Abstract: A self training tire pressure monitoring system for a vehicle includes at least two pressure sensors, at least two wheel sensors and a control. The pressure sensors are positioned at respective tires and are operable to provide a measured pressure output indicative of the pressure of the respective tires. The wheel sensors are positioned at respective wheels of the vehicle and are operable to provide a characteristic output indicative of rotation of the wheels over a period of time. The control receives the characteristic outputs and the measured pressure outputs and is operable to integrate the outputs to determine the particular wheels at which the pressure sensors and associated tires are positioned. The measured pressure and location of the tires may be displayed at a display of the vehicle. Preferably, the control deduces a deduced rolling radius of the tires in response to the characteristic output of the wheel sensors.

Abstract: A monitoring assembly for a pneumatic tire is designed to be loosely disposed within the tire and rim combination. The monitoring assembly includes a protective body that surrounds a monitoring device. The protective body at least includes a rigid encapsulation material and may include a cushion layer disposed outside the rigid encapsulation layer. One embodiment of the invention provides channels disposed through the protective body to speed the temperature response of the monitoring assembly.

Abstract: The present invention relates to a method and system for detecting air leaks in tires and in a tire testing machine. Each of the tires is mounted on the tire testing machine; inflated with an air flow from an inflation system to a first pressure; and maintained at the first pressure by continued supply of air from the inflation system into the tire. The flow of the continued supply of air is measured with a calorimetric flow sensor calibrated to output a sensor signal having a full scale value corresponding to an identical model tire mounted on the tire testing machine with no air leaks in the model tire or the testing machine. The flow of the continued supply of air is compared with an averaged flow for previously measured tires mounted on the tire testing machine with no air leaks in the tires or the testing machine. A control signal indicating an air leak is outputted if the sensor signal is 20% to 80% of the full scale value.

Abstract: A pressure monitoring system has a first chamber (11) and a second chamber (12) separated by a diaphragm. The diaphragm carries respective SAW devices on the respective sides thereof, the SAW devices having different resonant frequencies. Variations in pressure within the second chamber (12) relative to the pressure within the first chamber (11) will cause deflection of the diaphragm and the resulting changes in resonant frequency of the SAW devices can be analyzed to indicate the pressure differential between the chambers. The pressure-measuring device is incorporated within a valve assembly for a vehicle tire. When the vehicle tire is inflated, the inflation pressure is trapped within the first chamber (11) as a reference. Any subsequent loss of pressure from the second chamber (12), e.g. as a result of a puncture, will cause deflection of the diaphragm and a corresponding output from the SAW devices.

Abstract: An on-road balancing system is provided that includes an analyzer, vibration sensor, and rotation sensor. The rotation sensor is coupled to at least one vehicle wheel and the vibration sensor is coupled to a component within the vehicle. The analyzer is responsive to input from the rotation sensor and the vibration sensor to calculate a phasor quantity representative of vibrations transmitted from the wheel to the component.

Abstract: A tire air pressure monitoring device is inexpensively constructed, and avoids misregistering ID codes from other vehicles by using a receiver that determines the ID code registration method based on the speed of the vehicle, and a function code setting process that sets the function code of the data intended for ID code registration based on the results of the ID code registration method determining process. The receiver identifies data intended for ID code registration by the function code, and then registers the ID code. Further, the receiver has an ID code permutation comparison process that permutes the ID codes received from a plurality of transmitters to form ID code permutation blocks. The receiver compares the ID code permutations of consecutive ID code permutation blocks, and registers the ID codes when the ID code permutations are the same in two consecutive ID code permutation blocks.

Abstract: A method for alarming decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed. A plurality of thresholds for judging bad road are set. Decrease in air-pressure of a tire can be judged and alarm is issued upon decrease in air-pressure also when running on a bad road so that it is possible to secure safe driving for the driver.

