A controller for controlling a pneumatic control valve (PCV) in a central tire inflation system (CTIS). The controller includes an electronic processor having an electrical input for receiving a supply-side pressure signal. The electronic processor is configured to control a first control valve (V.sub.INSS) to generate a pneumatic control signal for changing an operating state of a pneumatic control valve (PCV). The electronic processor also monitors the supply-side pressure signal and identifies a change in the operating state of the pneumatic control valve (PCV) in dependence on a change in the supply-side pressure. The electronic processor is configured to output a first valve close signal upon determining that the pneumatic control valve (PCV) has changed operating state. Also provided is a CTIS incorporating a controller; to a vehicle; and to a method of controlling a pneumatic control valve (PCV).

Disclosed herein are valve assemblies, such as for use in a tire inflation system, the valve assemblies comprising: a first fluid port and a second fluid port fluidly connectable with one another via a fluid passage; a first valve having an open position and a closed position, the first valve in its closed position blocking the fluid passage and in its open position unblocking the fluid passage; a second valve having an open position and a closed position, the second valve in its closed position blocking the fluid passage and in its open position unblocking the fluid passage; and a control volume fluidly connected or fluidly connectable with the first fluid port via a flow restrictor, wherein the first valve, the second valve and the control volume are configured such that a fluid pressure in the control volume biases each of the first valve and the second valve toward their closed position.

A dual wheel tyre inflation pressure control system including a pair of vehicle wheels having tyre interiors providing first and second fluid chambers. A first valve arrangement is installed remote from the wheels and is connectable to a pressurised fluid source. A second valve arrangement, suitably mounted on one of the wheels, is connected to the first valve arrangement by means of first and second fluid connections. The second valve arrangement is controllably operable to connect the first fluid connection to either fluid chamber. Controlled variation of fluid pressure in and between the fluid connections is provided by the first valve arrangement to control said second valve arrangement for operating the tyre pressure control system to connect the second fluid chamber to the first valve arrangement, and to connect the first and second fluid chambers.

A method of setting the rides height of the air springs and air pressures of the tires, including receiving a user selected setting or preprogrammed ride height settings; sensing a ride height of, and air pressure within, each of the air springs; determining the weight of the vehicle based on the sensed ride height and air pressure within each of the air springs; providing specified ride heights for the left and right front and rear air springs; determining specified air pressures for the left and right front and rear tire inflators, based upon the determined weight of the vehicle and selected setting; inflating the left and right front and rear air springs to the specified ride heights; and inflating the left and right front and rear tires to the specified air pressures.

A rotary joint is configured to transfer a fluid between two entities, one of which is in rotary motion with respect to the other. The rotary joint comprises a cylindrical internal element, apt to be fixed to the entity in rotary motion, and a plurality of annular external elements. The external elements comprise at least two head elements, at least two housing elements of respective gaskets, two bearing elements, and at least one fluid inlet. The fluid inlet is placed between said two bearing elements. Housing elements of respective gaskets are arranged externally to the bearing elements, and head elements are arranged externally to the housing elements. The gaskets define an annular shaped sealed area. The sealed area is accessible on one side through said fluid inlet and on the other side through at least one fluid passage channel passing through the body of said internal element.

A central tire inflation system (CTIS) for a vehicle includes a reservoir for supplying air to the vehicle tires, a pressure sensor for monitoring air pressure in the reservoir, a compressor for supplying compressed air along a first flow path to the reservoir, a compressor timer for monitoring the run-time of the compressor, a dryer disposed on the first flow path for drying air supplied by the compressor, a purging system for routing air through the dryer along a second flow path to purge liquid from the dryer, and a controller for controlling the flow of air in the CTIS. The controller is configured: to activate the compressor in response to a request for a compressor operation, after which operation the air in the reservoir is at a post-operation pressure; when the compressor operation is complete, to determine a compressor activation period, and to determine if the compressor activation period is greater than or equal to a target period; and if the compressor activation period is less than the target period, to keep the compressor activated until pressure in the reservoir increases to a base target pressure greater than the post-operation pressure; and if the compressor activation period is greater than or equal to the target period, to keep the compressor activated until pressure in the reservoir increases to an elevated target pressure higher than the base target pressure and to activate the purging system to route air from the reservoir to purge the dryer of liquid.

A rotary joint assembly for a tire inflation system includes a rotating portion. The rotating portion is attached to a wheel rim for rotation therewith. The rotating portion includes a center portion which has an air passageway formed therein. The rotary joint assembly also includes a non-rotating portion. The non-rotating portion has a non-rotating portion air passageway formed therein. The non-rotating portion air passageway is in fluid communication with the air passageway formed in the rotating portion via a chamber. A pair of annular sealing members are attached to the rotating portion and sealingly contact a sealing surface of the non-rotating portion. The annular sealing members define an inboard end and an outboard end of the chamber.

An on-board centralized system for regulating pressure of tyres of a vehicle includes a pressurized air source, a circuit communicating the source with a plenum of each wheel, and an arrangement for connecting the plenum of each wheel to the inner chamber of the respective tyre that includes first and second connection lines for deflation and inflation, respectively, of the tyre, and first and second one-way valves interposed, respectively, in the first and second connection lines to allow only a flow of air respectively from and to the inner chamber. The first valve includes a spring having a pre-set load so as to isolate the inner chamber from a part of the circuit upstream of the first valve when said upstream part is at atmospheric pressure, and to guarantee a pre-set minimum value of pressure in the inner chamber when the upstream part is at a pressure lower than atmospheric pressure.

A tyre inflation pressure control system including a vehicle wheel having a tyre interior providing a first fluid chamber and an air reservoir providing a second fluid chamber. A first valve arrangement is installed remote from the wheel and is connectable to a pressurised fluid source. A second valve arrangement, suitably mounted on the wheel, is connected to the first valve arrangement by means of first and second fluid connections. The second valve arrangement is controllably operable to connect the first fluid connection to either fluid chamber. Controlled variation of fluid pressure in and between the fluid connections is provided by the first valve arrangement to control said second valve arrangement for operating the tyre pressure control system to connect the second fluid chamber to the first valve arrangement, and to connect the first and second fluid chambers.

A tire inflation system is provided for a vehicle supported by a plurality of inflatable tires. The system includes a compressor carried on the vehicle, and an air storage tank carried on the vehicle and connected to the compressor for storing compressed air. A plurality of automatically operable fill valves are provided, each fill valve being associated with a respective one of the tires so that each tire is communicated with the air storage tank via a separate one of the fill valves to increase inflation pressure in the tire when its respective fill valve is in an open position. A controller is operably associated with all of the fill valves. The controller has a multiple tire rapid inflation mode in which the fill valves associated with at least two of the tires are maintained in their open positions for an initial period until pressure in the air storage tank and the at least two tires substantially equalizes, and for a subsequent period during which the compressor provides additional inflation air to the at least two tires.