# US 11,077,723 B2 · Pneumatic tire > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,077,723 B2 - Document ID: US11077723B2 - Status: Granted - Kind: B2 - Application number: 15/813,587 - Filed: 2017-11-15 - Published: 2018-05-17 - Granted: 2021-08-03 - Earliest claimed: 2016-11-16 - Assignees: Sumitomo Rubber Industries, Ltd. - Applicants: Sumitomo Rubber Industries, Ltd. - Inventors: Haruyuki Sano - Web page: https://patentgrep.com/patent/US11077723B2 ## CPC - B60C 15/05: multiple, i.e. with two or more cores in each bead - B29D 30/48: Bead-rings or bead-cores (from wire B21F37/00); Treatment thereof prior to building the tyre - B60C 15/0027: {with low ply turn-up, i.e. folded around the bead core and terminating at the bead core} - B60C 15/04: Bead cores - B60C 2015/046: {Cable cores, i.e. cores made-up of twisted wires} - B60C 2200/04: for road vehicles, e.g. passenger cars - B60C 2200/10: for motorcycles, scooters or the like - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) ## Abstract A pneumatic tire 1 comprises an annular bead core 5 embedded in each bead portion 4 of the tire. The bead core 5 is composed of a plurality of wire rings 10 each of which is made of a spirally overlap-wound bead wire 11 and which are arranged in the tire axial direction. The wire rings 11 include a first ring 13 whose bead wire 11 is a twisted cord 13a made of a plurality of filaments 15 twisted together, and a second ring 14 whose bead wire 11 is a monofilament cord 14a made of a single filament. ## Claims ### Claim 1 A pneumatic tire comprising a tread portion, a pair of sidewall portions, a pair of bead portions, an annular bead core embedded in each bead portion of the tire, and a carcass comprising a carcass ply extending between the bead portions through the tread portion and the sidewall portions, and turned up around the bead core in each bead portion, wherein the bead cores are each composed of a plurality of wire rings each of which is made of a spirally overlap-wound bead wire and which are arranged in the tire axial direction, and said plurality of wire rings are arranged adjacently one next to the other in the tire axial direction, wherein the bead cores each have a radially outer end and a radially inner end, and the bead wire of each of the wire rings extends spirally and continuously from the radially outer end to the radially inner end of the bead core, wherein the wire rings include a first ring configuration whose bead wire is a twisted cord made of a plurality of filaments twisted together, and a second ring configuration whose bead wire is a monofilament cord made of a single filament, wherein said plurality of wire rings comprises an axially outermost wire ring which has the first ring configuration, a middle wire ring which has the first ring configuration disposed on the axially inside of the axially outermost wire ring, and an axially inner wire ring which has the second ring configuration disposed on the axially inside of the middle wire ring wherein the number of spiral turns of the bead wire of each wire ring is not less than 1.5 times the number of the wire rings arranged in the tire axial direction. ### Claim 2 (depends on 1) The pneumatic tire according to claim 1, wherein a bending rigidity of the twisted cord is lower than a bending rigidity of the monofilament cord. ### Claim 3 (depends on 2) The pneumatic tire according to claim 2, wherein the bending rigidity of the twisted cord is 0.10 to 0.29 times the bending rigidity of the monofilament cord. ### Claim 4 (depends on 1) The pneumatic tire according to claim 1, wherein the bending rigidity of the twisted cord is 100 N to 260 N. ### Claim 5 (depends on 1) The pneumatic tire according to claim 1, wherein an elongation of the twisted cord is not less than 0.03% when the tension of the twisted cord is increased from 2.5N to 49.0N. ### Claim 6 (depends on 1) The pneumatic tire according to claim 1, wherein the number of the wire ring or rings having the first ring configuration is not less than the number of the wire ring or rings having the second ring configuration. ### Claim 7 (depends on 1) The pneumatic tire according to claim 1, wherein the radially outer end of each of the bead cores is positioned radially inside a radially outer end of a rim-flange when the pneumatic tire is mounted on a standard wheel rim having said rim-flange and inflated