A towable crash-attenuating vehicle is shown having a frame; at least two axles coupled to the frame, each of the axles having wheels attached thereto; a ballast coupled to the frame; deflection shields coupled to the right and left sides of the frame, wherein the deflection shields cover the frame and a majority of the wheels on each side of the vehicle; a tow connection coupled to the front of the frame; an impact attenuator coupled to the rear of the frame; wherein the vehicle is provided with a brake system, and wherein the vehicle is provided with an mechanism for locking and unlocking the brake system.

A towable crash-attenuating vehicle is shown having a frame; at least two axles coupled to the frame, each of the axles having wheels attached thereto; a ballast coupled to the frame; deflection shields coupled to the right and left sides of the frame, wherein the deflection shields cover the frame and a majority of the wheels on each side of the vehicle; a tow connection coupled to the front of the frame; an impact attenuator coupled to the rear of the frame; wherein the vehicle is provided with a brake system, and wherein the vehicle is provided with an mechanism for locking and unlocking the brake system.

A brake master cylinder arrangement includes a housing with a cylindrical recess, a pressure piston moveable in the cylindrical recess along a longitudinal axis and guided in a sealing manner, and a reservoir for storing brake fluid that is fluidically connected via a fluid channel to the housing. The pressure piston and the housing enclose a pressure chamber that is connected to a fluid circuit of the brake system. Depending on the position of the associated pressure piston, the pressure chamber is either fluidically connected to the fluid reservoir or disconnected therefrom. In a region that axially spans the sealing arrangement in a starting position of the pressure piston, the outer circumferential surface of the pressure piston has profiling that provides a fluidic connection between the fluid reservoir and the pressure chamber.

A brake master cylinder arrangement includes a housing with a cylindrical recess, a pressure piston moveable in the cylindrical recess along a longitudinal axis and guided in a sealing manner, and a reservoir for storing brake fluid that is fluidically connected via a fluid channel to the housing. The pressure piston and the housing enclose a pressure chamber that is connected to a fluid circuit of the brake system. Depending on the position of the associated pressure piston, the pressure chamber is either fluidically connected to the fluid reservoir or disconnected therefrom. In a region that axially spans the sealing arrangement in a starting position of the pressure piston, the outer circumferential surface of the pressure piston has profiling that provides a fluidic connection between the fluid reservoir and the pressure chamber.

A hydraulic system includes a motor. A brake is to be actuated by an operation fluid to brake the motor when a hydraulic pressure is relieved and to release the braking when the hydraulic pressure is applied. A switch valve is to be switched to a first position and to a second position, the first position being provided for relieving the hydraulic pressure from the brake, the second position being provided for applying the hydraulic pressure to the brake. A first fluid tube is to connect the switch valve and the brake. A second fluid tube is connected to the first fluid tube at a connecting portion and communicated with a tank A first throttle is disposed on the second fluid tube. A second throttle is disposed on the first fluid tube and on an upstream side between the connecting portion and the switch valve.

A hydraulic system includes a motor. A brake is to be actuated by an operation fluid to brake the motor when a hydraulic pressure is relieved and to release the braking when the hydraulic pressure is applied. A switch valve is to be switched to a first position and to a second position, the first position being provided for relieving the hydraulic pressure from the brake, the second position being provided for applying the hydraulic pressure to the brake. A first fluid tube is to connect the switch valve and the brake. A second fluid tube is connected to the first fluid tube at a connecting portion and communicated with a tank A first throttle is disposed on the second fluid tube. A second throttle is disposed on the first fluid tube and on an upstream side between the connecting portion and the switch valve.

A system for controlling a brake of a unit hauled by a work vehicle may generally include a valve assembly. When a speed of the work vehicle exceeds a predetermined speed threshold, the valve assembly may be configured to allow the brake to be actuated when first and second brake pedals of the work vehicle are depressed, either individually or simultaneously. However, when the speed of the work vehicle is less than the predetermined speed threshold, the valve assembly may only be configured to allow the brake to be actuated when both of the first and second brake pedals are depressed simultaneously.

A system for controlling a brake of a unit hauled by a work vehicle may generally include a valve assembly. When a speed of the work vehicle exceeds a predetermined speed threshold, the valve assembly may be configured to allow the brake to be actuated when first and second brake pedals of the work vehicle are depressed, either individually or simultaneously. However, when the speed of the work vehicle is less than the predetermined speed threshold, the valve assembly may only be configured to allow the brake to be actuated when both of the first and second brake pedals are depressed simultaneously.

Disclosed is a master cylinder for a brake system. The master cylinder includes a cylinder body that has a bore therein; at least one piston provided in the bore to be moved forwards and rearwards; a liquid pressure chamber compressed by the piston; a brake liquid port that is connected to a reservoir and configured to supply brake liquid to the liquid pressure chamber; and a brake liquid discharge opening for discharging the brake liquid in the liquid pressure chamber to a wheel brake of a wheel. A valve unit that includes a check valve to control the unidirectional flow of the brake liquid that is introduced from the reservoir to the liquid chamber and a fluid resistance hole opened in two directions and is smaller than the size of the brake liquid discharge opening is provided in the brake liquid port.

Disclosed is a master cylinder for a brake system. The master cylinder includes a cylinder body that has a bore therein; at least one piston provided in the bore to be moved forwards and rearwards; a liquid pressure chamber compressed by the piston; a brake liquid port that is connected to a reservoir and configured to supply brake liquid to the liquid pressure chamber; and a brake liquid discharge opening for discharging the brake liquid in the liquid pressure chamber to a wheel brake of a wheel. A valve unit that includes a check valve to control the unidirectional flow of the brake liquid that is introduced from the reservoir to the liquid chamber and a fluid resistance hole opened in two directions and is smaller than the size of the brake liquid discharge opening is provided in the brake liquid port.