Compagnie Generale Des Etablissements Michelin

Michelin Recherche Et Technique S.a.

Societe Detechnologie Michelin

François Barbarin

Guillaume Demaziere

Robert C Radulescu

Jean Coue

Jacques Besson

Olivier Ropars

Alain Domingo

Robert Ciprian Radulescu

Aurore Lardjane

Philippe Mansuy

William License

Olivier Reix

Gilles Sallaz

Lucas Lauby

Jean-Luc Guerbert-Jubert

Robert Radulescu

Radial carcass tire for a civil engineering vehicle, having two bead wires () of radial height Ht, and carcass reinforcement made of two layers, the first () being radially innermost with a radial height Hdc, is anchored in each bead to form a main part () and a turn-up (). The second layer () is radially outside the first layer (). The free end (A) of the turn-up () is at a radial distance from the radially outermost point () of the bead wire that is at least equal to 1 and at most equal to 2 times Ht. From the end A of the turn-up () to the point B at 85% of the radial height Hdc, the distance between carcass layers is at least equal to 2 and at most equal to 11 times the diameter of metal reinforcers of first carcass layer ().

Optimized architecture of a civil engineering tire

Tire () for a heavy-duty vehicle of civil engineering type, and more particularly to the tread () thereof, and seeks to improve the grip thereof, while at the same time ensuring a satisfactory compromise with wearing and thermal endurance. The tread () comprises cuts () distributed, in a circumferential direction (XX') of the tire, among circumferential grooves () and, in an axial direction (YY&#x2032;) of the tire, transverse sipes () and transverse grooves (), the cuts () delimiting elements in relief (), each cut () being delimited by two faces facing one another and each face intersecting the tread surface () along an edge corner (). The tread () having a longitudinal edge corners ratio TAequal to the ratio L/S between the sum Lof the projections, on to the circumferential direction (XX&#x2032;), of the effective edge corner lengths, contained in an elementary tread surface portion of surface area S, and the surface area S, and a transverse edge corners ratio TAequal to the ratio L/S between the sum Lof the projections, onto the axial direction (YY&#x2032;), of the effective edge corner lengths, contained in an elementary tread surface portion of surface area S, and the surface area S, the longitudinal edge corners ratio TAis at least equal to 4 mand the transverse edge corners ratio TAis at least equal to 6 m.

Tread for a tire of a heavy civil engineering vehicle

Tread () for a tire of an off-road vehicle. Total width Wt of the tread is greater than 600 mm and has at least three circumferential main grooves () at least 60 mm deep that divide the tread into intermediate ribs () and edge ribs (). The edge ribs have a width&#x2264;0.25 Wt. At least one of the intermediate ribs () has fine grooves () of depth Hdelimiting blades of material () of mean width BH. Grooves () are oriented in the axial direction of the tire. Each intermediate rib () has a mean width&#x2264;0.25 Wt and &#x2265;0.75 Ht (thickness of material to be worn away). Grooves, () have, over a height Hat least equal to 65% of H, a width&#x2264; to the value obtained from 0.04&#x221a;{square root over (B&#xb7;H)}.

Siped tread for off-road tire

Tread of a tire () for a heavy-duty vehicle of civil engineering type. The tread (), having an axial width Wand having a radial thickness Hat least equal to 70 mm, comprises at least two circumferential grooves () positioned axially on each side of an equatorial plane (XZ). Each circumferential groove () has an axial width W and a radial depth H, such that the ratio W/H is at least equal to 0.06, the axial distance C between two consecutive circumferential grooves () is at least equal to 12% and at most equal to 21% of the axial width Wof the tread and each of the axially outermost circumferential grooves () is positioned axially, with respect to the equatorial plane XZ, at an axial distance Lat least equal to 35% of the axial width Wof the tread.

Tire tread for a heavy civil-engineering vehicle

The tread has a total width W and is provided with circumferential cuts that have a mean depth at least equal to 70 mm and at most equal to the thickness of wearable material. The circumferential cuts divide the tread into a middle region with an axial width Wm of 50% to 80% of the total width W. The middle region has transverse or oblique sipes opening into the circumferential cuts and closing at least in part when they enter the contact patch. The sipes have a depth at least equal to 75% of the depth of the circumferential cuts and delimit elements of material of height equal to the mean depth H of the said sipes and of circumferential length B equal to the mean distance between two sipes. For all the elements of material, the ratio H/B is greater than 0.5 and at most equal to 2.5.

Incised tread for civil engineering tire

A tire comprising a crown reinforcement formed from at least two working crown layers of reinforcing elements and at least one layer of circumferential reinforcing elements, wherein, the tensile modulus of elasticity at 10% elongation of at least one skim coat of at least one working crown layer is greater than 9 MPa and the maximum value of tan(&#x3b4;), denoted tan(&#x3b4;)max, of said skim coat is less than 0.100.

Tire comprising a layer of circumferential reinforcing elements

Tire tread

A tire having a crown reinforcement formed of at least two working crown layers having unequal axial widths, a layer C of rubber mixture being positioned between at least the ends of the said at least two working crown layers, and the crown reinforcement having at least one layer of circumferential reinforcing elements positioned radially between two working crown layers. The distance d between the end of the axially narrowest working layer and the working layer separated from the axially narrowest working layer by the layer C of rubber mixture is such that 1.1&#xf8;&#x3c;d&#x3c;2.2&#xf8;, &#xf8; being the diameter of the reinforcing elements of the said at least one layer of circumferential reinforcing elements, and, in a meridian plane, the thickness of the layer C of rubber mixture is substantially uniform.

A tire having a radial carcass reinforcement comprising a crown reinforcement formed of at least two working crown layers of inextensible reinforcement elements, which are crossed from one ply to the other, forming angles of between 10&#xb0; and 45&#xb0; with the circumferential direction, which itself is topped radially by a tread, said tread being joined to two beads by means of two sidewalls and at least two working layers having different axial widths. At least one first profiled element P of rubber mix separates one working layer from at least one end of a second, axially narrower, layer, said profiled element P being radially separated at least in part from the liner C of said axially narrower working layer by a second profiled element of rubber mix G, said first and second profiled elements of rubber mix P and G and said liner C having secant moduli of elasticity under tension at 10% elongation MP, MG, MC respectively such that MC&#x2267;MG&#x3e;MP, said tire additionally comprising in each shoulder at least one layer of reinforcement elements, which are parallel to each other in the additional layer and are oriented substantially perpendicular relative to the reinforcement elements of the working layer radially adjacent to said additional layer, and the axially inner end of said additional layer being radially adjacent to the edge of at least one working crown layer.

Tire for heavy vehicles

A tire having a radial carcass reinforcement comprising a crown reinforcement formed of at least two working crown layers of inextensible reinforcement elements, which are crossed from one ply to the other, forming angles of between 10&#xb0; and 45&#xb0; with the circumferential direction, which itself is topped radially by a tread, said tread being joined to two beads by means of two sidewalls and the axially widest working crown layer being radially internal to the other working crown layers. The tire comprises additionally in each shoulder at least one layer of reinforcement elements which are parallel to each other in the layer and are oriented circumferentially, the axially inner end of said additional layer being radially adjacent to the edge of a working crown layer, at least part of said additional layer being radially and/or axially adjacent to the edge of the axially widest working crown layer and the axially outer end of said additional layer being radially internal to the axially widest working crown layer.

Growing community of inventors

Clermont-Ferrand, France

François Barbarin