The positive PIV CHAIN CONVERTORS Variable Chain Drives linkage among chain and gear wheel 
permits constant speeds despite having torque fluctuations and incredibly good reproducibility of speeds. Standard variable gear models force the transmission element through the use of excessive force – that is unnecessary and reduces the degree of efficiency.
Adjustable chain drives apply a lever system, which applies just as much pressure on the slat chain as required. This results in low operating temperatures, long life, high power density and a great efficiency – actually in the partial load range.