It is an embodiment of Chebyshev’s Lambda Mechanism.
Input: pink crank rotating continuously.
Lengths of pink crank and blue bar: a
Length of green bar: 2.5a
Length of yellow bar: 5a
Length of violet bar: 2.5a + 2.5a
Length of orange and brown bars: b
Distances between stationary bearings: b + 2a
Green line is locus of a point on the brown bar.
The brown bar that has linear translating motion in a portion of its way can be used as legs in plantigrade machines.
The mechanism has purely revolute joints.