The mechanism has three degrees of movement. Certainty of motion is provided for by the force loads from pans 1 and 2 and the loads being weighed. Equilibrium of the system is achieved by selecting the masses of the links. Owing to the equality of the link lengths in the right-and left-hand parts of the balance and their symmetrical arrangement, pans 1 and 2 have translational motion.
$783$LW,B$