# US 10,864,776 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 10,864,776 B2 - Document ID: US10864776B2 - Status: Granted - Kind: B2 - Application number: 15/935,619 - Filed: 2018-03-26 - Published: 2018-10-18 - Granted: 2020-12-15 - Earliest claimed: 2017-04-17 - Assignees: Sumitomo Rubber Industries, Ltd. - Applicants: Sumitomo Rubber Industries, Ltd. - Inventors: Kazuki Higashiura - Web page: https://patentgrep.com/patent/US10864776B2 ## CPC - B60C 11/1353: {with special features of the groove bottom} - B60C 11/0302: {directional pattern, i.e. with main rolling direction} - B60C 11/1204: {with special shape of the sipe} - B60C 11/1236: {with special arrangements in the tread pattern} - B60C 2011/0369: {with varying depth of the groove} - B60C 2011/0372: {with particular inclination angles} - B60C 2011/0374: {Slant grooves, i.e. having an angle of about 5 to 35 degrees to the equatorial plane} - B60C 2011/0381: {Blind or isolated grooves} - B60C 2011/1213: {sinusoidal or zigzag at the tread surface} - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES ## Abstract A pneumatic tire includes first and second tread patterns which are formed as substantially line symmetrical shape with respect to a tire equator and are shifted with respect to one another in a tire circumferential direction. Each of the first and second tread patterns is provided with lateral inclined grooves each extending axially inwardly from each tread edge to an axially inner end without reaching the tire equator. The tire is further provided with central connecting grooves each extend across the tire equator to connect lateral inclined grooves arranged on the first and second tread patterns. The central connecting grooves each include a first end and a second end such that the first end is located nearer to the tire equator than the second end and that a depth thereof decreases gradually from the first end to the second end. ## Claims ### Claim 1 A pneumatic tire comprising: a tread portion comprising a first tread pattern formed between a tire equator and one of tread edges and a second tread pattern formed between the tire equator and the other one of the tread edges, the first tread pattern and the second pattern being formed as a substantially line symmetrical shape with respect to the tire equator and being shifted with respect to one another in a tire circumferential direction; each of the first and second tread patterns being provided with lateral inclined grooves each extending axially inwardly from the tread edge to an axially inner end located adjacent to the tire equator without reaching the tire equator, and connecting inclined grooves each having an inclination opposite to the lateral inclined grooves and connecting a pair of circumferentially adjacent lateral inclined grooves; and central connecting grooves each extending across the tire equator to connect one of the lateral inclined grooves arranged on the first tread pattern with one of the lateral inclined grooves arranged on the second tread pattern, wherein the central connecting grooves each comprise a first end and a second end such that the first end is located nearer to the tire equator than the second end and that a depth (D6) of each central connecting groove decreases gradually from the first end to the second end, and the first end has a depth that is the same as the depth of the lateral inclined groove to which the first end is connected. ### Claim 2 (depends on 1) The pneumatic tire according to claim 1, wherein each of the central connecting grooves has groove volume (V6) in a range of from 52% to 62% of a virtual groove volume (V0) of the concerned central connecting groove, wherein the virtual groove volume (V0) is measured when assuming that the concerned central connecting groove has a constant reference depth that is the same as the lateral inclined grooves to which the concerned central connecting groove is connected. ### Claim 3 (depends on 1) The pneumatic tire according to claim 1, wherein each of the central connecting grooves has a depth (D62) at the second end, and the depth (D62) of the second end is in a range of from 4% to 24% of the depths (D3) of the lateral inclined grooves. ### Claim 4 (depends on 1) The pneumatic tire according to claim 1, wherein the tread portion comprises a row of central blocks which are divided by the lateral inclined grooves, the connecting inclined grooves and the central connecting grooves, and the central blocks are provided with sipes extending substantially in a tire axial direction. ### Claim 5 (depends on 1) The pneumatic tire according to claim 1, wherein in a tire cross-section of a 5% inner pressure state in which the tire is mounted on a standard wheel rim with 5% pressure of a standard inner pressure, a tread profile of a surface of the tread portion comprises: a first arc portion having a radius (R1) of curvature with the center located on a tire equatorial plane, a second arc portion having a radius (R2) of curvature connected to the first arc portion at an intersection point (Q1) and a third arc portion having a radius (R3) of curvature connected to the second arc portion at an intersection point (Q2), wherein the radius (R2) of curvature is in a range of from 50% to 54% of the radius (R1) of curvature, and the radius (R3) of curvature is in a range of from 20% to 24% of the radius (R1) of curvature; a distance (L1) from the tire equator to the intersection point (Q1) is in a range of from 40% to 50% of a tread half width (TW) which is an axial distance from the tire equator to one of the tread edges; and a distance (L2) from the tire equator to the intersection point (Q2) is in a range of from 75% to 80% of the tread half width TW. ### Claim 6 (depends on 1) The pneumatic tire according to claim 1, wherein the connecting inclined grooves comprise axially inner connecting inclined grooves and axially outer connecting inclined grooves, and the tread portion comprises a row of middle blocks which are divided by the lateral inclined grooves, the inner connecting inclined grooves, and the outer connecting inclined grooves and a row of shoulder blocks which are divided by the lateral inclined grooves, the outer connecting inclined grooves, and one of the tread edges, wherein the middle blocks are provided with sipes extending substantially parallel with the inner connecting inclined grooves, and the shoulder blocks are provided with sipes extending substantially perpendicular to the outer connecting inclined grooves. ### Claim 7 (depends on 1) The pneumatic tire according to claim 1, wherein a bottom of each central connecting groove forms a slant surface inclined at a constant angle so that the depth of each central connecting groove decreases from the first end to the second end at a fixed ratio. ### Claim 8 (depends on 2) The pneumatic tire according to claim 2, wherein a bottom of each central connecting groove forms a slant surface inclined at a constant angle so that the depth of each central connecting groove decreases from the first end to the second end at a fixed ratio. ### Claim 9 (depends on 3) The pneumatic tire according to claim 3, wherein a bottom of each central connecting groove forms a slant surface inclined at a constant angle so that the depth of each central connecting groove decreases from the first end to the second end at a fixed ratio. ### Claim 10 (depends on 1) The pneumatic tire according to claim 1, wherein a bottom of each central connecting groove forms a curved surface in a convex arc manner or concave arc manner. ### Claim 11 (depends on 1) The pneumatic tire according to claim 1, wherein a bottom of each central connecting groove forms a stepped surface having three or more steps so that the depth of each central connecting groove decreases stepwise.