Title of Invention	"A TYRE HAVING AN HEIGHT TO MAXIMUM AXIAL WITDTH RATIO OF AT LEAST 0.50"
Abstract	A tire having an Heterologous/S form ratio of at least 0.50, having a radial carcass reinforcement (1) and crown rein¬forcement (3) composed of at least two working crown plies (31,33) made of inextensible metal cables, crossed from one ply to the next, forming angles of between 10° and 45° with the circumferentail direction, and of an additional ply (32) which is axially continuous and formed of metallic elements oriented substantially parallel circumferential direction. Said ply (32) over the working ply (31) radially closest carcass reinforcement (1,) and the ratio of its rigidity of extension per unit of width to the total of the rigidities of extension of the other plies of the crown reinforcement being between 0.35 and 0.70.

Title of Invention

"A TYRE HAVING AN HEIGHT TO MAXIMUM AXIAL WITDTH RATIO OF AT LEAST 0.50"

Abstract

A tire having an Heterologous/S form ratio of at least 0.50, having a radial carcass reinforcement (1) and crown rein¬forcement (3) composed of at least two working crown plies (31,33) made of inextensible metal cables, crossed from one ply to the next, forming angles of between 10° and 45° with the circumferentail direction, and of an additional ply (32) which is axially continuous and formed of metallic elements oriented substantially parallel circumferential direction. Said ply (32) over the working ply (31) radially closest carcass reinforcement (1,) and the ratio of its rigidity of extension per unit of width to the total of the rigidities of extension of the other plies of the crown reinforcement being between 0.35 and 0.70.