Abstract: In a system for remote monitoring of vehicle tire pressure, a system and method for automatically identifying tire location. A tire pressure monitor mounted in each tire includes a sensor for sensing tire pressure, a transmitter for transmitting a signal representative of the sensed tire pressure, and a magnetic switch for actuating the transmitter. An electromagnets is mounted on the vehicle in proximity to each tire location and generates a magnetic field causing the magnetic switch to actuate the transmitter of the associated tire pressure monitor. A controller mounted on the vehicle is provided in communication with the electromagnets, processes the tire pressure signals from the transmitters, and conveys tire pressure and location information to a user. The controller energizes the electromagnets so that each received tire pressure signal is automatically associated with a specific tire location.

Abstract: A method for determining the axle load on a rotating tire or the percentage axle load of a first axle of a moving vehicle. The relationship between the axle load on a test tire and the rolling radius of the test tire under a constant pressure is empirically determined, and optionally the relationship between the pressure of the test tire and the rolling radius of the test tire at a constant axle load is empirically determined. A measurement of the rotational speed of the rotating tire is taken, and optionally a measurement of the pressure of the rotating tire is taken using a pressure sensor. The axle load or percentage axle load is determined from the measurement (or optionally from the measurements) and from the relationship (or optionally from the relationships).

Abstract: A method for the detection of a pressure drop in a tire of a wheel of a vehicle including the steps of determining a test variable from the wheel radii or from variables representing these wheel radii of the wheels of the vehicle, wherein the test variable is a quotient of two sums of each two wheel radii or variables representing these wheel radii of each one pair of vehicle wheels, comparing the test variable with a threshold value, and detecting a pressure drop with respect to the result of the comparison, wherein several test variables are determined with respect to several different wheel pair combinations, and pressure drop is considered to have been identified only if a defined vehicle wheel is identified by all found test variables as a wheel with a possible pressure drop.

Abstract: A device for monitoring at least one parameter for vehicle wheels includes, on each wheel, a detector unit having a transmitter unit that respectively transmits a phase-modulated or frequency-modulated signal to a central evaluation and control unit. Each detector unit transmits, at specific time intervals, a brief signal that contains a uniquely defined identifier. After a wheel is changed, a renewed assignment of the detector unit to the respective wheel positions can be carried out in an assignment mode of the detector unit and of the control unit, by registering a profile of the mean reception power for each detector unit as a function of the angular position of the respective wheel and comparing such signature profile with stored signature information. The comparison can be carried out by cross-correlating the two respectively decisive curves, or by comparing individual values or specific characteristic variables of the profiles.

Abstract: A tire deflation warning system is based solely on the measured distance traveled by each tire of a: vehicle. The vehicle is equipped with a sensor which generates pulses representative of the distance traveled by each wheel such as generated by an ABS brake system. The system accumulates the pulses in the controller to determine whether the vehicle is stable. If the vehicle is stable, it performs a test to cover individual tires, opposing diagonal tires or any combination of three tires using an average of the diagonal ratio. These tests are performed by utilizing the pulses generated by each wheel representing the distance traveled by the wheel.

Abstract: A system for monitoring at least one tire condition value in each of a plurality of pneumatic tires of a moving vehicle, wherein each of the tires has associated therewith a passive electronic tire tag for sensing the at least one tire condition value and is responsive to an interrogation signal transmitted thereto to transmit a data modulated signal representative of the at least one tire condition value. The monitoring system includes portable ramp apparatus for supporting the moving vehicle, portable vehicle sensing apparatus for sensing the presence of the moving vehicle and tire pressure sensing apparatus embedded in the ramp apparatus for detecting the presence thereon of a vehicle tire on the ramp apparatus. In addition, the monitoring system includes transmitter antenna structure and receiver antenna structure respectively embedded in the ramp apparatus.

Abstract: The invention relates to a system for monitoring the wheels (R1, R2, R3, R4) of a motor vehicle (10) for fault states, in particular for incorrect tire pressures, each wheel (R1, R2, R3, R4) to be monitored being assigned a wheel unit (E1, E2, E3, E4) which, after the reception of a trigger signal (TR), supplies data (D1, D2, D3, D4) which is suitable for detecting a fault state and/or for determining the wheel position (FL, FR, RL, RR) of at least one wheel (R1, R2, R3, R4). There is provision for a portable transmitter (12) which can be included with which a trigger signal (TR), in particular a radio-frequency trigger signal, can be generated for at least one wheel unit (E1, E2, E3, E4).

