US5231391A — Passive pick-up device for monitoring the state o…

Claim 1

Independent Claim 243 words

A device for monitoring a state of a tire of a vehicle wheel and for measuring rotation characteristics of the wheel, comprising: an encoder assembly securely attached to a rotating part of a hub of a wheel, the encoder assembly including a multipolar magnetic ring provided with magnetized segments of different polarity distributed circumferentially in a regular and alternating manner, and a transmitter coil mounted coaxially with the multipolar magnetic ring on the rotating part of the wheel hub; a fixed pick-up means cooperating with the encoder assembly to deliver a signal representing the rotation characteristics of the wheel and a state of the tire; monitoring means for monitoring the state of the tire of the wheel in rotation adapted to modify characteristics of the encoder assembly depending on a value of a predetermined parameter of the state of the tire; wherein the transmitter coil is energized with an alternating electric current either only when the value of the parameter monitored is considered to be abnormal with respect to a critical threshold, or continuously, the transmitter coil generating a magnetic field superimposing itself on a magnetic field created by the multipolar ring, whereby the frequency of the alternating current is situated outside a range of frequencies relating to variations in the magnetic field generated by the multipolar ring in rotation with the wheel, the amplitude of the magnetic field created by the transmitter coil being proportional to the value of the parameter monitored.

Claim 2

Independent Claim 243 words

A device for monitoring a state of a tire of a vehicle wheel and for measuring rotation characteristics of the wheel, comprising: an encoder assembly securely attached to a rotating part of a hub of a wheel, the encoder assembly including a multipolar magnetic ring provided with magnetized segments of different polarity distributed circumferentially in a regular and alternating manner, and a transmitter coil mounted coaxially with the multipolar magnetic ring on the rotating part of the wheel hub; a fixed pick-up means cooperating with the encoder assembly to deliver a signal representing the rotation characteristics of the wheel and a state of the tire; monitoring means for monitoring the state of the tire of the wheel in rotation adapted to modify characteristics of the encoder assembly depending on a value of a predetermined parameter of the state of the tire; wherein the transmitter coil is energized with an alternating electric current either only when the value of the parameter monitored is considered to be abnormal with respect to a critical threshold, or continuously, the transmitter coil generating a magnetic field superimposing itself on a magnetic field created by the multipolar ring, whereby the frequency of the alternating current is situated outside a range of frequencies relating to variations in the magnetic field generated by the multipolar ring in rotation with the wheel, the amplitude of the magnetic field created by the transmitter coil being proportional to the value of the parameter monitored.

Claim 3

Dependent Claim 47 words

A device according to claim 1, wherein the transmitter coil includes two or more independent parts, each being energized by a source of alternating current and corresponding to a specific parameter of the state of the tire, the frequencies of the currents being different from one another.

Claim 4

Dependent Claim 41 words

A device according to claim 1, wherein the parameter monitored is the pressure of the tire, and the critical threshold is constituted either by a minimum pressure threshold, or a maximum pressure threshold, or by both minimum and maximum pressure thresholds.

Claim 5

Dependent Claim 26 words

A device according to claim 1, wherein the parameter monitored is the temperature of the tire, and the critical threshold corresponds to a maximum temperature threshold.

Claim 6

Dependent Claim 33 words

A device according to claim 1, wherein the device monitors simultaneously the pressure and the temperature of the tire by means of two independent sources of current, each connected to the transmitter coil.

Claim 7

Dependent Claim 47 words

A device according to claim 4, wherein the transmitter coil includes two or more independent parts, each being energized by a source of alternating current and corresponding to a specific parameter of the state of the tire, the frequencies of the currents being different from one another.

Claim 8

Dependent Claim 64 words

A device according to claim 1, wherein the pick-up element includes an annular induction coil and an annular magnetic flux focusing element arranged coaxially with the multipolar ring and presenting a U-shaped cross-section having two end branches, wherein the end branches of the U-shaped cross section surround the induction coil and define an annular space in which the multipolar ring is located during rotation.

Claim 9

Dependent Claim 41 words

A device according to claim 7, wherein the parameter monitored is the pressure of the tire, and the critical threshold is constituted either by a minimum pressure threshold, or a maximum pressure threshold, or by both minimum and maximum pressure thresholds.

Claim 10

Dependent Claim 26 words

A device according to claim 7, wherein the parameter monitored in the temperature of the tire, and the critical threshold corresponds to a maximum temperature threshold.

Claim 11

Dependent Claim 33 words

A device according to claim 7, wherein the device monitors simultaneously the pressure and the temperature of the tire by means of two independent sources of current, each connected to the transmitter coil.

Claim 12

Dependent Claim 69 words

A device according to claim 7, wherein one of the end branches of the U-shaped cross-section of the flux focusing element has its end part provided with teeth regularly spaced circumferentially, each tooth having a width substantially the same as a circumferential width of one magnetized segment of the multipolar ring, all of the teeth being situated opposite magnetized segments of the multipolar ring having the same magnetic polarity.

Claim 13

Dependent Claim 47 words

A device according to claim 11, wherein the transmitter coil includes two or more independent parts, each being energized by a source of alternating current and corresponding to a specific parameter of the state of the tire, the frequencies of the currents being different from one another.

Claim 14

Dependent Claim 41 words

A device according to claim 11, wherein the parameter monitored is the pressure of the tire, and the critical threshold is constituted either by a minimum pressure threshold, or a maximum pressure threshold, or by both minimum and maximum pressure thresholds.

