This linkage was proposed in 1877 by A. B. Kempe, London.
It is a development of “Inverse parallelogram mechanism 11”.
Revolution joint centers of the yellow (or blue) V-shaped arm create a isosceles right triangle.
Axle distance between the revolution joints of the green table, axle distance between the ground revolution joints and length of the pink bar are equal.
The green table moves along an absolutely straight line.
Pay attention to the red variable rectangular and two variable parallelograms.