Patent ID: 7204563

Claim:
A brake valve assembly for a tractor and trailer park brake system comprising: a trailer hand control valve; an interlock valve assembly including a valve body having at least a first interlock inlet adapted for fluid connection to the trailer hand control valve, a second interlock inlet adapted for fluid connection to an air supply, at least one interlock outlet adapted for fluid connection to a tractor protection valve, and a check valve assembly cooperating with said first and second interlock inlets and said at least one interlock outlet to supply an air signal to the tractor protection valve from one of the air supply and said trailer hand control valve to apply a trailer brake; and a park brake control valve having fluid connections to trailer and tractor park brakes, said valve body including a park valve outlet that is fluidly connected to said park brake control valve, and wherein said valve body includes at least one air supply port adapted for direct fluid connection to the air supply and wherein said valve body houses a valve disc that prevents an air signal from being delivered from said at least one air supply port to said park brake control valve via said park valve outlet unless a service brake has been applied.