Full Text	The invention relates to a tyre with radial carcass reinforcement anchored in each bead to at least one bead wire, and comprising a crown reinforcement formed by at least two so-called working plies, superposed and formed of reinforcing elements which are parallel to each other in each ply and are crossed from one ply to the next, forming angles of at most 40° in absolute value with the circumferential direction of the tyre. French Application FR 94/15,736, which has not hitherto been published, relates to a tyre as described above, and more particularly to a "heavy goods vehicle"-type tyre, the ratio of the height above rim H to the maximum axial width S of which is at most 0.60. Said application, in order to improve the life of the crown reinforcement of such a tyre, and also the regularity of wear of the tread thereof, requires an architecture of the crown reinforcement characterised by the combined presence in said reinforcement of an axially continuous ply formed of inextensible metal reinforcing elements forming an angle of at least 60° with the circumferential direction of the tyre, and a ply of metallic elements oriented substantially parallel to the circumferential direction, arranged radially between the two working crown plies. Such an architecture makes it possible to obtain better resistance to separation between working plies, and also better fatigue strength of the cables of the carcass reinforcement located beneath the crown reinforcement thus formed. The axial width of the additional ply of circumferential reinforcing elements may be less than the widths of the working plies. Since the operating temperatures in the tyres of form ratio of at least 0.50 are not negligible, the Applicants' research has led them to look for a solution which is more effective from the thermic and economic points of view. In order to improve the life of the crown reinforcement and subjacent carcass reinforcement of a tyre, without using a crown ply formed by metal cables very greatly inclined relative to the circumferential direction of the tyre and located radially above the carcass reinforcement, the present invention proposes a more economic solution than that described in the above French application. The tyre having an H/S form ratio of at least 0.50, according to the invention, comprises a radial carcass reinforcement and a crown reinforcement composed of at least two working crown plies made of inextensible metal cables, crossed from one ply to the next, forming angles of between 10° and 45° with the circumferential direction, and of an additional ply which is axially continuous and formed of metallic reinforcing elements oriented substantially parallel to the circumferential direction, the presence of a crown ply formed of metal cables oriented relative to the circumferential direction by an angle greater than 45° being ruled out. Said additional ply is arranged radially over the working crown ply radially closest to the carcass reinforcement, and the ratio of its rigidity of extension • under tensile stress to the total of the rigidities of extension of the other plies of the crown reinforcement is between 0.35 and 0.70. Advantageously, from both the technical and the economic point of view, the value of this ratio will be obtained by using in the so-called additional ply metallic elements made of steel, of a larger diameter than that of the metal cables made of steel forming the working plies. "Inextensible cable" is to be understood to mean a cable, for instance a steel cable, which has a relative elongation of less than 0.5% measured at 25% of its breaking load. Metallic elements oriented substantially parallel to the circumferential direction are elements which form angles within the range of +2.5°, -2.5° around 0° with said direction. The rigidity of extension of a ply of reinforcing elements results from the tensile force exerted in the direction of the cables per unit of width of ply which is necessary to obtain a given relative elongation e, and may be expressed by the formula R = l/p . dF/de, R being the rigidity of the ply in question, p the pitch between the elements of said ply, dF/de the derivative of the tensile force relative to the relative elongation, and e being equal to 0.5%. In the above context, the additional ply may be formed of so-called semi-elastic continuous steel cables, that is to say cables having relative elongations upon rupture of between 2% and 6%. These cables make it possible to obtain the level of rigidity suitable for proper distribution of the circumferential tension between the working crown plies and the additional ply. Said cables are advantageously said to be "bimodular", that is to say, having a curve of tensile stress as a function of relative elongation having gradual slopes for the low elongations and a substantially constant, steep slope for the higher elongations. The very low modulus before curing for elongations of less than 2% permits an increase in the circumferential development of the additional ply during the curing of the tyre. The additional ply may also be formed of metal cables made of steel, oriented circumferentially and cut so as to form sections of a length very much less than the circumferential length of the ply, the cuts between sections being circumferentially offset relative to each other. Such an embodiment makes it possible, in simple manner, to impart to the additional ply the desired rigidity, whatever it may be. The crown reinforcement according to the invention will advantageously be finished off by a so-called protective crown ply, formed of elastic metal cables made of steel, oriented relative to the circumferential direction at an angle egual to the angle formed by the cables of the radially outermost working crown ply, and the axial width of which is greater than the axial width of the additional ply of metallic elements made of steel, whilst remaining less than the axial width of the radially outermost working ply. The characteristics and advantages of the invention will be better understood with reference to the following description, which refers to the drawing, illustrating in non-limitative manner an example of embodiment, and in which the single figure 1 shows a diagram, viewed in meridian section, of a crown reinforcement according to the invention. The tyre P, of dimension 315/80 R 22.5, has an H/S form ratio of 0.8, H being the height of the tyre P on its mounting rim and S its maximum axial width. Said tyre P comprises a radial carcass reinforcement (1) formed by a single ply of metal cables made of steel, anchored in each bead to at least one bead wire, forming an upturn. The carcass reinforcement (1) is hooped by a crown reinforcement (3), formed radially from the inside to the outside by a first working crown ply (31) formed of inextensible metal cables made of steel and oriented by an angle a of 22°, and the central part of which is parallel to the carcass reinforcement (1), the cables respectively of the carcass ply and of the working ply being separated only by the calendering thicknesses, the lateral