Tire with working layers comprising an optimized architecture and tread design

A tire comprising:

• a tread intended to come into contact with a ground via a tread surface having an axial width L and comprising a central part of the tread having a width equal to 0.8*L, the central part of the tread comprising at least two circumferential furrows,
• each circumferential furrow forming a space that opens onto the tread surface around an entire circumference of the tire and being delimited by two main lateral faces connected by a bottom face, and having a mean width Ws at least equal to 6 mm and a depth D at least equal to 4 mm,
• the central part of the tread comprising grooves forming a space that opens onto the tread surface, forming an angle at least equal to 15° with a circumferential axis, and being delimited by two main lateral faces connected by a bottom face, a groove having a width Wr defined by a mean distance between the two lateral faces, and having a width Wr at least equal to 0.5 mm, at least fifty percent of the grooves being open grooves that open into one or two circumferential furrows, and
• each open groove comprising a bottom curve Cf formed by all of the radially innermost points of the bottom surface of the groove, each bottom curve comprising at least one point Ps, and at most two, in common with the furrow or the two furrows into which the groove opens, and a radially outermost point Pext;
• a carcass layer and a crown reinforcement, radially on the inside of the tread, comprising at least one crown layer, the crown layer being a layer of reinforcing elements,
• the crown reinforcement comprising a working reinforcement comprising at least one working layer,
• each working layer comprising reinforcing elements which are at least partially made of metal coated in an elastomer material, are mutually parallel and form with the circumferential direction of the tire an oriented angle of which the absolute value is at least equal to 15° and at most equal to 50°,
• each crown layer extending radially from a radially inner surface to a radially outer surface,
• the radially outermost crown layer vertically beneath the central part of the tread comprising at least one central undulation with a radial amplitude A,
• the portion of the radially outer surface of the crown layer of the central undulation is radially on the outside of the points of the radially outermost crown layer vertically beneath the bottom face of the circumferential furrow closest to the central undulation,
• over at least 10% of the radially outer surface of the crown layer vertically beneath the central part of the tread, a radial distance between the radially outer surface of the radially outermost crown layer and the tread surface at the central undulation is at least 1 mm less than a radial distance between the radially outer surface of the radially outermost crown layer and the tread surface, this being the distance vertically beneath the bottom face of the circumferential furrow closest to the point in question on the surface, and
• the radial distance between the radially outer surface of the radially outermost crown layer and the bottom face of the circumferential furrows is at most equal to 4 mm,
• wherein at least 50% of the open grooves radially on the outside of the central undulation of the radially outermost layer of reinforcing elements are adapted to the central undulation,
• wherein an open groove that is adapted to the undulation which it is radially on the outside of being such that the intersection point Ps of the bottom curve Cf of the open groove adapted to the undulation and of the circumferential furrow into which the open groove adapted to the undulation opens are at a distance from the radially outermost point Pext of the bottom curve Cf by a radial distance at least equal to one third of the radial amplitude of the central undulation situated vertically beneath the open groove adapted to the undulation, and
• wherein the curve Cf increases radially from the intersection point Ps to the point Pext.