A kinematic chain is an assembly of links in which the relative motions of the links is possible and the motion of each relative to the other is definite.
The most important kinematic chains are those which consist of four lower pairs, each pair being a sliding pair or a turning pair. The following three types of kinematic chains with four lower pairs are important.
- Four bar chain or Quadratic cycle chain
- Single slider crank chain
- Double Slider crank chain