Abstract: A tire pressurization arrangement on a vehicle in which the pressurization of the tire is controlled by a vehicle control unit and the vehicle control unit is notified of a desired tire pressure or desired tire volume. An air flow rate in a supply line to the tire is established so that the time to pressurize the tire to the desired tire pressure/volume is calculable, or the time taken to pressurize the tire to an interval pressure/volume is calculable, said interval pressure/volume being between a current tire pressure/volume and the desired pressure/volume, and if the time to pressurize the tire to the desired pressure is exceeded, the control unit gives a warning signal and/or stops deflation or inflation.

Abstract: A method of inflating and deflating a tire on a vehicle, said vehicle having a rotatable air passage connectable to a tire and a non rotatable air passage through which air is conducted from a pressurized air supply. One of the passages has an associated sealing means for co-operating with a contact component associated with the other passage and wherein prior to inflation and deflation of the tire, one of the passages is pressurized to ensure the integrity of the sealing means with the contact component.

Abstract: An air supply system on a vehicle for inflating and deflating a tire. The system includes a compressor connected to a drier having drying material to extract water from the air and a deflation line connectable between the tire and the dryer. The air dryer is operable in a first mode in which air passing through the dryer in a first direction is dried by the dryer and a second regeneration mode in which air passes through the dryer in a direction opposite to the first to remove water collected by the dryer, characterized in that the air used for the regeneration is air deflated from the tire.

Abstract: A tire pressurization arrangement on a vehicle in which the pressurization of the tire is controlled by a vehicle control unit and the vehicle control unit is notified of a desired tire pressure or desired tire volume. An air flow rate in a supply line to the tire is established so that the time to pressurize the tire to the desired tire pressure/volume is calculable, or the time taken to pressurize the tire to an interval pressure/volume is calculable, said interval pressure/volume being between a current tire pressure/volume and the desired pressure/volume, and if the time to pressurize the tire to the desired pressure is exceeded, the control unit gives a warning signal and/or stops deflation or inflation.

Abstract: A tire pressurization arrangement on a vehicle in which the pressurization of the tire is controlled by a vehicle control unit and the vehicle control unit is notified of a desired tire pressure or desired tire volume. An air flow rate in a supply line to the tire is established so that the time to pressurize the tire to the desired tire pressure/volume is calculable, or the time taken to pressurize the tire to an interval pressure/volume is calculable, said interval pressure/volume being between a current tire pressure/volume and the desired pressure/volume.

Abstract: A vehicle brake circuit including a brake actuator, a manually operable valve, an electrically operable valve and a fluid reservoir for the supply of fluid to the actuator. The manually operated valve may be connected to the fluid reservoir either directly or indirectly through the electrically operable valve, when its position blocks a direct fluid connection with the fluid reservoir. The electrically operated valve controls activation or deactivation of the actuator except when the mechanically operated valve is in an unblocked position and overrides the electrically operated valves control of the actuator.

Abstract: A pilot controlled valve including an air inlet passage, an air outlet passage and a slider. The slider is moveable within a bore between a closed position and an open position in which the connection between the passages is closed and opened respectively. The slider is provided with a resilient member to bias the slider into the closed position. A part of the slider registers with the bore to define a chamber within the bore, and the slider is provided with a discharge passage that connects the chamber to the inlet passage so that an increase in pressure in the chamber resulting from a leak can be released.

Abstract: An air supply system on a vehicle for inflating and deflating a tire. The system includes a compressor connected to a drier having drying material to extract water from the air and a deflation line connectable between the tire and the dryer. The air dryer is operable in a first mode in which air passing through the dryer in a first direction is dried by the dryer and a second regeneration mode in which air passes through the dryer in a direction opposite to the first to remove water collected by the dryer, characterized in that the air used for the regeneration is air deflated from the tire.

Abstract: A tyre pressurisation arrangement on a vehicle in which the pressurisation of the tyre is controlled by a vehicle control unit and the vehicle control unit is notified of a desired tyre pressure or desired tyre volume. An air flow rate in a supply line to the tyre is established so that the time to pressurise the tyre to the desired tyre pressure/volume is calculable, or the time taken to pressurise the tyre to an interval pressure/volume is calculable, said interval pressure/volume being between a current tyre pressure/volume and the desired pressure/volume.

Abstract: A method of inflating and deflating a tyre on a vehicle, said vehicle having a rotatable air passage connectable to a tyre and a non rotatable air passage through which air is conducted from a pressurised air supply. One of the passages has an associated sealing means for co-operating with a contact component associated with the other passage and wherein prior to inflation and deflation of the tyre, one of the passages is pressurised to ensure the integrity of the sealing means with the contact component.

Abstract: A vehicle brake circuit including a brake actuator, a manually operable valve, an electrically operable valve and a fluid reservoir for the supply of fluid to the actuator. The manually operated valve may be connected to the fluid reservoir either directly or indirectly through the electrically operable valve, when its position blocks a direct fluid connection with the fluid reservoir. The electrically operated valve controls activation or deactivation of the actuator except when the mechanically operated valve is in an unblocked position and overrides the electrically operated valves control of the actuator.