The main innovation in the braking system presented for patent protection is that it avoids the use of a main brake valve, as well as the other cocks and valves used presently in the air brakes. The pressure in the brake chambers is regulated hydraulically or electrically at the input of each brake chamber individually. This minimizes, to the extent possible, the delay in the execution of the brake commands given by the driver. ABS control will also be individual for each wheel and will work several times faster and more accurately. Overall, the system will use much fewer air ducts, will be simpler and more secure. The diagnostics will be much faster and easier. For reequipping the vehicles with the presented braking system, no changes in their design are required.

The main innovation in the braking system presented for patent protection is that it avoids the use of a main brake valve, as well as the other cocks and valves used presently in the air brakes. The pressure in the brake chambers is regulated hydraulically or electrically at the input of each brake chamber individually. This minimizes, to the extent possible, the delay in the execution of the brake commands given by the driver. ABS control will also be individual for each wheel and will work several times faster and more accurately. Overall, the system will use much fewer air ducts, will be simpler and more secure. The diagnostics will be much faster and easier. For reequipping the vehicles with the presented braking system, no changes in their design are required.

A spring-type brake actuator for a vehicle brake such as a pneumatically-actuated brake is provided, in which the actuator's operating rod is pulled toward the actuator to apply the brake. The actuator's parking brake release piston is located closer to the brake than the service brake piston, and the parking brake power spring is positioned between the mounting end of the actuator and the parking brake piston such that when parking brake release pressure is removed from the parking brake release chamber the parking brake piston biases the operating rod in the brake application direction, drawing the operating rod further into the actuator. The operating rod may penetrate the parking brake piston and an intermediate flange between the parking brake piston and the service brake piston, and be connected to the service brake piston such that the service brake piston may control brake application when the parking brake piston is in its parking brake release position adjacent to the end of the actuator that is mounted to the brake.

A spring-type brake actuator for a vehicle brake such as a pneumatically-actuated brake is provided, in which the actuator's operating rod is pulled toward the actuator to apply the brake. The actuator's parking brake release piston is located closer to the brake than the service brake piston, and the parking brake power spring is positioned between the mounting end of the actuator and the parking brake piston such that when parking brake release pressure is removed from the parking brake release chamber the parking brake piston biases the operating rod in the brake application direction, drawing the operating rod further into the actuator. The operating rod may penetrate the parking brake piston and an intermediate flange between the parking brake piston and the service brake piston, and be connected to the service brake piston such that the service brake piston may control brake application when the parking brake piston is in its parking brake release position adjacent to the end of the actuator that is mounted to the brake.

One variation of a system includes a drive subsystem and a controller. The drive subsystem includes: a chassis configured to transiently install on a trailer over a range of longitudinal positions; a set of retention features configured to transiently engage a first subset of engagement features, in a first array of engagement features on a left rail of the trailer and in a second array of engagement features on a right rail of the trailer, to couple the drive subsystem to the trailer in a particular longitudinal position in the range of longitudinal positions; a driven axle suspended from the chassis; and a motor coupled to the driven axle. The controller is configured to: trigger the motor to output torque to the driven axle; and trigger the motor to regeneratively brake the driven axle.

One variation of a system includes a drive subsystem and a controller. The drive subsystem includes: a chassis configured to transiently install on a trailer over a range of longitudinal positions; a set of retention features configured to transiently engage a first subset of engagement features, in a first array of engagement features on a left rail of the trailer and in a second array of engagement features on a right rail of the trailer, to couple the drive subsystem to the trailer in a particular longitudinal position in the range of longitudinal positions; a driven axle suspended from the chassis; and a motor coupled to the driven axle. The controller is configured to: trigger the motor to output torque to the driven axle; and trigger the motor to regeneratively brake the driven axle.

A valve assembly is dimensioned for interconnection between a pressurized gas supply system and a pressurized gas braking system of a rail vehicle. The valve assembly can include a valve housing and a valve body. The valve housing can include a housing wall that at least partially defines a housing chamber and includes a plurality of communication ports in fluid communication with the housing chamber. The valve body is supported within the housing chamber for sliding movement relative to the housing wall. The valve body can be displaced between a plurality of positions in which different ones of the communication ports are in fluid communication with one another. A pressurized gas system and a rail vehicle are also included.

A spring-type brake actuator for a vehicle brake such as a pneumatically-actuated brake is provided, in which the actuator's operating rod is pulled toward the actuator to apply the brake. The actuator's parking brake release piston is located closer to the brake than the service brake piston, and the parking brake power spring is positioned between the mounting end of the actuator and the parking brake piston such that when parking brake release pressure is removed from the parking brake release chamber the parking brake piston biases the operating rod in the brake application direction, drawing the operating rod further into the actuator. The operating rod may penetrate the parking brake piston and an intermediate flange between the parking brake piston and the service brake piston, and be connected to the service brake piston such that the service brake piston may control brake application when the parking brake piston is in its parking brake release position adjacent to the end of the actuator that is mounted to the brake.

A spring-type brake actuator for a vehicle brake such as a pneumatically-actuated brake is provided, in which the actuator's operating rod is pulled toward the actuator to apply the brake. The actuator's parking brake release piston is located closer to the brake than the service brake piston, and the parking brake power spring is positioned between the mounting end of the actuator and the parking brake piston such that when parking brake release pressure is removed from the parking brake release chamber the parking brake piston biases the operating rod in the brake application direction, drawing the operating rod further into the actuator. The operating rod may penetrate the parking brake piston and an intermediate flange between the parking brake piston and the service brake piston, and be connected to the service brake piston such that the service brake piston may control brake application when the parking brake piston is in its parking brake release position adjacent to the end of the actuator that is mounted to the brake.

A spring brake actuator for braking a wheel of a vehicle includes a housing defining a chamber, a push rod extending from the chamber such that pneumatic activation of the spring brake actuator causes the push rod to further extend out of the chamber to thereby activate braking of the wheel of the vehicle and such that pneumatic deactivation of the spring brake actuator causes the push rod to retract back into the chamber to thereby deactivate braking of the wheel of the vehicle, and a sensor assembly located in the chamber such that the housing limits movement of the sensor assembly in the chamber.