Patent Publication Number: US-9902011-B2

Title: Welding consumables and consumable holders

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional Patent Application of U.S. patent application Ser. No. 13/090,965 entitled “Welding Consumables and Consumable Holders”, filed Apr. 20, 2011, which is a Non-Provisional Patent Application of U.S. Provisional Patent Application No. 61/346,970 entitled “Welding Electrode Holder with Specialized Electrode”, filed May 21, 2010, both of which are herein incorporated by reference. 
    
    
     BACKGROUND 
     The invention relates generally to a welding torch and, more particularly, to a welding electrode and a welding electrode holder. 
     Welding is a process that has become increasingly ubiquitous in various industries and applications. While such processes may be automated in certain contexts, a large number of applications continue to exist for manual welding operations. Such welding operations rely on a variety of types of equipment to ensure the supply of welding consumables (e.g., electrodes, etc.) is provided to the weld in an appropriate amount at the desired time. For example, shielded metal arc welding (SMAW) typically relies on a welding electrode to provide filler material for a weld. 
     Power is typically provided to the welding electrode via a welding torch coupled to a welding power source. That is, an electric current from the welding power source is typically used to strike an arc between a workpiece and the welding electrode. To that end, welding electrodes are often secured by the welding torch on one end, while the arc is formed utilizing the opposite end. In some circumstances, a welding operator may find it advantageous to alter the shape of the welding electrode prior to initiating the arc to obtain better control over the welding process. For example, some welding operators may bend the welding electrode for improved control of stick welding processes. Unfortunately, these practices are often associated with a variety of drawbacks since only a portion of the length of the welding electrode is utilized for the weld, while the remaining portion is discarded. Accordingly, there exists a need for improved welding systems that overcome these drawbacks. 
     BRIEF DESCRIPTION 
     In an exemplary embodiment, a welding torch includes a securing mechanism and an insulated grip. The securing mechanism is configured to secure an exposed central portion of a welding rod bounded by flux covered first and second sides. The securing mechanism is also configured to make electrical contact with the central portion of the rod for arc welding with the first side. The insulated grip is configured to cover the second side of the welding rod. 
     In another embodiment, a welding system includes a welding power supply having power conversion circuitry configured to receive primary power and to convert the primary power to a weld power output suitable for use in a welding operation. The welding system also includes an electrode holder having a first assembly configured to electrically insulate a first end of a welding electrode and a securing assembly configured to secure a portion of the welding electrode to expose a second end of the welding electrode. The welding system includes a welding cable configured to electrically couple the welding power supply to the electrode holder to apply the weld power output to the second end of the welding electrode. 
     In another embodiment, a welding rod includes a central portion having an electrode core material. The welding rod also includes a first side portion extending from a first side of the central portion and having the electrode core material coated in flux. The welding rod includes a second side portion extending from a second side of the central portion and having the electrode core material coated in flux. The first side portion and the second side portion are each configured to be utilized as a welding electrode in a welding operation, one at a time. 
     In another embodiment, a method of manufacturing a welding rod includes providing a rod of electrode core material, clamping a central portion of the rod of electrode core material, coating the clamped rod with flux, and drying the flux coated rod. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is a perspective view of a welding system illustrating an embodiment of an electrode and an electrode holder in accordance with aspects of the present invention; 
         FIG. 2  illustrates an embodiment of the welding electrode of  FIG. 1 ; 
         FIG. 3  is a side view of the exemplary welding electrode of  FIG. 2  in accordance with an embodiment of the present invention; 
         FIG. 4  is a perspective view of a welding torch assembly having a securing mechanism and an insulated grip in accordance with an embodiment of the present invention; 
         FIG. 5  is a perspective view of the welding torch assembly of  FIG. 4  illustrating an embodiment of an electrode holder in an open position; 
         FIG. 6  is an exploded view of the welding torch assembly of  FIG. 4 ; 
         FIG. 7  is a side view of an exemplary cam handle of a securing mechanism of an electrode holder in accordance with an embodiment of the present invention; 
         FIG. 8  is an exploded view of a welding torch assembly in accordance with an aspect of the present invention; 
         FIG. 9  illustrates an embodiment of a securing mechanism including jaws for clamping a welding electrode in accordance with an embodiment of the present invention; and 
         FIG. 10  illustrates a method of manufacturing an exemplary welding electrode in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     As described below, provided herein are welding systems including one or more features that may improve the efficiency of a shielded metal arc welding (SMAW) process (i.e., stick welding). For example, embodiments of presently disclosed welding torch assemblies and welding rods may enable a welding operator to more fully utilize the length of a welding electrode in a stick welding process. For example, in one embodiment, a welding electrode is made of an electrode core material having a first flux section and a second flux section that flank an exposed central section. The foregoing embodiment of the welding electrode may be compatible with embodiments of welding electrode holders disclosed herein to provide for arc ignition and welding with both the first flux section and the second flux section, one at a time. To that end, welding electrode holders disclosed herein may include securing assemblies and insulating assemblies capable of securing the central section of the welding electrode such that one of the flux sections may be utilized for welding while the other flux section remains electrically insulated within the electrode holder. 
