公开(公告)号：JPH04223108A

公开(公告)日：1992-08-13

申请号：JP8024091

申请日：1991-04-12

Applicant: PIRELLI

Inventor： JIYUZETSUPE GARI ,  RENAATO GARETSUTA

IPC: B29C33/10 ,  B29C33/30 ,  B29C33/38 ,  B29C33/42 ,  B29C35/02 ,  B29D30/06 ,  B29K21/00 ,  B29K105/24 ,  B29L30/00 ,  B60C11/04

Abstract: PURPOSE: To provide a mold for vulcanizing an unvulcanized tire without forming a flash or a bubble by applying to various tread patterns. CONSTITUTION: In a metallic mold, all or a part of an annular portion for molding at least a tread of a tire is formed by a plurality of small separate pieces which can be combined to form the annular portion. Between these small pieces, during the molding of the tire, clearances are maintained so as to permit the passage of air but not the passage of rubber. The above clearances are connected via vent holes 21, 23b to air suction means. Such vent holes 21, 23b are also connected with means for blowing pressure fluid via the clearances. A construction of this mold by means of small pieces made with cuts of the portions in the axial and the circumferential direction permits regulation of the width of the clearances with respect to the rheometric characteristics of the elastometic material to be molded and to adapt easily the mold to different tire sizes by increasing or decreasing the number of such pieces.