Method for leveling a string groove of a hollow metal racket

Abstract

A method for leveling a string groove of a hollow metal racket includes various steps of preparing a hollow metal tube with a string groove formed lengthwise, of preparing an outer mold consisting of an upper and a lower mold respectively having a straight groove forming a straight hole after the upper and the lower mold is combined together, of preparing two inner molds to be inserted in the two ends of the inner hole of the metal tube, of placing the hollow metal in the straight hole of the outer mold, of pushing the two inner molds into the two free ends of the inner hole of the hollow metal tube to level a section of two ends of the metal tube not to be netted and then retracting out of the metal tube. Then the metal tube with the string groove left in the netted portion is to be made into a finished metal racket by subsequent processes.

1 . A method for leveling a string groove of a hollow metal racket, said method comprising”
 A first step of preparing a hollow metal tube with a string groove of the length of the whole body of said hollow metal tube by means of a mold provided with a string groove:    A second step of preparing an outer mold consisting of an upper mold and a lower mold, said upper and said lower mold respectively having a straight groove and the same length as said hollow metal tube, said straight groove of said upper and said lower mold forming a hole of its cross-sectional shape the same as the inner hole of said hollow metal tube after said upper and said lower mold are combined with each other to form the outer mold:    A third step of preparing two inner molds having a preset length and having the same cross-section as that of said hollow metal tube, a front end of each said inner mold possible to smoothly fit into the inner hole of said hollow metal tube:    A fourth step of placing said hollow metal tube stably in the straight grooves of said upper mold and said lower mold of said outer mold, two free ends of the inner hole of said hollow metal tube exposed out, said two inner molds respectively positioned to align to the two free ends of the inner hole of said hollow metal tube so that said two inner mold may be pushed forward and backward:    A fifth step of pushing said two inner molds respectively in the two free ends of the inner hole of said hollow metal tube for a present distance tantamount to the length of the sections of said meta tube not to be netted so as to level the recessed string groove of said metal tube to let the string groove in the portion of the metal tube to be netted as original, and then said two inner molds retracted back out of the inner hole of said hollow metal tube, finishing leveling the string groove of said hollow metal tube.    
   
   
       2 . The method for leveling a string groove of a hollow metal racket as claimed in  claim 1 , wherein said two inner molds respectively have a short cone-shaped section formed in the front end to guide each said inner mold into the inner hole of said hollow metal tube.  
   
   
       3 . The method for leveling a string groove of a hollow metal racket as claimed in  claim 1 , wherein said outer mold is fixed stably on a table before performing said fifth step.  
   
   
       4 . The method for leveling a string groove of a hollow metal racket as claimed in claim  11 , wherein said two inner molds are fixed on a table possible to be pushed forward and retraced backward before performing said fifth step.