13 and 14 and finally with another assembly taken among fig1 to 20 that is to say a total of 2 u00d7 3 u00d7 8 48 variants besides of those that can be derived from the fig7 and 9 on which the modules of continuity are based and already mentioned on fig1 to 6 fig3 and 6 show adequated structures for longitudinal engines arrangements that is the case in the commercial vehicles and in some passenger cars whereas fig1 and 5 are preferred arrangements for cross engines assemblies that is the most frequent case on passengers cars although they can also be used for longitudinal engines arrangements as the example showed in fig2 and 26 the first one corresponds to a vertical section scheme and the second one to a horizontal section scheme all these nodules of continuity variations have a common basic feature that could be defined as a universal mechanical law that relates the maximum power d that is directed through the trunco conical pulleys and that is a fraction of the power that arrives to the module of continuity coming from the engine with the operating field of the above mentioned module of continuity c that is the quotient between their higher transmission ratios e i maximum and minimum values this functional dependence is expressed by the following formula equ1 this formula has been deduced from the appropriate mathematical kinematics and dynamics developments submitted to that d is limited to a same maximum value for the rotations in both rotative senses of some of the elements of one of the epicyclic gears that are integrated in the module of continuity it has been assumed the hyphotesis of 100 on the mechanical efficiency of power transmission.