parts being separated from the carcass reinforcement by rubber profiled elements (2) so as to impart a slight curvature to said ply; radially surmounting the first working ply (31), by an additional ply (32) formed of inextensible metallic elements made of steel, each element having a circumferential length substantially equal to 1/6 of the circumferential length of the ply (32), and said elements being oriented at 0°; then by a second working crown ply (33) formed of metal cables identical to those of the first ply (31), and forming an angle (3, opposed to the angle a and, in the case illustrated, equal to said angle a of 22° (but possibly being different from said angle a), with the circumferential direction; and finally by a final ply (34) of so-called elastic steel cables, oriented relative to the circumferential direction by an angle 9 of the same direction as the angle (3 and equal to said angle /3 (but possibly being different) , this last ply being a so-called protective ply, and so-called elastic cables being cables having a relative elongation of at least 4% upon rupture. The axial width L31 of the first working ply is equal to 0.28 times the maximum axial width SQ of the centre section of the carcass reinforcement (1), namely 226 mm, which for the tyre in question is substantially equal to the width of the tread, which is equal in the case in question to 235 mm. The axial width L^ of the second working ply (33) is less than the width Lj, of the first working ply (31) by an amount equal to 0.026 S0, namely a width of 204 mm. The axial width L^ of the additional ply (32) is equal to 160 mm, which represents 0.2 SQ. The final crown ply (34), referred to as a protective ply, has a width I>j4 which is very slightly greater than the width L^ of the additional ply, namely 170 mm. The rigidity of extension per unit of width of the working ply (31) or of the working ply (33), identical in the present case, since they are formed of the same non-hooped 9.28 metal cables made of steel, of a diameter of 1.09 mm, which are inextensible and continuous over the entire width of the ply, said cables being arranged with the same pitch of 1.8 mm, is greater than 4000 daN/mm at 0.5% relative elongation, and in the case in question equal to 5500 daN/mm. The rigidity of the same name and measured under the same conditions of the additional ply (32), formed of non-hooped 27.23 metal cables made of steel, and of a diameter of 1.4 mm, and cut so as to have sections of cables the circumferential length of which is substantially equal to 20% of the circumferential length of the ply, the rows of elements being separated from each other by a pitch of 2 mm, is then equal to 5500 daN/mm for the relative elongation of 0.5%. The tyre described above was tested, firstly on a test drum, under conditions simulating travel on a vehicle under a load of 4000 kg for an inflation pressure of 8.5 bar and at a drift angle of 5° and at a speed of 80 km/h, and secondly on a test vehicle under a load greater than 4500 kg for an inflation pressure of 8.5 bar, at an average speed of 105 km/h, the vehicle being able to be considered as travelling in a straight line. The measurements of temperature, in the tests on the vehicle, taken at the ends of the working crown plies show a slight gain in terms of operating temperature, but, on the other hand, a gain of at least 100% in mileage before rupture compared with a tyre of conventional architecture, that is to say with a crown reinforcement composed of a ply of greatly inclined cables, of two working plies of cables slightly inclined and crossed from one ply to the next, and a protective ply of elastic cables. The gain in mileage is just as great in the case of travelling on a test drum and at a drift of 5°, since it attains 80%: 7800 km covered by the tyre according to the invention, whereas the conventional tyre only covered 4430 km. The additional ply (32) may also be formed of so-called "bimodular" steel cables. Since a certain elasticity of the ply (32) is only useful during the shaping of the tyre in the vulcanisation mould, a cable having a low modulus, for example of at most 1000 daN/mm2, from the origin to 1% relative elongation and a modulus for instance greater than 8000 daN/mm2 for a relative elongation of more than 2%, can be used. 1. A tyre having an H/S form ratio of at least 0.50, comprising a radial carcass reinforcement (1) and a crown reinforcement (3) composed of at least two working crown plies (31, 33) made of inextensible metal cables, crossed from one ply to the next, forming angles of between 10° and 45° with the circumferential direction, and of an additional ply (32) which is axially continuous and formed of metallic reinforcing elements oriented substantially parallel to the circumferential direction, the presence of a crown ply formed of metallic elements forming an angle greater than 45° with the circumferential direction being ruled out, characterised in that said ply (32) is arranged over the working ply (31) radially closest to the carcass reinforcement (1), the ratio of its rigidity of extension per unit of width to the total of the rigidities of extension of the other plies of the crown reinforcement being between 0.35 and 0.70. 2. A tyre according to Claim 1, characterised in that the reinforcing elements of the additional ply (32) are made of steel and are of a larger diameter than that of the steel cables of the two working plies (31, 33). 3. A tyre according to one of Claims 1 or 2, characterised in that the additional ply (32) is formed of so-called semi-elastic continuous steel cables, having relative elongations upon rupture of between 2% and 6%, and a curve of tensile stress as a function of relative elongation having gradual slopes for the low elongations and a substantially constant, steep slope for the higher elongations. 4. A tyre according to Claim 3, characterised in that the cables have a low modulus, at most equal to 1000 daN/mm2, from the origin to 1% relative elongation and a modulus greater than 8000 daN/mm2 for a relative elongation of more than 2%. 5. A tyre according to one of Claims 1 or 2, characterised in that the additional ply (32) is formed of metal cables made of steel, oriented circum- ferentially and cut so as to form sections of a length very much less than the circumferential length of the ply, the cuts between sections being axially offset relative to each other. 6. A tyre according to one of Claims 1 to 5, characterised in that the crown reinforcement (3) is advantageously finished off by a crown ply (34), referred to as a protective ply, formed of elastic metal cables made of steel, oriented relative to the circumferential direction by an angle 8 of the same direction as the angle (3 of the cables of the radially outermost working ply (33), and the axial width L^ of which is greater than the axial width L^ of the additional ply (32) of metallic elements made of steel, whilst remaining less than the axial width Lj3 of the radially outermost working ply (33). 7. A tyre substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Full Text

