A brake device for braking a wheel includes a brake drum, a brake pad carrier which is arranged or can be arranged in the brake drum and has at least one brake pad, and an actuator apparatus for the reversible transfer of the brake pad carrier between a braking state, in which the brake pad is operatively connected to the brake drum, and a freewheeling state, in which the operative connection between the brake pad and the brake drum is canceled, the brake pad carrier being elastically deformable for the transfer from the freewheeling state into the braking state.

A two stage brake actuation system including a push rod, a first actuator coupled to the push rod, and a second actuator. The first actuator may apply a first force to the push rod to move it between a brake clearance position and a brake adjacent position. The second actuator may apply a second force to the push rod to move it between the brake adjacent position and a brake applied position. The first actuator may be a large displacement, low force actuator, and the second actuator may be a small displacement, high force actuator. A method for braking a vehicle by applying a first force to a push rod to move it a first distance from a brake clearance to a brake adjacent position, and applying a second force to the push rod to move it a second distance from the brake adjacent to a brake applied position.

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.

To test a vehicle power braking system, a piston of a power brake pressure generator is displaced twice for a pressure build-up and in between back preferably by a longer distance. Extension of the piston travel during the second displacement is an indication of air in a cylinder of the power brake pressure generator due to an excessively low brake fluid level in a brake fluid reservoir.

To test a vehicle power braking system, a piston of a power brake pressure generator is displaced twice for a pressure build-up and in between back preferably by a longer distance. Extension of the piston travel during the second displacement is an indication of air in a cylinder of the power brake pressure generator due to an excessively low brake fluid level in a brake fluid reservoir.

A parking brake system is disclosed and includes a parking brake valve configured to maintain a fluid pressure of the parking brake system and one or more pressure transducers that monitor the fluid pressure of the parking brake system. The parking brake system also includes a bistable control valve fluidly connected to the parking brake valve, one or more processors in electronic communication with the bistable control valve, the parking brake valve, and the one or more pressure transducers, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the parking brake system to instruct the bistable control valve to actuate into the opened position when the fluid pressure of the parking brake system is less than a threshold pressure.

A parking brake system is disclosed and includes a parking brake valve configured to maintain a fluid pressure of the parking brake system and one or more pressure transducers that monitor the fluid pressure of the parking brake system. The parking brake system also includes a bistable control valve fluidly connected to the parking brake valve, one or more processors in electronic communication with the bistable control valve, the parking brake valve, and the one or more pressure transducers, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the parking brake system to instruct the bistable control valve to actuate into the opened position when the fluid pressure of the parking brake system is less than a threshold pressure.

A brake device for a vehicle includes a housing unit, a cylinder unit installed inside the housing unit, a motor unit connected to the cylinder unit and provides a rotational force, a screw shaft provided inside the cylinder unit and axially rotated by receiving the rotational force of the motor unit, a nut unit coupled to the screw shaft through a ball member and reciprocated in an axial direction of the screw shaft according to a rotation direction of the screw shaft, a piston unit coupled to the nut unit and moving in conjunction with the nut unit, and a bearing unit provided inside the cylinder unit, coupled to the screw shaft, and supporting an axial load when forming hydraulic pressure of the cylinder unit.

A parking brake system is disclosed and includes a parking brake valve configured to maintain a fluid pressure of the parking brake system and one or more pressure transducers that monitor the fluid pressure of the parking brake system. The parking brake system also includes a bistable control valve fluidly connected to the parking brake valve, one or more processors in electronic communication with the bistable control valve, the parking brake valve, and the one or more pressure transducers, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the parking brake system to instruct the bistable control valve to actuate into the opened position when the fluid pressure of the parking brake system is less than a threshold pressure.

A parking brake system is disclosed and includes a parking brake valve configured to maintain a fluid pressure of the parking brake system and one or more pressure transducers that monitor the fluid pressure of the parking brake system. The parking brake system also includes a bistable control valve fluidly connected to the parking brake valve, one or more processors in electronic communication with the bistable control valve, the parking brake valve, and the one or more pressure transducers, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the parking brake system to instruct the bistable control valve to actuate into the opened position when the fluid pressure of the parking brake system is less than a threshold pressure.