     Turning now to the figures,  FIG. 1  is a perspective view of an exemplary welding system  10  in accordance with an embodiment of the present invention. As appreciated, the welding system  10  may be utilized in a SMAW process (i.e., stick welding). The welding system  10  includes a welding power supply  12  having power conversion circuitry adapted to receive primary power and to convert the primary power to a weld power output suitable for use in a welding operation. For example, the primary power may be received from any primary source, such as a power grid, a generator, a wall outlet, and so forth. In some embodiments, the power conversion circuitry may be configured to output weld power at a substantially constant current consistent with conventional SMAW processes. 
     In the illustrated embodiment, the welding power supply  12  includes a housing  14  having a top panel, side panels, a front panel, and a rear panel. In some embodiments, the top panel may include a handle that facilitates transport of the welding power supply  12  by an operator. Furthermore, the welding power supply  12  may include a controller configured to control operation of the welding power supply  12 . The front panel of the welding power supply  12  includes a control panel  16  through which an operator may set one or more parameters of the welding process, for example, via knob  18  (or multiple knobs, buttons, touchscreens, etc.). 
     The front of the welding power supply  12  also includes welding terminals  20  and  22 . A cable  24  terminating in a ground clamp  26  is attached to terminal  20  of the welding power supply  12 . The clamp  26  is adapted to clamp to a workpiece  28  during a welding operation. A second cable  30  extends from terminal  22  to couple a welding torch assembly  32  to the welding power supply  12 . When the welding torch assembly  32  is utilized in a welding operation to establish a welding arc, the ground clamp  26  clamps to the workpiece  28  to close the circuit between the welding power source  12 , the workpiece,  28 , and the welding torch  32 . 
     The illustrated welding torch assembly  32  includes an electrode holder  34 , which holds a welding electrode  36 . As described in more detail below, the welding torch assembly  32  includes a securing mechanism that secures the welding electrode  36  within the assembly and enables a welding current to flow from the welding power supply  12  through the exposed portion of the welding electrode  36  shown in  FIG. 1 . Furthermore, the electrode holder  34  may include an insulated grip that covers a contained portion (not shown in  FIG. 1 ) of the electrode  36  to electrically isolate the contained portion and a welding operator from the electrically conductive illustrated portion of the welding electrode  36  when a welding arc is established between the electrode  36  and the workpiece  28 . 
       FIG. 2  illustrates an embodiment of the welding electrode  36  of  FIG. 1  adapted for use with the exemplary welding electrode holders disclosed herein. The welding electrode  36  includes a central portion  38 , a first side portion  40 , and a second side portion  42 . The illustrated central portion  38  is an exposed portion of a rod made of an electrode core material  39  that extends through the welding electrode  36 . The welding rod may be made from a variety of suitable materials, such as metals including but not limited to steel, stainless steel, nickel, copper-nickel, and iron-nickel. The first side portion  40  and the second side portion  42  of the welding electrode  36  are coated with flux  43  that surrounds the electrode core material  39 . During a welding operation, the flux  43  is adapted to disintegrate to produce a shielding gas (e.g., CO 2 ) and/or slag, which may protect the weld from oxidation and contamination. In some embodiments, the flux  43  may be made from rutile, potassium silicate, sodium silicate, quartz, calcite, mica, iron alloys, or any other suitable material. 
