Eight-bar linkage

In kinematics, an eight-bar linkage is a mechanism with one degree of freedom that is constructed from eight links and ten joints.

Eight-bar linkages are classified by how many binary, ternary and quaternary links they have.

The Peaucellier linkage (or Peaucellier–Lipkin cell, or Peaucellier–Lipkin Inversor) is an eight-bar linkage constructed from hinged joints that traces a pure straight line from a rotary input.

It is named after Charles-Nicolas Peaucellier (1832–1913), a French army officer, and Yom Tov Lipman Lipkin (1846–1876), a Lithuanian Jew and son of the famed Rabbi Israel Salanter.

The first is the end of the drive crank, the second is the other base pivot and the third is one side of the triangle that forms the lower leg.