The invention relates to a tyre with radial carcass reinforcement anchored in each bead to at least one bead wire, and comprising a crown reinforcement formed by at least two so-called working plies, superposed and formed of reinforcing elements which are parallel to each other in each ply and are crossed from one ply to the next, forming angles of at most 40° in absolute value with the circumferential direction of the tyre.
French Application FR 94/15,736, which has not hitherto been published, relates to a tyre as described above, and more particularly to a "heavy goods vehicle"-type tyre, the ratio of the height above rim H to the maximum axial width S of which is at most 0.60. Said application, in order to improve the life of the crown reinforcement of such a tyre, and also the regularity of wear of the tread thereof, requires an architecture of the crown reinforcement characterised by the combined presence in said reinforcement of an axially continuous ply formed of inextensible metal reinforcing elements forming an angle of at least 60° with the circumferential direction of the tyre, and a ply of metallic elements oriented substantially parallel to the circumferential direction, arranged radially between the two working crown plies.
Such an architecture makes it possible to obtain better resistance to separation between working plies, and also better fatigue strength of the cables of the carcass reinforcement located beneath the crown reinforcement thus formed. The axial width of the additional ply of circumferential reinforcing elements may be less than the widths of the working plies.
Since the operating temperatures in the tyres of form ratio of at least 0.50 are not negligible, the
Applicants' research has led them to look for a solution which is more effective from the thermic and economic points of view.
In order to improve the life of the crown reinforcement and subjacent carcass reinforcement of a tyre, without using a crown ply formed by metal cables very greatly inclined relative to the circumferential direction of the tyre and located radially above the carcass reinforcement, the present invention proposes a more economic solution than that described in the above French application.
The tyre having an H/S form ratio of at least 0.50,
according to the invention, comprises a radial carcass
reinforcement and a crown reinforcement composed of at
least two working crown plies made of inextensible
metal cables, crossed from one ply to the next, forming
angles of between 10° and 45° with the circumferential
direction, and of an additional ply which is axially
continuous and formed of metallic reinforcing elements
oriented substantially parallel to the circumferential
direction, the presence of a crown ply formed of metal
cables oriented relative to the circumferential
direction by an angle greater than 45° being ruled out.
Said additional ply is arranged radially over the
working crown ply radially closest to the carcass
reinforcement, and the ratio of its rigidity of
extension • under tensile stress to
the total of the rigidities of extension
of the other plies of the crown reinforcement is between 0.35 and 0.70.
Advantageously, from both the technical and the economic point of view, the value of this ratio will be obtained by using in the so-called additional ply metallic elements made of steel, of a larger diameter
than that of the metal cables made of steel forming the working plies.
"Inextensible cable" is to be understood to mean a cable, for instance a steel cable, which has a relative elongation of less than 0.5% measured at 25% of its breaking load.
Metallic elements oriented substantially parallel to the circumferential direction are elements which form angles within the range of +2.5°, -2.5° around 0° with said direction.
The rigidity of extension of a ply
of reinforcing elements results from the tensile force exerted in the direction of the cables per unit of width of ply which is necessary to obtain a given relative elongation e, and may be expressed by the formula R = l/p . dF/de, R being the rigidity
of the ply in question, p the pitch between the elements of said ply, dF/de the derivative of the tensile force relative to the relative elongation, and e being equal to 0.5%.
In the above context, the additional ply may be formed of so-called semi-elastic continuous steel cables, that is to say cables having relative elongations upon rupture of between 2% and 6%. These cables make it possible to obtain the level of rigidity suitable for proper distribution of the circumferential tension between the working crown plies and the additional ply. Said cables are advantageously said to be "bimodular", that is to say, having a curve of tensile stress as a function of relative elongation having gradual slopes for the low elongations and a substantially constant, steep slope for the higher elongations. The very low modulus before curing for elongations of less than 2%
