Abstract: A tire tread (1), for a heavy-duty construction plant vehicle, having an improved compromise between resistance to mechanical attack caused by stony ground and grip on muddy ground. The tread (1) having five rows (41, 42, 43) separated in pairs by a longitudinal cut (51, 52) and distributed, along the transverse direction (YY?), in a median row (43), two intermediate rows (42), and two lateral rows (41), the blocks (31, 32, 33) in one and the same row (41, 42, 43) being separated in pairs by a transverse cut (61, 62, 63), each transverse cut in a lateral row (41) is a transverse groove, each transverse cut (62) in an intermediate row (42) with a first transverse groove portion (621) and a second transverse sipe portion (622), and each transverse cut (63) in the median row (43) is a transverse sipe which is offset along the longitudinal direction (XX?).

Abstract: A tire tread (1), for a heavy-duty construction plant vehicle, having an improved compromise between resistance to mechanical attack caused by stony ground and grip on muddy ground. The tread (1) has five rows (41, 42, 43) separated in pairs by a longitudinal cut (51, 52) and are distributed, along the transverse direction (YY?), in a median row (43), two intermediate rows (42), and two lateral rows (41), the blocks (31, 32, 33) in one and the same row (41, 42, 43) separated in pairs at least partially by a transverse cut (61, 62, 63), each transverse cut in a lateral row (41) is a transverse groove, each transverse cut (62) in an intermediate row (42) is either a blind transverse groove (621), or a transverse sipe (622), are arranged in alternation along the longitudinal direction XX?, and each inner longitudinal cut (52) separating two adjacent rows (42, 43), respectively intermediate and median, is a longitudinal groove.

Abstract: A tire (1) for a heavy construction plant vehicle with satisfactory compromise between the breaking strength of its circumferential hoop reinforcement (7), having an axial width LF and having a circumferential hooping layer (71, 72) with elastic metallic reinforcers having a structural elongation AS and a force at break FR, and forming an angle at most equal to 5° with the circumferential direction (XX), and the endurance of its working reinforcement (6), formed by two working layers (61, 62) with inextensible metallic reinforcers, the mean angle AM of which with the circumferential direction (XX?) is at least equal to 15° and at most equal to 45°. The axial width LF, the structural elongation As, the force at break Fr and the mean angle AM satisfy the relationship: Zn/Z0*(T0+(a1+a2*As)/AM+b*LF*(AM?A0)/A0+c*AM)<Fr/CS, where Zn is the nominal load, Z0=100 t, T0=7000 N, a1=?230,000 N*°, a2=?160,000 N*°/%, b=?34,000 N/m, A0=29°, c=550 N/°, CS>=1.

Abstract: A tire tread for a heavy-duty vehicle of construction plant type and aims to reduce the risk of cracking at the sipe bottom, without significantly reducing the volume of material of the tread so as not to shorten the lifetime of the tire in respect of wear. The tread (I) has transverse sipes (5) having a depth H and a width E, each transverse sipe (5) having a radially inner end formed by a bulge (53) having an end radius R, the transverse sipes (5) being distributed longitudinally at a longitudinal spacing B, the depth H, the width E of each transverse sipe (5), the end radius R of the bulge (53) and the longitudinal spacing B satisfying the relationship (R*B)/(E*H)>=1.8.

Abstract: Crown of a tire for a heavy vehicle that is desensitized to attacks. The tire (1) comprises tread (2) having a median degree of surface siping TLC, expressed in m/m2, equal to the ratio between the cumulative length LDC of the cuts (21), present in a median portion of tread of axial width WC, and the median area AC of the radially outer surface (23) of the tread (2), and protective reinforcement (4) comprising at least two protective layers (41, 42) that are formed of elastic metallic reinforcers and have a maximum breaking strength Rmax, expressed in daN/m, such that the median degree of surface siping TLC of tread (2) is at least equal to 5 m/m2 and a coupling ratio CC, equal to the ratio between the maximum breaking strength Rmax and the median degree of surface siping TLC, is at least equal to 18 000 daN.

Abstract: Tread (1) having tread surface (10) axially bounded by edge parts (11), and provided with cuts (3, 4) delimiting material parts forming raised elements (2), each raised element (2) comprising contact face (20), there being formed, in a plurality of raised elements (2), a ventilation cavity (5) having a depth at least equal to 70% of the thickness of the tread material to be worn away, each ventilation cavity (5) being delimited by wall surface (50) ending at bottom surface (530). Each ventilation cavity (5) comprises first cavity part (51) continued into the depth by second cavity part (52). The first cavity part (51) is situated between the tread surface and intermediate depth level H1 situated at between 30% and 70% of maximum depth H of ventilation cavity (5), the mean relief angle A of the wall is at least equal to 20 degrees. In the second cavity part (52), mean relief angle B of the wall is at most equal to 15 degrees.

Abstract: Tread (1) of a tire for an off-road vehicle, with total width (W) and total thickness of wearable material at least equal to 60 mm. The tread is delimited axially by shoulder regions (5) provided with grooves (7). This tread (1) comprises, in central region (6), narrow groove (61) and, between each shoulder region (5) and the central region (6), an intermediate region (4) in which there are formed a plurality of oblique or transverse narrow grooves (411, 412). Narrow groove (61) of the central part is made up of first narrow-groove parts (611) of depth (P1) and of second narrow-groove parts (612) of depth (P2). Depth (P1) is greater than depth (P2). Narrow grooves (411, 412) of one same intermediate region comprise, in the circumferential direction, an alternation of narrow grooves (411) of first depth (P11) and of narrow grooves (412) of second depth (P22).