Abstract: The tire pressure sensor housing for a motor vehicle, provided to be mounted on a wheel rim comprises elastically deformable support wings of variable height and a device for positional fixing and locking having snap-on tongues.

Abstract: Tire air pressure during high speed travel is estimated without a sensor for detecting the tire air pressure directly. An apparatus is constituted by a wheel speed sensor, road surface friction state estimator for estimating a friction state estimation value representing friction between the tire and a road surface from wheel speed detected by the wheel speed sensor, tire air pressure estimator for estimating any reduction in the tire air pressure based on the friction state estimation value, and a display for displaying the estimated reduction in the tire air pressure.

Abstract: A vehicle is provided with an air pressure detection device for a tire which includes a temperature sensor for measuring the temperature of a tire and an air pressure sensor for measuring the air pressure of the tire. A reduced air pressure arithmetic portion is provided for calculating a reduced air pressure Pm from the temperature Tx measured by the temperature sensor and the air pressure Px measured by the air pressure sensor by the formula set forth below. An alarm signal generating portion is provided for generating an alarm signal when the reduced air pressure Pm calculated by the reduced air pressure arithmetic portion is decreased to or below a first threshold value Pa. Pm=Px−K(Tx−T0) The condition where the tire air pressure is lowered to or below a threshold value determined based on a recommended air pressure can be accurately detected, and an alarm can be issued, without being affected by tire temperature rise or temperature variations.

Abstract: A method for allocating identifiers, that are contained in signals issued by transmitters arranged in a tire pressure monitoring system, to the positions of the wheels by transmitting the signals to a receiving and analysis circuit, which analyses the information, contained in the signal, wherein for differentiating between wheels on the right side of the vehicle and wheels on the left side of the vehicle, the sign of a translation acceleration b is determined for each running wheel, the sign of the variation of the centrifugal acceleration z occurring during the translation acceleration b is additionally determined and multiplied by the sign of the translation acceleration b determined for the respective wheel, and the differentiation between wheels on the right side of the vehicle and wheels on the left side of the vehicle is effected by comparing the products of the two signs determined for the wheels.

Abstract: An apparatus is capable of determining inflation pressure of a pneumatic tire mounted on the wheel of a vehicle, the tire being in contact with a support over a contact area. The apparatus comprises: (i) sensing means comprising one or more sensors within said support, each sensor being adapted to measure the average contact pressure over the sensor between said tire and said support, and each having a surface area less than the said contact area; and (ii) processing means adapted to determine an average contact pressure between said tire and said support from an output of only a sensor or sensors which fall entirely within said contact area so as to provide a measure of the inflation pressure of the tire to a first order of accuracy. A corresponding method is also disclosed.

Abstract: The module comprises an air pressure sensor (3) with an air intake (4), a card (5) for supporting a printed circuit, the sensor (3) being mounted on said card, and an anti-contamination filter (6) for protecting the air inlet (4).

Abstract: The inventor discloses and claims a device for signaling the inflation condition of tires, as externally visible or as may be registered by remote audio or visual cues. The device generally is adapted to be attached to the stem valve of a tire without causing substantial loss of air pressure in the tire. The device may be loaded to register the inflation condition of the tire, following which loading the device may continue to register the inflation condition, without causing substantial loss of pressure in the tire.

Abstract: An apparatus for testing tires performs the following steps: rotating the tire relative to a camera; projecting light sections on a tire surface; capturing projected light sections by the camera at defined rotary positions of the tire relative to the camera; applying signals representing the captured projected light sections to an image processing system; determining the shape of the captured projected light sections by the image processing system; determining the shape of the tire surface from the shape of the captured projected light sections; repeating the above steps for different inflation pressures of the tire; and comparing the determined shapes of the tire surface for different inflation pressures of the tire for determining shape changes of the tire due to changes in the inflation pressure.

