Coupler Torsion Spring Centering Device

Abstract

A coupler for a railway vehicle includes a coupler anchor and a coupler centering device having a pair of arm sub-assemblies. Each arm subassembly has an upper centering arm connected to a lower centering arm via a torsion bar extending through the coupler anchor. The lower centering arms are connected by a cross link such that movement of one of the upper centering arms causes a corresponding movement of both of the lower centering arms. Each upper centering arm engages a roller that rolls along a curved surface of the centering arm when the coupler is rotated horizontally toward the upper centering arm. A centering stop element prevents the movement of the opposing upper centering arm to generate a restoring force in the torsion bars that facilitates horizontal movement of the coupler. The coupler centering device may be disengaged from an active centering position to facilitate servicing of the coupler.

The invention claimed is: 
     
         1 . A coupler for a railway car, comprising:
 a coupler anchor;   a coupler mechanism pivotal relative to the coupler anchor from an on-center position to an off-center position in a substantially horizontal plane; and   a coupler centering device for centering the coupler mechanism relative to the coupler anchor, the coupler centering device comprising:
 a first centering arm subassembly having a first centering arm and a first centering link connected to a first torsion bar extending though the coupler anchor in a substantially vertical direction; 
 a second centering arm subassembly having a second centering arm and a second centering link connected to a second torsion bar extending though the coupler anchor in the substantially vertical direction; 
 a cross link connecting the first and second centering links; and 
 a pair of first and second rollers in contact with the respective first and second centering arms. 
   
     
     
         2 . The coupler of  claim 1 , further comprising a support bracket coupled to the coupler mechanism, wherein the first and second rollers are connected to the support bracket such that a first and second roller axes are oriented substantially perpendicular to a longitudinal axis of the coupler mechanism. 
     
     
         3 . The coupler of  claim 1 , wherein the first and second centering arms are preloaded against the first and second roller to generate a restoring force in the first and second torsion bar for restoring the coupler mechanism to the on-center position when the coupler mechanism is pivoted to the off-center position. 
     
     
         4 . The coupler of  claim 1 , wherein pivotal movement of the coupler mechanism from the on-center position causes one of the first and the second centering arms to roll along the one of the first and second rollers to generate a restoring force in the first and second torsion bars. 
     
     
         5 . The coupler of  claim 4 , wherein the restoring force in the first and second torsion bars increases in proportion to the pivotal movement of the coupler mechanism from the on-center position. 
     
     
         6 . The coupler of  claim 1 , wherein the restoring force in the first and second torsion bars restores the coupler mechanism to the on-center position. 
     
     
         7 . The coupler of  claim 1 , wherein the first and second centering arms are movable to a disengaged position in which the coupling mechanism is not urged to an on-center position. 
     
     
         8 . The coupler of  claim 1 , wherein the first and second centering arms have a curved shape. 
     
     
         9 . The coupler of  claim 1 , wherein the first and second torsion bars have a substantially hexagonal cross-sectional shape. 
     
     
         10 . A railway car coupler for coupling railway cars, the railway car coupler comprising:
 a coupler anchor connected to a railway car body;   a coupler mechanism pivotal relative to the coupler anchor from an on-center position to an off-center position in a substantially horizontal plane; and
 a coupler centering device for centering the coupler mechanism relative to the coupler anchor, the coupler centering device comprising: 
 a first centering arm subassembly having a first centering arm and a first centering link connected to a first torsion bar extending though the coupler anchor in a substantially vertical direction; 
 a second centering arm subassembly having a second centering arm and a second centering link connected to a second torsion bar extending though the coupler anchor in the substantially vertical direction; 
 a cross link connecting the first and second centering links; and 
 a pair of first and second rollers in contact with the respective first and second centering arms. 
   
     
     
         11 . The coupler of  claim 10 , further comprising a support bracket coupled to the coupler mechanism, wherein the first and second rollers are connected to the support bracket such that a first and second roller axes are oriented substantially perpendicular to a longitudinal axis of the coupler mechanism. 
     
     
         12 . The coupler of  claim 10 , wherein the first and second centering arms are preloaded against the first and second roller to generate a restoring force in the first and second torsion bar for restoring the coupler mechanism to the on-center position when the coupler mechanism is pivoted to the off-center position. 
     
     
         13 . The coupler of  claim 10 , wherein pivotal movement of the coupler mechanism from the on-center position causes one of the first and the second centering arms to roll along the one of the first and second rollers to generate a restoring force in the first and second torsion bars. 
     
     
         14 . The coupler of  claim 13 , wherein the restoring force in the first and second torsion bars increases in proportion to the pivotal movement of the coupler mechanism from the on-center position. 
     
     
         15 . The coupler of  claim 10 , wherein the restoring force in the first and second torsion bars restores the coupler mechanism to the on-center position. 
     
     
         16 . The coupler of  claim 10 , wherein the first and second centering arms are movable to a disengaged position in which the coupling mechanism is not urged to an on-center position. 
     
     
         17 . The coupler of  claim 10 , wherein the first and second centering arms have a curved shape and wherein the first and second torsion bars have a substantially hexagonal cross-sectional shape. 
     
     
         18 . A coupler centering device for centering a coupler mechanism relative to a coupler anchor of a railway car, the coupler centering device comprising:
 a first centering arm subassembly having a first centering arm and a first centering link connected to a first torsion bar extending though the coupler anchor;   a second centering arm subassembly having a second centering arm and a second centering link connected to a second torsion bar extending though the coupler anchor;   a cross link connecting the first and second centering links; and   a pair of first and second rollers in contact with the respective first and second centering arms.   
     
     
         19 . The coupler of  claim 18 , further comprising a support bracket coupled to the coupler mechanism, wherein the first and second rollers are connected to the support bracket such that a first and second roller axes are oriented substantially perpendicular to a longitudinal axis of the coupler mechanism. 
     
     
         20 . The coupler of  claim 18 , wherein the first and second centering arms have a curved shape and wherein the first and second torsion bars have a substantially hexagonal cross-sectional shape.