U.S. patent application number 10/033248 was filed with the patent office on 2002-05-09 for elastomeric tire having magnetized sidewall and method of manufacturing same.
Invention is credited to Cetin, A. Yuecel, Giustino, James M..
Application Number | 20020053385 10/033248 |
Document ID | / |
Family ID | 23365151 |
Filed Date | 2002-05-09 |
United States Patent
Application |
20020053385 |
Kind Code |
A1 |
Cetin, A. Yuecel ; et
al. |
May 9, 2002 |
Elastomeric tire having magnetized sidewall and method of
manufacturing same
Abstract
The present invention provides a tire with a sidewall having a
magnetized outer layer. The sidewall outer layer is peripherally
divided into sections with radially extending ribs between each
adjacent pair of sections. The ribs protrude above the sections. In
the peripheral direction, the ribs are significantly narrower than
the sections. The sections are magnetized in a peripheral
direction, but with alternating polarity. The ribs close the
circles of magnetic flux by allowing lines of magnetic flux to
enter and exit the sidewall outer layer after moving through the
surrounding air and the magnetized sections, respectively. The ribs
focus the location of the entry and exit of the lines of magnetic
flux into and out of the sidewall outer layer. This focused entry
and exit is achieved by the accumulation of magnetized material in
the ribs which causes the lines of magnetic flux moving through the
ribs to point in a direction perpendicular to the plane of the tire
sidewall. As a result of this focused entry and exit, sharp edges
between the areas of opposite polarization are achieved which
enables the precise measurement of the peripheral locations of the
lines of magnetic flux. By enabling such a precise measurement, the
present invention provides for a more accurate determination of
information relating to the dynamic behavior of the tire.
Inventors: |
Cetin, A. Yuecel;
(Cornelius, NC) ; Giustino, James M.; (Waxhaw,
NC) |
Correspondence
Address: |
CALFEE HALTER & GRISWOLD, LLP
800 SUPERIOR AVENUE
SUITE 1400
CLEVELAND
OH
44114
US
|
Family ID: |
23365151 |
Appl. No.: |
10/033248 |
Filed: |
October 29, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10033248 |
Oct 29, 2001 |
|
|
|
09347757 |
Jul 6, 1999 |
|
|
|
Current U.S.
Class: |
152/523 |
Current CPC
Class: |
B60C 2019/005 20130101;
G01P 3/487 20130101; B60C 13/02 20130101; B60C 13/04 20130101; Y10T
152/10495 20150115 |
Class at
Publication: |
152/523 |
International
Class: |
B60C 005/00 |
Claims
What is claimed is:
1. An elastomeric tire with at least one magnetized surface area,
wherein the at least one magnetized area comprises protrusions at
locations where lines of magnetic flux enter or exit the surface
area.
2. A tire according to claim 1, wherein the protrusions consist of
accumulations of magnetizable material.
3. A tire according to claim 1, wherein the protrusions form one
piece with the respective magnetized area.
4. A tire according to claim 1 with an intended rotary direction,
wherein the protrusions are shaped as ribs extending
perpendicularly to the rotary direction.
5. A tire according to claim 1, wherein at least one tire sidewall
comprises a magnetized area.
6. A method of manufacturing an elastomeric tire with at least one
magnetized area comprising the steps of: applying a surface area of
magnetizable material; forming a plurality of protrusions on the
surface area; magnetizing the surface area in a pattern with lines
of a magnetic flux entering and exiting the surface area at the
locations of the protrusions.
7. A method according to claim 6 including the step of producing
the magnetizable material by adding ferromagnetic particles to an
elastomeric material.
8. A method according to claim 7, wherein the ferromagnetic
particles comprise strontium ferrite.
9. A method of manufacturing an elastomeric tire with at least one
magnetizable area comprising the steps of: producing a magnetizable
material by adding ferromagnetic particles to an elastomeric
material; applying a layer of magnetizable material as a surface
area to an unvulcanized elastomeric tire; and forming a plurality
of protrusions on the surface area.
10. A method according to claim 9, comprising the step of:
vulcanizing the tire.
11. A tire, comprising: a magnetized outer layer; the magnetized
outer layer being peripherally divided into sections of alternating
polarity; and the magnetized outer layer including radially
extending ribs between each adjacent pair of sections, the ribs
protruding above the sections.
12. The tire of claim 11, wherein the magnetized outer layer is a
part of a sidewall of the tire.
13. The tire of claim 12, wherein the ribs extend over at least
part of the radially outer area of the sidewall outer layer.
14. The tire of claim 11, wherein the ribs are equidistant from one
another in the peripheral direction.
15. The tire of claim 11, wherein the ribs are significantly
narrower than the sections in the peripheral direction.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to an elastomeric
tire and a method of manufacturing same and, more particularly, to
a tire with a sidewall having a magnetized outer layer, the
sidewall outer layer being peripherally divided into sections of
alternating polarity with radially extending ribs between each
adjacent pair of sections, and a method of manufacturing same.
