Abstract: Tread for heavy-duty vehicle tire, having tread surface in the new state, having a first volume of cavities opening onto the tread surface, a second volume of cavities formed entirely under the tread surface and having at least one channel of height Hc delimited by two main walls spaced apart from one another by a width Lc and connected together by a lower part and by an upper part, this channel intended to form, after partial wear corresponding to a thickness Lu, an additional groove, such that each channel has a plurality of extensions forming cavities extending between this channel and the tread surface over a height He at least equal to 20% and at most equal to 75% of the thickness Lu, each extension opening at least into the upper part of the channel through an opening having a cross-sectional area Sa at least equal to 0.8*(Hc*Lc).

Abstract: Tread for heavy-duty vehicle tire, having tread surface in the new state, having a first volume of cavities opening onto the tread surface, a second volume of cavities formed entirely under the tread surface and having at least one channel of height Hc delimited by two main walls spaced apart from one another by a width Lc and connected together by a lower part and by an upper part, this channel intended to form, after partial wear corresponding to a thickness Lu, an additional groove, such that each channel has a plurality of extensions forming cavities extending between this channel and the tread surface over a height He at least equal to 20% and at most equal to 75% of the thickness Lu, each extension opening at least into the upper part of the channel through an opening having a cross-sectional area Sa at least equal to 0.8*(Hc*Lc).

Abstract: Tread with longitudinally oriented grooves (31, 41, 42) at least one is wavy (31) opening onto tread surface (10), at least one rib (21) oriented in the longitudinal direction and delimited by (31) with external cavities (311) opening to tread surface and internal cavities (312) hidden within the thickness of the tread, cavities (311) opening onto the surface (10) when new with a contour (310) having farthest-spaced endpoints A and B separated by a distance Lm, the rib (21) of width Ln having transverse sipes (5), made at a mean pitch Pi, where the length Lm of contour (310) of cavity (311) is equal to or greater than an integer multiple N of the pitch Pi times an amount at most equal to 25% of this integer multiple N of the pitch Pi, when new, N+1 transverse sipes (5) of rib (21) open into cavity (311) bordering the rib.

Abstract: Mould for moulding a tread of a tire, this tread having a thickness of material to be worn away and a tread surface intended to come into contact with the road surface when the tire is running, this mould having a moulding surface intended to mould the tread surface of the tread, and having a moulding element formed of a blade and a bar, the blade being attached to the moulding surface to mould a sipe in the tread, the bar, borne by the blade to form an enlarged part of maximum width D, being intended to mould a channel in the tread, this channel itself being intended to form a new groove when the tread becomes part worn. Each blade is delimited by two lateral faces forming between them a mean angle of between 6° degrees and 18°. The blade width decreasing from the mould surface when new, as far as the connection with the bar, the blade width meets the bar being at least equal to between 0.2 and 0.4 times the maximum width D.

Abstract: The tread has a total axial width W and a wearable thickness PMU of material and has at least four grooves on each side of a midplane that divides the tread axially into two parts. The grooves divide the tread into a middle, intermediate and edge regions 6. The middle region has an axial width Lm of at least 30% and at most 60% of the total width W. The total volume void ratio when new is less than 17%, and the middle region has a volume void ratio that is less than half the total volume void ratio. The middle region comprises a plurality of transverse sipes opening into the grooves, and the sipes have depths at least equal to 75% of the depth of the grooves. The number of transverse sipes in the middle region is greater than the number of transverse sipes on each intermediate or edge region.

Abstract: The tread comprises circumferential grooves which delimit an intermediate row (I) and edge rows (B). The tread also has a plurality of V-shaped oblique grooves with branches that make an angle of 30° to 60° with the axial direction. The circumferential and oblique grooves delimit a plurality of V-shaped blocks in each intermediate row. In each V-shaped block, there is a canal below the tread surface, and this canal has a width of 2 to 6 mm and is intended to generate a new groove after a predetermined amount of wear. When new, each canal has openings that open into the oblique grooves. A bridge of material is formed between the V-shaped blocks and occupies heightwise at least 40% of the depth of the oblique grooves and doing so over a width at least 10 mm. The bridge of material is suitable for not closing the openings of the canals.

Abstract: The tread has four grooves that delimit a central, intermediate and edge regions. Each intermediate region is divided into elongated raised elements that delimit oblique grooves which open into the circumferential grooves and are inclined at an average angle of between 30 and 60 degrees relative to the circumferential direction. The raised elements have an average circumferential length of between 50 and 70 mm. The depth of the oblique grooves is at least 30% of the depth of the circumferential grooves. Each raised element has a plurality of sipes that open into the oblique grooves. Each raised element also has an internal and oblique cut that has a total depth at least equal to 75% of the thickness PMU to be worn away. The oblique cut has a wide part and a part that forms a sipe that extends by a channel that forms a new groove after wear.