permits an increase in the circumferential development of the additional ply during the curing of the tyre.
The additional ply may also be formed of metal cables made of steel, oriented circumferentially and cut so as to form sections of a length very much less than the circumferential length of the ply, the cuts between sections being circumferentially offset relative to each other. Such an embodiment makes it possible, in simple manner, to impart to the additional ply the desired rigidity, whatever it may be.
The crown reinforcement according to the invention will advantageously be finished off by a so-called protective crown ply, formed of elastic metal cables made of steel, oriented relative to the circumferential direction at an angle egual to the angle formed by the cables of the radially outermost working crown ply, and the axial width of which is greater than the axial width of the additional ply of metallic elements made of steel, whilst remaining less than the axial width of the radially outermost working ply.
The characteristics and advantages of the invention will be better understood with reference to the following description, which refers to the drawing, illustrating in non-limitative manner an example of embodiment, and in which the single figure 1 shows a diagram, viewed in meridian section, of a crown reinforcement according to the invention.
The tyre P, of dimension 315/80 R 22.5, has an H/S form ratio of 0.8, H being the height of the tyre P on its mounting rim and S its maximum axial width. Said tyre P comprises a radial carcass reinforcement (1) formed by a single ply of metal cables made of steel, anchored in each bead to at least one bead wire, forming an
upturn. The carcass reinforcement (1) is hooped by a crown reinforcement (3), formed radially from the inside to the outside
by a first working crown ply (31) formed of inextensible metal cables made of steel and oriented by an angle a of 22°, and the central part of which is parallel to the carcass reinforcement (1), the cables respectively of the carcass ply and of the working ply being separated only by the calendering thicknesses, the lateral parts being separated from the carcass reinforcement by rubber profiled elements (2) so as to impart a slight curvature to said ply;
radially surmounting the first working ply (31), by an additional ply (32) formed of inextensible metallic elements made of steel, each element having a circumferential length substantially equal to 1/6 of the circumferential length of the ply (32), and said elements being oriented at 0°;
then by a second working crown ply (33) formed of metal cables identical to those of the first ply (31), and forming an angle (3, opposed to the angle a and, in the case illustrated, equal to said angle a of 22° (but possibly being different from said angle a), with the circumferential direction;
and finally by a final ply (34) of so-called elastic steel cables, oriented relative to the circumferential direction by an angle 9 of the same direction as the angle (3 and equal to said angle /3 (but possibly being different) , this last ply being a so-called protective ply, and so-called elastic cables being cables having a relative elongation of at least 4% upon rupture.
The axial width L31 of the first working ply is equal to 0.28 times the maximum axial width SQ of the centre section of the carcass reinforcement (1), namely 226 mm, which for the tyre in question is substantially equal to the width of the tread, which is equal in the case in question to 235 mm. The axial width L^ of the second working ply (33) is less than the width Lj, of the first working ply (31) by an amount equal to 0.026 S0, namely a width of 204 mm. The axial width L^ of the additional ply (32) is equal to 160 mm, which represents 0.2 SQ. The final crown ply (34), referred to as a protective ply, has a width I>j4 which is very slightly greater than the width L^ of the additional ply, namely 170 mm.
The rigidity of extension per unit
of width of the working ply (31) or of the working ply (33), identical in the present case, since they are formed of the same non-hooped 9.28 metal cables made of steel, of a diameter of 1.09 mm, which are inextensible and continuous over the entire width of the ply, said cables being arranged with the same pitch of 1.8 mm, is greater than 4000 daN/mm at 0.5% relative elongation, and in the case in question equal to 5500 daN/mm. The rigidity of the same name and measured under the same conditions of the additional ply (32), formed of non-hooped 27.23 metal cables made of steel, and of a diameter of 1.4 mm, and cut so as to have sections of cables the circumferential length of which is substantially equal to 20% of the circumferential length of the ply, the rows of elements being separated from each other by a pitch of 2 mm, is then equal to 5500 daN/mm for the relative elongation of 0.5%.
The tyre described above was tested, firstly on a test drum, under conditions simulating travel on a vehicle

