Endless power transmission belt structure

An endless power transmission belt structure having a longitudinal dimension and a trapezoidal cross-sectional outline at each position along said longitudinal dimension, said belt structure being made primarily of elastomeric material and comprising a pair of oppositely arranged surfaces disposed in spaced relation to define an outside and inside surface of said belt structure:

• a load-carrying section arranged midway between said outside and inside surfaces;
• a tension section having a plurality of layers including a layer means providing transverse rigidity adjoining said load-carrying section and a fabric layer disposed remote from said load-carrying section and adjoining said layer means;
• a compression section having a plurality of layers including a layer means providing transverse rigidity adjoining said load-carrying section and a fabric layer disposed remote from said load-carrying section and adjoining said layer means of said compression section;
• each of said layer means allowing longitudinal flexibility while providing transverse rigidity greater than its longitudinal rigidity and being free of shear planes parallel to said load-carrying section from said load-carrying section to its respective fabric layer;
• the innermost fabric layer in each of said tension and compression sections having an inside surface which is located at least 25% of one-half the thickness of the belt structure away from a central plane bisecting said load-carrying section when viewing the belt structure in cross-section.