Springs

Springs a Mechanical Device

History:
Spring is a mechanical device used to store mechanical energy, the credit of its invention goes to Greek engineer Ctesibius of Alexandria who made a device bronze having spring like features. With the passage of time, more advanced shapes and different types of springs were introduced for multiple applications. Springs are made of metals like non ferrous metal, hardened steel, annealed steel, titanium and copper.

Working:
Springs obey Hook's law, according to which within the elastic limit strain produced in an object is directly proportional to applied stress. Mathematically,
F= -kx
Where F is the restoring force, k is spring constant and x is the displacement from mean position. Applying simple harmonic motion rules that state acceleration of body is directly proportional to its displacement from mean position and is always directed towards mean position, mathematically
a �‡ -x
Where ea�f is the acceleration and x is the displacement.

The rate of a spring is the change in the force it exerts, divided by the change in deflection of the spring. Hook�fs law is applicable only when deformation of the spring is small as compared to the total length of the rod. If deformation goes beyond elastic limit the atomic bonds between the atoms of a substance breaks down deforming the spring permanently. All materials have different elastic limit so only coil springs do obey Hook�fs law, it does not hold true for linear springs.

Types of Springs:
Compression springs, extension springs and torsion springs are the three sub classes of springs and are used widely all over the world. Pushing back the load and trying to get back to its original length compression springs are used in ballpoints, pogo sticks, etc. extension strings are attached on both ends and are used in garage door assemblies, carburetors. The ends of torsion things are fixed with other objects, when these objects rotate around the torsion springs, the springs try to push them back to their original position, and these springs are used in car engines. Strings are also categorized depending on their materials with which they are made of: wire and flat springs are the two known classes. Coil, helical, conical, tapered, hourglass or variable pitch springs are sub classes of torsion springs, the wire often used for torsion springs is rectangular shaped. Volute spring is a compression spring that resists to a compressive force, Belleville, cantilever are also some other prominent types of compression springs. Some other renowned styles of springs contain garage door springs, box springs and leaf springs, where garage door spring is like a torsion or extension spring, box spring can be either specialized form of torsion or compression spring and leaf springs regarded one of the oldest springs is a flat spring.

Applications:
In thousand of machines that we use in our day to day life have springs in their system. Torsion springs are used for hinges, counterbalances application. Aided by rod torsion springs perform in a more advanced way, load should be applied at winding end. Garage door springs are used to lift and lower the garage doors whether these doors are opened manually or automatically. Garage doors can weigh up to 400 pounds, therefore the length of the spring depends on the size of the door, and the maladjustments of the springs in a garage door cause accidents so routine safety checks should be carried out. Springs are used for multiple applications inside switches, automotive suspensions, in clocks, wind up toys, in seat recliners and bouncy decoration pieces.