Abstract:
A tyre for a wheel of a vehicle comprises a toroidal carcass provided with axially opposite sidewalls and beads for anchoring the tyre to a rim of the wheel, a tread band located crownwise on the carcass, comprising a surface with a plurality of hollows and grooves defining a raised tread pattern, and a belt structure interposed between the carcass and the tread band, axially extending between the sidewalls. The tread band comprises at least first and second circumferential axially-contiguous portions arranged to contact a road surface. The first portion is formed of a first composition comprising a reinforcing filler having at least 40%-by-weight carbon black and at least some white filler, the second portion is formed of a second composition comprising a reinforcing filler having at least 20%-by-weight white filler, and the first composition is different from the second composition. A difference of compositions between the at least first and second portions achieves a tyre operating temperature lower than a reference temperature.
Abstract:
The present invention relates to a pneumatic tire having a tread comprising a tread base layer and a tread cap. The tread cap comprises a first tread cap layer and a second tread cap layer of different polymeric compositions, the tread cap having a central cap zone ZC and two lateral cap zones ZL the lateral cap zones ZL being located axially adjacent to the central cap zone ZC and on axially opposite sides of the central cap zone ZC.
Abstract:
Tire tread has a central rib (411-413) and two lateral ribs (421-422) which are separated by circumferential grooves (141-144). A first lateral rib (421) adjacent to the outer axial edge of the tread and a central rib have a first portion (4211, 4111, 4121, 4131) the axial width of which exceeds 20% of the axial width of the relevant rib made from a first rubber composition containing an elastomer and a reinforcing filler consisting predominantly of carbon black, and an axially adjacent second portion (4212, 4112, 4122, 4132) made of a second rubber composition containing an elastomer and a reinforcing filler a minority proportion of which consists of carbon black. The second rubber composition has a tan d0 value which is less than the tan d0 value of the first rubber composition, the tan d0 values being measured at a temperature of 0 C and under a stress of 0.7 MPa.
Abstract:
Tread rubber forms a ground contact surface. When the ground contact surface is divided into two parts: a mounting inner side and a mounting outer side, the tread rubber has an inner cap part that forms an inner ground contact surface and is produced from non-conductive rubber, and an outer cap part that forms an outer ground contact surface. The inner cap part has a branched conductive part that is formed from conductive rubber ranging from the ground contact surface of a mounting outer end of the inner cap part to the side surface or bottom surface of a mounting inner end while branching off at a plurality of positions. The outer cap part does not have branched conductive rubber. The branched conductive part is formed from the conductive rubber with a rubber hardness different from that of the non-conductive rubber that forms the inner cap part.
Abstract:
A tire comprising a tread portion designed to be worn off during the life of the tire having a radial thickness T, an outer edge and an inner edge, the axial distance between the outer edge and the inner edge defining the axial width L of the tread, the tread comprising four adjacent portions made of a four rubber compounds, wherein the rubber compounds making up the first and third portions are predominantly filled with carbon black filler, wherein the rubber compounds making up the second and fourth portion are predominantly filled with non carbon black filler, wherein the rubber compounds making up the first and third portions have a value for tan δ at 0° C., at a stress of 0.7 MPa, that is lower than that of the rubber compounds making up the second and fourth portion, and wherein the axial width of the first portion decreases and the axial width of the second portion increases as a function of the distance from the rolling surface of the tread when unworn.
Abstract:
A proper balance between ride comfort, steering stability, and road noise is achieved. A pneumatic tire (1) has a band layer (9) comprising a band ply (9A) where band cords are arranged at an angle of not more than 5 deg. with respect to the circumferential direction of the tire on the radially outer side of a belt layer (7). The band ply (9A) comprises a first ply piece (9a) covering only one side of end portions of the belt layer (7) and a second ply piece (9b) disposed adjacently to the first ply piece (9a), covering continuously the central portion of the belt layer (7) and another side of the end portions, and having a width larger than that of the above-mentioned first ply piece (9a). And, the band cords of said first ply piece (9a) and band cords of said second ply piece (9b) are different in modulus.
Abstract:
A pneumatic tire includes at least two types of cap tread rubber layers made from differing rubber compositions disposed in a tread portion. A tan δ at 60° C. of a rubber composition forming the cap tread rubber layer on a vehicle outer side is greater than a tan δ at 60° C. of a rubber composition forming the cap tread rubber layer on a vehicle inner side. A ratio (tan δH/tan δL) of a maximum tan δH to a minimum tan δL at 60° C. of the tan δ of the rubber compositions forming the at least two types of cap tread rubber layers is from 1.05 to 1.80 . An under tread rubber layer disposed in the tread portion has an average thickness from 0.8 mm to 4.0 mm. A hardness of a rubber composition forming the under tread rubber layer is from 73 to 83. A tan δ at 60° C. of the rubber composition forming the under tread rubber layer is 0.25 or less.
Abstract:
In the invention, a run-flat tire including a pair of bead portions having an annular first bead, sidewall portions respectively extending to an outer side in a tire diametrical direction from the bead portions, reinforce rubber layers arranged in the sidewall portions, a tread portion connecting outer peripheral side ends of the sidewall portions via shoulder portions, wherein the run-flat tire includes an annular inflating portion provided on the outside in a tire width direction of the bead portion arranged on the outside of the vehicle, and having an inner circumferential side face opposing to an outer circumferential curved side face of a rim flange when a regular rim is fixed; and an annular second bead arranged at the annular inflating portion, wherein the reinforce rubber layer arranged on the outside of the vehicle has a rubber hardness of 60 to 82 degree, the reinforce rubber layer arranged on the inside of the vehicle has a rubber hardness of 65 to 90 degree, and the reinforce rubber layer arranged on the inside of the vehicle has the rubber hardness which is equal to or more than that on the outside of the vehicle, and has a maximum thickness which is larger than that on the outside of the vehicle by at least 0.5 mm.
Abstract:
The invention relates to a tire having a circumferential tread of a cap/base configuration composed of an outer tread rubber cap layer with a running surface of the tread and an underlying tread rubber base layer, wherein said tread cap layer is composed of two longitudinal adjacent zones, namely a primary tread cap zone and a minor lateral outboard control element (zone). The primary tread cap zone and the lateral outboard tread cap element provide a significant gradation of cold dynamic storage moduli (G′) at −25° C. and hot tan delta values at 100° C., yet similar warm dynamic storage moduli (G′) at 60° C. The primary tread cap zone and lateral outboard control tread cap element are load bearing in the sense of extending from the running surface of the tread radially inward to the unitary (non-zoned) tread base rubber layer. The zoned rubber tread cap layer and unitary rubber tread base layer are an integral tread composite in a sense of being co-extruded. In one aspect of the invention, the primary tread cap zone rubber composition is silica-rich and the lateral, outboard element rubber composition is carbon black-rich and which furthermore provide a gradation of filler reinforcement content; provide a gradation of silica to carbon black ratio and provide a gradation of cis 1,4-polybutadiene rubber content.
Abstract:
A tire for a vehicle includes a radial carcass, a tread band disposed radially outward of the carcass, and a belt structure interposed between the carcass and the tread band. The tread band also includes a first portion of a first elastomeric compound having a first modulus of elasticity between about 12 MPa and 16 MPa, measured at 23° C., and a second portion of a second elastomeric compound having a second modulus of elasticity between about 7 MPa and 11 MPa, measured at 23° C. Additionally, a first tread pattern formed on the first portion is different from a second tread pattern formed on the second portion. A related tread band, method for making an asymmetrical tire, and wheel for a vehicle are also disclosed.