The sprockets of the P.I.V chain drive are two pairs of the cone- shaped radically – grooved wheels mounted on splined shafts.

The chain is made from unique links which contain packes of self – tooth – forming hardened steel slats. Each slat is free to move sidewise and conform to the tooth shape of the paired sprockets. When the paired wheels are far apart the chain actually operates around a small diameter. When the wheels are close together the chain operates around a large diameter.

This principle – varying the driving and driven diameters – is the principle on which all variable speed control with positive power transmission.