Abstract: An air braking unit for use in an air braking system. The air braking unit is arranged to be positioned, in use, at a vehicle wheel, and comprises an inlet for receiving, in use, compressed air from a central source. At least one first valve is arranged to selectively allow compressed air from the inlet to enter a wheel brake chamber in use. At least one second valve is arranged to selectively allow air from the brake chamber to be released via an outlet to the atmosphere in use and control means controls the first and second valves to operate to selectively control the air pressure in the brake chamber in use.

Abstract: An electromagnetic valve comprises a yoke, a magnet having pole pieces defining a gap, a flexure assembly having one end attached to the yoke such that part of the flexure assembly extends into the gap, and a mechanism configured to polarize the magnetizable portion so that the extending part of the flexure assembly is attracted towards a pole piece by a magnetic force, thereby defining a valve state. The flexure assembly has at least one resilient portion and at least one magnetizable portion, wherein the extending part of the flexure assembly is movable between the pole pieces through an intermediate position towards which it is resiliently biased such that a resilient mechanical force is generated by deflecting the resilient portion from an undeflected position. The magnetizable portion and the resilient portion are configured such that the magnetic force defining the valve state is greater than the resilient mechanical force.

Abstract: An electromagnetic valve comprises a yoke, a magnet having pole pieces defining a gap, a flexure assembly having one end attached to the yoke such that part of the flexure assembly extends into the gap, and a mechanism configured to polarize the magnetizable portion so that the extending part of the flexure assembly is attracted towards a pole piece by a magnetic force, thereby defining a valve state. The flexure assembly has at least one resilient portion and at least one magnetizable portion, wherein the extending part of the flexure assembly is movable between the pole pieces through an intermediate position towards which it is resiliently biased such that a resilient mechanical force is generated by deflecting the resilient portion from an undeflected position. The magnetizable portion and the resilient portion are configured such that the magnetic force defining the valve state is greater than the resilient mechanical force.

Abstract: An apparatus for controlling the stability of a vehicle including a controller which is adapted to detect when conditions exist under which vehicle rollover is likely and, when such conditions exist, to trigger an alarm signal or initiate a control intervention by means of which the vehicle travel is controlled to reduce the likelihood of vehicle rollover, wherein the apparatus further includes an accelerometer, the accelerometer being configured to measure the acceleration of the vehicle along two non-parallel axes.

Abstract: An electromagnetic valve comprises a yoke, a magnet having pole pieces defining a gap, a flexure assembly having one end attached to the yoke such that part of the flexure assembly extends into the gap, and a mechanism configured to polarize the magnetizable portion so that the extending part of the flexure assembly is attracted towards a pole piece by a magnetic force, thereby defining a valve state. The flexure assembly has at least one resilient portion and at least one magnetizable portion, wherein the extending part of the flexure assembly is movable between the pole pieces through an intermediate position towards which it is resiliently biased such that a resilient mechanical force is generated by deflecting the resilient portion from an undeflected position. The magnetizable portion and the resilient portion are configured such that the magnetic force defining the valve state is greater than the resilient mechanical force.

Abstract: A method of controlling travel of a vehicle equipped with an antilock braking system, including the steps of determining potential for one or more wheels to lift off the ground, deactivating the system in respect of the wheels with the lift off potential so the speed of these wheels is not taken into consideration when determining if anti-lock braking is required, applying a low-level test braking force to one or more of the wheels that has the lift off potential, monitoring the speed of the one or more wheels, and if the test braking force causes the wheel speed to fall below a predetermined percentage of the vehicle speed, triggering a stability alarm signal and/or applying a controlled braking force to reduce the vehicle speed.

Abstract: A valve comprising an inlet port, an outlet port, an exhaust port and a diaphragm disposed between the inlet and exhaust ports which is moveable, in response to air pressure within the valve, between a first position in which it seals the exhaust port and a second position in which the exhaust port is open, there being one or more projections associated with the exhaust port on which the diaphragm is able to rest in its first position.

Abstract: A braking system including a brake, a brake actuator which is operable to apply a force to the brake to effect braking, an automatic braking controller, and a manually operable brake actuator control device, the brake actuator control device including a manually operable control part which is movable between a release position and an apply position and which is adapted such that movement of the control part by a user from the release position to the apply position causes the brake actuator to apply the brake and movement of the control part by a user from the apply position to the release position causes the brake actuator to release the brake, the brake actuator control device being characterized in that it further includes a control actuator which engages with the control part and which is adapted to effect movement of the control part from the release position to the apply position on receipt of an appropriate signal from the automatic braking controller.

