Compression Springs

Compression springs absorb a compression load by contracting along the length of their axis. In effect, a compression spring absorbs the energy of a force that is acting upon it by becoming shorter. Whereas extension springs are designed to resist forces, called tension loads, that are pulling outward from their ends, compression springs resist forces that press into their ends. This compression is allowed for by the gaps that exist between their coils and the potential for work that has been transferred to the spring during the creation of the coils. A compression spring stores energy when it is compacted, whereas an extension spring stores energy, or the potential for work, when it is stretched.

Compression springs are found in many applications that require the temporary absorption, yet later release, of force. A common example is that of automobile shock absorbers. As a vehicle travels its shock absorbers compress when receiving a force applied by the interaction of the vehicle and a bump or curve in the road. As the vehicle passes beyond that bump the energy that has been stored by its shock absorbers is released, keeping the vehicle relatively stable. Another notable example of compression springs are the springs used in bedding. As an individual sleeper rolls across their mattress the force their body is applying is absorbed by the compression of the bedsprings. As they roll away from any given spot the energy stored in its springs is released, allowing the bed to retain an even, and comfortable, shape. Yet another, easily visualized, example of a compression spring is the coil used in a ‘Jack in the Box’ toy. When closed, the toy’s spring stores the energy that was put into closing its lid. Upon opening the lid, however, that energy is released.