| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a heating furnace having a sealing structure capable of effectively sealing a clearance gap between a preform insertion opening and a preform to be heated even when an outer diameter of the preform to be heated fluctuates in the longitudinal direction. <P>SOLUTION: The heating furnace 2 for heating the preform 1 inserted from the insertion opening 2a includes an annular sealing body 9 for sealing the clearance gap between the preform 1 and the insertion opening 2a. The annular sealing body 9 is formed from a plurality of stacked annular disks 10 each having an insertion hole 10a for inserting the preform 1 in its center area. The annular disk has a plurality of slits 10b formed from an inner edge of the insertion hole 10a toward its periphery side and a plurality of flexible portions 10c that are defined by the plurality of the slits 10b and bend by an interference with the preform 1 to be inserted into the insertion hole 10a. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
