Abstract: An apparatus and method for protecting an intact portion of a service brake system from a failed wheel end of a vehicle is provided. A failure in a wheel end is detected by determining an operation state of each of the wheel ends by monitoring parameters including the pressure in a parking brake air supply line. When it is determined that a failed wheel end is present in the service brake system, a service brake isolation valve is switched to a state in which the failed wheel end is isolated from the rest of the brake system. The service brake of the failed wheel end is disabled, while the service brakes of the other wheel ends are enabled for normal operation. The parking brake of the failed wheel end is enabled, while the parking brakes of the other wheel ends are disabled to prevent immobilization of the vehicle.

Abstract: An electronic controller includes an electrical input and an electrical output. The electronic controller is adapted to receive an electronic status signal at the electrical input. The electronic status signal is indicative of a pneumatic pressure in a supply line communicating pneumatic fluid between a towing portion of a vehicle and a towed portion of the vehicle. The electronic controller is also adapted to transmit an electronic control signal from the electrical output to an associated valve, based on the electronic status signal, for controlling delivery of a pneumatic control signal from the towing portion of the vehicle to the towed portion of the vehicle.

Abstract: An electronic controller includes an electrical input and an electrical output. The electronic controller is adapted to receive an electronic status signal at the electrical input. The electronic status signal is indicative of a pneumatic pressure in a supply line communicating pneumatic fluid between a towing portion of a vehicle and a towed portion of the vehicle. The electronic controller is also adapted to transmit an electronic control signal from the electrical output to an associated valve, based on the electronic status signal, for controlling delivery of a pneumatic control signal from the towing portion of the vehicle to the towed portion of the vehicle.

Abstract: An apparatus and method for protecting an intact portion of a service brake system from a failed wheel end of a vehicle is provided. A failure in a wheel end is detected by determining an operation state of each of the wheel ends by monitoring parameters including the pressure in a parking brake air supply line. When it is determined that a failed wheel end is present in the service brake system, a service brake isolation valve is switched to a state in which the failed wheel end is isolated from the rest of the brake system. The service brake of the failed wheel end is disabled, while the service brakes of the other wheel ends are enabled for normal operation. The parking brake of the failed wheel end is enabled, while the parking brakes of the other wheel ends are disabled to prevent immobilization of the vehicle.

Abstract: An apparatus and method for protecting an intact portion of a service brake system from a failed wheel end of a vehicle is provided. A failure in a wheel end is detected by determining an operation state of each of the wheel ends by monitoring parameters including the pressure in a parking brake air supply line. When it is determined that a failed wheel end is present in the service brake system, an antilock braking modulator or a service brake isolation valve is switched to a state in which the failed wheel end is isolated from the rest of the brake system. The service brake of the failed wheel end is disabled, while the service brakes of the other wheel ends are enabled for normal operation including antilock braking. And the parking brake of the failed wheel end is enabled, while the parking brakes of the other wheel ends are disabled to prevent immobilization of the vehicle.

Abstract: A system and method of controlling an air dryer system having first and second air dryers configured to receive compressed air from a compressor, such as a compressor of a vehicle, including operating the first and second air dryers in a first mode corresponding to a high flow mode wherein the first and second air dryers are connected in parallel with the air compressor, monitoring a condition related to a low compressor output state, and operating the first and second air dryers in a second mode corresponding to a continuous flow mode when the low compressor output state is detected.

Abstract: A braking system is provided that enables application and release of a parking brake with fluid control and that also maintains application of the brake during a loss of fluid pressure—all without using springs and using only a single fluid control conduit. The brake actuator for the system includes a housing defining service and parking chambers. A pushrod in the parking chamber is configured for movement with a diaphragm in the chamber. The parking brake is applied by introducing fluid on one side of the diaphragm. A clutch surrounds the pushrod and includes a tooth configured to engage corresponding teeth on the pushrod to hold the position of the pushrod even during a loss of fluid pressure. The clutch is rotated under fluid control to move the clutch tooth into and out of alignment with the teeth on the pushrod to hold and release the parking brake.

Abstract: A system and method of controlling an air dryer system having first and second air dryers configured to receive compressed air from a compressor, such as a compressor of a vehicle, including operating the first and second air dryers in a first mode corresponding to a high flow mode wherein the first and second air dryers are connected in parallel with the air compressor, monitoring a condition related to a low compressor output state, and operating the first and second air dryers in a second mode corresponding to a continuous flow mode when the low compressor output state is detected.

Abstract: A brake system and related components including a metering device are configured to regulate a control signal received from a brake control device such that a control valve delays the supply of a level of requested braking pressure for a prescribed amount of time. The metering device can be an inversion valve and orificed check valve in a control circuit adapted to allow relatively unrestricted flow until a threshold pressure is reached, after which pressure the inversion valve closes and the flow is metered through an orifice. This has the effect of allowing rapid brake actuation to a first level, and then slowing further application of the brake until full requested braking is achieved. An electronic control unit can also be configured to regulate a control signal to delay development of the requested brake pressure.

Abstract: When a vehicle decelerates quickly or otherwise experiences a hard brake event, the described systems and methods facilitate reducing load transfer between axles of a common set of axles (e.g. a tandem axle, a tridem axle, etc.). Transfer of suspension pressure from a dynamically unloaded axle to a more loaded axle is limited by a suspension control component such as a valve or solenoid or the like that closes upon detection of a hard brake event in order to lock air in the suspension components of the respective axles. This in turn limits the dynamically unloaded axle from lifting, thereby permitting it to contribute more significantly to the braking effort and improving stopping distance.

