Method for measuring the thickness of a layer of rubber-like material

Patent metadata

Field	Value
Publication number	US-2017322012-A1
Application number	US-201515535138-A
Country	US
Kind code	A1
Filing date	Dec 11, 2015
Priority date	Dec 17, 2014
Publication date	Nov 9, 2017
Grant date	—

Abstract

A method is provided for measuring a thickness of a layer of rubber-like material. The layer of rubber-like material includes a free face in contact with air and a face joined to an adjacent reinforcement made of elements electrically insulated from one another. Each of the elements includes at least one hysteretic material having a magnetic permeability greater than the magnetic permeability of air. According to the method, a sensitive element, which emits an alternating magnetic field, is brought towards the layer of rubber-like material whose thickness is to be measured, hysteretic losses in the adjacent reinforcement are measured at terminals of the sensitive element, and a thickness of the layer of rubber-like material is evaluated based on the hysteretic losses.

First claim

1 - 10 (canceled)

11 : A method for measuring a thickness of a layer of rubber-like material that includes a free face in contact with air and a face joined to an adjacent reinforcement made of elements electrically insulated from one another, each of the elements containing at least one hysteretic material having a magnetic permeability greater than a magnetic permeability of air, the method comprising steps of:
causing a sensitive element, which emits an alternating magnetic field, to be moved towards the layer of rubber-like material; measuring hysteretic losses in the adjacent reinforcement, the hysteretic losses being measured at terminals of the sensitive element; and evaluating a thickness of the layer of rubber-like material based on the hysteretic losses.

12 : The method according to claim 11 , wherein the step of causing the sensitive element to be moved towards the layer of rubber-like material includes applying to the free face of the layer of rubber-like material a housing in which the sensitive element is installed.

13 : The method according to claim 12 , wherein the housing includes, in addition to the sensitive element, an electronic measuring device.

14 : The method according to claim 11 , wherein the sensitive element is a solenoid formed as one of: a printed circuit, a copper wire wound with a ferromagnetic support, and a copper wire wound without a ferromagnetic support.

15 : The method according to claim 11 , further comprising steps of:
supplying the sensitive element with an alternating electrical signal; and causing a frequency of the alternating electrical signal to vary.

16 : The method according to claim 15 , wherein the frequency of the alternating electrical signal is below a cut-off frequency of the sensitive element.

17 : The method according to claim 15 , further comprising a step of determining an appropriate excitation frequency of the sensitive element.

18 : The method according to claim 11 ,
wherein the sensitive element is formed from turns of a coil, and wherein the step of causing the sensitive element to be moved towards the layer of rubber-like material includes positioning the sensitive element in such a way that a plane parallel to the turns of the coil is parallel to a surface of the free face of the layer of rubber-like material.

19 : The method according to claim 11 , wherein an electrical conductivity of the adjacent reinforcement is such that a resistivity measured between two points located on two separate elements, or a resistivity measured between two points located on a same non-metallic element, is greater than one megaohm meter.

20 : The method according to claim 11 , wherein an electrical conductivity of the adjacent reinforcement is such that a resistivity measured between two points located on two separate elements, or a resistivity measured between two points located on a same non-metallic element, is greater than ten megaohm meter.

Assignees

• Michelin & Cie
• Michelin Rech Tech

Inventors

• Ledoux Thomas
• Martin Denis
• Pernot Alexandre
• Heredia Guillaume
• Meneroud Patrick
• Goeau Cédric

Classifications

• G01N27/72

  by investigating magnetic variables · CPC title

• G01M17/02

  Tyres · CPC title

• G01B7/10 Primary

  using magnetic means, e.g. by measuring change of reluctance · CPC title

• G01R33/123

  Measuring loss due to hysteresis (G01R33/14 takes precedence) · CPC title