Abstract: A tire inflation pressure monitoring system (10) and a method for monitoring air pressure within a tire (14) are provided. The system (10) includes a tire based unit (18) for sensing air pressure within the tire (14) and for transmitting a pressure signal indicative thereof. The system (10) also includes a vehicle based unit (16) for receiving the pressure signal and for comparing the pressure signal to a predefined pressure range. The vehicle based unit (16) is operable in one of (i) a normal operating mode that outputs an alert signal in response to the air pressure within the tire (14) being outside of the predefined pressure range and (ii) a pressure gauge operating mode that outputs an in-range signal in response to the air pressure within the tire (14) being within the predetermined pressure range.

Abstract: A tire air pressure detecting apparatus has an tire air pressure detecting mechanism for detecting the air pressure of a tire of a motorcycle, and a second control mechanism for comparing an actual air pressure detected by the tire air pressure detecting mechanism with a stored air pressure threshold, and controlling an engine output when the actual air pressure becomes lower than said air pressure threshold. Since the air pressure detecting apparatus comprises a small number of constituent elements including the tire air pressure detecting mechanism and the second control mechanism for reducing an engine output under certain conditions, the tire air pressure detecting apparatus can easily be reduced in size and cost.

Abstract: A method and a system for recongnizing both a driving-dynamic state of a vehicle and a surface quality of the carriageway of which the vehicle is moving. The pressures of the tires of the vehicle are measured and evaluated so that conclusions can be draw on both current driving-dynamic states and existing surface qualities of the carriageway.

Abstract: Tire pressure is automatically checked when the motor vehicle is started. At the same time, the type of operation, either off-road operation or on-road operation, is detected. According to the inventive method, in the on-road operation of the motor vehicle, the speed of all four wheels is measured and it is made sure whether or not there is an inadmissible difference in wheel speed. If the wheel speeds do not differ, the theoretical tire pressure is determined. If the actual tire pressure differs from the theoretical pressure, the inflation or deflation valves of the tires are actuated until the theoretical value is achieved, thereby adjusting the theoretical value. If the wheel speeds differ, as for example, during the operation state of the off-road mode, the vehicle speed is measured and is compared with a threshold value.

Abstract: In a method for checking tires of vehicles during driving, signals which provide information about an adhesion between the tire and the roadway in the vertical direction with respect to the roadway are detected by sensors provided at the tire. The signals are evaluated in an evaluation unit with respect to their amplitude, such that the amplitude characteristic for the detected signals can indicate a disturbance occurring at the tire. An occurrence of a disturbance is indicated on a display unit and is stored for diagnostic purposes.

Abstract: A pressure indicating device, e.g. for securing to a tire valve, is disclosed. The device includes a flexible impermeable diaphragm on one wall of a permanently hermetically sealed chamber is pressurized to a given pressure. A mechanical linkage moves depending on whether the pressure, e.g. in a tire to which the device is attached, is greater or less than that in the chamber, e.g., rotates a bicolored ball so that the color displayed provides a visual signal that indicates if the tire pressure is above or below the given pressure. This enables a puncture or air loss to be detected by a rapid glance.

Abstract: This invention relates to a tire testing device, and in particular to a device for testing the tires of aircraft. The invention provides a tire testing device including a pressure sensor and a temperature sensor, allowing the calculation of the effective pressure at a reference temperature; the tires can therefore be tested hot or cold. The device can also include an oxygen sensor, so that the oxygen content of the tire can also be determined.

Abstract: An apparatus for estimating a tire pressure condition amount of a tired wheel mounted in a vehicle is provided with a wheel speed sensor (10) for detecting a vehicle wheel speed representing an angular speed of the tired wheel and for outputting a vehicle wheel speed signal in response thereto and an estimating unit (20) for estimating the tire pressure condition amount based upon the vehicle wheel speed signal outputted from the wheel speed sensor. The estimating unit includes a vehicle condition amount detecting device (40) for detecting a vehicle condition amount and for outputting a vehicle condition amount signal in response thereto. An estimation of the tire pressure condition amount by using the vehicle wheel speed signal is normalized based upon the vehicle condition amount signal outputted from the vehicle condition amount detecting device.

