Flexible belt and its associated transmission

Flexible and elastically stretchable belt made from an elastomeric material, adapted for being mounted around at least two pulleys, upon whose outer surfaces there are exchanged frictional forces for transmitting motion, said belt comprising an annular body delimited by two outer base surfaces and by two lateral sides, with at least one of the said base surfaces being active for the exchange of said frictional forces, and with both of the said lateral sides being inactive for the exchange of said frictional forces, said belt comprising at least one group of three layers with discontinuous fibers embedded therein, with one of these layers having fibers directed transversely with respect to the longitudinal direction of the belt, the other two layers having fibers whose direction is inclined and opposed to one another with respect to the longitudinal direction of the belt, the angle of inclination of the fibers of said other two layers relative to the said longitudinal direction being at most 45.degree., the modulus of rigidity under tensile stress of said other two layers with said inclined fibers, measured in the longitudinal direction of the belt, being equal to each other, the three said layers being directly in contact respectively with one another with said annular body being devoid of any continuous, longiform and inextensible elements and the modulus of rigidity, under the tensile stress, measured in the longitudinal direction of the belt, being uniform over the entire transversal section of the annular body, whereby said belt, subjected to elastic stretching between the two pulleys, has equal tractional states on the different layers of the entire thickness and remains always in a state of traction, before, during and after the winding on the pulleys.