Abstract: A brake system and related components including a metering device are configured to regulate a control signal received from a brake control device such that a control valve delays the supply of a level of requested braking pressure for a prescribed amount of time. The metering device can be an inversion valve and orificed check valve in a control circuit adapted to allow relatively unrestricted flow until a threshold pressure is reached, after which pressure the inversion valve closes and the flow is metered through an orifice. This has the effect of allowing rapid brake actuation to a first level, and then slowing further application of the brake until full requested braking is achieved. An electronic control unit can also be configured to regulate a control signal to delay development of the requested brake pressure.

Abstract: A braking system is provided that enables application and release of a parking brake with fluid control and that also maintains application of the brake during a loss of fluid pressure—all without using springs and using only a single fluid control conduit. The brake actuator for the system includes a housing defining service and parking chambers. A pushrod in the parking chamber is configured for movement with a diaphragm in the chamber. The parking brake is applied by introducing fluid on one side of the diaphragm. A clutch surrounds the pushrod and includes a tooth configured to engage corresponding teeth on the pushrod to hold the position of the pushrod even during a loss of fluid pressure. The clutch is rotated under fluid control to move the clutch tooth into and out of alignment with the teeth on the pushrod to hold and release the parking brake.

Abstract: Various embodiments of a controller, system and method of preventing vehicle rollaway for a heavy vehicle are disclosed. The controller receives a service brake signal indicating an operator has engaged the service brakes, a parking brake signal indicating the operator intent to actuate the parking brake and a signal indicative of motion. The controller transmits a control signal to at least two braking system components in response the service brake signal, the parking brake signal, and the motion of the vehicle to maintain engagement of the vehicle service brakes after the service brake pressure signal begins to decrease.

Abstract: When a vehicle decelerates quickly or otherwise experiences a hard brake event, the described systems and methods facilitate reducing load transfer between axles of a common set of axles (e.g. a tandem axle, a tridem axle, etc.). Transfer of suspension pressure from a dynamically unloaded axle to a more loaded axle is limited by a suspension control component such as a valve or solenoid or the like that closes upon detection of a hard brake event in order to lock air in the suspension components of the respective axles. This in turn limits the dynamically unloaded axle from lifting, thereby permitting it to contribute more significantly to the braking effort and improving stopping distance.

Abstract: A vehicle hand control brake valve includes a piston, positioned based on an engagement of a vehicle parking brake, a service brake actuation valve, and a control mechanism. The control mechanism mechanically interacts with the service brake actuation valve to set a position of the service brake actuation valve. A level of actuation of vehicle service brakes is set based on the position of the service brake actuation valve. The service brake actuation valve is set to a position to actuate the service brakes when the control mechanism is set to a latch position. The control mechanism only is latched in the latch position when the vehicle parking brake is engaged.

Abstract: An apparatus and method for preventing parking brake-caused disabling of a vehicle is provided. In at least one of the vehicle's parking brake release actuators' supply lines there is provided a flow arrangement which allows parking brake release fluid to flow to and from the release actuator when its supply line is undamaged, and restricts flow from the release pressure source when the line between the flow arrangement and the actuator is damaged. The flow arrangement may be a pilot-operated, non-graduated control valve, a combination of a pressure protection valve and a check valve arranged in parallel, a velocity-sensing check valve, or any other device or combination of devices which provide the damaged line shutoff or metering functionality. Such an arrangement prevents automatic application of the parking brake by releasing pressure from all of the vehicle's parking brake actuators, thereby precluding automatic vehicle immobilization following damage at one wheel end.

Abstract: A foot valve that can be activated either by the driver or an electronic control unit, wherein the foot valve can be the central driving device for automated braking applications such as Hill Start Aid and Work Brake Systems. Pneumatic pressure delivered by an electronically controlled proportional modulator to the foot valve activates either primary and/or secondary portions of the brake valve. The driver can mechanically override the electronic intervention when he presses on the brake pedal. For applications such as ESC and ATC, driver demand can be sensed by sensors in the foot valve and transmitted to the braking system electronic controller on the vehicle.

Abstract: Various embodiments of a controller, system and method of preventing vehicle rollaway for a heavy vehicle are disclosed. The controller receives a service brake signal indicating an operator has engaged the service brakes, a parking brake signal indicating the operator intent to actuate the parking brake and a signal indicative of motion. The controller transmits a control signal to at least two braking system components in response the service brake signal, the parking brake signal, and the motion of the vehicle to maintain engagement of the vehicle service brakes after the service brake pressure signal begins to decrease.

Abstract: An apparatus and method for protecting an intact portion of a service brake system from a failed wheel end of a vehicle is provided. A failure in a wheel end is detected by determining an operation state of each of the wheel ends by monitoring parameters including the pressure in a parking brake air supply line. When it is determined that a failed wheel end is present in the service brake system, an antilock braking modulator or a service brake isolation valve is switched to a state in which the failed wheel end is isolated from the rest of the brake system. The service brake of the failed wheel end is disabled, while the service brakes of the other wheel ends are enabled for normal operation including antilock braking. And the parking brake of the failed wheel end is enabled, while the parking brakes of the other wheel ends are disabled to prevent immobilization of the vehicle.

Abstract: A foot valve that can be activated either by the driver or an electronic control unit, wherein the foot valve can be the central driving device for automated braking applications such as Hill Start Aid and Work Brake Systems. Pneumatic pressure delivered by an electronically controlled proportional modulator to the foot valve activates either primary and/or secondary portions of the brake valve. The driver can mechanically override the electronic intervention when he presses on the brake pedal. For applications such as ESC and ATC, driver demand can be sensed by sensors in the foot valve and transmitted to the braking system electronic controller on the vehicle.