Abstract: Mould for moulding a tread of a tire, this tread having a thickness of material to be worn away and a tread surface intended to come into contact with the road surface when the tire is running, this mould having a moulding surface intended to mould the tread surface of the tread, and having a moulding element formed of a blade and a bar, the blade being attached to the moulding surface to mould a sipe in the tread, the bar, borne by the blade to form an enlarged part of maximum width D, being intended to mould a channel in the tread, this channel itself being intended to form a new groove when the tread becomes part worn. Each blade is delimited by two lateral faces forming between them a mean angle of between 6° degrees and 18°. The blade width decreasing from the mould surface when new, as far as the connection with the bar, the blade width meets the bar being at least equal to between 0.2 and 0.4 times the maximum width D.

Abstract: The tread has a total width W and two main grooves. The main grooves divide the tread into a middle region and edge regions. The middle region has an axial width Lm that is 45% to 70% of the total width W. The volume void ratio of the tread when new is less than 17%. An internal surface extends parallel to the tread surface when new and is in contact radially with the innermost points of the deepest main grooves. The middle part has a plurality of transverse sipes, each of which has a depth at least equal to the depth of the main grooves. The transverse sipes open into the main grooves. The middle region has a volume void ratio when new that is less than half the total volume void ratio of the tread, and at least one circumferential channel appears when the tread becomes part worn.

Abstract: Tire for a heavy goods vehicle, comprising a crown reinforcement, and, radially outside this crown reinforcement, a tread having a total thickness PMU of material intended to become worn during running, the crown reinforcement being formed by at least two working plies and a protection ply positioned radially outside the working plies and radially inside the tread, the narrowest working ply having a width in the range from 70% to 90% of the width W of the tread, the protection ply having a width at most equal to 70% of the width of the narrowest working ply, the tread comprising grooves only in the part radially outside the protection ply, each circumferentially orientated groove having a depth at least equal to 75% of the maximum thickness intended to become worn PMU.

Abstract: The tread has four grooves that delimit a central, intermediate and edge regions. Each intermediate region is divided into elongated raised elements that delimit oblique grooves which open into the circumferential grooves and are inclined at an average angle of between 30 and 60 degrees relative to the circumferential direction. The raised elements have an average circumferential length of between 50 and 70 mm. The depth of the oblique grooves is at least 30% of the depth of the circumferential grooves. Each raised element has a plurality of sipes that open into the oblique grooves. Each raised element also has an internal and oblique cut that has a total depth at least equal to 75% of the thickness PMU to be worn away. The oblique cut has a wide part and a part that forms a sipe that extends by a channel that forms a new groove after wear.

Abstract: Tread having a maximum thickness PMU of material to be worn away during running, having: at least two grooves of circumferential overall orientation delimiting at least one intermediate row and two edge rows, a plurality of cuts of transverse overall orientation on each intermediate and edge row, representing, in the new state, a void of total volume Vco open onto the tread surface, at most equal to 13% of the total volume of the tread, channels or cavities extending under the tread surface in the new state, adapted to form new grooves after the tread has partially worn away, and having, in the initial state, a total volume Vcc at least equal to 30% of the total void volume Vco in the new state, intermediate rows of suffix (i) and edge rows of suffix (e) each provided with a plurality of cuts of transverse or oblique orientation distributed over each row evenly or near-evenly with a mean pitch of Pi and Pe respectively, having mean depths, Di and De respectively, which are at least equal to 20% of the thickne

Abstract: The tread has a total width W and two main grooves. The main grooves divide the tread into a middle region and edge regions. The middle region has an axial width Lm that is 45% to 70% of the total width W. The volume void ratio of the tread when new is less than 17%. An internal surface extends parallel to the tread surface when new and is in contact radially with the innermost points of the deepest main grooves. The middle part has a plurality of transverse sipes, each of which has a depth at least equal to the depth of the main grooves. The transverse sipes open into the main grooves. The middle region has a volume void ratio when new that is less than half the total volume void ratio of the tread, and at least one circumferential channel appears when the tread becomes part worn.

Abstract: Tread for a tire for the driven axle of a heavy goods vehicle, comprising a plurality of circumferential grooves delimiting at least three ribs each having a height and a width measured in the axial direction, axially delimited by two edge rows, each rib having a plurality of sipes able to close at least in part as they enter the contact patch, and opening onto each lateral face of the rib to form two edge corners and having a depth at least equal to 50% of the height of the rib, these sipes in pairs delimiting an elementary rib volume and an elementary contact surface, wherein each elementary volume delimited by two sipes of one and the same rib has a void volume opening on the contact face in the new state, having a total area on the tread surface at least equal to 0.4% and at most equal to 1.