Abstract: A snug fitting apparatus for improving the finished quality of a tire assembly 1 without sacrificing productivity, including a first pressing member 25 (25a) adapted to be pressed against the ground contact surface F of a tire assembly 1 and a second pressing member 25 (25b) adapted to be pressed against the ground contact surface F to receive the radial reactional force of the ground contact surface F. Measuring device is provided to read variation in the reactional force. As a result, a large, expensive uniformity checking machine is made unnecessary, making it possible to assure quality for all the quantity of tire assemblies 1 on the production line and to fully automate the process.

Abstract: The present invention provides a method and apparatus for estimating a state of tire air pressure with high accuracy in a range of vehicle speeds from a low travel speed to a high travel speed. A wheel speed of each of a right-hand front wheel and a right-hand rear wheel is detected based on wheel speed signals outputted from vehicle speed sensors, and characteristic amounts (power) of frequency characteristics of the wheel speeds are calculated. A value of difference which represents a degree of difference between the obtained characteristic amounts of the right-hand front wheel and the right-hand rear wheel is calculated. Based on the value of difference, the state of air pressure of a tire is determined. As a result, it can be determined if the air pressure of one of tires on the right-hand front wheel and the right-hand rear wheel has been reduced.

Abstract: A tire tag includes a monitoring package, a battery, and an antenna encapsulated within an encapsulation mold. The antenna is connected to the encapsulation mold so that the antenna does not move during the encapsulation process. The antenna remains spaced apart from the monitoring package but connected to the monitoring package by connectors that are completely surrounded by encapsulation material so that the connectors are protected during the operation of the tire tag. The antenna may be connected to the encapsulation mold by an adhesive, by pins, by an interference fit, or by clips. The connection between the antenna and the monitoring device may be made by soldered wires or by spring loaded connector pins. The method of encapsulating the tire tag in this manner allows the position of the antenna to be precisely known before, during, and after the encapsulation process.

Abstract: A low-pressure testing device for an automobile tire has a base, a warning device, two parallel separated resilient tubes The base is firmly placed on the ground. The warning device is mounted on one end of the base and has a first switch, a second switch and a warning circuit. Each of the parallel separated resilient tubes has a first closed end and a second end connected to the first switch or the second switch, as appropriate. When the two tubes are pressed simultaneously, the first and second switches close the warning circuit to sound an alarm.

Abstract: A transmitter includes a main body and a valve stem. The main body has a resin casing, which includes a cylinder. A metal cylindrical collar is inserted in the cylinder. An inserting section of the valve stem is inserted in the collar, and a nut is fastened to a threaded portion of the inserting section. Accordingly, the cylinder and the collar are clamped between a step of the valve stem and the nut. The fastening force of the nut is applied mainly to the collar, thus barely affecting the cylinder. As a result, the valve stem is reliably attached to the main body in a stable manner.

Abstract: The present invention comprises and system and method for detecting a change in the state of pneumatic tires. The change of state refers to the state of internal air pressure, temperature or other such parameter. Herein, a difference of at least two successive readings are taken or a further analysis is performed and either is compared with a threshold value below which a change of state has occurred.

Abstract: The invention relates to the in-service monitoring of the condition of a tire of a wheel of a vehicle. To this end it proposes a process and, in particular, a device comprising: a sensor (4) mounted on the wheel, coupling means (BVF2, BRF2) for transmitting to the vehicle indications derived from this sensor (4), and electrical energizing means (BVF1, BRF1). According to the invention, the sensor (4) is a miniature acceleration-sensitive sensor implanted in the tread of the tire or in the vicinity of the tread. The coupling means, mounted on the wheel, then transmit indications relating to the measurements made at the moment at which the tread is in contact with the ground.

