Abstract:
Hydraulic braking system with slip control, comprises a working piston guided within the brake pressure generator, a booster piston of a hydraulic brake force booster for actuating the working piston, at least one wheel brake connected to the brake pressure generator and an electrically operable auxiliary pressure source adapted to be connected to the brake force booster, a control and regulating electronic unit for detecting the wheel rotating pattern and for controlling the wheel brake pressure by means of pressure modulating valves, and an electronic sensor means for detecting the relative movement between the push rod and the booster piston, the output signals of which sensor means are capable of influencing the operation of the auxiliary pressure source, wherein the auxiliary pressure source includes a quick-fill piston which is guided within a servo cylinder arranged on a servo drive.
Abstract:
A braking system includes a brake actuator which is moveable by pressurised hydraulic fluid fed to the actuator along a transmission line, in a first direction, to move a brake applying member to apply a braking force to a member to be braked, a master valve including an operating piston which upon operation of a brake operating member, moves in an operating cylinder, to direct the hydraulic fluid under pressure to the transmission line to apply the brake, the system further including a charging valve, the charging valve being operable when activated, to deliver a predetermined volume of pressurised hydraulic fluid to the master valve to move the brake applying member in the first direction towards the member to be braked to reduce the clearance between them, and the operating piston, when the charging valve is deactivated, being moveable in the operating cylinder to allow hydraulic fluid to pass from the transmission line thus to permit the brake actuator to move in a second direction opposite to the first direction to increase the running clearance between the brake applying member and the member to be braked.
Abstract:
A braking system includes a brake actuator which is moveable in a first direction to cause a brake applying member to apply a braking force to a member to be braked. A master valve includes a piston assembly which upon operation of a brake operating member, directs the hydraulic fluid under pressure to the brake actuator to apply the brake. A charging valve is operable in first and second states. The master valve piston assembly includes a pair of coupled pistons separated by a chamber. In a first state, the charging valve connects a source of pressurized hydraulic fluid to the master valve chamber to move the pistons apart, directing a volume of hydraulic fluid to the brake actuator. In a second state, the charging valve connects the chamber to a lower pressure area to allow the pair of pistons to be moved towards one another by a restoring force.
Abstract:
An apparatus engageable with a railway vehicle truck-mounted braking system for compensating for truck bolster movement which includes at least one force transmitting wedge member movable in a reciprocating motion by a pneumatic actuator. The at least one force transmitting wedge member engage rollers rotateably attached to a return push rod member disposed within the truck-mounted braking system for extending the return push rod member to reduce brake shoe clearance prior to brake shoe application. A method for compensating for truck bolster movement also includes fully pressurizing a wedge actuator prior to pressurizing the main brake apparatus actuator. Depressurization of the system returns the force transmitting wedges and return push rod to their original positions upon completion of brake application, subsequently increasing brake shoe clearance for allowable truck bolster movement.
Abstract:
An apparatus engageable with a railway vehicle truck-mounted braking system for compensating for truck bolster movement which includes at least one force transmitting wedge member movable in a reciprocating motion by a pneumatic actuator. The at least one force transmitting wedge member engage rollers rotateably attached to a return push rod member disposed within the truck-mounted braking system for extending the return push rod member to reduce brake shoe clearance prior to brake shoe application. A method for compensating for truck bolster movement also includes fully pressurizing a wedge actuator prior to pressurizing the main brake apparatus actuator. Depressurization of the system returns the force transmitting wedges and return push rod to their original positions upon completion of brake application, subsequently increasing brake shoe clearance for allowable truck bolster movement.
Abstract:
Hydraulic Brake System with a Device for Active Braking In order to enable a hydraulic brake system which has a self-priming return pump (14) to quickly fill the wheel brakes (5) in an active braking operation, the present invention discloses the provision of a pressure-volume converter (20) on the pressure side of the return pump (14). The converter (20) causes a large pressure fluid volume to be conducted into the brake line (4) to the wheel brake (5) concerned at a small delivery volume of the return pump (14). This is possible because a return pump can generate high pressure and, thus, produce a sufficient amount of force to displace a stepped piston which can then displace a large quantity of pressure fluid. To permit the development of a sufficient back pressure on the pressure side of the return pump (14), a pilot pressure non-return valve (19) is arranged in the pressure line (18) which extends in parallel to the pressure-volume converter (20). Valve (19) permits the passage of the delivered pressure fluid volume to the brake line (4) only when a pilot pressure prevails.
Abstract:
A braking system includes a brake actuator which is moveable by pressurised hydraulic fluid fed to the actuator along a transmission line, in a first direction, to move a brake applying member to apply a braking force to a member to be braked, a master valve including an operating piston which upon operation of a brake operating member, moves in an operating cylinder, to direct the hydraulic fluid under pressure to the transmission line to apply the brake, the system further including a charging valve, the charging valve being operable when activated, to deliver a predetermined volume of pressurised hydraulic fluid to the master valve to move the brake applying member in the first direction towards the member to be braked to reduce the clearance between them, and the operating piston, when the charging valve is deactivated, being moveable in the operating cylinder to allow hydraulic fluid to pass from the transmission line thus to permit the brake actuator to move in a second direction opposite to the first direction to increase the running clearance between the brake applying member and the member to be braked.