The mechanism determines the product zu. Variable z is entered by turning flat spring 1 about axis x-x. Grooved member 2 is turned about axis y-y by sylphon bellows 3 into which air is admitted through tube 4. The pressure of this air is the second multiplier u. The force developed by the pressure in bellows 3 is counterbalanced by the elastic resistance of spring 1 in torsion. Inversely, when spring 1 is turned, grooved member 2, in whose groove roller a slides, is turned until the elastic force of spring 1 is counterbalanced by the force developed in sylphon bellows 3. Thus the whole mechanism is always in a state of elastic equilibrium and the total angle of rotation of member 2 about axis y-y is proportional to the product zu.
$2141$EL,MO$