Rubber bead
The rubber bead is a special form of a seal at the transition between two passenger coaches , which shields it from the elements.
The rubber bead transition consists of two vertical and one horizontal bead, consisting of an abrasion-resistant rubber compound , which are attached to the car body with clamping rails on both sides and above the front door .
In contrast to the bellows , no additional handles are required with the rubber bead in order to connect the two halves of the transition protection when coupling. That is why the rubber bead has almost completely replaced the bellows in single wagons of mainline railways. Only in the case of narrow-gauge railways with tight radii was the rubber bead unable to prevail over the bellows, since the rubber bead does not follow curves as flexibly as a bellows. Too large a gap would form there on the side. Due to the principle-related poorer sealing of rubber beads, even today multi-part, but usually sticking multiple units such as. B. the ICE bellows are used.
Rubber bead junctions are standardized in UIC Code 561 (transfer devices for passenger coaches). The clear width of the transition is 1060 mm, the middle of the upper bead is installed 2255 mm above the buffer level, the center-to-center distance of the side beads is 1360 mm. The rubber bead is equipped with a foldable transition bridge that is at least 940 mm wide. Rubber beads can be equipped with connecting elements for mixed coupling with bellows transitions.