Claim 15

Dependent Claim 26 words

A device according to claim 11, wherein the parameter monitored is the temperature of the tire, and the critical threshold corresponds to a maximum temperature threshold.

Claim 16

Dependent Claim 33 words

A device according to claim 11, wherein the device monitors simultaneously the pressure and the temperature of the tire by means of two independent sources of current, each connected to the transmitter coil.

Claim 17

Dependent Claim 76 words

A device according to claim 7, wherein the two end branches of the U-shaped cross-section of the flux focusing element are provided with teeth, wherein a width of a tooth is substantially the same as a circumferential width of one magnetized segment of the multipolar ring, the teeth being regularly distributed circumferentially so that magnetic poles of a magnetized segment of the multipolar ring are respectively opposite the two end branches of the flux focusing element.

Claim 18

Dependent Claim 47 words

A device according to claim 16, wherein the transmitter coil includes two or more independent parts, each being energized by a source of alternating current and corresponding to a specific parameter of the state of the tire, the frequencies of the currents being different from one another.

Claim 19

Dependent Claim 41 words

A device according to claim 16, wherein the parameter monitored is the pressure of the tire, and the critical threshold is constituted either by a minimum pressure threshold, or a maximum pressure threshold, or by both minimum and maximum pressure thresholds.

Claim 20

Dependent Claim 26 words

A device according to claim 16, wherein the parameter monitored is the temperature of the tire, and the critical threshold corresponds to a maximum temperature threshold.

Claim 21

Dependent Claim 33 words

A device according to claim 16, wherein the device monitors simultaneously the pressure and the temperature of the tire by means of two independent sources of current, each connected to the transmitter coil.

Claim 22

Independent Claim 236 words

A method for monitoring a state of a tire of a vehicle wheel and for measuring rotation characteristics of the wheel, comprising: providing an encoder assembly including a multipolar magnetic ring with magnetized segments of different polarity distributed circumferentially in a regular and alternating manner, and providing a transmitter coil mounted coaxially with the multipolar magnetic ring on a rotating part of a wheel hub; fixing the encoder assembly to the rotating part of the wheel hub; delivering a signal representing the rotation characteristic of the wheel and the state of the tire using a stationary pick-up means which cooperates with the encoder assembly; monitoring the state of the tire of the wheel in rotation by modifying characteristics of the encoder assembly according to a value of a predetermined parameter of the state of the tire; energizing the transmitter coil with an alternating electric current either only when the value of the parameter monitored is considered to be abnormal with respect to a critical threshold, or continuously, wherein the transmitter coil generates a magnetic field superimposing itself on a magnetic field created by the multipolar ring, the frequency of the alternating current being situated outside a range of frequencies relating to variations in the magnetic field generated by the multipolar ring in rotation with the wheel, the amplitude of the magnetic field created by the transmitter coil being proportional to the value of the parameter monitored.

Claim 23

Independent Claim 236 words

A method for monitoring a state of a tire of a vehicle wheel and for measuring rotation characteristics of the wheel, comprising: providing an encoder assembly including a multipolar magnetic ring with magnetized segments of different polarity distributed circumferentially in a regular and alternating manner, and providing a transmitter coil mounted coaxially with the multipolar magnetic ring on a rotating part of a wheel hub; fixing the encoder assembly to the rotating part of the wheel hub; delivering a signal representing the rotation characteristic of the wheel and the state of the tire using a stationary pick-up means which cooperates with the encoder assembly; monitoring the state of the tire of the wheel in rotation by modifying characteristics of the encoder assembly according to a value of a predetermined parameter of the state of the tire; energizing the transmitter coil with an alternating electric current either only when the value of the parameter monitored is considered to be abnormal with respect to a critical threshold, or continuously, wherein the transmitter coil generates a magnetic field superimposing itself on a magnetic field created by the multipolar ring, the frequency of the alternating current being situated outside a range of frequencies relating to variations in the magnetic field generated by the multipolar ring in rotation with the wheel, the amplitude of the magnetic field created by the transmitter coil being proportional to the value of the parameter monitored.

Claim 24

Dependent Claim 52 words

A method according to claim 21, wherein in the energizing step, the transmitter coil includes two or more independent pars, each being energized by a source of alternating current and corresponding to a specific parameter of the state of the tire, wherein the frequencies of the currents are different from one another.

Claim 25

Dependent Claim 41 words

A method according to claim 21, wherein the parameter monitored is the pressure of the tire, and the critical threshold is constituted either by a minimum pressure threshold, or a maximum pressure threshold, or by both minimum and maximum pressure thresholds.

Claim 26

Dependent Claim 26 words

A method according to claim 21, wherein the parameter monitored is the temperature of the tire, and the critical threshold corresponds to a maximum temperature threshold.

Claim 27

Dependent Claim 30 words

A method according to claim 21, wherein the pressure and the temperature of the tire are monitored simultaneously by two independent sources of current, each connected to the transmitter coil.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-07-26	1997-01-25	1997-07-27	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-07-26	2001-01-25	2001-07-27	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-07-26	2005-01-25	2005-07-27	$7700.00	Window Closed / Lapsed

Passive pick-up device for monitoring the state of the tire of a vehicle wheel and measuring the rotation characteristics of the wheel

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag