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.

A brake actuator has a plurality of actuator housing portions, a parking piston axially displaceable within one of the actuator housing portions, and a service piston axially displaceable independently of the parking piston within another of the actuator housing portions. A brake actuator rod projecting from the other of the actuator housing portions moves outward of that actuator housing portion upon at least one of fluid supply to a first substantially torus-shaped service brake bladder and fluid relief from a second substantially torus-shaped parking brake bladder. The brake actuator rod can be moved inward into the other of the actuator housing portions upon fluid relief from the first substantially torus-shaped service brake bladder, and fluid supply to the second substantially torus-shaped parking brake bladder or both.

A spring brake actuator is for braking a wheel of a vehicle and has a push rod assembly having a base located in a service brake chamber and a push rod extending from a service brake chamber. Pneumatic activation of the spring brake actuator causes the push rod to further extend out of the service brake chamber to thereby engage a wheel brake with a wheel of the vehicle. Pneumatic deactivation of the spring brake actuator causes the push rod to retract back into the service brake chamber to thereby disengage the wheel brake from the wheel of the vehicle. The push rod extends between a first end portion that is fixed to the base and an opposite, second end portion that is removably coupled to the first end portion so that the second end portion is manually attachable and detachable from the push rod assembly.

A brake actuator for a railway vehicle brake system has a thrust sleeve configured to provide braking force to the brake system, and a slide axially moveable in the thrust sleeve between a release position and a locking position. The actuator further has a piston biased by spring means and linked to an anchoring member. A plurality of balls are disposed in respective openings of the sleeve between the slide and the anchoring member. In the locking position, the balls are configured to move under the action of a profiled surface of the slide to axially couple the anchoring member with the sleeve. In the release position, the balls are configured to axially uncouple the anchoring member from the sleeve. The profiled slide surface has a locking groove configured to engagingly receive the balls when the slide is in the locking position.

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.

Disclosed is a railway braking system including a first pneumatic distribution device formed by a first distributor provided with a single inlet opening connected to a source for supplying pneumatic pressure mediums and with a single outlet opening connected to a parking brake chamber in order to optionally supply a parking brake with a second pneumatic pressure medium so as to place the brake in either of inoperative and operative configurations, and a second pneumatic distribution device formed by a second distributor provided with a single inlet opening connected to the supply source and with a single outlet opening connected to a service pressure chamber in order to supply a service brake with a third pneumatic pressure medium of which the pressure value is predetermined, so as to apply a predetermined braking force when the parking brake is in the operative configuration thereof.

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 brake actuator for a railway vehicle brake system has a thrust sleeve configured to provide braking force to the brake system, and a slide axially moveable in the thrust sleeve between a release position and a locking position. The actuator further has a piston biased by spring means and linked to an anchoring member. A plurality of balls are disposed in respective openings of the sleeve between the slide and the anchoring member. In the locking position, the balls are configured to move under the action of a profiled surface of the slide to axially couple the anchoring member with the sleeve. In the release position, the balls are configured to axially uncouple the anchoring member from the sleeve. The profiled slide surface has a locking groove configured to engagingly receive the balls when the slide is in the locking position.

A spring brake chamber for pneumatic braking systems used in heavy commercial vehicles such as buses, trucks, trailers and tractors, includes a power spring configured to detect the parking position, the driving position and the situation in which the power spring is broken. The present invention allows the driver to be notified by sending a signal.

Disclosed is a rail braking system including a detection and storage device designed to receive first information representing the position of a device for locking a service brake piston, to receive second information representing the supply of a service brake pressure chamber with a pneumatic pressure agent, to deduce information representing the application of a parking brake from the first and second information, and to store the deduced information; as a result of which the information representing the application of the parking brake is kept even if the service brake pressure chamber is no longer supplied with the pneumatic pressure agent.