An inflation viewing device has a main body which is externally provided with a transparent viewing portion and internally provided with an inner passage where an air path assembly is arranged. An air entrance connector is operatively connected to an external air source and to a first end of the main body. An air exit connector is connected to a second, opposed end of the main body and to an inflation valve. A guide spacer is provided between the air entrance connector and the main body. The guide spacer has an inner passage having a wider section in communication with the inner passage of the main body and a reduced section defining a communication opening with the air entrance connector. A filter is arranged in the communication opening. A plunger, biased by a spring, is slidably arranged within the inner passage of the guide spacer and guide section of the main body inner passage.

A tire position determination system includes a first tire detector, a revolving body detector, and a monitoring unit. The first tire detector is attached to a first tire and detects an acceleration. The revolving body detector is attached to a first revolving body and detects an acceleration. The monitoring unit obtains first correspondence representing relation between a first value and a second value during a first period, obtains second correspondence representing relation between a third value and a fourth value during a second period, compares the first correspondence and the second correspondence with each other, and determines whether or not the first tire revolves in synchronization with the first revolving body.

A tire revolution direction determination system includes a detection device arranged in each of two tires coupled back-to-back and a monitoring unit. The detection device includes a first detector that detects a first acceleration in a tire diameter direction and a second detector that detects a second acceleration in the tire diameter direction. The first detector is arranged in front of the second detector in a reference direction. When the monitoring unit receives the first acceleration and the second acceleration from the detection device while a vehicle travels forward, it specifies change over time of the first acceleration and change over time of the second acceleration and determines whether a direction of revolution of the tire where the detection device is arranged is the reference direction based on whether change over time of the first acceleration is more advanced than change over time of the second acceleration.

A rotary union having a housing, a shaft rotatably disposed within the housing, and a tube having a first end sealingly disposed within the shaft and a second end sealingly coupled to the housing. A tire inflation system may comprise a rotary union externally mounted to a vehicle wheel end or mounted to a vehicle fairing.

An inflation manifold connected to dual pneumatic tires by air hoses provides a central location for tire inflation and location of pressure sensors. A hose block connected to dual pneumatic tires by air hoses provides a central location for location of pressure sensors. The pressure sensors may be TPMS sensors or a combination of TPMS sensor and pressure gauge.

An apparatus is provided for auto-locating positions of a plurality of wireless sensors on a vehicle. The apparatus comprises a receiving unit for receiving signals from the plurality of wireless sensors. The apparatus further comprises a processing unit arranged to calculate a probability value for each one of the plurality of wireless sensors based upon signals that have accumulated over a period of time to provide a table of probability values. Each probability value contained in the table during a calculation cycle of the processing unit is indicative of likelihood of one of the plurality of wireless sensors being located at a corresponding one of a plurality of positions on the vehicle. Each one of the plurality of wireless sensors is associated with the position having the highest probability value during the calculation cycle.

A method of determining an orientation of a tire mounted device with respect to a wheel rim using an acceleration sensor. With the wheel in a designated orientation and not rotating, a polarity of acceleration along a vertical axis is determined. Then it is determined which of a first absolute orientation or a second absolute orientation the tire mounted device is in depending on the determined polarity. The determined absolute orientation is correlated with the designated orientation to determine which of a first or second orientation with respect to the wheel rim the tire mounted device is in.

A tire mounting position detection system measures a first signal strength which is the strength of a radio signal received by a first receiver (R1) for each transmitter, measures a second signal strength which is the strength of the radio signal received by a second receiver (R2) for each transmitter, and calculates an strength ratio which is a ratio using the first signal strength and the second signal strength for each transmitter. The tire mounting position detection system detects a wheel position where a tire equipped with a transmitter is mounted on the basis of the first signal strength, the second signal strength and a strength ratio for each transmitter.

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 locating a wheel-mounted electronic device, such as a tire pressure monitoring device. A wireless signal is transmitted from an interrogation device from each of a plurality of interrogation locations. The signals are received by the wheel-mounted device and received signal strength is measured for each interrogation location. The wheel-mounted device then transmits, in respect of each interrogation location, a wireless signal indicating the measured signal strength. These signals are received by the interrogation device which determines from them a location of the wheel-mounted device with respect to a wheel.