Traction and suspension control assembly

Abstract

A proportional load transfer valve is disclosed to shift a predetermined ratio of approximately fifty percent (50%) of the weight on a tag axle to the drive axle. The load transfer valve acts in response to a pneumatic signal indicative of a traction event. The valve alters the ratio of supply port pressure associated with the air suspension bags of the drive axle that is forwarded to the delivery port associated with the air bag suspension assembly of the tag axle. As the weight imposed on the drive axle approaches a predetermined maximum, the load transfer valve transfers less weight so that the drive axle is not overloaded.

Having thus described the invention, it is claimed:  
     
         1 . A proportional load transfer assembly for a vehicle having a traction and suspension control assembly, the assembly comprising: 
 a drive axle;    a traction control assembly for the drive axle for selectively controlling torque to a wheel mounted on the drive axle in response to a traction control event;    a suspension assembly for proportioning vehicle load between the drive and non-drive axles;    a non-drive axle; and    a valve assembly operatively associated with the suspension assembly for selectively transferring a predetermined ratio of vehicle load from the non-drive axle to the drive axle up to a preselected maximum in response to a traction control event.    
     
     
         2 . The invention of  claim 1  wherein the valve assembly includes a valve member interposed between a supply port and a delivery port that moves in response to a pressure signal from the traction control assembly.  
     
     
         3 . The invention of  claim 2  wherein the valve assembly includes a moveable member operatively associated with the valve member and including a pressure surface thereon that communicates with a control port in communication with the traction control assembly.  
     
     
         4 . The invention of  claim 3  wherein the valve assembly includes an exhaust port selectively sealed by the valve member, whereby a ratio of supply pressure provided to the delivery port depends on the position of the valve member relative to the exhaust port.  
     
     
         5 . The invention of  claim 4  wherein the valve assembly includes a biasing member urging the moveable member toward a first position whereby the valve member closes an exhaust port and all of the supply pressure is provided to the delivery port.  
     
     
         6 . The invention of  claim 5  wherein the valve assembly further includes a second biasing member urging the valve member toward a valve seat associated with the exhaust port.  
     
     
         7 . The invention of  claim 6  wherein the valve assembly includes a second seat between the supply and delivery ports that is selectively engaged by the valve member when the pressure at the delivery port reaches a predetermined limit.  
     
     
         8 . A method of controlling traction of a drive axle in a 6×2 truck system having a suspension control assembly associated with a non-drive axle and the drive axle comprising the steps of: 
 providing a pressure to the suspension control assembly associated with the drive axle;  
 providing a pressure to the suspension control assembly associated with the non-drive axle;  
 regulating the pressure to the suspension control assembly associated with the drive axle in response to a traction event; and  
 limiting the pressure to the drive axle suspension control assembly to a predetermined maximum.  
 
     
     
         9 . The method of  claim 8  comprising the further steps of regulating the pressure to the drive axle suspension control assembly at any pressure below the predetermined maximum.  
     
     
         10 . The method of  claim 8  wherein the pressure regulating step ranges from a zero percent (0%) transfer ratio to a one-hundred percent (100%) transfer ratio.  
     
     
         11 . The method of  claim 8  comprising the further step of providing a pressure signal to the suspension control assembly in response to a traction event.