ABDX-C service graduating valve and slide valve and slide valve design incorporating accelerated application valve (AAV) functionality

A service valve portion of a brake control valve, the service valve portion comprising:

• a body having a first side, a second side, and a piston passageway defined therein extending from the top side to the bottom side;
• a main bushing, the main bushing including an interior slide valve seat having a porting pattern defined therein;
• and
• a main piston assembly movably disposed within the main bushing inside the piston passageway, the main piston assembly comprising:
• a service graduating valve having a body, the body of the service graduating valve including a first side having a porting pattern defined therein;
• and
• a service slide valve having a body, the body of the service slide valve including a first side with a graduating valve seat having a porting pattern defined therein and an opposing second side with a service slide valve face having a porting pattern defined therein,
• wherein the first side of the service graduating valve is configured to movably engage the graduating valve seat of the service slide valve to establish a variety of porting connections between the service graduating valve and the service slide valve based on the relative position of the service graduating valve and the service slide valve,
• wherein the second side of the service slide valve is configured to movably engage the interior slide valve seat of the main bushing to establish a variety of porting connections between the service slide valve and the main bushing based on the relative position of the service slide valve within the main bushing,
• wherein the service valve portion is controlled to perform brake valve functions based at least in part on the relative position of the service graduating valve and the service slide valve and the relative position of the service slide valve within the main bushing,
• wherein the porting pattern of the first side of the service graduating valve includes accelerated application valve exhaust ports, the porting pattern of the graduating valve seat of the service slide valve includes brake pipe to local reduction room ports, and the porting pattern of the service slide valve face of the service slide valve includes a brake pipe pressure to the graduating valve seat port and a brake pipe pressure from the graduating valve seat down to the local reduction room port that are configured to cooperate to allow the service valve portion to perform an accelerated application valve function,
• wherein the porting pattern of the first side of the service graduating valve includes an accelerated release reservoir to auxiliary reservoir bleeder port configured to direct compressed air to move the service graduating valve to discontinue the accelerated application valve function, and
• wherein the porting pattern of the graduating valve seat of the service slide valve includes an accelerated release reservoir port to the graduating valve seat and the porting pattern of the service slide valve face of the service slide valve includes an accelerated release reservoir to the graduating valve seat port configured to cooperate to direct compressed air to the service graduating valve to discontinue the accelerated application valve function.