Sawing wire spool with two concentric drums as core

Abstract

A spool ( 20 ) made of thick metal sheet for a fine metal wire comprises a core ( 22 ), and two flanges ( 24 ), coupled to the core ( 12 ). The core ( 22 ) comprises two concentric drums, an inner drum ( 26 ) with inner diameter d, and an outer drum ( 28 ) with outer diameter D. The spool changes the load distribution of side pressure on the flanges and further improves the structural rigidity of the spool to against deformation.

1 . A spool made of thick metal sheet for a fine metal wire comprising: a core, and
 two flanges, coupled to said core,   characterized in that said core comprising two concentric drums, an inner drum with inner diameter d, and an outer drum with outer diameter D.   
     
     
         2 . A spool as claimed in  claim 1 , characterized in that the thickness of metal sheet is between 2.5 mm and 7.0 mm. 
     
     
         3 . A spool as claimed in  claim 2 , characterized in that the thickness of metal sheet is between 3.0 mm and 5.0 mm. 
     
     
         4 . A spool as claimed in  claim 3 , characterized in that said outer diameter D of said outer drum is between 1.3 and 2.1 times of said inner diameter d of said inner drum. 
     
     
         5 . A spool as claimed in  claim 4 , characterized in that the diameter φ of said flanges is between 2.2 and 2.8 times of said inner diameter d of said inner drum. 
     
     
         6 . A spool as claimed in  claim 5 , characterized in that the ratio φ/D is between 1.0 and 2.0. 
     
     
         7 . A spool as claimed in  claim 6 , characterized in that the ratio φ/D is between 1.3 and 1.6. 
     
     
         8 . A spool as claimed in  claim 7 , characterized in that the height H of said outer drum is between 2.0 and 3.0 times of said inner diameter d of said inner drum. 
     
     
         9 . A spool as claimed in  claim 8 , characterized in that said flanges have one center hole and evenly distributed slots around said center hole. 
     
     
         10 . A spool as claimed in  claim 9 , characterized in that the outer periphery of said inner drum is welded to the inner periphery of the center hole on said flanges at the both ends of said inner drum. 
     
     
         11 . A spool as claimed in  claim 10 , characterized in that the inner periphery of said outer drum is welded to said evenly distributed slots on said flanges at the both ends of said outer drum. 
     
     
         12 . A spool as claimed in  claim 11 , characterized in that the outer periphery of said outer drum is welded to the surface of said flanges at the both ends of said outer drum. 
     
     
         13 . A spool as claimed in  claim 9 , characterized in that support plates are welded between the outer periphery of said inner drum and the inner periphery of said outer drum.