A control valve (12) for applying a spring-loaded brake pressure (p3b) to spring-loaded parts of a rear-axle wheel brake is provided. The control valve (12) is activatable pneumatically via a second control input (12b) with a parking-brake control pressure (p5). The parking-brake control pressure (p5) can act in such a manner on a control mechanism (14b, 15b, 17c, 22, 23, 24) arranged in a valve housing (12f) of the control valve (12) that a spring-loaded brake pressure (p3b) arises at a control output (12c) of the control valve (12) as a function of the parking-brake control pressure (p5) for bringing about a parking-brake braking specification with the spring-loaded parts of the rear-axle wheel brakes. The control valve (12) has a first control connection (12a) connectable to an adjustable first control chamber (14a), which is operatively connected to the control mechanism (14b, 15b, 17c, 22, 23, 24).

A control valve (12) for applying a spring-loaded brake pressure (p3b) to spring-loaded parts of a rear-axle wheel brake is provided. The control valve (12) is activatable pneumatically via a second control input (12b) with a parking-brake control pressure (p5). The parking-brake control pressure (p5) can act in such a manner on a control mechanism (14b, 15b, 17c, 22, 23, 24) arranged in a valve housing (12f) of the control valve (12) that a spring-loaded brake pressure (p3b) arises at a control output (12c) of the control valve (12) as a function of the parking-brake control pressure (p5) for bringing about a parking-brake braking specification with the spring-loaded parts of the rear-axle wheel brakes. The control valve (12) has a first control connection (12a) connectable to an adjustable first control chamber (14a), which is operatively connected to the control mechanism (14b, 15b, 17c, 22, 23, 24).

A valve-arrangement is operable to switch between a bistable-valve (BV) behavior and a relay-valve (RV) behavior to control a parking-brake, and includes a housing with a supply-pressure-inlet (SPI), a service brake-control-inlet (SBCI) to provide a control-pressure, a pressure-outlet, and an exhaust-port, and includes a first-piston and a second-piston both movable along a same direction in the housing to define a first-chamber communicating with the SBCI, a second-chamber between the first-piston and the second-piston, and third chamber communicating with the pressure-outlet and with a controllable connection to the SPI, in which upon the control-pressure the second-piston moves with the first-piston to connect the pressure-outlet with the exhaust-port or with the SPI. The valve arrangement includes a throttle unit adapted, depending on the control-pressure, to connect the second-chamber with the third-chamber to enable the BV behavior or disconnect the second-chamber from the third-chamber to enable the RV behavior.

A valve-arrangement is operable to switch between a bistable-valve (BV) behavior and a relay-valve (RV) behavior to control a parking-brake, and includes a housing with a supply-pressure-inlet (SPI), a service brake-control-inlet (SBCI) to provide a control-pressure, a pressure-outlet, and an exhaust-port, and includes a first-piston and a second-piston both movable along a same direction in the housing to define a first-chamber communicating with the SBCI, a second-chamber between the first-piston and the second-piston, and third chamber communicating with the pressure-outlet and with a controllable connection to the SPI, in which upon the control-pressure the second-piston moves with the first-piston to connect the pressure-outlet with the exhaust-port or with the SPI. The valve arrangement includes a throttle unit adapted, depending on the control-pressure, to connect the second-chamber with the third-chamber to enable the BV behavior or disconnect the second-chamber from the third-chamber to enable the RV behavior.

A hydraulic arrangement for connecting a tractor hydraulic brake circuit to a trailer hydraulic brake circuit is disclosed. The hydraulic arrangement includes a coupler stage fluidly connecting a source of fluid in pressure to the trailer braking hydraulic circuit and a trailer brake valve fluidly connecting the tractor hydraulic brake circuit and the trailer hydraulic brake circuit. The hydraulic arrangement further includes a selection pilot stage fluidly connected to the source of fluid in pressure and being fluidly connectable to the trailer hydraulic brake circuit via at least a connector and a selection stage fluidly connected to the selection pilot stage and to the trailer brake valve. The selection stage being configured to impart an actuation signal to the trailer brake valve in function of an hydraulic signal coming from the selection pilot stage.

A control valve (12) for applying a spring-loaded brake pressure (p3b) to spring-loaded parts of a rear-axle wheel brake is provided. The control valve (12) is activatable pneumatically via a second control input (12b) with a parking-brake control pressure (p5). The parking-brake control pressure (p5) can act in such a manner on a control mechanism (14b, 15b, 17c, 22, 23, 24) arranged in a valve housing (12f) of the control valve (12) that a spring-loaded brake pressure (p3b) arises at a control output (12c) of the control valve (12) as a function of the parking-brake control pressure (p5) for bringing about a parking-brake braking specification with the spring-loaded parts of the rear-axle wheel brakes. The control valve (12) has a first control connection (12a) connectable to an adjustable first control chamber (14a), which is operatively connected to the control mechanism (14b, 15b, 17c, 22, 23, 24).

A control valve (12) for applying a spring-loaded brake pressure (p3b) to spring-loaded parts of a rear-axle wheel brake is provided. The control valve (12) is activatable pneumatically via a second control input (12b) with a parking-brake control pressure (p5). The parking-brake control pressure (p5) can act in such a manner on a control mechanism (14b, 15b, 17c, 22, 23, 24) arranged in a valve housing (12f) of the control valve (12) that a spring-loaded brake pressure (p3b) arises at a control output (12c) of the control valve (12) as a function of the parking-brake control pressure (p5) for bringing about a parking-brake braking specification with the spring-loaded parts of the rear-axle wheel brakes. The control valve (12) has a first control connection (12a) connectable to an adjustable first control chamber (14a), which is operatively connected to the control mechanism (14b, 15b, 17c, 22, 23, 24).

A hydraulic valve assembly for a work vehicle includes a fan and brake function module. A first pump supplies hydraulic pressure to a fan circuit and to first and second service brake circuits of the vehicle. A second pump supplies hydraulic pressure to a steering and work function module that in turn supplies hydraulic pressure to a steering circuit and a work function circuit of the vehicle. The hydraulic valve assembly may also include a work control module and an auxiliary module. The modules of the hydraulic valve assembly are separably connected together via interface surfaces.

A valve system includes an isolation check valve delivering pneumatic fluid as a supply pressure, a double-check valve adapted to deliver a braking demand control signal of the pneumatic fluid based on a higher of a first braking demand in a first pneumatic braking circuit and a second braking demand in a second pneumatic braking circuit, and a control module. The control module is adapted to receive the supply pressure as a control module supply pressure of the pneumatic fluid, receive a control module control pressure of the pneumatic fluid based on the braking demand control signal, and deliver a control module delivery pressure of the pneumatic fluid based on the control module supply pressure and the control module control pressure. A park control module selectively transmits the pneumatic fluid at the supply pressure based on a park brake control signal.

A brake retarder valve for a tractor-trailer combination includes a valve housing and a valve assembly. The valve assembly includes a poppet valve biased by a spring and a gravity spool. The valve assembly is selectively operable between the operative closed configuration and an open configuration in response to a resultant of the fluid pressure between a trailer axle brake and a tractor axle brake. The tractor axle brake is actuated with a time delay from actuation of the trailer axle brake. This delay is actuation of the tractor axle brake prevents jack knifing of the trailer onto the tractor in a tractor-trailer combination, thereby ensuring safety during operation of a tractor-trailer combination.