Vehicle air braking system

Abstract

A vehicle air braking system having a source of fluid under pressure ( 1 ), an air dryer (A) downstream of said source ( 1 ), and an air consumer circuit ( 2 ) downstream of the air dryer (A), the system having control means to suspend the source ( 1 ) on demand to permit backflow of air under pressure from the air consumer circuit ( 2 ) through the air dryer (A) to a drain valve (B), the control means comprising a regeneration valve (D), and a command valve (C) having an inlet connected to the air consumer circuit ( 2 ), and a supply outlet operably connected to the drain valve (B), wherein the regeneration valve (D) is operable to permit regeneration backflow in response to connection of the inlet and supply outlets of the command valve (C).

1 . A vehicle air braking system having a source of fluid under pressure, an air dryer downstream of said source, and an air consumer circuit downstream of the air dryer, the system having control means to suspend the source on demand to permit backflow of air under pressure from the air consumer circuit through the air dryer to a drain valve, the control means comprising a regeneration valve, and a command valve having an inlet connected to the air consumer circuit, and a supply outlet operably connected to the drain valve, wherein the regeneration valve is operable to permit regeneration backflow in response to connection of the inlet and supply outlets of the command valve.  
     
     
         2 . A vehicle air braking system as claimed in clam  1  wherein the drain valve is resiliently biased to a closed position and movable from said closed position to an open position on connection of the command valve inlet and supply outlet.  
     
     
         3 . A vehicle air braking system as claimed in  claim 1  or  claim 2  wherein the regeneration valve is spring biased to a closed position and connected to the supply outlet against movement of the closure spring.  
     
     
         4 . A vehicle air braking system as claimed in  claim 2  or  claim 3  when dependent upon  claim 2  wherein the regeneration valve and the drain valve are connected to a common signal line leading from said supply outlet  
     
     
         5 . A vehicle air braking system as claimed in any preceding claim wherein the control means suspend the source by exhausting through the drain valve.  
     
     
         6 . A vehicle air braking system as claimed in any preceding claim wherein the system includes a compressor unloader, the source being suspendable via said compressor unloader.  
     
     
         7 . A vehicle air braking system as claimed in  claim 6  wherein the compressor unloader is operable via an unloader valve.  
     
     
         8 . A vehicle air braking system as claimed in  claim 7  wherein said unloader valve has an inlet connected to the air consumer circuit and an outlet connected to the compressor unloader, said valve being resiliently biased to a closed position and movable to an open position thereby connecting the inlet to the outlet.  
     
     
         9 . A vehicle air braking system as claimed in  claim 7  or  claim 8  wherein said unloader valve is electrically operable.