Railway truck bolster friction assembly

Abstract

A railway freight truck bolster friction assembly and more particularly improved friction assemblies of elastomeric material which are adapted to be captively retained intermediate an axial end portion of a bolster member and an adjacent side frame.

I claim: 
     
       1. A railway truck bolster friction assembly adapted to be .[.captively.]. retained within a pocket of an elongated truck bolster member which extends between spaced elongated side frame members of a railway truck vehicle comprising: elastomeric .[.friction.]. means adapted to have a first portion thereof in .[.communication.]. .Iadd.engagement .Iaddend.with adjacent surfaces of such a pocket and a second portion thereof in frictional engagement with .Iadd.an .Iaddend.adjacent .[.portions.]. .Iadd.portion having a surface .Iaddend.of .Iadd.a .Iaddend.wearing surface means of a column guide of a respective one of such side frame members.[.,.]..Iadd.; .Iaddend.said second portion being spaced .[.transversly.]. .Iadd.transversely .Iaddend.outwardly, with respect to the longitudinal axis of such a bolster member, from such a pocket and said first portion extending .[.transversly.]. .Iadd.transversely .Iaddend.inwardly from said second portion; and said elastomeric .[.friction.]. means being .[.operative to deform and.]. .Iadd.deformable in shear to .Iaddend.maintain said frictional engagement, without slipping .[.between adjacent engaging surfaces.]., during .[.at least.]. initial vertical and transverse movements of such a bolster member with respect to such a respective one of such side frame members .Iadd.until such deformation in shear reaches a given magnitude.Iaddend.. 
     
     
       2. A railway truck bolster friction assembly as specified in claim 1 additionally including biasing means to bias said elastomeric .[.friction.]. means into said .[.communication.]. .Iadd.engagement with such adjacent surfaces of such a pocket .Iaddend.and said frictional engagement. 
     
     
       3. A railway truck bolster friction assembly as specified in claim 2 wherein during .[.a.]. subsequent .[.vertical movement.]. .Iadd.relative movements .Iaddend.of such a bolster member .Iadd.with respect to such a respective one of such side frame members .Iaddend.said elastomeric .[.friction .]. means are operative such that at least sections of .Iadd.said surface of .Iaddend.said second portion will slip with respect to .Iadd.such .Iaddend.adjacent .[.portions.]. .Iadd.portion .Iaddend.of such wearing surface means. 
     
     
       4. A railway truck bolster friction assembly as specified in claim .[.1.]. .Iadd.2 .Iaddend.additionally including said wearing surface means .[.of such respective one of such side frame members, and said adjacent portions of said wearing surface means extend.]. .Iadd.extending .Iaddend.downwardly and .[.slope transversly.]. .Iadd.sloping transversely .Iaddend.inwardly, with respect to the longitudinal axis of such bolster member, to be operative as said biasing means by providing a wedging action on said elastomeric bearing means as such a bolster member moves vertically .Iadd.downward.Iaddend.. 
     
     
       5. A railway truck bolster friction assembly as specified in claim .[.2 additionally including said wearing surface means of such respective one of such side frame members, and said wearing surface means includes.]. .Iadd.1 wherein .Iaddend.heat dissipation means .[.thereon which are operative.]. .Iadd.are cooperable with said wearing surface means .Iaddend.to .[.directly.]. draw heat from said adjacent .[.portions.]. .Iadd.portion .Iaddend.of said wearing surface means and dissipate such heat to the atmosphere. 
     
     
       6. A railway truck bolster friction assembly as specified in claim 2 wherein said biasing means continuously biases said elastomeric .[.friction.]. means into said .[.communication.]. .Iadd.engagement with such adjacent surfaces of such a pocket .Iaddend.and said frictional engagement. 
     
     
       7. A railway truck bolster assembly as specified in claim 6 wherein .Iadd.support means engage the downwardly facing portion of said elastomeric means and .Iaddend.said biasing means includes at least one elongated spring element extending substantially vertically intermediate said .[.elastomeric friction.]. .Iadd.support .Iaddend.means and a generally horizontally extending spring seating portion of such a respective one of such side frame members, such seating portion being spaced downwardly from said .[.elastomeric friction.]. .Iadd.support .Iaddend.means. 
     
     
       8. A railway truck bolster friction assembly as specified in claim 7 .[.additionally including.]. .Iadd.wherein said support means is .Iaddend.a spring follower interposed vertically intermediate said elastomeric .[.friction.]. means and said spring element, said spring follower having.[.;.]. an underside surface thereof in .[.communication.]. .Iadd.engagement .Iaddend.with an upper axial end portion of said spring element, an upperside surface thereof in engagement with an underside surface of said elastomeric .[.friction.]. means and having the .[.transversly.]. .Iadd.transversely .Iaddend.innermost surface thereof, with respect to the longitudinal axis of such a bolster member, in .[.communication.]. .Iadd.engagement .Iaddend.with .Iadd.an .Iaddend.adjacent .[.surfaces.]. .Iadd.surface .Iaddend.of such a pocket. 
     
     
       9. A railway truck bolster friction assembly as specified in claim 8 wherein said upperside and underside surfaces lay in a common plane, which plane slopes .[.upwardly as it extends transversly inwardly, with respect to the longitudinal axis of such a bolster member, from said second portion.]. .Iadd.upwardly and towards said second portion from said underside surface of said elastomeric means.Iaddend.. 
     
