Rail road car truck with rocking sideframe

Abstract

A swing motion rail road freight car truck is provided that does not have lateral underslung cross bracing in the nature of a transom, a frame brace, or lateral rods. The truck has a truck bolster and a pair of sideframes, the truck bolster being mounted transversely relative to the sideframes. The sideframes have spring seats for the groups of springs. The springs seats may be on rockers, or may be rigidly mounted in the sideframes. Friction dampers are provided in inboard and outboard pairs. The biasing force on the dampers urges then to that act between the bolster ands and sideframes to resist parallelogram deflection of the truck.

1 . (canceled) 
   
   
       2 . A railroad car truck having:
 wheelsets, a pair of first and second sideframes and a truck bolster;   said truck bolster being mounted cross-wise between said sideframes, said truck bolster being carried on respective first and second spring groups, those spring groups being groups of coil springs;   said sideframes being mounted to permit non-trivial yaw of said sideframes relative to said bolster;   said sideframes having sideframe pedestals that seat on said wheelsets;   said sideframes being mounted to rock angularly sideways;   said truck having a response to lateral track perturbations that includes a first component associated with shear deflection of springs, and a second component associated with sideways rocking motion of the sideframes, said response being dominated by the relative softness of the second component, said bolster having a non-trivial range of sideways travel relative to said sideframes, said non-trivial range of sideways travel being bounded by abutments; and   said truck being free of unsprung lateral cross-bracing.   
   
   
       3 . The railroad car truck of  claim 2  wherein said truck has biasing members mounted to give resistance to yawing motion of said sideframes relative to said truck bolster, said resistance increasing with increasing deflection. 
   
   
       4 . The railroad car truck of  claim 2  wherein said truck includes first and second independently biased members operable yieldingly co-operable to generate a moment couple resisting yaw deflection of said first sideframe relative to said bolster; and said first independently biased member is mounted laterally inboard of said second independently biased member. 
   
   
       5 . The railroad car truck of  claim 2  wherein:
 said truck includes first, second, third and fourth independently biased members co-operable yieldingly to generate a moment couple resisting yaw deflection of said first sideframe relative to said bolster;   said first and second independently biased members are mounted to work against said first sideframe forward of said bolster, said third and fourth independently biased members are mounted to work against said first sideframe rearward of said bolster;   said first independently biased member is mounted inboard of said second independently biased member in the cross-wise direction;   said third independently biased member is mounted inboard of said fourth independently biased member in the cross-wise direction; and   said moment couple of said biased members to resist yaw deflection of said bolster being proportional to deflection of said biased members.   
   
   
       6 . The railroad car truck of  claim 2  wherein:
 said truck includes first, second, third and fourth independently biased friction dampers operable yieldingly to resist yaw deflection of said first sideframe relative to said bolster;   said first and second independently biased friction dampers are mounted to work against said first sideframe forward of said bolster, said third and fourth independently biased friction dampers are mounted to work against said first sideframe rearward of said bolster;   said bolster has damper pockets defined therein and each of said dampers seats in a respective one of said damper pockets in said bolster;   said first sideframe has a sideframe window defined between a pair of first and second sideframe columns on either side thereof, a tension member below and a compression member above;   said sideframe columns have wear plates mounted thereto, said wear plates being oriented cross-wise to said sideframes;   each of said independently biased friction dampers works against one of said wear plates;   said first independently biased friction damper is mounted inboard of said second independently biased friction damper in the cross-wise direction; and   said third independently biased friction damper is mounted inboard of said fourth independently biased friction damper in the cross-wise direction.   
   
   
       7 . The railroad car truck of  claim 6  wherein:
 said bolster has first and second ends;   said first spring group is mounted in said first sideframe window;   said first end of said bolster is resiliently mounted on said first spring group;   said first spring group includes first, second, third and fourth corner springs;   said first corner spring is a forward inboard corner spring of said first spring group;   said second corner spring is a forward outboard corner spring of said first spring group;   said third corner spring is a rearward inboard corner spring of said first spring group;   said fourth corner spring is a rearward outboard corner spring of said first spring group;   said first friction damper is mounted over said first corner spring;   said second friction damper is mounted over said second corner spring;   said third friction damper is mounted over said third corner spring; and   said fourth friction damper is mounted over said fourth corner spring.   
   
