초록 ▼

An extrusion head is provided for extruding flat profiles for producing tread strip portions of vehicle tires from mixtures of rubber or plastics materials, which permits one of the constituents such as the tread strip mixture to be changed without adversely affecting the other constituent parts of

An extrusion head is provided for extruding flat profiles for producing tread strip portions of vehicle tires from mixtures of rubber or plastics materials, which permits one of the constituents such as the tread strip mixture to be changed without adversely affecting the other constituent parts of the mixture, such as the lateral rubber strip mixtures and the base rubber layer. This is achieved by suitably deflecting the flow channels for the lateral rubber layers in a front template. The flow channel for the lateral strips enters the template below the flow channel for the tread strip but discharges alongside the lateral edges of the tread strip. The head comprises a fixed central portion and pivotable upper and lower portions, the flow channels for the constituents of the mixture being defined by channels formed in insert members located between the head portions. By so doing, the flow channels for the base layer and for the lateral strips can be formed in one of the insert members leaving only the flow channel for the tread strip to be formed in the other insert member. Since it is the tread strip mixture which is most frequently changed, this can now be effected without adversely affecting the other two mixtures.

대표청구항 ▼

An extrusion head for extruding a flat profile for forming the tread strip portion of a vehicle tyre from different mixtures of materials selected from rubber and plastics materials, said tread strip portion comprising a tread strip, lateral strip portions disposed laterally of said tread strip and

An extrusion head for extruding a flat profile for forming the tread strip portion of a vehicle tyre from different mixtures of materials selected from rubber and plastics materials, said tread strip portion comprising a tread strip, lateral strip portions disposed laterally of said tread strip and a base layer supporting said tread strip, said head comprising a fixed central portion, said central portion including opposed planar faces, first and second outer portions disposed proximate said opposed faces of said central portion on opposed sides of said central portion, both said first and said second outer portions including opposed planar faces and both said outer portions including pivot mounting means to permit said outer portions to be pivoted away from said central portion, insert members disposed between each of said outer portions and said fixed central portions, each said insert member including opposed major surfaces abutting said planar surface of said head portion adjacent thereto, at least one of said major surfaces of each said insert member defining at least one groove such that said groove defines a flow channel bounded by said abutting planar surface of said head portion adjacent thereto, wherein at least first, second and third said flow channels are defined, first, second and third feed means for supplying different mixtures of material respectively to said first, second and third flow channels wherein said respective feed means are disposed one above the other, said first feed means supplying said mixture for said tread strip, said second feed means supplying said mixture for said lateral strips and said third feed means supplying said mixture for said base layer, said head further comprising an interchangeable front template receiving material discharged from said flow channels in said insert members, said front template defining at least first, second and third flow channels communicating, respectively with said first, second and third flow channels formed in said insert members, and an interchangeable end template member mounted at the discharge end of said front template member, said end template member defining the external configuration of said extruded flat profile, wherein said second flow channel for said lateral strip mixture is bifurcated in at least said front template member and wherein said channel for said lateral strip mixture enters said front template member from said second flow channel in said insert member below said flow channel for said tread strip and is directed towards opposite sides of the upper surface of said tread strip flow channel, said flow channel in said front template member for said lateral strip mixture discharging said mixture along the lateral, longitudinally extending, walls of said tread strip mixture.