BACKGROUND OF THE INVENTION
[0002] Published European Patent Application 849 597 describes a
tire comprising at least one magnetized area which can be used for
instance for providing information about the rotary speed of the
tire when mounted on a vehicle and to measure other physical
quantities. The subject of this published patent application is a
tire that, at least at one predetermined location, contains a
rubber mixture that is permeated with magnetizable particles. These
magnetizable locations, in general an annular band in the sidewall
of the tire, have successive sections of alternating magnetization,
either equidistant or in a pattern. Thus, with the aid of a sensor
that is secured to the chassis, not only the rotational speed of
the respective wheel can be provided, but also, by measuring the
tire distortion through deflection of the applied magnetized
sections, forces acting on the tires can be determined.
[0003] This known tire is manufactured by mixing ferromagnetic
particles into the rubber mixture which is applied to the area
where the magnetization is carried out. The magnetization is then
achieved by applying magnetic fields with lines of flux that extend
in the peripheral direction of the tire in alternating
polarizations. This magnetization is effected after installation of
the magnetizable rubber mixture and after vulcanization thereof.
Also described is an apparatus to carry out the magnetization.
[0004] It has been found, however, that, on the tire described, the
desired magnetization is very hard to achieve. Depending on the
method applied, either there is no identifiable signal at all, or
the magnetized areas of opposite polarizations are not separated by
the desired narrow line but, instead, wide lines are formed which
blur and distort the signals detected by a respective sensor. Thus
the measurements obtained are imprecise.
SUMMARY OF THE INVENTION
[0005] The present invention provides a tire with a sidewall having
a magnetized outer layer. The sidewall outer layer is peripherally
divided into sections with radially extending ribs between each
adjacent pair of sections. The ribs protrude above the sections. In
the peripheral direction, the ribs are significantly narrower than
the sections. The sections are magnetized in a peripheral
direction, but with alternating polarity. The ribs close the
circles of magnetic flux by allowing lines of magnetic flux to
enter and exit the sidewall outer layer after moving through the
surrounding air and the magnetized sections, respectively.
[0006] The ribs focus the location of the entry and exit of the
lines of magnetic flux into and out of the sidewall outer layer.
This focused entry and exit is achieved by the accumulation of
magnetized material in the ribs which causes the lines of magnetic
flux moving through the ribs to point in a direction perpendicular
to the plane of the tire sidewall. As a result of this focused
entry and exit, sharp edges between the areas of opposite
polarization are achieved which enables the precise measurement of
the peripheral locations of the lines of magnetic flux. By enabling
such a precise measurement, the present invention provides for a
more accurate determination of information relating to the dynamic
behavior of the tire.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows a side view of a tire constructed according to
the principles of the present invention in which an outer layer of
a sidewall of the tire is peripherally divided into sections of
alternating polarity with radially extending ribs between each
adjacent pair of sections;
[0008] FIG. 2 shows a cross-sectional view of the sidewall outer
layer shown in FIG. 1 taken along arcuate line 2-2;
[0009] FIG. 3 shows an alternate embodiment for the arrangement of
radially extending ribs on a sidewall outer layer; and
[0010] FIG. 4 shows another alternate embodiment for the
arrangement of radially extending ribs on a sidewall outer
layer.
DETAILED DESCRIPTION OF THE INVENTION
[0011] In FIG. 1, a tire 1 is depicted with a sidewall 2 having a
magnetized outer layer 3. Throughout the following description, the
term "peripheral" is used for the direction along a rotary movement
of the tire sidewall, while "radial" is used for directions
perpendicularly crossing an imaginary rotary axis of the tire,
i.e., from hub to tread. The sidewall outer layer 3 is peripherally
divided into sections 4 and 5 with radially extending protrusions
or ribs 6 between each adjacent pair of sections 4 and 5. The ribs
6 protrude above the sections 4 and 5 (see FIG. 2).
[0012] In the embodiment of the invention shown in FIGS. 1 and 2,
the ribs 6 are equidistant from one another in the peripheral
direction. However, depending on the purpose to be served, the
peripheral distance between the ribs 6 could vary. By varying the
peripheral distance between the ribs 6, a unique pattern can be
established. In the peripheral direction, the ribs 6 are
significantly narrower than the sections 4 and 5. Generally, the
sidewall outer layer 3 includes as many ribs as feasible to enable
the precise measurement of the lines of magnetic flux, even at low
speeds. For a standard passenger tire, the sidewall outer layer 3
includes approximately 96 ribs where the height x of the ribs 6 is
less than or equal to {fraction (1/16)} of an inch, the width y of
the ribs 6 is less than or equal to {fraction (1/16)} of an inch,
and the width z of the sections 4 and 5 is approximately 2 inches.
For a larger truck tire, however, the sidewall outer layer could
include 200 or more ribs. In the embodiment of the invention shown
in FIG. 2, the ribs 6 have a generally semicircular shape in
cross-section. However, the ribs 6 could have other shapes, e.g.,
triangular, square.
