# US 11,298,985 B2 · Tread with concealed cavities comprising a wear indicator having improved visibility > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,985 B2 - Document ID: US11298985B2 - Status: Granted - Kind: B2 - Application number: 15/769,650 - Filed: 2016-10-28 - Published: 2018-11-01 - Granted: 2022-04-12 - Earliest claimed: 2015-10-29 - Assignees: Compagnie Generale Des Etablissements Michelin - Applicants: Compagnie Generale Des Etablissements Michelin - Inventors: Stéphanie Cambon; Olivier Muhlhoff - Web page: https://patentgrep.com/patent/US11298985B2 ## CPC - B60C 11/24: Wear-indicating arrangements - B60C 11/0323: {tread comprising channels under the tread surface, e.g. for draining water} - B60C 11/12: characterised by the use of narrow slits or incisions, e.g. sipes - F16L 11/02: made of fibres or threads, e.g. of textile - F16L 33/00: Arrangements for connecting hoses to rigid members; Rigid hose-connectors, i.e. single members engaging both hoses (connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics F16L47/00) - F16L 33/30: comprising parts inside the hoses only (F16L33/24 takes precedence) - F16L 33/32: comprising parts outside the hoses only (F16L33/24 takes precedence) - Y02E 10/30: Energy from the sea, e.g. using wave energy or salinity gradient - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A tire comprising a tread, this tread comprising at least one channel and at least one wear indicator that is disposed on the bottom of the channel. The wear indicator has a contact face which is intended to come into contact with a road surface when the tire reaches a wear limit. The contact face has a texture that contrasts with the bottom of the channel. ## Claims ### Claim 1 A tire comprising a tread, the tire comprising at least one channel that is situated entirely below a tread surface when said tread is in a new state and extending circumferentially around the tire and wherein the at least one channel is configured intended to open up to the tread surface after a given amount of wear in order to form a groove, this channel comprising two opposite walls connected by a bottom and at least one wear indicator on this bottom, the wear indicator comprising a contact face that is intended to come into contact with a road surface when the tire reaches a wear limit, wherein the contact face of the wear indicator comprises a texture that gives it lightness known as first lightness (L*1) when said tread is new, the bottom of the channel being without a texture so that it has a lightness known as second lightness (L*2) when said tread is new, the lightnesses being expressed using a scale that ranges from 0 to 100 according to the L*a*b* color model established by the International Commission on Illumination, this tread being such that the first lightness is less than the second lightness in order to create a contrast between the bottom of the channel and the contact face of the wear indicator, the texture for obtaining the first lightness including integrally formed motifs with a repetitive mean spacing at least equal to 0.1 mm and at most equal to 0.6 mm, and wherein at least one measuring well is formed that opens onto the tread surface in the new state and leads into the channel in order to allow a part of the contact face of a wear indicator with the texture and the bottom of the channel without the texture to be seen. ### Claim 2 (depends on 1) The tire according to claim 1, wherein the difference in lightness between the first and second lightnesses is at least 5 units of lightness. ### Claim 3 (depends on 1) The tire according to claim 1, wherein the bottom of the channel without the texture has an arithmetic mean roughness Ra of this bottom is less than 12. ### Claim 4 (depends on 1) The tire according to claim 1, wherein the first lightness (L*1) is between 5 and 18 units. ### Claim 5 (depends on 1) The tire according to claim 1, wherein the lightness of the bottom of the channel is between 20 and 35 units. ### Claim 6 (depends on 1) The tire according to claim 1 wherein the wear indicator comprises at least one lateral face connecting the contact face of the wear indicator to the bottom of the channel, this lateral face having a texture that has a lightness (L*1) that is less than the lightness of the bottom of the channel. ### Claim 7 (depends on 1) The tire according to claim 1, wherein the components a* and b* of the bottom of the channel are less than 5 points. ### Claim 8 (depends on 1) The tire according to claim 1 wherein the at least one channel is hidden when said tread is new. ### Claim 9 (depends on 8) The tire according to claim 8 wherein the groove that is formed by the at least one channel that is hidden when the tread is new and that includes the wear indicator is a first groove, wherein the at least one channel extends from the contact face to a first depth, the tire further including at least one second groove opens to the contact face when the tread is new, the at least one second groove extending from the contact face to a second depth, the first depth being greater than the second depth.