Truck bolster with laterally wider friction shoe pocket and means for lateral travel of the friction shoe

摘要

Prior art railcar bolsters and friction shoe assemblies were constructed such that the friction shoe was tightly restrained within the friction shoe pocket. The present invention utilizes a friction shoe sled for promoting lateral sliding of the friction shoe assembly within a laterally wider bolster friction shoe pocket. The sliding mechanism incorporates the use of an pad is countersunk into the floor of the friction shoe pocket and the base of the sled. The sled is fitted underneath the friction shoe to support the friction shoe biasing spring as well as the friction shoe. The top of the sled has a post attached to it, for insertion into the bottom of the friction shoe biasing spring. The bottom of the sled preferably has the elastomeric pad attached to it, although it can be smoothly machined, so that the bottom surface of the sled slides along the elastomeric pad anchored to the friction shoe pocket floor. The spring sled and the elastomeric pad anchored to the friction shoe pocket floor create a very low coefficient of friction environment for ultimately allowing the friction shoe, the biasing spring, and the sled, to laterally slide or "float" in unison within the wider friction shoe pocket. By providing relative lateral movement between the friction shoe and the bolster friction shoe pocket, any laterally directed forces which act upon the railcar and cause lateral acceleration on the car, can be isolated in order to decrease lateral car instability.