     The central portion  38  of the welding electrode  36  is exposed (i.e., is not covered in flux) because the central portion  38  is not configured to be consumed during the welding process. Instead, the central portion  38  is provided to facilitate securing the welding electrode  36  within a welding torch assembly. To that end, the exposed central portion  38  extends for a distance  44  between the flux covered sides  40  and  42  to provide an area that may be retained, for example, in a clamp, for securing the electrode  36  within a welding torch. It should be noted that the distance  44  may be subject to considerable variations between embodiments of the welding electrode  36  depending on factors associated with the given welding application. For example, the distance  44  of the exposed central portion  38  may be approximately 1 to 6 cm, 3 to 8 cm, 5 to 10 cm, or any other suitable value. The exposed central portion  38  also has a diameter  46 , which is the diameter of the rod of electrode core material. Here again, the diameter  46  may be subject to variations between embodiments and may be approximately 1 to 5 mm, 4 to 9 mm, 7 to 14 mm, or any other value. For further example, in some embodiments, the diameter  46  may be between approximately 3/32″ and approximately ⅛″. 
     The first side portion  40  is covered with flux  43  extending from the central portion  38  to a first end  48 . That is, the first side portion  40  extends for a distance  50  between the central portion  38  and the first end  48 . The distance  50  may vary between embodiments of the welding electrode  36 . For example, the distance  50  of the first side  40  may be approximately 10 to 18 cm, 15 to 25 cm, 21 to 30 cm, or any other suitable value. Further, the first side  40  is defined by a diameter  52  that is approximately equal to the diameter  46  of the electrode core material combined with the distance the flux  43  extends outward from the electrode core material. The diameter  52  may vary from one embodiment of the welding electrode  36  to another. For example, the diameter  52  of the first side  40  may be approximately 2 to 10 mm, 8 to 18 mm, 14 to 28 mm, or any other suitable value. 
     Similarly, the second side portion  42  is covered with flux  43  extending from the central portion  38  to a second end  54 . That is, the second side portion  42  extends for a distance  56  between the central portion  38  and the second end  54 . The distance  56  may vary between embodiments of the welding electrode  36 . For example, the distance  56  of the second side  42  may be approximately 10 to 18 cm, 15 to 25 cm, 21 to 30 cm, or any other value. The second side  42  also has a diameter  58  that is defined by the diameter  46  of the electrode core material as well as the flux surrounding the electrode core material. Again, the diameter  58  may vary from one embodiment of the welding electrode  36  to another. For example, the diameter  58  of the second side  42  may be approximately 2 to 10 mm, 8 to 18 mm, 14 to 28 mm, or any other suitable value. 
     In certain embodiments, one or both of the side portions  40  and  42  may be bent by a welding operator to improve control over a welding process. For example, as illustrated in  FIG. 2 , the second side  42  may be bent as shown by arrow  60  so that bent side  62  is rotated approximately 90 degrees from its unbent position. Such a bent position may be one of many bends that may be made to the welding electrode  36  prior to performing a welding operation. For example, the electrode  36  may be bent in an “L” manner as shown, an “S” manner, or any other desired manner. In such embodiments, a single side portion may be configured for use in the current welding operation, while the remaining side portion is configured to be electrically isolated from the weld operation. After one side portion is consumed during welding, the electrode  36  may be repositioned within an electrode holder to utilize the remaining side portion for additional welding. In such a way, presently disclosed embodiments may provide for welding with both the first side portion  40  and the second side portion  42 , one at a time. 
       FIG. 3  is a side view of the welding electrode  36  of  FIG. 2  illustrating features of the end  48  in more detail. As shown, the first end  48  of the electrode  36  includes the electrode core material  39  having diameter  46  and being surrounded by flux  43  having diameter  72 . Accordingly, the diameter  52  of the first end  48  of the welding electrode  36  is defined by the diameter  46  and the diameter  72 . As noted above, this diameter  52  of the welding electrode  36  may be between approximately 3/32″ and approximately ⅛″. As such, the flux  43  provided on the first end  48  increases the diameter of the first end portion  40  of the welding electrode  36  as compared to the central portion  38 . In some embodiments, the flux  43  may increase the diameter  46  by approximately 0.5 to 2.5 mm, 2.0 to 4.5 mm, 3.5 to 7.0 mm, or any other suitable amount. 
