Semi-permanent coupler with anti-climbing feature
For the first time, a semi-permanent coupler for metro vehicles assumes anti-climbing function. Contrary to conventional systems, this coupler has a stabilising effect even before any overriding occurs. The dimensions of the coupler remain unaffected by this new technology.
Anti-climbing feature: working principle
During a train crash or heavy impact, the longitudinal forces are converted into vertical swerving movements leading to an overriding of the cars once a critical momentum has been exceeded. This may cause the wagon to disconnect from its Jacobs bogie and damage softer structures.
The anti-climbing feature has been designed to prevent this overriding right from the start. To do so, it uses a simple, yet highly efficient principle: The rear end of the coupler shank features a special geometry. As soon as the reversible stroke of the coupler has been utilised, this geometry interlocks with the bearing bracket, building a counter-momentum that holds the wagons down.
Additional energy absorbing components of the semi-permanent coupler, e.g. deformation tubes or hydrostatic dampers, convert kinetic energy and help to keep the load on a controllable level.