SYSTEM FOR MEASURING THE THICKNESS OF A LAYER OF RUBBER FOR A TYRE

• US 20160153763A1
• Filed: 06/20/2014
• Published: 06/02/2016
• Est. Priority Date: 06/20/2013
• Status: Active Grant

• Current Assignee: Compagnie Generale DES Etablissements Michelin SCA
• Original Assignee: Compagnie Generale DES Etablissements Michelin SCA, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Ledoux, Thomas, Martin, Denis, Meneroud, Patrick, MICHAUD, Gr?gory
• Granted Patent: US 10,113,855 B2
• Time in Patent Office: Days
• CPC Class Codes: G01B 7/26 for measuring depth
• CPC Class Codes: G01M 17/02 Tyres

Abstract

A system for measuring a thickness of a layer of rubber material of a tyre includes a sensor. The layer includes a joined face, which is joined to an adjacent metal reinforcement, and a free face, which is in contact with air. The sensor, which measures a distance d between the joined face and the free face, includes a source of a static magnetic field and a sensitive element whose output signal is a function of a level of a local magnetic field. The sensor is positioned in such a way that a magnetic field strength measured by the sensitive element varies when the distance d decreases.

Claims

1-20. -20:

(canceled)

21. :

A system for measuring a thickness of a layer of rubber material of a tyre, in which the layer includes a joined face and free face, the joined face being joined to an adjacent reinforcement made with at least one material having a magnetic permeability greater than a magnetic permeability of air, and the free face being in contact with air, the system comprising;

a sensor configured to measure a distance d between the joined face and the free face of the layer of rubber material, wherein the sensor includes;

a static magnetic-field source, and

a sensitive element whose output signal is a function of a level of a local magnetic field, the sensitive element being positioned so that a magnetic field strength measured by the sensitive element varies when the distance d decreases.

22. :

The system according to claim 21, wherein the static magnetic-field source includes at least one coil supplied with a direct electrical current.

23. :

The system according to claim 22, wherein each of the at least one coil surrounds, or is surrounded by, a material having high magnetic permeability and low electrical conductivity.

24. :

The system according to claim 21, wherein the static magnetic-field source includes at least one permanent magnet.

25. :

The system according to claim 24, wherein each of the at least one permanent magnet has an axial magnetic field.

26. :

The system according to claim 25, wherein each of the at least one permanent magnet has a geometrical shape of a ring.

27. :

The system according to claim 25, wherein each of the at least one permanent magnet is a straight bar or a U-shaped bar.

28. :

The system according to claim 24, wherein the static magnetic-field source includes a plurality of uniaxially magnetized magnets positioned radially and with a same pole orientation as the sensitive element.

29. :

The system according to claim 24, wherein the static magnetic-field source includes a plurality of permanent magnets positioned in a source line.

30. :

The system according to claim 29, wherein

each permanent magnet has a north pole and a south pole,

the permanent magnets are positioned such that the poles are aligned with the source line, and

each pair of adjacent permanent magnets has inverted polarities such that poles having a same polarity face each other.

31. :

The system according to claim 30, wherein the sensor includes a plurality of sensitive elements, each sensitive element being positioned between two adjacent permanent magnets.

32. :

The system according to claim 26, wherein

the static magnetic-field source includes a plurality of permanent magnets having a geometrical shape of a ring, and

axes of the permanent magnets are arranged in a plane that extends through a source line and are orientated perpendicularly to the source line.

33. :

The system according to claim 32, wherein each permanent magnet is associated with a sensitive element positioned on the axis of the permanent magnet.

34. :

The system according to claim 33, wherein each sensitive element is arranged on a point of the axis of the permanent magnet having a zero magnetic field when the layer of rubber material is absent.

35. :

The system according to claim 21, wherein the sensitive element is one of;

an eddy-current sensor,

a magnetoresistive sensor, and

a magnetostrictive sensor.

36. :

The system according to claim 21, wherein the system is positioned inside an electrically non-conductive casing and is made of materials having a magnetic susceptibility equal to zero or similar to a magnetic susceptibility of air or a vacuum environment.

37. :

The system according to claim 36, wherein the casing is a portable casing.

38. :

The system according to claim 36, wherein the casing is structured to be positioned on or embedded in a roadway.

39. :

A method for measuring a thickness of a layer of rubber material of a tyre, in which the layer includes a joined face and free face, the joined face being joined to an adjacent reinforcement made with at least one material having a magnetic permeability greater than a magnetic permeability of air, and the free face being in contact with air, the method comprising;

measuring a distance d between the joined face and the free face of the layer of rubber material by utilizing a sensor that includes;

a static magnetic-field source, and

a sensitive element whose output signal is a function of a level of a local magnetic field, the sensitive element being positioned so that a magnetic field strength measured by the sensitive element varies when the distance d decreases.

40. :

The method according to claim 39, wherein the layer of rubber material is a layer of remaining rubber material on a tread of the tyre.

41. :

The method according to claim 39, wherein the layer of rubber material is a layer of a sidewall or an internal rubber element of the tyre.