| 摘要 |
PROBLEM TO BE SOLVED: To prevent rubber from staying inside an air passage by forming the air passage through a venting means as short as possible, and to extend a durable life of venting performance and the venting means by securing the volume of a center passage as large as possible, in the case when rubber can not be perfectly shut-off from entering into the center passage of a casing of the venting device. SOLUTION: The center passage 46 formed in the casing 44 is taper shaped so as to become larger in the upper side and smaller in the lower side in internal diameter and, angles are set mutually different for an upper edge part 58 of the center passage and for an inclined side face 60 of a valve head 56 which makes point (line) contact with the part 58. By this way, an air venting capacity is improved, vent-rubber formation on a completed tyre by the rubber flowing into the venting means is suppressed, failure of operation at the time of vulcanizing is prevented, the durable life of the venting device is extended and maintenance is made easy. COPYRIGHT: (C)2004,JPO |