[0013] FIG. 2 shows the lines of magnetic flux in the sidewall
outer layer 3, including the sections 4 and 5 and the ribs 6.
Generally, the sections 4 are magnetized in a clockwise orientation
with respect to the tire as shown by lines of magnetic flux 7 and
the sections 5 are magnetized in a counterclockwise orientation as
shown by lines of magnetic flux 8. Thus, the magnetization of the
sections 4 and 5 is always applied in a peripheral direction, but
with alternating polarity. Outside of the sidewall outer layer 3 in
the surrounding air, lines of magnetic flux 9 correspond to lines 7
and lines of magnetic flux 10 correspond to lines 8. The ribs 6
close the circles of magnetic flux by allowing lines of magnetic
flux 11 to enter the sidewall outer layer 3 after moving through
the surrounding air and lines of magnetic flux 12 to exit the
sidewall outer layer 3 after moving through either magnetized
section 4 or 5. Thus, one circle of magnetic flux is formed by the
lines of magnetic flux 7, 12, 9, 11, in this order. A circle of
magnetic flux in the opposite direction is formed by the lines of
magnetic flux 8, 12, 10, 11. As can be seen from FIG. 2, the
present invention utilizes the principle of a horseshoe magnet in
the magnetized sidewall outer layer 3. The ribs 6 form alternating
North and South poles N and S, where each of the poles is shared by
two adjacent imaginary horseshoe magnets. The sidewall outer layer
3, including the sections 4 and 5 and the ribs 6, can be magnetized
using any known method of magnetization. Such methods are
well-known in the art and will not be discussed herein.
[0014] As can be seen from FIGS. 1 and 2 the ribs 6 focus the
location of the entry and exit of the lines of magnetic flux into
and out of the sidewall outer layer 3. This focused entry and exit
is achieved by the accumulation of magnetized material in the ribs
6 which causes the lines of magnetic flux 11 and 12 to point in a
direction perpendicular to the plane of the tire sidewall 2. As a
result of this focused entry and exit, sharp edges between the
areas of opposite polarization are achieved which enables the
precise measurement of the peripheral locations of the lines of
magnetic flux. By enabling such a precise measurement, the present
invention provides for a more accurate determination of information
relating to the dynamic behavior of the tire (as will be discussed
in greater detail below).
[0015] The ribs 6 separating the sections 4 and 5 of opposite
polarization of magnetization do not have to radially extend over
the entire sidewall outer layer 3. FIG. 3 shows an alternate
embodiment of the invention where ribs 16 only extend over the
radially outer half of sidewall outer layer 13. Similarly, FIG. 4
shows another alternate embodiment where ribs 26 only extend over
the radially central area of sidewall outer layer 23. Generally,
however, the ribs preferably extend over at least part of the
radially outer area of the sidewall outer layer. The ribs 16 and 26
in FIGS. 3 and 4 serve the same purpose as the ribs 6 in FIGS. 1
and 2.
[0016] Typically, the present invention is applied to a pneumatic
tire and the magnetization is carried out from the outside of the
inner sidewall of the tire. However, the present invention could be
applied to any piece of rubber or other elastomeric material that
can be magnetized.
[0017] For a suitable rubber mixture, European Patent Application
849 597 discloses a mixture that contains particles of neodymium
iron boride or of another ferromagnetic substance. Tests have shown
that iron oxide, Fe.sub.2O.sub.3, and strontium ferrite, SrFe, are
also suitable for this purpose. The ferromagnetic substance will be
mixed into the soft rubber in powder form. Due to the fact that the
applied magnetization is reduced at temperatures above the
vulcanization temperature, the magnetization is applied after
vulcanization. The sidewall 2, including the sidewall outer layer
3, is extruded from the rubber mixture. The tire 1, including the
sidewall 2 and all other components of the tire, will be put into
its final form using a tire mold, as is well-known in the art. Only
afterwards, the peripherally alternating magnetic fields are
applied to the sidewall outer layer 3 which results in the
magnetization shown in FIGS. 1 and 2.
[0018] A tire constructed according to the principles of the
present invention can be used to generate signals which can be
detected by sensors and used to identify the tire or to determine
information relating to the dynamic behavior of the tire. Some of
the information which can be determined using the present invention
include the rotational speed of the tire, the angular position of
the tire, the lateral or cornering forces on the tire, the radial
forces on the tire, and the longitudinal forces on the tire (e.g.,
sidewall torsion, torques, and fore-aft forces). For example, in
order to determine the sidewall torsion, a tone wheel can be
attached to a vehicle chassis and used to compare the location of
the radially inner and outer portions of the ribs. The results of
such a comparison are used to determine the sidewall torsion of the
tire. The determination of accurate information relating to the
dynamic behavior of the tire depends on the precise measurement of
the lines of magnetic flux. By enabling such a precise measurement,
the present invention provides for a more accurate determination of
the information.
* * * * *