itsekierteittävät

Itsekierteittävät is a Finnish term that translates to "self-winding" or "self-rotating." It is primarily used in the context of mechanical watches and refers to a type of automatic movement. In an automatic watch, the movement of the wearer's wrist powers a rotor, which in turn winds the mainspring. This process eliminates the need for manual winding, as the watch continuously replenishes its power reserve through daily activity.

The mechanism typically involves a semi-circular or full-circle weight, the rotor, that is suspended on a pivot. As the wearer's arm moves, gravity causes the rotor to swing or rotate. This rotation is then translated through a series of gears to wind the mainspring, storing energy. The efficiency of an itsekierteittävät movement can vary depending on the design and the wearer's activity level. Some movements employ bidirectional winding, meaning the rotor can wind the mainspring regardless of the direction of its rotation, while others are unidirectional. The development of the itsekierteittävät mechanism was a significant innovation in watchmaking, offering convenience and a more consistent power reserve compared to manual-wind watches of the past.