   
       8 . A railroad car truck for rolling motion in a longitudinal direction along cross-wise spaced apart rail road tracks, said rail road car truck having a load rating, said rail road car truck comprising:
 a bolster, a first sideframe, a second sideframe, a first wheelset, a second wheelset, a first spring group, and a second spring group;   said bolster having a first end and a second end;   said bolster being mounted cross-wise between said sideframes;   said bolster being permitted a non-trivial range of travel cross-wise relative to said sideframes;   said sideframes having upper regions rockingly mounted to said wheelsets, in operation said sideframes being operable to swing cross-wise;   said sideframes being mounted to yaw appreciably relative to said bolster;   said first spring group being mounted on a lower region of said first sideframe, and said first end of said bolster being mounted on said first spring group;   said second spring group being mounted on a lower region of said second sideframe, and said second end of said bolster being mounted on said second spring group;   each of said sideframes having a stiffness opposing cross-wise swinging thereof, k P ;   each of said spring groups having a cross-wise shear stiffness, k SS ;   when loaded to said load rating, k P  being less than k SS ;   said truck having resistance to yawing of said sideframes relative to said bolster; and   said resistance to yawing of said sideframes relative to said bolster including a moment couple arising from yaw displacement of said sideframes relative to said bolster.   
   
   
       9 . The railroad car truck of  claim 8  wherein said resistance to yawing is linearly proportional to angular yaw displacement of said sideframes to said bolster. 
   
   
       10 . The railroad car truck of  claim 8  wherein said truck includes a first yaw resisting member and a second yaw resisting member, said first and second yaw resisting members being independently biased; said first yaw resisting member being mounted cross-wise inboard of said second yaw resisting member. 
   
   
       11 . The railroad car truck of  claim 9  wherein said truck also includes third and fourth yaw resisting members, said first and second yaw resisting members being mounted lengthwise away from said third and fourth yaw resisting members respectively, said third yaw resisting member being mounted cross-wise inboard of said fourth yaw resisting member. 
   
   
       12 . The railroad car truck of  claim 8  wherein:
 said truck has a first set of four individually driven friction dampers mounted to work between said first end of said bolster and said first sideframe;   said truck has a second set of four individually driven friction dampers mounted to work between said second end of said bolster and said second sideframe; and   said dampers work against wear plates that are square to the longitudinal direction.   
   
   
       13 . The railroad car truck of  claim 12  wherein:
 said first set of four individually driven friction dampers includes a first friction damper, a second friction damper, a third friction damper; and a fourth friction damper;   said first spring group includes a first corner spring, a second corner spring, a third corner spring and a fourth corner spring; said first corner spring is a lengthwise forward and most cross-wise inboard spring of said first spring group; said second corner spring is a lengthwise forward and most cross-wise outboard spring of said first spring group;   said third corner spring is a lengthwise rearward and most cross-wise inboard spring of said first spring group; said fourth corner spring is a lengthwise rearward and most cross-wise outboard spring of said first spring group;   said first friction damper is mounted over said first corner spring;   said second friction damper is mounted over said second corner spring;   said third friction damper is mounted over said third corner spring; and   said fourth friction damper is mounted over said fourth corner spring.   
   
   
       14 . The railroad car truck of  claim 13  wherein each of said first, second, third and fourth corner springs has another spring nested therewithin. 
   
   
       15 . The railroad car truck of  claim 10  wherein:
 said truck has four individually spring driven friction damper wedges mounted to work between said first end of said bolster and said first sideframe;   said first spring group has an overall vertical spring rate, k V ;   said first spring group includes damper springs driving said damper wedges, said damper springs having a total spring rate k D ;   k D  is at least 15% of k V ;   each wedge has a first face mounted to work in a sliding relationship against a wear plate and an hypotenuse face mounted to seat in a damper pocket; and   each of said damper wedges has a primary wedge angle, said primary wedge angle being that angle included between said first face and said hypotenuse face, said primary wedge angle being greater than 35 degrees.   
   
   
       16 . The railroad car truck of  claim 10  wherein;
 said resistance is linearly proportional to angular yaw displacement of said sideframes to said bolster;   said first sideframe has an upper compression member, a lower tension member, and a pair of lengthwise spaced sideframe columns defining a sideframe window therebetween;   said sideframe columns have respective wear plates mounted thereto, said wear plates being mounted square to said longitudinal direction;   said bolster has four damper accommodations at said first end thereof;   said truck has four individually spring driven friction damper wedges each seated in a respective one of said accommodations and being mounted to work between said first end of said bolster and said first sideframe;   said first spring group has an overall vertical spring rate, k V ; said first spring group includes damper springs driving said damper wedges, said damper springs having a total spring rate k D ; and k D  is at least 15% of k V ;   each wedge has a first face mounted to work in a sliding relationship against a one of said wear plates and an hypotenuse face mounted to seat in a damper pocket;   each of said damper wedges has a primary wedge angle, said primary wedge angle being that angle included between said first face and said hypotenuse face, said primary wedge angle being greater than 35 degrees;   a first set of four individually driven friction dampers including a first friction damper, a second friction damper, a third friction damper; and a fourth friction damper;   said first spring group includes a first corner spring, a second corner spring, a third corner spring and a fourth corner spring;   said first corner spring is a lengthwise forward and most cross-wise inboard spring of said first spring group; said second corner spring is a lengthwise forward and most cross-wise outboard spring of said first spring group;   said third corner spring is a lengthwise rearward and most cross-wise inboard spring of said first spring group; said fourth corner spring is a lengthwise rearward and most cross-wise outboard spring of said first spring group;   said first friction damper is mounted over said first corner spring;   said second friction damper is mounted over said second corner spring;   said third friction damper is mounted over said third corner spring;   said fourth friction damper is mounted over said fourth corner spring; and   each of said first, second, third and fourth corner springs has another spring nested therewithin.   
   
