the door unassisted, it is too tight and could pose a potential hazard of breaking the door, operator, or both.