Bolster spring suspension assembly

Abstract

A bolster spring assembly is adapted for securement to a vehicle having a primary suspension system for securing an axle to the vehicle. The bolster spring assembly is located and secured between the leaf spring over the axle and the undercarriage of the vehicle as a supplement to the primary suspension system.

1 . A bolster spring configured to be attached to a suspension system of a vehicle including a leaf spring connecting an axle to a frame of the vehicle, the bolster spring being configured to supplement the support provided by the suspension system, and the bolster spring comprising: 
 a first end connected to the axle;    a second end connected to the vehicle frame;    a plurality of resilient core members located intermediate said ends; and    a plurality of separator plates, positioned so that at least one of said separator plates is located intermediate a pair of adjacent resilient core members;    wherein said bolster spring is positioned so that said separator plates are arranged at an angle within a range of about 5° to about 25° with respect to a substantially vertical axis.    
   
   
       2 . The bolster spring as set forth in  claim 1 , further comprising a first bracket connected to said first end and a second bracket connected to said second end.  
   
   
       3 . The bolster spring as set forth in  claim 2 , wherein said first bracket is offset vertically and laterally from said second bracket.  
   
   
       4 . The bolster spring as set forth in  claim 3 , wherein said first bracket includes a pair of mounting holes configured to receive a U-bolt connected to the axle.  
   
   
       5 . The bolster spring as set forth in  claim 4 , wherein said first bracket includes a horizontal plate positioned adjacent to the leaf spring and a vertical plate connected to said bolster spring.  
   
   
       6 . The bolster spring as set forth in  claim 1 , wherein said second end is located vertically above said first end.  
   
   
       7 . The bolster spring as set forth in  claim 1 , wherein said bolster spring is configured to allow only one bolster spring to connect to both the frame and the leaf spring.  
   
   
       8 . A suspension system for attaching an axle to a vehicle frame comprising: 
 a leaf spring fixed to the frame at a first point and joined by a linkage to the frame at a second point; and    a bolster spring assembly fixed to the frame at a third point and connected to the leaf spring at a fourth point, said bolster spring assembly comprising at least one bolster spring being longitudinally offset from said fourth point, said bolster spring assembly acting in both shear and torsion.    
   
   
       9 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 8 , wherein said bolster spring assembly includes only one said bolster spring.  
   
   
       10 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 8 , wherein said third point is located vertically above said fourth point.  
   
   
       11 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 10 , wherein said third point is located forward of said fourth point.  
   
   
       12 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 8 , further including a first bracket and a second bracket, said first bracket connected to said bolster spring at said third point and said second bracket connected to said bolster spring at said fourth point.  
   
   
       13 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 12 , further including a U-bolt configured to connect said second bracket to the axle.  
   
   
       14 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 8 , wherein said bolster spring assembly includes a plurality of resilient core members located intermediate said third point and said fourth point and a plurality of separator plates, positioned so that at least one of said separator plates is located intermediate a pair of adjacent resilient core members; wherein said bolster spring assembly is positioned so that said separator plates are arranged at an angle within a range of about 5° to about 25° with respect to a substantially vertical axis.  
   
   
       15 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 14 , wherein said cores and said separator plates are generally vertically disposed and said third point is spaced apart forwardly and upwardly from said fourth point.  
   
   
       16 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 8 , wherein said bolster spring assembly extends in the direction of said first point.  
   
   
       17 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 16 , wherein said bolster spring assembly is located vertically above said axle.  
   
   
       18 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 17 , further including a bracket connecting said leaf spring to said frame.  
   
   
       19 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 18 , wherein said bracket retains said leaf spring in a relatively fixed position with respect to said frame.  
   
   
       20 . The suspension system for attaching an axle to a vehicle frame as set forth in  claim 19 , wherein the linkage allows for substantially horizontal movement of the leaf spring with respect to the frame at said second point.