A spring brake system includes a service brake chamber, a spring brake chamber adjacent to the service brake chamber, a wall separating the service brake chamber from the spring brake chamber, a shaft, and a device. The shaft extends from the service brake chamber into the spring brake chamber through an opening in the wall. The device is disposed along the shaft through the wall, the device being configured to: i) allow air to flow from the service chamber into the spring brake chamber, and ii) prevent air from flowing from the spring brake chamber into the service chamber. The air is within a range that is sufficient to reduce a pressure differential between the service brake chamber and the spring brake chamber. The air is also within a range that is sufficient to generate an anti-compounding effect.

The present disclosure relates to an engagement structure of a push rod guide and a push rod guide cover of a brake chamber for a vehicle, in which a pair of semi-circular, hingedly connected, half members in a shape of a plate are assembled at a side surface of axial direction of the push rod into a shape of a disk, a push rod opening is formed at the center of the disk to guide a movement of the push rod, a protrusion projecting upwards is provided at a central part of the push rod guide, forming a step in a radial direction of the push rod guide, and a receiving groove corresponding to the step is formed on an inner circumferential surface of the push rod guide cover and is connected to the step.

A spring brake actuator (2) for use in a commercial vehicle includes a cylinder housing (4) including a spring brake piston (10) for applying a braking force, a spring guide (12) attached to the spring brake piston (10). The spring guide (12) includes a valve (14) and a retaining device (16) for retaining the valve (14). The retaining device (16) includes a basic body (34) and clamping portions (36) for clamping the retaining device (16) to the spring guide (12). The clamping portions (36) are arranged at the basic body (34) along a circumference (38) thereof, and the clamping portions (36) are spaced apart from each other forming slits (40) between the clamping portions (36) to allow for a circulation of air through the slits (40).

A brake release mechanism for a spring brake actuator includes a brake release bolt having a threaded portion, a running engaging the threaded portion, the running nut being adapted to axially travel along the threaded portion in order to move a spring brake actuator piston against a force of an actuator power spring, an indicator device comprising an indicator pin being at least partially accommodated in a receiving space of the release bolt, wherein the indicator device further comprises a pin actuator for axially moving the pin relative to the receiving space. It is proposed according to the invention that the pin actuator comprises an indicator cap being attached to the pin, the indicator cap comprising a basic body and at least one spacing element being attached to the basic body, the spacing element being configured to abut against the running nut.

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 T-shaped ballast coupled to the frame, and oriented such that the weight of the ballast is biased toward the front end of 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, pivotable from a deployed state to an undeployed state; an impact attenuator coupled to the rear of the frame; wherein the vehicle is provided with a brake system, and wherein said brake system may be locked and unlocked and wherein the vehicle is provided with an on-board mechanism for locking and unlocking the brake system.

A spring brake actuator has a service brake with a service brake housing and a service brake working chamber located in the service brake housing. The service brake working chamber is confined by a diaphragm. A service brake piston movable along an actuator-longitudinal axis and abuts the diaphragm, which applies a brake force onto the service brake piston. A spring between the service brake piston and the service brake housing pushes the service brake piston against the direction of the brake force. A modulator valve unit communicates with the service brake working chamber and is configured to regulate the inlet and outlet of fluid into and out of the service brake working chamber. The modulator valve unit is integrated into the spring brake actuator and includes a controllable inlet valve communicating with the service brake working chamber and a controllable outlet valve communicating with the service brake working chamber.

An electromechanical brake apparatus includes a housing supporting an inboard brake pad and an oppositely facing outboard brake pad for selective frictional contact with a rotor interposed longitudinally therebetween. An adjuster ramp assembly indirectly receives torque from the motor unit. A spindle is provided for selectively moving the inboard brake pad longitudinally. The spindle is operatively connected with the adjuster ramp assembly to indirectly receive torque from the motor unit therethrough. A leading ramp assembly is configured to transmit applied torque from the motor unit to the adjuster ramp assembly via at least one ramp ball longitudinally interposed therebetween. A predetermined amount and direction of torque is applied to each of the adjuster ramp assembly and the leading ramp assembly to assist with a selected one of (1) service brake application and (2) service brake release functions. The electromechanical brake apparatus is operative, at different times, for both functions.

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 spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

Systems and methods allow for controlling brakes of a trailer coupled to a tractor. The systems and methods utilize an inversion valve input between an emergency brake controller and a trailer connection at the tractor. The inversion valve receives a supply air from an output of the emergency brake controller, and a control air output from a treadle valve of the tractor. Depending on the control air, the emergency brakes at the tractor may be released/activated to simulate service brake control without requiring connecting the tractor to the trailer service brake line.