Abstract: A brake control device for a vehicle, which controls a pressure difference control valve and a pump provided at a main and a auxiliary conduits respectively to control a flow of brake fluid supplied from a master cylinder to a wheel cylinder, includes a determining step for determining whether or not to execute a brake control in an emergency situation, a first control step for controlling the pressure difference control valve to be in a pressure difference generating state and for controlling the pump to supply the brake fluid to the main conduit through the auxiliary conduit, and a second control step for controlling the pressure difference control valve to be in a fluid communicating state, and for controlling the pump to supply the brake fluid to the main conduit through the auxiliary conduit, wherein the second control means is executed before the first control means in the emergency situation.

Abstract: The invention provides an emergency brake apparatus for a vehicle which can brake both of front and rear tire wheels of a vehicle by using an oil pressure, at an emergency time. For this purpose, a pressure oil of a hydraulic power source is changed to a pilot oil pressure which is reduced from a high pressure to a low pressure in correspondence to an operation amount of an emergency brake valve (77) operated at the emergency time, and this pressure is output to a relay valve (3). The pressure oil of the hydraulic power source is increased in an inverse proportional manner from a low pressure to a high pressure in correspondence to the pilot oil pressure, and this pressure is output to a front tire wheel brake (64), thereby urgently braking the front tire wheel.

Abstract: A grade speed control system and method for a railway freight vehicle can include a microprocessor receiving input from, for example, the dynamic and independent brakes on the locomotive, and the brakes on each rail car. The microprocessor can store values for desired train speed and actual train speed as well as constants and equations for converting raw data to derive brake cylinder pressure adjustments for implementing train speed control functions. The grade speed control system can also include communicate with brake cylinder control devices on articulated rail cars to increase or decrease the brake cylinder pressures to control the train speed. If actual speed differs from target speed by more than a predetermined amount, a target acceleration can be calculated and brake cylinder pressures adjustments can be derived to achieve the target acceleration to bring the actual speed of the train to the target speed in a reasonably brief time period.

Abstract: The railway freight car brake control utilizes sequential pressurization of the brake cylinder from a first auxiliary reservoir and a second auxiliary reservoir during emergency. Embodiments utilize a first supply reservoir larger in volume than a second supply reservoir. The first supply reservoir is used during a service braking mode. The larger first supply reservoir provides improved braking in a service mode, while the sequential utilization of both reservoirs provides an improved level of emergency braking available during a loaded freight car condition.

Abstract: A fluid brake control system is disclosed having an improved emergency application and stability control device for use in association with a brake control pipe, emergency and auxiliary fluid reservoirs, a first quick action chamber, a brake cylinder, and emergency and service control valves. An improved emergency application and stability control valve is provided comprising a housing containing a differential abutment subject to actuation axially by differences in fluid pressures in respective brake pipe pressure and quick action control pressure chambers on opposite sides of the abutment. The control device has at least one ball poppet type valve on each side of the abutment that is spring biased toward a closed position and has an operating push rod longitudinally disposed between the associated valve and the abutment. The poppet valve on one side of the abutment is opened by movement of the abutment in one direction for permitting application of fluid from the emergency reservoir to the brake cylinder.