       FIG. 4  is a perspective view of an embodiment of the electrode holder  34  of  FIG. 1 . As shown, the electrode holder  34  includes an insulated grip  73  that is depicted with the welding electrode  36  extending therefrom. The insulated grip  73  includes a first side assembly  74  and a second side assembly  76 . The side assemblies  74  and  76  are made of an insulating material to enable a welding operator to hold the insulated grip  73 . Further, as discussed in more detail below, the side assemblies  74  and  76  receive and cover the second side of the electrode  36 . 
     The electrode holder  34  also includes a securing mechanism  78  having jaws  80  and  82  that are shown clamping the electrode  36 . That is, the jaws  80  and  82  press against or clamp the central portion  38  of the electrode  36  to secure the electrode  36  in the electrode holder  34  such that the portion  48  is exposed for use in a welding operation, and the second portion of the welding electrode  36  is electrically insulated within the insulating grip  73 . During operation, a cable  84  enables the welding current to flow through the first side portion  40  of the welding electrode  36 . In the illustrated embodiment, the cable  84  includes a conductor  86  surrounded by an insulator  88 . During welding, current is transferred to the first side portion  40  of the welding electrode  36  via the conductor  86  and the securing mechanism  78 . Again, while the first side portion  40  of the welding electrode  36  is used to establish a welding arc, the second side portion of the welding electrode  36  is retained within the insulated grip  73  and is electrically isolated from the welding current path. It should be noted that in other embodiments, the second side portion of the welding electrode  36  may be used to establish a welding arc, while the first side portion  40  of the welding electrode  36  is retained within the insulated grip  73 . 
     Although the insulated grip  73  is depicted having multiple side assemblies  74  and  76 , certain embodiments of the insulated grip  73  may include more or fewer parts. For example, the insulated grip  73  may include a single piece of insulating material that slides over the second side of the welding electrode  36 , thereby enabling the insulated grip  34  to provide insulation and/or a handle for a welding operator to use during a welding operation. 
       FIG. 5  illustrates the electrode holder  34  with the first side assembly  74  rotated to expose a recess  90  disposed in the second side assembly  76 . As illustrated, the recess  90  is adapted to receive and retain the second side  42  of the welding electrode  36 . As may be appreciated, if the electrode  36  is rotated to use the second side  42  for establishing a welding arc, the first side  40  may be held within the recess  90  of the second side assembly  76 . In the illustrated embodiment, when the second side  42  of the welding electrode is retained in the recess  90  and the first side assembly  74  is in a closed position, the first side portion  40  of the welding electrode  36  is exposed for welding. That is, when the side assembly  74  is closed, the second side portion  42  is electrically insulated from the first side portion  40 , through which welding current may flow when a weld power output from the welding power supply is applied. 
     As previously mentioned, the first side assembly  74  may move away from or toward the second side assembly  76 , as depicted by arrow  92 . When the first side assembly  74  is moved away from the second side assembly  76 , the jaws  80  and  82  of the securing mechanism  78  may separate from each other and loosen their grip on the central portion  38  of the electrode  36 . In the contrary, when the first side assembly  74  moves toward the second side assembly  76 , the jaws  80  and  82  of the securing mechanism  78  move toward each other and tighten their grip on the central portion  38  of the electrode  36 . As such, when the first side assembly  74  and the second side assembly  76  are pressed together, the electrode  36  is secured by the securing mechanism  78  and the first portion  40  of the welding electrode  36  is exposed. 
       FIG. 6  is an exploded view of the embodiment of a welding torch assembly of  FIG. 4 . As previously mentioned, the second side assembly  76  includes the recess  90 . The second side assembly  76  also includes an opening  96  adapted to receive an inserted conductor  98  when the torch  94  is assembled. The conductor  98  includes a lower end  100 . The lower end  100  is coupled to the welding cable  84  so that a welding current may flow through the conductor  86  of the welding cable  84  and the conductor  98 . An opening  102  in the conductor  98  enables a bolt  104  to be inserted into the conductor  98  to form one end of the securing mechanism  78 . When assembled, the bolt  104  holds the securing mechanism  78  together. 
     Further, a jaw  106  includes a clamping surface  108  with ridges that press against an electrode when securing the electrode within the securing mechanism when the electrode holder is assembled. An opening  110  in the jaw  106  enables the bolt  104  to pass through the jaw  106 . A second jaw  112  forms the opposite side of the clamp. The jaw  112  has a clamping surface and an indention  114  (i.e., cam portion) where a cam presses or relieves pressure on the jaws  106  and  112 . An opening  116  in the jaw  112  enables the bolt  104  to pass through the jaw  112 . 