Abstract: A keyless entry device includes a plurality of antennas which receive high frequency signals, a high frequency receiver which reproduces data from the high frequency signals received by the plurality of antennas, an intermittent controller which changes over an operation of the high frequency receiver between a continuous operation and an intermittent operation in an interlocking manner with turning on or off of an ignition key of an automobile, and a data processor which outputs data as control signals, wherein when the ignition key is turned on, the keyless entry device is operated as the tire pressure monitoring device and when the ignition key is turned off, the keyless entry device is operated as the keyless entry device.

Abstract: An apparatus for detecting decrease in air-pressure for use in a two-wheeled vehicle including: a wheel speed detecting means for detecting wheel speeds; an acceleration calculating means for obtaining accelerations of a vehicle body of the two-wheeled vehicle; a slip rate calculating means for calculating slip rates when the acceleration of the vehicle body is in a specified range which is proximate to zero; an average value calculating means for obtaining average values of the slip rates and average vehicle body speeds; a difference calculating means for obtaining differences between the average values of the slip rates and a reference value which is based on an average vehicle body speed as preliminarily set when an internal pressure is normal; and a means for judging decrease in internal pressure. A decrease in air-pressure in a two-wheeled vehicle can be judged so as to enable safe driving.

Abstract: An apparatus for alarming a decrease in internal pressure of tires attached to a four-wheeled vehicle using judgement values obtained based on rotational information obtained from the tires. The apparatus comprises rotational information detecting means for detecting rotational information on each of the tires; memory means for storing the rotational information; arithmetic processing means for processing a judgement value from the rotational information; and judgement value correcting means for correcting the judgement value using a weight determined based on a rudder angle obtained by a rudder angle sensor attached to a steering wheel. The frequency of the occurrence of erroneous alarms during cornering can be reduced. As a result, it is possible to improve accuracy for detecting the pressure reduction of tires.

Abstract: An apparatus for alarming decrease in tire air-pressure which detects the decrease in internal pressure of the tire based on wheel speed information obtained from wheels of a vehicle and accordingly alarms a driver. The apparatus comprises: a wheel speed information detecting means, a memory means for storing the wheel speed information of the respective tires, a calculating means for calculating a judged value based on a vehicle velocity and wheel speed information, and a judging means for determining a decrease in tire air-pressure based on correlation of the vehicle velocity and an outer diameter of the tire at the time of performing high-speed running. It is possible to determine a decompression of a tire based on the correlation also in case the judged value will not become large owing to increased influence of centrifugal force during high-speed running even though a tire is in a decompressed condition.

Abstract: An apparatus for alarming decrease in tire air-pressure comprising: a rotational information detecting means for detecting rotational information of the respective tires; a rotational information memory means; a judged value calculating means for calculating judged values based on the rotational information; a judged value memory means; a transition calculating means for calculating transition of the judged values based on the stored judged values; a judging means for determining a decrease in tire air-pressure; and an alarming means for issuing preliminary alarm prior to issuing a predetermined alarm for informing decrease in internal pressure in case the judged value tends to move to exceed a predetermined threshold. It is possible to appropriately inform the driver of the vehicle of a decompressed condition of a tire for making the driver drive safely.

Abstract: A system for identifying the position of a tire on a vehicle based on wireless messages received from the tire includes a receiver circuit, a signal strength circuit, a memory, and a processing circuit. The receiver circuit is configured to receive the wireless messages. The signal strength circuit is configured to determine the signal strengths of the wireless messages. The memory is configured to store a predetermined frequency distribution. The processing circuit is configured to provide a frequency distribution of the wireless messages based on the signal strengths and to compare the frequency distribution to the predetermined frequency distribution to determine the position of the tire on the vehicle.

Abstract: A radio frequency (RF) transponder (200) capable of measuring parameters associated with an object and transmitting data to an external reader/interrogator (106, 400). In use with a pneumatic tire (104), the transponder measures temperature and pressure within the tire. The transponder includes circuitry (226) for controlling windows of time (WT and WP) during which real-time temperature and pressure measurements are made, and for storing (236) calibration data, transponder ID number and the like, and for transmitting this information in a data stream (FIG. 3C) to the reader/interrogator. An excessive temperature condition may also be sensed (MTMS 218) and included in the data stream. The circuitry of the transponder is preferably implemented on a single IC chip (204), using CMOS technology, with few components external to the IC chip. The transponder is preferably passive, deriving its operating power from an RF signal provided by the exernal reader/interrogator.

