Patent ID: 6474748
Filing Date: 2002-11-05
Classification: B60T

Abstract:
An electronically controlled vent valve for a pneumatic brake system, such pneumatic brake system including a master controller processing circuit for generating electrical braking command signals and a brake pipe carrying compressed air, said electronically controlled vent valve comprising:a valve housing: a valve disposed within said valve housing for connecting to such brake pipe and for being in fluid communication with such compressed air carried by such brake pipe; said valve having an open position for substantially venting such compressed air from such brake pipe and a closed position for substantially retaining such compressed air within such brake pipe; a brake pipe pressure sensor disposed on and connected to said valve housing and in fluid communication with an interior of said valve for generating brake pipe pressure signals indicative of such pressure of such compressed air in such brake pipe; an electrically operated actuator for moving said valve between said open position and said closed position; and a microprocessor for controlling said electrically operated actuator to move said valve between said open position and said closed position; said microprocessor including: means for moving said valve between said open position and said closed position in response to an emergency electrical braking command signal generated by such master controller processing circuit; and emergency pressure monitoring means for calculating a rate of change of said brake pipe pressure signals generated by said brake pipe pressure sensor and for controlling said electrically operated actuator to move said valve to said open position to substantially vent such compressed air from such brake pipe when said calculated rate of change of said brake pipe pressure signals exceeds a threshold value; said threshold value corresponding to an emergency rate of change of said brake pipe pressure.