# US 2018/0021989 A1 · System with plug assembly for continuous molding and curing of tire tread > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0021989 A1 - Document ID: US20180021989A1 - Status: Published application - Kind: A1 - Application number: 15/538,708 - Filed: 2016-04-19 - Published: 2018-01-25 - Earliest claimed: 2015-05-28 - Assignees: Compagnie Generale Des Etablissements Michelin - Applicants: Compagnie Generale des Etablissements Michelin - Inventors: David Lung; John Hommerson; Michael Petrovich - Web page: https://patentgrep.com/patent/US20180021989A1 ## CPC - B29C 43/3607: {with sealing means or the like} - B29C 35/0277: {Apparatus with continuous transport of the material to be cured (B29C35/025, B29C35/06, B29C35/10, B29C35/14 take precedence)} - B29C 69/02: of moulding techniques only - B29D 30/06: Pneumatic tyres or parts thereof {(e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)} - B29D 30/52: Unvulcanised treads, e.g. on used tyres; Retreading (apparatus for forming {treads by extrusion B29C48/00; apparatus for} vulcanising treads B29C35/02; apparatus characterised by the means for holding wheels or parts thereof B60B30/00) - B29C 37/006: {Degassing moulding material or draining off gas during moulding (venting means in moulds B29C33/10)} - B29C 43/06: continuously movable {in one direction, e.g. mounted on chains, belts} - B29C 43/085: {and material fed in a continuous form, e.g. as a band} - B29C 43/22: of articles of indefinite length - B29C 43/44: Compression means for making articles of indefinite length - B29C 48/08: flexible, e.g. films - B29K 2021/00: Use of unspecified rubbers as moulding material - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## Abstract A system for the continuous extrusion, molding, and curing of tread for tires. An elongated strip of rubber material can be molded and cured shortly after extrusion such that the material retains much of the heat energy of extrusion and does not have to be stored. A plurality of discrete mold assemblies are conveyed adjacent to each other. As the mold assemblies are advanced sequentially, the uncured and unmolded strip of rubber material are extruded and positioned onto the mold assemblies. While the rubber strip advances, individual portions are sequentially molded and cured by passing through a mold press and then a curing press. A plug assembly is used to prevent the backflow of rubber material during the molding and curing. ## Claims ### Claim 1 A method for continuous molding and curing of tire tread using a plurality of movable mold assemblies arranged adjacent to each other along a conveying direction, the method comprising: feeding an elongated strip of rubber material over a lower platen assembly; positioning the mold assemblies and a plug assembly over the lower platen assembly with the elongated strip of rubber material therebetween and the plug positioned upstream of, and adjacent to, the mold assemblies; pressing the mold assemblies and the plug assembly against the elongated strip of rubber material and the lower platen assembly; advancing the mold assemblies, the plug assembly, and the elongated strip of rubber material along the conveying direction; forcing the mold assemblies and the plug assembly against the elongated strip of rubber material and the lower platen assembly; heating at least portions of the elongated strip of rubber material during the forcing; and retracting the plug assembly away from the mold assemblies. ### Claim 2 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, wherein the plurality of mold assemblies comprises a first mold assembly and a plurality of downstream mold assemblies positioned downstream along the conveying direction from the first mold assembly, wherein the pressing comprises: lowering a first upper platen assembly against the plug and the first mold assembly of the plurality of mold assemblies; and lowering a second upper platen assembly against the plurality of downstream mold assemblies. ### Claim 3 (depends on 2) The method for continuous molding and curing of tire tread as in claim 2, wherein the advancing comprises: raising the first upper platen assembly and the second upper platen assembly; and moving the plug assembly, the first mold assembly, and the plurality of downstream mold assemblies along the conveying direction. ### Claim 4 (depends on 3) The method for continuous molding and curing of tire tread as in claim 3, wherein forcing comprises: lowering the first upper platen assembly against the plug assembly; and lowering the second upper platen assembly against the first mold assembly and at least a portion of the plurality of downstream mold assemblies. ### Claim 5 (depends on 4) The method for continuous molding and curing of tire tread as in claim 4, further comprising: positioning a second mold assembly upstream of, and adjacent to, the first mold assembly; positioning the plug assembly