to a standard pressure and loaded with no tire load. ### Claim 8 (depends on 1) The pneumatic tire according to claim 1, wherein the twisted cord has a layer twist structure comprising at least one core filament, and sheath filaments surrounding said at least one core filament. ### Claim 9 (depends on 1) The pneumatic tire according to claim 1, wherein the twisted cord has a bunch-twisted structure in which all the filaments as a bunch are twisted in one direction. ### Claim 10 (depends on 1) The pneumatic tire according to claim 1, wherein the bead core consists of three wire rings which are the axially outermost wire ring, the middle wire ring, and the axially inner wire ring. ### Claim 11 (depends on 10) The pneumatic tire according to claim 10, wherein the number of spiral turns of the bead wire of each wire ring is not less than 1.5 times the number of all of the wire rings. ### Claim 12 (depends on 11) The pneumatic tire according to claim 11, wherein said number of spiral turns is same for all of the wire rings. ### Claim 13 (depends on 12) The pneumatic tire according to claim 12, wherein the bending rigidity of the twisted cord is 0.10 to 0.29 times the bending rigidity of the monofilament cord. ### Claim 14 (depends on 1) The pneumatic tire according to claim 1, wherein the carcass consists of said carcass ply. ### Claim 15 (depends on 1) The pneumatic tire according to claim 1, wherein the number of the wire ring or rings having the first ring configuration is not less than the number of the wire ring or rings having the second ring configuration, the number of spiral turns of the bead wire of each wire ring is not less than 1.5 times the number of the wire rings arranged in the tire axial direction, and the twisted cord has a layer twist structure comprising at least one core filament, and sheath filaments surrounding said at least one core filament, or alternative a bunch-twisted structure in which all the filaments as a bunch are twisted in one direction, so that an elongation of the twisted cord is not less than 0.03% when the tension of the twisted cord is increased from 2.5N to 49.0N, a bending rigidity of the twisted cord is 0.10 to 0.29 times a bending rigidity of the monofilament cord, and the bending rigidity of the twisted cord is 100 N to 260 N. ### Claim 16 (depends on 15) The pneumatic tire according to claim 15, wherein the carcass consists of said carcass ply. ### Claim 17 (depends on 16) The pneumatic tire according to claim 16, wherein each of said plurality of wire rings is arranged in a plane substantially parallel with the tire radial direction, and said number of spiral turns is same for all of the wire rings. ### Claim 18 (depends on 17) The pneumatic tire according to claim 17, which is a motorcycle tire in which the tread portion is curved convexly so that the maximum tire cross section width occurs between tread edges. ### Claim 19 A pneumatic tire comprising a tread portion, a pair of sidewall portions, a pair of bead portions, an annular bead core embedded in each bead portion of the tire, and a carcass comprising a carcass ply extending between the bead portions through the tread portion and the sidewall portions, and turned up around the bead core in each bead portion, wherein the bead cores are each composed of a plurality of wire rings each of which is made of a spirally overlap-wound bead wire and which are arranged in the tire axial direction, and said plurality of wire rings are arranged adjacently one next to the other in the tire axial direction, wherein the bead cores each have a radially outer end and a radially inner end, and the bead wire of each of the wire rings extends spirally and continuously from the radially outer end to the radially inner end of the bead core, wherein the wire rings include a first ring configuration whose bead wire is a twisted cord made of a plurality of steel filaments twisted together, and a second ring configuration whose bead wire is a monofilament cord made of a single filament, wherein said plurality of wire rings comprises an axially outermost wire ring which has the first ring configuration, a middle wire ring which has the first ring configuration disposed on the axially inside of the axially outermost wire ring, and an axially inner wire ring which has the second ring configuration disposed on the axially inside of the middle wire ring.