System for Preserving Brake System Fluid Following a Disconnection Between Members of a Combination Vehicle

A system for preserving fluid in a fluid source on a towing member of a combination vehicle following a disconnection between the towing member and a towed member of the combination vehicle, comprising:

• a control valve including
• a valve housing defining
• a supply port in communication with the fluid source;
• and
• a delivery port in communication with a supply conduit that extends between the towing member and the towed member and is configured to transmit fluid from the towing member to the towed member;
• and,
• an exhaust port;
• a first trim element configured for movement, responsive to a differential pressure between a fluid pressure at the supply port and a fluid pressure at the delivery port, from an open position in which fluid at the supply port is delivered to the delivery port to a closed position in which fluid at the supply port is not delivered to the delivery port;
• and,
• a second trim element configured to assume a closed position if fluid pressure at the delivery port meets a predetermined condition relative to a threshold pressure and an open position connecting the delivery port and the exhaust port if the fluid pressure at the delivery port does not meet the predetermined condition relative to the threshold pressure to thereby reduce fluid pressure at the delivery port to cause movement of the first trim element from the open position to the closed position.

A system for preserving fluid in a fluid source on a towing member of a combination vehicle following a disconnection between the towing member and a towed member of the combination vehicle, comprising:

• a control valve including
• a valve housing defining
• a supply port in communication with the fluid source;
• and
• a delivery port in communication with a supply conduit that extends between the towing member and the towed member and is configured to transmit fluid from the towing member to the towed member;
• and,
• a first trim element configured for movement, responsive to a differential pressure between a fluid pressure at the supply port and a fluid pressure at the delivery port, from an open position in which fluid at the supply port is delivered to the delivery port to a closed position in which fluid at the supply port is not delivered to the delivery port;
• and,
• an inversion valve including
• a valve housing defining
• a supply port in communication with the supply conduit and the delivery port of the control valve;
• and,
• a delivery port open to atmosphere;
• and,
• a second trim element configured to assume a closed position if fluid pressure at the delivery port of the control valve meets a predetermined condition relative to a threshold pressure and an open position connecting the supply port of the inversion valve and the delivery port of the inversion valve if the fluid pressure at the delivery port of the control valve does not meet the predetermined condition relative to the threshold pressure to thereby reduce fluid pressure at the delivery port of the control valve to cause movement of the first trim element of the control valve from the open position to the closed position.