upstream of, and adjacent to, the second mold assembly; lowering the first upper platen assembly against the plug assembly and the second mold assembly; and lowering the second upper platen assembly against the second mold assembly and at least a portion of the plurality of downstream mold assemblies. ### Claim 6 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, further comprising connecting the plug assembly with one of the mold assemblies prior to the pressing. ### Claim 7 (depends on 6) The method for continuous molding and curing of tire tread as in claim 6, further comprising disconnecting the plug assembly from one of the mold assemblies prior to the retracting. ### Claim 8 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, wherein the forcing further comprises lowering a first upper platen assembly and a second upper platen assembly against the plug and the mold assemblies. ### Claim 9 (depends on 8) The method for continuous molding and curing of tire tread as in claim 8, wherein the pressing further comprises lowering the first upper platen assembly against the plug assembly and at least one of the mold assemblies. ### Claim 10 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, wherein the forcing further comprises lowering a first upper platen assembly against the plug assembly and a second upper platen assembly against the mold assemblies. ### Claim 11 (depends on 10) The method for continuous molding and curing of tire tread as in claim 10, wherein during the forcing, the plug assembly prevents a back flow of rubber material from the elongated strip of rubber material located under the second upper platen assembly. ### Claim 12 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, wherein the pressing further comprises: lowering a first upper platen assembly and a second upper platen assembly against the mold assemblies and the plug assembly. ### Claim 13 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, wherein the feeding comprises extruding the elongated strip of rubber material along the conveying direction. ### Claim 14 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, wherein the pressing imparts tread features into at least a portion of the elongated strip of rubber material. ### Claim 15 (depends on 1) The method for continuous molding and curing of tire tread as in claim 1, wherein the heating cures at least portions of the elongated strip of rubber material. ### Claim 16 An apparatus for the continuous molding and curing of tire tread, the apparatus defining a longitudinal axis, the apparatus comprising: a plurality of movable mold assemblies; a mold assembly transport mechanism arranged along the longitudinal axis and configured for moving mold assemblies along a conveying direction, the mold assembly transport mechanism having an in-feed end and an out-feed end; a lower platen assembly extending along the mold assembly transport mechanism; a first upper platen assembly positioned near the in-feed end of the mold assembly transport mechanism and over the lower platen assembly, the first upper platen assembly selectively movable along a vertical direction relative to the lower platen assembly; a second upper platen assembly positioned adjacent and downstream of the first upper platen assembly and over the lower platen assembly, the second upper platen assembly selectively movable along the vertical direction relative to the lower platen assembly; and a plug assembly is movable between i) a first position away that is not under the first upper platen assembly or the second upper platen assembly and ii) a second position wherein the plug assembly is located between the first upper platen assembly and the lower platen assembly, the plug assembly configured for selective placement against one of the movable mold assemblies so as to block a back flow of rubber material therefrom. ### Claim 17 (depends on 16) The apparatus for the continuous molding and curing of tire tread as in claim 16, further comprising one or more motors for moving the first and second upper platen assemblies along the vertical direction. ### Claim 18 (depends on 16) The apparatus for the continuous molding and curing of tire tread as in claim 16, further comprising an extruder positioned upstream from the mold assembly transport mechanism and configured for extruding a strip of rubber material for positioning over the lower platen assembly. ### Claim 19 (depends on 16) The apparatus for the continuous molding and curing of a tire tread as in claim 16, further comprising: a mold assembly return mechanism extending longitudinally in an adjacent and parallel manner to the mold assembly transport mechanism, the mold assembly return mechanism configured for transporting one or more mold assemblies in a direction opposite to the conveying direction of the mold assembly transport mechanism and back to the in-feed end of the mold assembly transport mechanism.