under a load of 4000 kg for an inflation pressure of 8.5 bar and at a drift angle of 5° and at a speed of 80 km/h, and secondly on a test vehicle under a load greater than 4500 kg for an inflation pressure of 8.5 bar, at an average speed of 105 km/h, the vehicle being able to be considered as travelling in a straight line. The measurements of temperature, in the tests on the vehicle, taken at the ends of the working crown plies show a slight gain in terms of operating temperature, but, on the other hand, a gain of at least 100% in mileage before rupture compared with a tyre of conventional architecture, that is to say with a crown reinforcement composed of a ply of greatly inclined cables, of two working plies of cables slightly inclined and crossed from one ply to the next, and a protective ply of elastic cables. The gain in mileage is just as great in the case of travelling on a test drum and at a drift of 5°, since it attains 80%: 7800 km covered by the tyre according to the invention, whereas the conventional tyre only covered 4430 km.
The additional ply (32) may also be formed of so-called "bimodular" steel cables. Since a certain elasticity of the ply (32) is only useful during the shaping of the tyre in the vulcanisation mould, a cable having a low modulus, for example of at most 1000 daN/mm2, from the origin to 1% relative elongation and a modulus for instance greater than 8000 daN/mm2 for a relative elongation of more than 2%, can be used.

1. A tyre having an H/S form ratio of at least 0.50,
comprising a radial carcass reinforcement (1) and a
crown reinforcement (3) composed of at least two
working crown plies (31, 33) made of inextensible metal
cables, crossed from one ply to the next, forming
angles of between 10° and 45° with the circumferential
direction, and of an additional ply (32) which is
axially continuous and formed of metallic reinforcing
elements oriented substantially parallel to the
circumferential direction, the presence of a crown ply
formed of metallic elements forming an angle greater
than 45° with the circumferential direction being ruled
out, characterised in that said ply (32) is arranged
over the working ply (31) radially closest to the
carcass reinforcement (1), the ratio of its rigidity of
extension per unit of width to the
total of the rigidities of extension
of the other plies of the crown reinforcement being between 0.35 and 0.70.
2. A tyre according to Claim 1, characterised in that
the reinforcing elements of the additional ply (32) are
made of steel and are of a larger diameter than that of
the steel cables of the two working plies (31, 33).
3. A tyre according to one of Claims 1 or 2,
characterised in that the additional ply (32) is formed
of so-called semi-elastic continuous steel cables,
having relative elongations upon rupture of between 2%
and 6%, and a curve of tensile stress as a function of
relative elongation having gradual slopes for the low
elongations and a substantially constant, steep slope
for the higher elongations.
4. A tyre according to Claim 3, characterised in that
the cables have a low modulus, at most equal to
1000 daN/mm2, from the origin to 1% relative elongation and a modulus greater than 8000 daN/mm2 for a relative elongation of more than 2%.
5. A tyre according to one of Claims 1 or 2,
characterised in that the additional ply (32) is formed
of metal cables made of steel, oriented circum-
ferentially and cut so as to form sections of a length
very much less than the circumferential length of the
ply, the cuts between sections being axially offset
relative to each other.
6. A tyre according to one of Claims 1 to 5,
characterised in that the crown reinforcement (3) is
advantageously finished off by a crown ply (34),
referred to as a protective ply, formed of elastic
metal cables made of steel, oriented relative to the
circumferential direction by an angle 8 of the same
direction as the angle (3 of the cables of the radially
outermost working ply (33), and the axial width L^ of
which is greater than the axial width L^ of the
additional ply (32) of metallic elements made of steel,
whilst remaining less than the axial width Lj3 of the
radially outermost working ply (33).
7. A tyre substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

378-del-1997-abstract.pdf

378-del-1997-claims.pdf

378-del-1997-correspondence-others.pdf

378-del-1997-correspondence-po.pdf

378-del-1997-description (complete).pdf

378-del-1997-drawings.pdf

378-del-1997-form-1.pdf

378-del-1997-form-13.pdf

378-del-1997-form-19.pdf

378-del-1997-form-2.pdf

378-del-1997-form-3.pdf

378-del-1997-form-4.pdf

378-del-1997-form-6.pdf

378-del-1997-gpa.pdf

378-del-1997-petition-137.pdf

378-del-1997-petition-138.pdf

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Patent Number

232360

Indian Patent Application Number

378/DEL/1997

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

16-Mar-2009

Date of Filing

17-Feb-1997

Name of Patentee

COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN-MICHELIN & CIE,

Applicant Address

12, COURS SABLON, F-63040 CLERMONT-FERRAND CEDEX 01, FRANCE.

Inventors:

#	Inventor's Name	Inventor's Address
1	ANDRE COLOM	64, AVENUE DE ROYAT, 63400 CHAMALIERES, FRANCE.

PCT International Classification Number

B60C 9/07

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	96/02177	1996-02-20	France