Exothermic welding assembly

Abstract

An assembly is disclosed for exothermic welding comprising a mold which is formed of a material which withstands exothermic welding temperatures and includes a weld cavity therein for positioning at least two members which are to be exothermically welded together, and an ignition cavity communicating with the weld cavity. The mold is capable of accommodating any one of several exothermic welding procedures which may involve either a flint igniter or the use of an electrical igniter which is readily accommodated by the mold in the performance of several of the procedures. The electrical igniter is formed of a pair of flat, longitudinally extending conductor strips with a sheet of insulation laminated therebetween, a filament adjacent one end of the strips, and one or more positioning tabs adjacent one end of the strips. A cartridge is also provided which contains the weld metal and the electrical igniter and which may be positioned in the ignition cavity of the mold. The cartridge is formed of a material which is consumed during the welding procedure and may contain a plate of a different material adjacent its bottom which melts at a higher temperature than the materials of the cartridge.

What is claimed is: 
     
         1 . An exothermic welding assembly comprising:
 a mold portion having a first cavity therein for positioning at least two members adjacent each other for exothermic welding, the mold portion including an exterior surface with an annular groove, and a second cavity in communication with the first cavity and configured for seating a cartridge containing a weld metal and a portion of an igniter; and   a cover portion having an exterior surface with an annular projection configured for sealingly engaging the annular groove, the cover portion further including a chamber in communication with the second cavity and configured for accommodating a filter for trapping emissions created during the exothermic welding.   
     
     
         2 . The assembly of  claim 1 , further including a preconstructed cartridge defining a chamber that contains particulate weld metal prior to ignition. 
     
     
         3 . The assembly of  claim 2 , wherein the cartridge includes a bottom wall formed of a material that melts with the particulate weld metal during the exothermic welding. 
     
     
         4 . The assembly of  claim 2 , wherein the cartridge further includes a filament end of the igniter. 
     
     
         5 . The assembly of  claim 4 , wherein the filament end is formed of a material that melts with the particulate weld metal during the exothermic welding. 
     
     
         6 . The assembly of  claim 1 , wherein the mold portion further includes a passage extending from the second cavity to the outside of the mold portion, the passage formed to accommodate electrical conductors of the igniter. 
     
     
         7 . The assembly of  claim 1 , wherein the cover portion includes a vent passage fluidly connecting the chamber in communication with the second cavity to the outside of the cover portion. 
     
     
         8 . An exothermic welding kit comprising:
 a mold portion having a first cavity therein for positioning at least two members adjacent each other for exothermic welding, the mold portion including an exterior surface with an annular groove, and a second cavity in communication with the first cavity and configured for seating a cartridge containing a weld metal and a first portion of an igniter;   a first cover portion having an exterior surface with an annular projection configured for sealingly engaging the annular groove, the first cover portion further configured to cover the second cavity during the exothermic welding; and   a second cover portion having an exterior surface with an annular projection configured for sealingly engaging the annular groove, the second cover portion further including a chamber in communication with the second cavity and configured for accommodating a filter for trapping emissions created during the exothermic welding.   
     
     
         9 . The kit of  claim 8 , wherein the mold portion further includes a passage extending from the second cavity to the outside of the mold portion, the passage formed to accommodate electrical conductors of the igniter. 
     
     
         10 . The kit of  claim 8 , wherein the second cover portion includes a vent passage fluidly connecting the chamber in communication with the second cavity to the outside of the second cover. 
     
     
         11 . An exothermic welding assembly, the assembly configurable for a smokeless or a non-smokeless welding procedure, the assembly comprising:
 a mold portion having a first cavity therein for positioning at least two members adjacent each other for exothermic welding, the mold portion including an exterior surface with an annular groove, and a second cavity in communication with the first cavity and configured for seating a cartridge containing a weld metal and a portion of an igniter;   a first cover portion having an exterior surface with an annular projection configured for sealingly engaging the annular groove and covering the second cavity during the non-smokeless welding procedure; and   a second cover portion having an exterior surface with an annular projection configured for sealingly engaging the annular groove during the smokeless welding procedure, the second cover portion further including a chamber in communication with the second cavity adapted to accommodate a filter for trapping emissions created during the exothermic welding.   
     
     
         12 . The assembly of  claim 11 , further including a preconstructed cartridge defining a chamber that contains particulate weld metal prior to ignition. 
     
     
         13 . The assembly of  claim 12 , wherein the cartridge includes a bottom wall formed of a material that melts with the particulate weld metal during the exothermic welding. 
     
     
         14 . The assembly of  claim 12 , wherein the cartridge further includes a filament end of the igniter. 
     
     
         15 . The assembly of  claim 14 , wherein the filament end is formed of a material that melts with the particulate weld metal during the exothermic welding. 
     
     
         16 . The assembly of  claim 11 , wherein the mold portion further includes a passage extending from the second cavity to the outside of the mold portion, the passage formed to accommodate electrical conductors of the igniter. 
     
     
         17 . The assembly of  claim 11 , wherein the second cover portion includes a vent passage fluidly connecting the chamber in communication with the second cavity to the outside of the second cover. 
     
     
         18 . A mold portion for an exothermic welding assembly, the mold portion comprising:
 a first cavity defined therein for positioning at least two members adjacent each other for exothermic welding;   a second cavity in communication with the first cavity and configured for seating a cartridge containing a weld metal and a portion of an igniter; and   an exterior surface with an annular groove configured to separately receive and engage 1) an annular projection of a first cover portion, the first cover portion cooperative with the mold portion to cover the second cavity during a non-smokeless exothermic welding procedure and 2) an annular projection of a second cover portion, the second cover portion defining a chamber therein adapted to accommodate a filter for trapping emissions created during a smokeless exothermic welding procedure.   
     
     
         19 . The mold portion of  claim 18 , further including a passage extending from the second cavity and in communication with the outside of the mold portion, the passage formed to accommodate electrical conductors of the igniter.