US 11,850,893 B2
Tire having optimized sidewalls and crown reinforcement made up of two working crown layers and a layer of circumferential reinforcing elements
Hichem Rehab, Clermont-Ferrand (FR); Sébastien Noel, Clermont-Ferrand (FR); Maxime Rolland, Clermont-Ferrand (FR); and Patrick Dayet, Clermont-Ferrand (FR)
Assigned to COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, Clermont-Ferrand (FR)
Appl. No. 17/616,089
Filed by COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, Clermont-Ferrand (FR)
PCT Filed Jun. 4, 2020, PCT No. PCT/EP2020/065416
§ 371(c)(1), (2) Date Dec. 2, 2021,
PCT Pub. No. WO2020/245240, PCT Pub. Date Dec. 10, 2020.
Claims priority of application No. 1906038 (FR), filed on Jun. 6, 2019.
Prior Publication US 2022/0314710 A1, Oct. 6, 2022
Int. Cl. B60C 15/00 (2006.01); B60C 15/06 (2006.01); B60C 9/00 (2006.01); B60C 9/04 (2006.01); B60C 15/024 (2006.01); B60C 9/02 (2006.01); B60C 9/20 (2006.01)
CPC B60C 15/0628 (2013.01) [B60C 9/0007 (2013.01); B60C 9/04 (2013.01); B60C 15/024 (2013.01); B60C 2009/0269 (2013.01); B60C 2009/2012 (2013.01); B60C 2015/065 (2013.01); B60C 2200/06 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A tire configured to be fitted on a drop-center rim of the “15° drop-center” type, comprising:
a radial carcass reinforcement made up of a single carcass reinforcement layer formed of reinforcement elements,
a crown reinforcement, comprising two working crown layers of reinforcing elements that are crossed from one layer to the other, making with the circumferential direction angles (α1, α2) greater than 8°, said angles α1 and α2 being oriented on either side of the circumferential direction, and at least one layer of circumferential reinforcing elements,
the crown reinforcement being radially capped by a tread,
said tread being connected to two beads via two sidewalls,
the carcass reinforcement layer being anchored in each of the beads by being turned up around a bead wire to form a main part of the carcass reinforcement layer extending from one bead wire to the other, and
a turn-up of the carcass reinforcement layer in each of the beads, said turn-up of the carcass reinforcement being reinforced by at least one layer of reinforcement elements or a stiffener, wherein:
said two working crown layers and said at least one layer of circumferential reinforcing elements are the only ones present to form the crown reinforcement over not less than 75% of the axial width of the crown reinforcement,
the reinforcing elements of the radially outermost working crown layer (52) form an angle (α2) with the circumferential direction that is greater in terms of absolute value than the angle (α1) formed by the reinforcing elements of the radially innermost working crown layer (51) with the circumferential direction,
the absolute value of the difference between the absolute values of the angles (α2) and (α1) is greater than 7°,
the mean angle α satisfies the relationship:
13+131*exp(−L/100)<α<28+110*exp(−L/100),
α being defined by the relationship α=Arctan((tan(|α1|)*tan(|α2|))1/2), L being the maximum width of the tire measured in the axial direction and expressed in mm,
the metal reinforcing elements of said carcass reinforcement layer are cords that, in the test referred to as the permeability test, yield a flow rate of less than 20 cm3/min, and
a rubber compound is present at least locally within the structure of said cords,
in each of the beads, in a meridian section of said tire:
any point of the profile of the outer surface (S) of the tire, between a first point (F), itself defined by the intersection of an axially oriented straight line, passing through the axially outermost point (E) of the main part of the carcass reinforcement layer and the outer surface (S) of the tire, and a point (A), is at a constant distance (T) from the main part of the carcass reinforcement layer, said distance being measured at any point in a direction normal to the main part of the carcass reinforcement layer,
wherein the point (A) is radially on the outside of a first circle (C1) of radius (R1) that is centered on the end of the turn-up of the carcass reinforcement layer, (R1) being between 8 and 13 mm,
radially on the inside of the point (A), the outer surface (S) of the tire extends by an arc of a circle of radius (R2), the center of which is axially on the outside of the surface (S) of the tire,
the circular arc of radius (R2) is tangential at its radially innermost end (B) to a circular arc of radius (R3), the center of which is axially on the inside of the surface (S) of the tire, and continues the outer surface (S) of the tire radially inwards as far as the point (C), said point (C) being a point of tangency between the circular arc of radius (R3) and the circle (C2) of radius (R1) centered on the radially outermost end of the stiffener, and
wherein said point (C) being radially on the inside of the axially outermost point (D) of the circle (C2).