New gearboxes size R/40-50-63-70-85

Our most historic products, the R line, are now renewing their 40-50-63-70-85 sizes
This change does not properly affect the products design but their technical contents,
which are innovative and updated.
The gearbox case is more stiff and completely worked in order to have its breather plug,
the usual green paper gaskets have been substituted by modern Oring.
The Viton oil seal, which is mounted on the input shaft, togheter with the use of the proper oil quantity,
grants the complete elimination of lubricant leakage.