Glass rod manufacturing method and glass rod manufacturing apparatus

Abstract

A method for manufacturing a glass rod (106), which is a parent material of an optical fiber (350), comprising: adjusting a vertical inclination of a standard rod (138) having a predetermined straightness; and heating and elongating a base material (102), which is a parent material of the glass rod (106), along an axis of the standard rod (138), the vertical inclination of which is adjusted, to generate the glass rod (106).

What is claimed is:  
     
         1 . A method for manufacturing a glass rod, which is a parent material of an optical fiber, comprising: 
 adjusting a vertical inclination of a standard rod having a predetermined straightness; and    heating and elongating a base material, which is a parent material of said glass rod, along an axis of said standard rod, said vertical inclination of which is adjusted, to generate said glass rod.    
     
     
         2 . A method as claimed in  claim 1 , wherein said base material is elongated with a furnace which heats said base material, a hanging mechanism which supplies said base material to said furnace, and an elongating mechanism which pulls said base material heated by said furnace along said axis of said standard rod to produce said glass rod, and wherein said adjusting said vertical inclination includes: 
 holding said standard rod by said hanging mechanism; and    adjusting a vertical inclination of said standard rod held by said hanging mechanism to be a vertical direction.    
     
     
         3 . A method as claimed in  claim 2 , wherein said adjusting said vertical inclination further includes: 
 holding said standard rod by said elongating mechanism; and    adjusting a vertical inclination of said standard rod held by said elongating mechanism to be a vertical direction.    
     
     
         4 . A method as claimed in  claim 3 , wherein said adjusting said vertical inclination further includes: 
 holding said standard rod by both of said hanging mechanism and said elongating mechanism; and    adjusting a vertical inclination of said standard rod held by both of said hanging mechanism and said elongating mechanism to be a vertical direction.    
     
     
         5 . A method as claimed in  claim 1 , wherein said base material is elongated with a furnace which heats said base material, a hanging mechanism which supplies said base material to said furnace, and an elongating mechanism which pulls said base material heated by said furnace along said axis of said standard rod to produce said glass rod, and wherein said adjusting said vertical inclination includes: 
 holding said standard rod by said elongating mechanism; and    adjusting a vertical inclination of said standard rod held by said elongating mechanism to be a vertical direction.    
     
     
         6 . A method as claimed in  claim 5 , wherein said adjusting said vertical inclination further includes: 
 holding said standard rod by said elongating mechanism; and    adjusting a vertical inclination of said standard rod held by said hanging mechanism to be a vertical direction.    
     
     
         7 . A method as claimed in  claim 6 , wherein said adjusting said vertical inclination further includes: 
 holding said standard rod by both of said hanging mechanism and said elongating mechanism; and    adjusting a vertical inclination of said standard rod held by both of said hanging mechanism and said elongating mechanism to be a vertical inclination.    
     
     
         8 . A method as claimed in  claim 1 , wherein said base material is elongated with a furnace which heats said base material, a hanging mechanism which supplies said base material to said furnace, and an elongating mechanism which pulls said base material heated by said furnace along said axis of said standard rod to produce said glass rod, and wherein said adjusting said vertical inclination includes: 
 holding said standard rod by both of said hanging mechanism and said elongating mechanism; and    adjusting a vertical inclination of said standard rod held by both of said hanging mechanism and said elongating mechanism to be a vertical direction.    
     
     
         9 . A method as claimed in  claim 5  or  8 , wherein said elongating mechanism holds an approximate center of longitudinal direction of said standard rod during said adjusting said vertical inclination.  
     
     
         10 . A method as claimed in  claim 8 , wherein said adjusting said vertical inclination of said standard rod held by both of said hanging mechanism and said elongating mechanism to be less than approximately 0.5 mm per 1 m length.  
     
     
         11 . An apparatus for manufacturing a glass rod, which is a parent material of an optical fiber, comprising: 
 a furnace which heats a base material, which is a parent material of said glass rod;    a standard rod having a predetermined straightness;    a hanging mechanism which supplies said base material to said furnace along an axis of said standard rod; and    an elongating mechanism which pulls said base material heated by said furnace along said axis of said standard rod to produce said glass rod, wherein:    at least one of said hanging mechanism and said elongating mechanism holds said standard rod to adjust a vertical inclination of said axis of said standard rod.    
     
     
         12 . An apparatus as claimed in  claim 11 , wherein said standard rod is made of ceramic.  
     
     
         13 . An apparatus as claimed in  claim 11 , wherein said standard rod has a length of said base material and dummy rods that are welded onto both ends of said base material.