SYSTEM FOR MEASURING THE THICKNESS OF A LINER LAYER OF A TIRE

• US 20160169657A1
• Filed: 07/25/2014
• Published: 06/16/2016
• Est. Priority Date: 07/26/2013
• Status: Abandoned Application

• Current Assignee: Compagnie générale des établissements Michelin
• Original Assignee: Compagnie générale des établissements Michelin, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: LEDOUX, Thomas, MARTIN, Denis, MENEROUD, Patrick
• Application Number:
  US14/907,174
• Publication Number:
  US 20160169657A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 7/26 for measuring depth
• CPC Class Codes: G01M 17/02 Tyres

Abstract

A system is provided for measuring a thickness of a rubber layer of a tire. The layer includes a joined face, which is joined to an adjacent metallic reinforcement, and a free face in contact with air. The system includes a casing with an application face for contacting the free face, and a sensor positioned in the casing and structured to measure a distance d between the joined face and the free face. The sensor includes a source coil element, which is a source of an alternating magnetic field, and a sensitive coil element, which is an element sensitive to a variation in a magnetic flux density in a vicinity of the source coil element. A frequency and an excitation power of the source coil element are such that the magnetic flux density between the adjacent metallic reinforcement and the source coil element increases as the distance d decreases.

Claims

1-30. -30. (canceled)

31-1. The measurement system according to claim 31, wherein the sensitive coil element is positioned between the source coil element and the application face of the casing.

31-2. The measurement system according to claim 31, wherein the source coil element is positioned between the sensitive coil element and the application face of the casing.

31-3. The measurement system according to claim 31, wherein the sensitive coil element and the source coil element are positioned without overlap so that the sensitive coil element and the source coil element are adjacent and substantially a same distance from the application face of the casing.

31-4. The measurement system according to claim 31, wherein the source coil element and the sensitive coil element surround, or are surrounded by, a material with high electrical resistivity and high magnetic permeability.

31-5. The measurement system according to claim 31, wherein, when the adjacent reinforcement is absent, the source coil element has no coupling or a weak coupling to the sensitive coil element.

31-6. The measurement system according to claim 31, wherein the source coil element includes one or more coils.

31-7. The measurement system according to claim 31, wherein the sensitive coil element includes one or more coils.

31-8. The measurement system according to claim 31, wherein the source coil element is supplied with an alternating voltage or an alternating current having a frequency below 500 kHz.

31-9. The measurement system according to claim 31, further comprising a measurement device for measuring an amplitude of a signal at terminals of the sensitive coil element.

31-10. The measurement system according to claim 31, wherein the casing is not electrically conductive and has magnetic properties similar to those of air, and the application face of the casing is parallel or normal to a direction of an axis of sensitivity of the source coil element.

36-1. The measurement system according to claim 36, wherein the source coil element and the sensitive coil element surround, or are surrounded by, a material with high electrical resistivity and high magnetic permeability.

36-2. The measurement system according to claim 36, wherein:

the source coil element has a given diameter, and

the sensitive coil element includes two coils, a diameter of a first of the two coils being greater than the given diameter of the source coil element, and a diameter of a second of the two coils being less than the diameter of the source coil element, and

the source coil element and the two coils of the sensitive coil element are concentric.

38. The measurement system according to claim 38, wherein the material having high electrical resistivity and high magnetic permeability is an H-shaped material.

39-1. The measurement system according to claim 39, where the source coil element is an excitation coil positioned around a central bar of the H-shaped material.

39-2. The measurement system according to claim 39, wherein the source coil element includes two excitation coils, each excitation coil being positioned around a lateral branch of the H-shaped material, respectively, with a position on each side of a central branch of the H-shaped material being preferable.

39-3. The measurement system according to claim 39, wherein the source coil element includes four excitation coils, each excitation coil being positioned around half a lateral branch of the H-shaped material, respectively.

39-4. The measurement system according to claim 39, wherein the sensitive coil element includes two coils positioned around a same lateral branch of the H-shaped material, one on each side of a central branch of the H-shaped material.

39-5. The measurement system according to claim 39, wherein the sensitive coil element includes two coils, each of the two coils being positioned on a distinct lateral branch of the H-shaped material, respectively, with one coil being positioned on each side of a central branch of the H-shaped material.

39-6. The measurement system according to claim 39, wherein the sensitive coil element includes four coils, each of the four coils being arranged on half a lateral branch of the H-shaped material, respectively.

47. The measurement system according to claim 47, wherein the source coil element and the sensitive coil element are flat coils.

48. The measurement system according to claim 48, wherein each of the flat coils is produced in a form of conducting tracks wound in a substantially spiral shape on a PCB or a plastronic support.

51-1. The measurement system according to claim 51, wherein the alternating voltage or the alternating current supplied to the source coil element has a frequency between 40 kHz and 150 kHz.

56. The measurement system according to claim 56, wherein the casing is a portable casing.

58. The measurement system according to claim 56, wherein the casing is structured to be positioned on or embeddable in a roadway.

59. A method for measuring a thickness of a remaining layer of rubber material on a tread of a tire, the layer including a joined face, which is joined to an adjacent reinforcement made with at least one material having a magnetic permeability greater than a magnetic permeability of air, and a free face, which is in contact with air, the method comprising utilizing a system that includes:

a casing structured to include an application face for contacting the free face of the layer, and

a sensor positioned in the casing and arranged to measure a distance d between the joined face and the free face of the layer, the sensor including;

a source coil element, which is a source of an alternating magnetic field, and

a sensitive coil element, which is an element sensitive to a variation in a magnetic flux density in a vicinity of the source coil element,

wherein a frequency and an excitation power of the source coil element are such that the magnetic flux density between the adjacent reinforcement and the source coil element increases as the distance d decreases.

60. A method for measuring a thickness of a layer of rubber material of a sidewall or an internal liner of a tire, the layer including a joined face, which is joined to an adjacent reinforcement made with at least one material having a magnetic permeability greater than a magnetic permeability of air, and a free face, which is in contact with air, the method comprising utilizing a system that includes:

a casing structured to include an application face for contacting the free face of the layer, and

a sensor positioned in the casing and arranged to measure a distance d between the joined face and the free face of the layer, the sensor including;

a source coil element, which is a source of an alternating magnetic field, and

a sensitive coil element, which is an element sensitive to a variation in a magnetic flux density in a vicinity of the source coil element,

wherein a frequency and an excitation power of the source coil element are such that the magnetic flux density between the adjacent reinforcement and the source coil element increases as the distance d decreases.