Suspension for a Rail Vehicle

Abstract

A suspension for a rail vehicle includes at least one spring ( 18 ) carrying a wedge element ( 20 ) constrained to move in a vertical direction and a load application member ( 24 ) for engaging the wedge ( 20 ) to transmit the load to the wedge ( 20 ) along a direction. The damping ration of the suspension is variable by altering the engagement between the load application member ( 24 ) and the wedge ( 20 ) and hence the direction.

1 . A suspension for a rail vehicle comprising at least one spring carrying a wedge constrained to move in a vertical direction and a load application member for engaging the edge to transmit load to the wedge along a direction such that the damping ratio of the suspension is variable by altering the engagement between the member and the wedge and hence the direction. 
   
   
       2 . The suspension as claimed in  claim 1  wherein one of the member or wedge has a generally flat engagement face and the other has a non-planar face whereby the flat face can pivot on the non-planar face to alter the direction. 
   
   
       3 . The suspension as claimed in  claim 2  wherein the member is pivotally mounted and further including a resilient element for urging the member against the wedge. 
   
   
       4 . The suspension as claimed in  claim 3  wherein the resilient element is rated to be fully compresses at the design maximum load. 
   
   
       5 . The suspension as claimed in  claim 1  wherein the member is a flat plate. 
   
   
       6 . The suspension as claimed in  claim 1  wherein one direction is substantially 50° to the vertical. 
   
   
       7 . The suspension as claimed in  claim 6  wherein another direction is at substantially 60° to the vertical.