Cold heading formed wedge for use in post tensioning concrete

Abstract

A wedge for use in post tensioning concrete is formed by cold heading. The cold heading operation may include providing a wire, feeding the end of the wire into a cold heading apparatus, cold heading the end of the wire to form at least one wedge blank, and finishing the wedge blank to form the wedge.

1 . A method for forming a wedge for post tensioning concrete comprising:
 providing a wire;   feeding a portion of the wire into a cold heading apparatus;   cold heading a portion of the wire to form at least one wedge blank; and   finishing the wedge blank to form the wedge.   
     
     
         2 . The method of  claim 1 , wherein cold heading a portion of the wire to form at least one wedge blank comprises:
 feeding the portion of the wire between a first and second forming die;   reshaping the portion of the wire by the first and second forming die; and   separating the portion of the wire from the wire to form the at least one wedge blank.   
     
     
         3 . The method of  claim 2 , wherein reshaping the portion of the wire by the first and second forming die comprises one or more of stamping, swaging, punching, forging, extruding, or upsetting the portion of the wire. 
     
     
         4 . The method of  claim 2 , further comprising further reshaping the portion of the wire by a third and fourth forming die. 
     
     
         5 . The method of  claim 1 , wherein finishing the wedge blank to form the wedge comprises one or more of tumbling, polishing, heat treating, hardening, tempering, grooving, or surface treating the wedge blank. 
     
     
         6 . The method of  claim 1 , wherein the process of feeding the wire to the cold heading apparatus is performed by one or more drive wheels. 
     
     
         7 . The method of  claim 6 , wherein the cold heading apparatus further includes a straightening apparatus, the straightening apparatus including a plurality of rollers. 
     
     
         8 . The method of  claim 1 , wherein two wedge blanks are formed simultaneously. 
     
     
         9 . The method of  claim 1  further comprising machining the wedge blanks to form grooves. 
     
     
         10 . A method comprising:
 providing a wire;   feeding a portion of the wire into a cold heading apparatus;   cold heading a portion of the wire to form at least one wedge blank;   finishing the wedge blank to form the wedge;   providing an anchor for post tensioning concrete;   threading a strand through the anchor; and   positioning the wedge on the strand.   
     
     
         11 . The method of  claim 10 , wherein positioning the wedge is on the strand is in a direction perpendicular to the longitudinal axis of the strand. 
     
     
         12 . The method of  claim 10 , wherein cold heading a portion of the wire to form at least one wedge blank comprises:
 feeding the portion of the wire between a first and second forming die;   reshaping the portion of the wire by the first and second forming die;   separating the portion of the wire from the wire to form the at least one wedge blank.   
     
     
         13 . The method of  claim 12 , wherein reshaping the portion of the wire by the first and second forming die comprises one or more of stamping, swaging, punching, forging, extruding, or upsetting the portion of the wire. 
     
     
         14 . The method of  claim 12 , further comprising further reshaping the portion of the wire by a third and fourth forming die. 
     
     
         15 . The method of  claim 10 , wherein finishing the wedge blank to form the wedge comprises one or more of tumbling, polishing, heat treating, hardening, tempering, grooving, or surface treating the wedge blank. 
     
     
         16 . The method of  claim 10  further comprising moving the wedge into a tapered recess. 
     
     
         17 . The method of  claim 16  further comprising applying a gripping force using the wedges on the strand. 
     
     
         18 . The method of  claim 10 , wherein the wedges have grooves.