     
       10. A railway truck bolster assembly as specified in claim 7 wherein .[.the underside surface of said elastomeric friction member slopes upwardly as it extends transversely inwardly, with respect to the longitudinal axis of such a bolster, from said second portion and is in communication with said biasing means,.]. said biasing means exerts a generally upwardly directed force on said elastomeric .[.friction.]. member and said frictional engagement primarily results from a horizontal component of said upwardly directed force .[.as applied at said underside surface.].. 
     
     
       11. In a railway truck assembly having an elongated bolster member which is supported adjacent the axial ends thereof on spring groups seated on spaced elongated said frame members and having bolster member friction assemblies positioned intermediate the bolster member and respective column guides of the side frame members, the improvement comprising: said friction assemblies each having elastomeric .[.friction.]. means received within a respective pocket of said bolster member, said elastomeric .[.friction.]. means having a first portion thereof in .[.communication.]. .Iadd.engagement .Iaddend.with adjacent surfaces of said pocket and a second portion .Iadd.having a surface .Iaddend.thereof in frictional engagement with a wearing surface means of said column guide, said second portion being spaced transversely outwardly, with respect to the longitudinal axis of said bolster member, from said pocket and said first portion extending .[.transversly.]. .Iadd.transversely .Iaddend.inwardly from said second portion; and said elastomeric .[.friction.]. means being .[.operative to deform and.]. .Iadd.deformable in shear to .Iaddend.maintain said frictional engagement, without slipping .[.between adjacent engaging surfaces,.]. during .[.at least.]. initial vertical and transverse movements of said bolster member with respect to said side frame members .Iadd.until such deformation in shear reaches a given magnitude.Iaddend.. 
     
     
       12. A railway truck assembly as specified in claim 11 wherein during subsequent vertical movement of said bolster member said elastomeric .[.friction.]. means are operatie such that at least sections of said second portion will slip with respect to .[.adjacent portions of.]. said wearing surface means .Iadd.until said deformation in shear reaches a given magnitude greater than said first mentioned given magnitude.Iaddend.. .Iadd. 
     
     
       13.  A railway truck bolster friction assembly adapted to be retained within a pocket of an elongated truck bolster member which extends between spaced elongated side frame members of a railway truck vehicle comprising: elastomeric means having a first portion with surfaces thereof adapted to frictionally engage adjacent surfaces of such a pocket and a second portion with a surface thereof adapted to frictionally engage an adjacent column guide surface of a respective one of such side frame members; said second portion being spaced transversely from said first portion such that when said surfaces of said first portion engage such adjacent surfaces of a pocket said second portion extends outwardly from the pocket; and said elastomeric means being deformable in shear to simultaneously frictionally engage such surfaces of a pocket at such a column guide surface engagements without slipping during initial relative movements of such a bolster member with respect to such a respective one of such side frame members until such deformation in shear reaches a given magnitude. .Iaddend. .Iadd.14. A device for maintaining engagement between a bolster and the side frames of a railway truck assembly in which an elongated bolster extends horizontally between spaced side frames with open ended pockets in the ends of the bolster being located in spaced adjacent relationship with surface means on the side frames, respectively, comprising: a formed block of elastomeric material of a configuration to be received in such a bolster pocket with an outer surface of said block being in deformed engagement with an adjacent one of such a surface means when the bolster and the side frames are in a relative position which is the same as the relative position when said bolster and said side frames are at rest;   said elastomeric block being of a composition that, upon movement of the bolster relative to such adjacent one of such surface means to produce a shearing deformation in said block while said block remains in deformed engagement with such adjacent one of such surface means, said block initially remains in essentially the same relative position with respect to such adjacent one of such surface means until such shearing deformation reaches a first magnitude and thereafter said block partially moves with respect to such adjacent one of such surface means until such shearing deformation reaches a second magnitude greater than said first magnitude and thereafter said block moves in its entirety with respect to such adjacent one of such surface means when the magnitude of such shearing deformation exceeds said second magnitude. .Iaddend. .Iadd.15. A railway truck assembly comprising: an elongated horizontally extending bolster; upstanding side frames at the ends of said bolster, respectively; open sided pockets in the ends of said bolster, respectively; said side frames having surface means adjacent the open sides of said pockets, respectively; elastomeric means in said pockets having outer surfaces in frictional engagement with said surface means, respectively; and said elastomeric means being of a composition that, upon movement of said bolster with respect to said surface means to produce a shear deformation in at least one of said elastomeric means, one said elastomeric means initially maintains such frictional engagement by undergoing shear deformation while remaining in essentially the same relative position with respect to the one of said surface means adjacent thereto until such deformation reaches a first magnitude and thereafter undergoing further shear deformation with only a portion thereof moving with respect to said one of said surface means until such deformation reaches a second magnitude greater than said first magnitude and undergoing still further shear deformation while moving in its entirety with respect to said one of said surface means when the magnitude of such shear deformation exceeds   
     
     
        said second magnitude. .Iaddend. .Iadd.16.  A railway truck assembly as specified in claim 15 wherein said frictional engagement results from initially deforming said elastomeric means prior to subjecting said elastomeric means to shear deformation. .Iaddend. .Iadd.17. A railway truck assembly as specified in claim 15 wherein biasing means carried by said side frames engages said elastomeric means, respectively, to bias said elastomeric means into said frictional engagement. .Iaddend.