Torsion springs are coiled springs made to work via a twisting or ‘torsion’ rotational motion, which in essence allows for a flexible object to store mechanical energy when it is twisted. This exerts a force in the opposite direction; dependent on the angle it is twisted. The most common design of a torsion spring is the helical looped design that consists of a coiled metal wire, which is twisted tighter and tighter by the sideways forces applied to either a left-hand or right-hand helix. A perfect example of a torsion spring in action would be that of a standard mouse trap ** Our torsion springs come in all shapes and sizes, small, large, extended length and double torsion springs can all be manufactured to our customer’s specific requirements. Door hinges are typically made from small torsion springs, allowing the door to bounce on its hinge, into its original position.
The torsion springs we design and manufacture here at European Springs are made in dimensions of 0.3mm to 26mm, with wire, body diameter, length, pitch and choice of material all down to customer specifications.
Torsion springs have a linear spring characteristic, i.e. if a spring is turned 10° to provide torque of 1 Nmm; the same spring will provide a torque of 2 Nmm at 20° torsion. Torque is equal to force x leg length: M= F x A. The closer to the end of the leg the load is applied, the less counter force is created.
There are generally two common types, single and double coil torsion springs, and for closed coiled helical torsion springs there is a friction between the coils producing hysteresis in the torque-angle performance so they may be wound with a clearance between coils if required. The coil can be either controlled inside, directed by a mandrel but also can be controlled by outer cylindrical housing. Fixed assembled legs allow the spring to work without coil body control, with tangential and axial legs giving the lowest stresses on the spring. When designing, the strain in the legs must be considered in order to meet your particular blueprint, which we are happy to help you develop.