Abstract: The tread comprises a plurality of blocks, each block being delimited by transverse or oblique grooves and circumferential grooves. Each block is provided with a sipe which has three branches. The branches have common ends. A first branch is oriented in a transverse or oblique direction. A second branch and a third branch each open when new into a transverse groove delimiting the block. The angle formed between the first and second branches is 100 to 125 degrees, and the angle formed between the first and the third branches is 100 to 125 degrees. After wear, each sipe represents between 45% and 70% of the total wearable thickness, such that the lengths of the three branches measured on the new tread surface, L1?, L2?, L3? respectively, are shorter than the lengths L1, L2, L3 respectively measured on the tread surface when new.

Abstract: Crown of a tire for a heavy vehicle that is desensitized to attacks. The tire (1) comprises tread (2) having a median degree of surface siping TLC, expressed in m/m2, equal to the ratio between the cumulative length LDC of the cuts (21), present in a median portion of tread of axial width WC, and the median area AC of the radially outer surface (23) of the tread (2), and protective reinforcement (4) comprising at least two protective layers (41, 42) that are formed of elastic metallic reinforcers and have a maximum breaking strength Rmax, expressed in daN/m, such that the median degree of surface siping TLC of tread (2) is at least equal to 5 m/m2 and a coupling ratio CC, equal to the ratio between the maximum breaking strength Rmax and the median degree of surface siping TLC, is at least equal to 18 000 daN.

Abstract: A method for evaluating the thermal stresses associated with the use of a tire mounted on a rim, the method comprising the steps during which a temperature of a gaseous fluid contained in an internal cavity of the tire, and a temperature of the rim, are measured at regular time intervals, and a temperature at at least one internal zone of the materials of which the tire is made is estimated using a pre-established law connecting this temperature to the temperature of the gaseous fluid contained in the internal cavity of the tire and to the temperature of the rim.

Abstract: Tread (1) having tread surface (10) axially bounded by edge parts (11), and provided with cuts (3, 4) delimiting material parts forming raised elements (2), each raised element (2) comprising contact face (20), there being formed, in a plurality of raised elements (2), a ventilation cavity (5) having a depth at least equal to 70% of the thickness of the tread material to be worn away, each ventilation cavity (5) being delimited by wall surface (50) ending at bottom surface (530). Each ventilation cavity (5) comprises first cavity part (51) continued into the depth by second cavity part (52). The first cavity part (51) is situated between the tread surface and intermediate depth level H1 situated at between 30% and 70% of maximum depth H of ventilation cavity (5), the mean relief angle A of the wall is at least equal to 20 degrees. In the second cavity part (52), mean relief angle B of the wall is at most equal to 15 degrees.

Abstract: A radial tire intended to be fitted to a heavy vehicle of construction plant type, and more particularly to the tread thereof. The tread of such a tire is desensitized to attack by indenting bodies that are likely to cause cracks at the cut bottom, in particular in the case of a tread with a high volumetric void ratio and a high degree of surface siping. Such a tire has a degree of surface siping TL of the tread at least equal to 3 m/m2, a number of cycles to failure NR of the elastomeric compound of the tread, at least present at the cut bottom, at least equal to 60000 cycles, and a ratio C between the number of cycles to failure NR of the elastomeric compound and the degree of surface siping TL at least equal to 20000 cycles/(m/m2).

Abstract: Tread (1) of a tire for an off-road vehicle, with total width (W) and total thickness of wearable material at least equal to 60 mm. The tread is delimited axially by shoulder regions (5) provided with grooves (7). This tread (1) comprises, in central region (6), narrow groove (61) and, between each shoulder region (5) and the central region (6), an intermediate region (4) in which there are formed a plurality of oblique or transverse narrow grooves (411, 412). Narrow groove (61) of the central part is made up of first narrow-groove parts (611) of depth (P1) and of second narrow-groove parts (612) of depth (P2). Depth (P1) is greater than depth (P2). Narrow grooves (411, 412) of one same intermediate region comprise, in the circumferential direction, an alternation of narrow grooves (411) of first depth (P11) and of narrow grooves (412) of second depth (P22).

Abstract: Crown of a tire for a heavy vehicle of construction plant type is desensitized to attacks. The tire includes a tread (2) having a degree of surface siping TL, expressed in m/m2, equal to the ratio between the cumulative length LD of the cuts (21) and the area A of the radially outer surface (23) of the tread (2), and a protective reinforcement (4) having at least two protective layers (41, 42) that are formed of elastic metallic reinforcers and have a maximum breaking strength Rmax, expressed in daN/m, such that the degree of surface siping TL of the tread (2) is at least equal to 3 m/m2 and a coupling ratio C, equal to the ratio between the maximum breaking strength Rmax and the degree of surface siping TL, is at least equal to 30000 daN.

Abstract: A method for evaluating thermal stresses associated with use of a tire mounted on a rim includes steps of measuring a temperature of a gaseous fluid contained in an internal cavity of the tire at regular time intervals in order to obtain a fluid temperature, measuring a temperature at a location on the rim at regular time intervals in order to obtain a rim temperature, and determining an estimated temperature at at least one internal zone of materials of which the tire is made using a pre-established law connecting the estimated temperature to the fluid temperature and the rim temperature.

Abstract: The tread comprises a plurality of blocks, each block being delimited by transverse or oblique grooves and circumferential grooves. Each block is provided with a sipe which has three branches. The branches have common ends. A first branch is oriented in a transverse or oblique direction. A second branch and a third branch each open when new into a transverse groove delimiting the block. The angle formed between the first and second branches is 100 to 125 degrees, and the angle formed between the first and the third branches is 100 to 125 degrees. After wear, each sipe represents between 45% and 70% of the total wearable thickness, such that the lengths of the three branches measured on the new tread surface, L1?, L2?, L3? respectively, are shorter than the lengths L1, L2, L3 respectively measured on the tread surface when new.