Scharfenberg coupler

The Scharfenberg coupler[1] (German: Scharfenbergkupplung, abbreviated Schaku) is a commonly used type of fully automatic railway coupling.

The Schaku is superior in many ways to the AAR (Janney/knuckle) coupler because it also automates electrical and pneumatic connections and disconnections.

In the coupled position, forces on the hoops and disk will balance out, which means that the Scharfenberg, unlike many other couplers, is not dependent on heavy latches to stay locked.

Small air cylinders, acting on the rotating heads of the coupler, ensure the engagement of the components, making it unnecessary to use force to get a good coupling.

Rail equipment manufacturers such as Alstom offer the Schaku as an option on their mass transit passenger cars and locomotives.