   
       17 . A railroad freight car truck for rolling motion in a longitudinal direction along cross-wise spaced apart railroad tracks, said railroad freight car truck having a load rating, said rail road freight car truck having:
 a bolster mounted cross-wise between first and second sideframes, and first and second wheelsets, said sideframes being mounted on said wheelsets;   said sideframes having upper regions seated on rocking mounts that permit said sideframes to swing cross-wise such that said sideframes define swing hangers;   said bolster being permitted a non-trivial range of lateral motion relative to said sideframes;   said sideframes being mounted to permit non-trivial yaw thereof relative to said bolster;   said bolster having a first end mounted upon a first spring group, said first spring group including a plurality of coil springs seated in a lower region of said first sideframe;   said bolster having a second end mounted upon a second spring group, said second spring group including a plurality of coil springs seated in a lower region of said second sideframe;   a first set of four independently driven friction dampers mounted at said first end of said bolster; and a second set of four independently driven friction dampers mounted at said second end of said bolster;   each of said sideframes having a stiffness opposing cross-wise swinging thereof, k P ;   each of said spring groups having a cross-wise shear stiffness, k SS ; and   when loaded to said load rating, k P  being less than k SS .   
   
   
       18 . The railroad freight car truck of  claim 17 , wherein:
 said sideframes have wear plates mounted thereto, said longitudinal direction being normal to said wear plates;   said first end of said bolster has four friction damper accommodations formed therein;   said first spring group includes a first corner spring, a second corner spring, a third corner spring and a fourth corner spring;   said first corner spring is located cross-wise inboard of said second corner spring;   said third corner spring is located cross-wise inboard of said fourth corner spring;   said first and second corner springs are located longitudinally forward of said third and fourth corner springs respectively; and   each of said four friction damper accommodations is located above a respective one of said corner springs.   
   
   
       19 . The railroad freight car truck of  claim 18  wherein:
 said first set of friction dampers includes four friction damper wedges, each said wedge having a first face for engagement with a wear plate of one of said sideframes, a second, hypotenuse face, and a base;   said four accommodations each include an angled face against which one said hypotenuse face of one of said dampers engages; and   said base of each of said friction damper wedges is engaged by a respective one of said corner springs.   
   
   
       20 . The rail road freight car truck of  claim 19  wherein each of said corner springs has another spring nested therewithin, and each of said damper wedges has a primary angle measured between said first face and said second face of greater than 35 degrees. 
   
   
       21 . The rail road freight car truck of  claim 18  wherein:
 said accommodations in said bolster include a first accommodation, a second accommodation, a third accommodation, and a fourth accommodation;   said second accommodation is cross-wise outboard of said first accommodation, said fourth accommodation is cross-wise outboard of said third accommodation;   said bolster has a first land intermediate said first and second accommodations, and a second land intermediate said third and fourth accommodations; and   a spring of said first spring group bears against said first land, another spring of said first spring group bears against said second land.   
   
   
       22 . A rail road freight car truck comprising:
 a bolster, first and second sideframes, first and second wheelsets; and first and second spring groups; the bolster having a first end and a second end;   each of said sideframes having an upper, compression member; a lower, tension member; a first sideframe column and a second sideframe column; and each of said sideframes having a sideframe window defined therebetween;   said first end of said bolster is seated upon said first spring group in said sideframe window of said first sideframe; said second end of said bolster is seated upon said second spring group in said sideframe window of said second sideframe;   said first and second sideframes having upper regions rockingly mounted on said first and second wheelsets, said first and second sideframes being operable to swing cross-wise when mounted thereon;   said sideframes being mounted to yaw appreciably relative to said bolster;   said truck having resistance to yawing proportionate to yaw deflection of said sideframes;   said truck having resistance to cross-wise swinging of said first sideframe and resistance to cross-wise shear of said first spring group; and   under a lateral perturbation said bolster has a first component of cross-wise displacement associated with cross-wise swinging of said first sideframe, a second component of cross-wise displacement associated with cross-wise shear of said first spring group; and a total displacement; said total displacement having a magnitude greater than either said first component and said second component.   
   
   
       23 . The rail road freight car truck of  claim 22  wherein said truck has a first set of friction dampers mounted to work between said first end of said bolster and said first sideframe, and a second set of friction dampers mounted to work between said second end of said bolster and said second sideframe; said first set of friction dampers includes four independently driven friction dampers, each of said four independently driven dampers being driven by a first spring having a second spring nested therewithin, and each of said first springs is a corner spring of said first spring group.