The Pellaton winding system is a special construction of a winding mechanism.
This system of an automatic winding was developed by the then technical director at IWC, Albert Pellaton. It was patented in 1946 and completed in 1950. The first movements to feature the Pellaton winding system were IWC's Cal. 81 and Cal. 85, introduced in 1950. It would continue in use through the quartz crisis and was reintroduced in the 2000's in the Cal. 89000 family.
The Pellaton winding system uses pawls rather than direct gearing between the rotor and barrel. This helps isolate the gear train from shocks. Unlike the Seiko magic lever system, which uses one pawl to “pull” and another to “push” the barrel, the IWC Pellaton system has both pawls pull on the barrel. This makes winding more efficient.