Abstract: A tire pressure and temperature measurement system (100) includes an oxygen sensing subsystem (140) that detects the oxygen concentration in the tire and presents an alarm condition (152) indicative of a potentially hazardous inflation gas mixture. The. oxygen sensing subsystem is mounted on or within the tire and may be implemented standalone or as a part of the temperature and pressure system. A “go no-go” indication is telemetered to the truck operator or to a remote measurement system (80) for monitoring and initiation of corrective action.

Abstract: A wireless tire inflation pressure measurement device is used to obtain inflation pressure information for a tire of a vehicle and a signal therefrom may be used for determining the location of the tire. An identifier may be associated with the inflation pressure information for each wheel of the vehicle. Tire rotation speed may be determined by amplitude fluctuations of a radio frequency carrier from a radio frequency transmitter rotating with the wheel. Differences in wheel rotation speeds during a turn may be used in determining the location of each tire of the vehicle. An antenna may be placed on each wheel toward the outer perimeter of the wheel and connected to the radio frequency transmitter. A radio frequency identification (RFID) tag and pressure sensor may be used as the wireless tire inflation pressure measurement device and a RFID pickup coil may be provided in each wheel well for pickup of the inflation pressure signals from each RFID tag on a wheel.

Abstract: An automatic car tire pressure detecting apparatus constitutes an emission means located at the wheel rim of the tire and a receiving means located at the brake pad. The emission means includes a generator, an emission end and a pressure sensor. The generator has a coil which has a positive and a negative end linked in series with a rectify switch and the emission end. The receiving means includes a magnet located at a corresponding tangent spot of the coil, a receiving end and a microprocessor attached to a display device. When the tire rotates, the magnet continuously cuts the coil to generate electric current to actuate the emission end. The rectify switch determines if the current flowing therethrough is positive. The positive current will be used for actuating the emission end to emit signals which are received by the receiving end thereby the detecting apparatus is able to provide self-generating power supply to transmit signals without an external power supply.

Abstract: In a tire air pressure warning device, an outside impact such as hydraulic brake pressure is intentionally applied in a pulsating way to a tire when the vehicle substantially stops so as to exert vibration (rotation variation) of the tire axle. Through data processes in analyzing signals of wheel speed sensors that reflect the rotation variation of the tire axle, tire air pressure is estimated for informing to a driver abnormal tire air pressure.

Abstract: A receiver includes circuits (17) for wireless reception of pressure-signal frames configured so as to forward the frames to processing circuits (15) that also process frames representative of other signals and controlled in consequence by frame-discrimination circuits (12, 13, 14). A transmitter is also disclosed that includes circuits for controlling transmission of a frame header with a duration at least equal to that of the header of a tire-pressure monitoring TPMS frame.

Abstract: A tire pressure control unit for motor vehicles with a rotary transmission leadthrough 2 for transmitting a pressure means from a part, stationary with respect to a rotatably supported wheel 3, of the motor vehicle to the rotatably supported wheel 3, wherein the rotary transmission leadthrough 2 comprises at least one chamber 14, 15 delimited by an annular body 4, 5 disposed at the stator side and by [an annular body (4, 5)] disposed at the rotor side concentrically with respect to the rotational axis of wheel 3, and wherein for sealing the at least one chamber 14, 15 sealing rings are inserted between the stator-side annular body 4 and the rotor-side annular body 5, is defined thereby that the stator-side annular body 4 and the rotor-side annular body 5 are disposed one next to the other in the axial direction with respect to the rotational axis of the wheel 3 leaving a motion gap 11, into the face facing toward the rotor-side annular body 5, of the stator-side annular body 4 for the radial sealing