Chains stiffening the lower rods of the suspension system.
The possibility of a slight rotation of the tool in the horizontal plane is necessary to facilitate the control of the tractor. If it was not possible, even slight turns of the tractor would force the implement into the soil. Such stiffening would expose the tool to high bending moments. Only shallow running tools, like for example. whiteners, may be fully stiffened in this plane. Chains stiffening the lower rods of the suspension system are used for such stiffening.
Third degree of freedom (in a vertical plane perpendicular to the direction of the aggregate movement) it is important only for tools with a working width greater than the track width of the tractor. The point is, that the lateral tilts of the tractor do not result in simultaneous tilting of the implement, because the extreme working parts of the tool would then significantly change the working depth. This is especially important in weeding aggregates. For this purpose, the left hanger is designed so that it can be changed from a rigid to a telescopic connection.