Split vulcanizing die

A split vulcanizing die comprising:

• a lower molding ring;
• an upper molding ring movable relative to said lower molding ring;
• a side molding ring composed of a plurality of arc-shaped segments movable in the radial direction of said die whereby when all said segments are moved to their radially innermost positions, said side molding ring is placed in tight contact with outside circumferential surfaces of said upper and lower molding rings which move toward each other to define a vulcanizing cavity inside said upper, lower and side molding rings;
• an outer ring having an inside circumferential truncated-cone-shaped surface and provided outside said side molding ring so that said outer ring can be moved in the axial direction of said die;
• oblique dovetail couplings which conjoin said segments to said outer ring, said segments having oblique planar surfaces provided on the circumferential outsides thereof;
• intermediate blocks corresponding to said segments removably attached to the truncated-cone-shaped surface of said outer ring;
• and the inside surfaces of said intermediate blocks having planar surfaces which are placed in slip contact with planar surfaces on said segments which face said blocks.