Abstract: A vehicle brake system comprising an actuator and a mechanical linkage, whereby a force produced by the weight of the vehicle is transmitted via the mechanical linkage to the actuator to provide a braking force.

Abstract: A control system for electronically controlled vehicle dynamics control systems and ride control systems includes a system ECU and a diagnostics ECU, each having a memory with vehicle parameters stored thereon. When one of the system ECU and the diagnostics ECU is replaced, the other one communicates via a communications link the vehicle parameters stored in the memory thereof to the replaced one of the system ECU and the diagnostics ECU. The vehicle parameters stored on at least one of the system ECU and the diagnostics ECU are user modifiable, and when the vehicle parameters stored on one of the system ECU and the diagnostics ECU are modified by a user, the one of the system ECU and the diagnostics ECU on which the vehicle parameters were modified communicates via the communications link the modified vehicle parameters to the other one.

Abstract: A brake actuator including a chamber in which is provided a movable pressure responsive element which divides the chamber into first and second compartments, the brake actuator also including a valve assembly with an inlet which is connected to a source of pressurised fluid, an outlet which is connected to a volume within the brake actuator not including the second compartment, and an exhaust port through which fluid from the volume may be released, wherein the exhaust port of the valve assembly is connected to the second compartment.

Abstract: A valve assembly comprising a valve body, a first movable pressure responsive element, and a second pressure responsive movable element, wherein the valve assembly further comprises a resilient biasing element and a movable third pressure responsive element, the resilient biasing element extending between the third pressure responsive element and the valve body and the third pressure responsive element being adapted to act on both the first and second pressure responsive elements to transmit the biasing force of the resilient biasing element to both the first and second pressure responsive elements.

Abstract: An electrical control network is laid over one or more vehicle dynamics control and/or ride control systems of a heavy vehicle, which control network controls actuation of components thereof. The invention offers many advantages including reduction of components, simplified design, unified communication for numerous different types of system components, simplified resolution of conflicts between competing control strategies, expandability to additional vehicle systems, and flexibility to upgrade for new, improved vehicle control schemes.

Abstract: An electrical control network is laid over one or more vehicle dynamics control and/or ride control systems of a heavy vehicle, which control network controls actuation of components thereof. The invention offers many advantages including reduction of components, simplified design, unified communication for numerous different types of system components, simplified resolution of conflicts between competing control strategies, expandability to additional vehicle systems, and flexibility to upgrade for new, improved vehicle control schemes.

Abstract: An electrical control network is laid over one or more vehicle dynamics control and/or ride control systems of a heavy vehicle, which control network controls actuation of components thereof. The invention offers many advantages including reduction of components, simplified design, unified communication for numerous different types of system components, simplified resolution of conflicts between competing control strategies, expandability to additional vehicle systems, and flexibility to upgrade for new, improved vehicle control schemes.

Abstract: A control system for a vehicle includes a first electronically controlled vehicle system, a second electronically controlled vehicle system, and a control unit. The control unit controls operation of at least one component of the first electronically controlled vehicle system while the vehicle is moving and preferably also while the vehicle is stationary, and controls operation of at least one component of the second electronically controlled vehicle system only while the vehicle is stationary.

Abstract: A valve assembly having a fluid switch and a main valve for controlling fluid pressure in a working volume in three control states wherein the main valve has three ports for fluid, flow of fluid through a first port and a second port being controlled by the fluid switch being provided with an electrical signal in a first state or a second state respectively, and flow of fluid through the third port being controlled by alternating the signal, preferably rapidly, between the first and second states.

Abstract: A modulator comprising an inlet, an exhaust and an outlet, the modulator comprising a piston moveable in response to a control pressure in a control chamber to vary to supply of fluid under pressure to the outlet, wherein the modulator comprises a first end face and a second end face wherein the exhaust and the inlet are provided in the first end face and the outlet is provided in the second end face. The modulator further comprising a hold solenoid connected between the inlet and the control chamber, and a dump solenoid connected between the control chamber and the exhaust, wherein the connections between the hold solenoid, the exhaust and the control chamber and the connections between the dump solenoid, the control chamber and the inlet do not cross the plane of the piston.

Abstract: An electrical control network is laid over one or more vehicle dynamics control and/or ride control systems of a heavy vehicle, which control network controls actuation of components thereof. The invention offers many advantages including reduction of components, simplified design, unified communication for numerous different types of system components, simplified resolution of conflicts between competing control strategies, expandability to additional vehicle systems, and flexibility to upgrade for new, improved vehicle control schemes.