Backstop assembly for use with cushioning device in sill of railway car

Abstract

A backstop assembly for use with a cushioning device in the sill of a railway car. The cushioning device has a body, or cylinder, slidable endwise in the sill and carrying a car coupler at its outer end. The cylinder has a piston centered on the sill axis and a piston rod projecting from its inner end terminating in an enlarged end collar of circular cross section which is received in a backstop. The backstop is of rectangular box shape secured in the sill and having an inner end wall, outer end wall, top wall and parallel side walls, the end walls being axially spaced to form a chamber for loose, axially captive accommodation of the collar. The outer end wall has an arch-shaped clearance opening for loose accommodation of the piston rod. A thin rectangular locator plate is provided in the chamber having a circular opening for snug accommodation of the collar, the plate being secured at its lower edge to a bridge member which spans, and is secured to, the walls of the sill for maintaining the plate in a transaxial position in the chamber with the circular opening precisely centered on the sill axis. Thus upon impact the piston rod engages the inner wall of the backstop in a position precisely aligned with the sill axis where it is frictionally maintained during buildup of compressive reaction force in the cushioning device thereby to insure that the force in the rod is purely axial.