Patent ID: 8011306
Filing Date: 2011-09-06
Classification: B61D,B61F

Abstract:
1. A railroad freight car truck having a load rating, said truck comprising: a bolster, first and second sideframes, first and second spring groups and first and second wheelsets; said bolster being mounted cross-wise to said sideframes; said bolster having first and second ends, said first end of said bolster being supported on said first spring group in said first sideframe, said second end of said bolster being supported on said second spring group in said second sideframe; said first and second spring groups having respective vertical spring rates; said sideframes having respective longitudinal axes; said sideframes being swingingly mounted on said wheelsets; said bolster being moveable through a lateral displacement relative to said sideframes, said lateral displacement having an overall magnitude and including a first component of lateral displacement associated with a first lateral stiffness, k said bolster being movable in non-trivial yaw relative to said sideframes; said bolster being movable in lateral translation relative to said sideframes and having a permitted range of motion of at least ¾″ to either side of a neutral position; said first sideframe having a tension member, a compression member, a first sideframe column and a second sideframe column, a first sideframe window defined therebetween; said tension member defining a bottom boundary of said first sideframe window, said compression member defining an upper boundary of said first sideframe window, said first and second sideframe columns defining respective sides of said first sideframe window; said first and second sideframe columns having sideframe column wear plates mounted thereto; said sideframe column wear plates being oriented to present respective planar surfaces perpendicular to said longitudinal axes of said first sideframe; said bolster having a first set of friction dampers mounted at said first end thereof, and a second set of friction dampers mounted at said second end thereof; said first set of friction dampers including first, second, third and fourth friction dampers, each of them being independently sprung and oriented to bear against said sideframe column wear plates respectively; said first and second friction dampers facing toward said first sideframe column of said first sideframe; said third and fourth friction dampers facing toward said second sideframe column of said first sideframe; said first friction damper being on a first, transversely inboard side of said longitudinal axis of said first sideframe; said second friction damper being on a second, transversely outboard side of said longitudinal axis of said first sideframe.