Patent attributes
A rail road freight car truck has a truck bolster and a pair of side frames, the truck bolster being mounted transversely relative to the side frames. The mounting interface between the ends of the axles and the sideframe pedestals allows lateral rocking motion of the sideframes in the manner of a swing motion truck such that the bolster can move laterally relative to the sideframes. The range of travel of the bolster may be greater when the car is fully laded than the car has no lading. This may be achieved by the use of tapered bolster gibs. Friction dampers are mounted to work between the bolster and the sideframes. The friction dampers may be provided with brake linings, or similar features, on the face engaging the sideframe columns, on the slope face, or both. The friction dampers may be mounted in a four-cornered arrangement at each end of the truck bolster. The friction dampers may include members having two rotational degrees of freedom such as may tend to permit the friction elements to accommodate changes in angular orientation between the bolster and the sideframes during pitch and yaw.