     During assembly, a pin  118  with an opening  120  is inserted into an opening in a cam handle  122 . The pin  118  and the cam handle  122  are positioned within the indention  114 , and the bolt  104  is screwed into the opening  120  to connect the securing mechanism  78  together. The cam handle  122  includes a lower portion  124  that is inserted into the first side assembly  74 . When the cam handle  122  is inserted into the first side assembly  74  and the conductor  98  is inserted into the second side assembly  76 , the first and second side assemblies  74  and  76  are pivotally coupled together via the securing mechanism  78 . The cam handle  122  also includes an upper portion with cams  126  and  128 . The cams  126  and  128  have openings  130  where the pin  118  is inserted before the pin  118  is secured with the bolt  104 . The conductor  98  and the jaws  106  and  112  are made of a metal conductor to enable a welding current to flow through the conductor  98  and the jaws  106  and  112  and also through a central portion of an electrode clamped or secured within the jaws  106  and  112 . 
     When the cams  126  and  128  are positioned within the indention  114 , the jaws  106  and  112  may be pressed together or have pressure relieved depending on the position of the cam handle  122  illustrated in  FIG. 7 . In the embodiment shown in  FIG. 7 , the cam  126  is depicted with the opening  130 . The opening  130  is positioned off-center in the cam  126 . That is, the uppermost distance  132  is smaller than the side distance  134 . Thus, when the cam side defined by distance  134  rests against the indention  114  of jaw  112  of  FIG. 6 , a greater clamping force is exerted between the jaws  106  and  112  than when the cam side defined by distance  132  rests against the indention  114  of jaw  112 . 
     An exploded view of another embodiment of a welding torch assembly  136  is illustrated in  FIG. 8 . As before, the welding torch assembly  136  includes the first and second side assemblies  74  and  76 , the conductor  98 , and the cam handle  122 . When assembled, the bolt  104  is inserted through the opening  102  in the conductor  98 . The bolt  104  is also inserted through the opening in the jaw  106  and through another jaw  138  with an opening  140  and a clamping surface. When assembled, the jaws  106  and  138  secure the central portion of an electrode between their respective clamping surfaces. A spring  142  is inserted between the jaw  138  and a cam receiver  144  to exert a force against both the jaw  138  and the cam receiver  144 . The cam receiver  144  includes an indention  146  where the cams  126  and  128  rest. The bolt  104  is inserted through the spring  142  and an opening  148  in the cam receiver  144 . Furthermore, the pin  118  is inserted through the openings  130  and secured by the bolt  104  by screwing the bolt into the threaded opening  120 . 
     As may be appreciated, with the addition of the spring  142  and jaw  138  as compared to previously described embodiments, the securing mechanism  78  of the embodiment illustrated in  FIG. 8  may enable securing an increased variety of welding electrode diameters. Furthermore, the jaws  106  and  138  may rotate while maintaining some or all of the clamping force applied when the first and second side assemblies  74  and  76  are pressed together. 
     The jaws  106  and  138  may include bevels, as illustrated in  FIG. 9 , to reduce the insertion force needed when an electrode is placed between the jaws. As shown,  FIG. 9  illustrates a securing mechanism  150  that includes a jaw  152  with bevels  154  and a jaw  156  with bevels  158 . A bolt  104  extends through a cavity  160  in the jaws  152  and  156 . A welding electrode  162  is depicted within the jaws  152  and  156 . A force  164  is applied to the electrode  162  to press the electrode  162  inside the jaws  152  and  156 . As previously noted, the bevels  154  and  158  may reduce the insertion force  164  necessary to insert the electrode  162  as compared to designs without bevels. Likewise, the bevels  154  and  158  may aid insertion of the electrode  162  by guiding the electrode  162  into the jaws  152  and  156 . 
     A flow chart of an embodiment of a method of manufacturing  166  a welding electrode is illustrated in  FIG. 10 . A central portion of a metal rod (i.e., a welding rod) may be clamped, at step  168 , for the metal rod to be held while it is coated with a flux. The metal rod may be made from a variety of metals including steel, stainless steel, nickel, copper-nickel, iron-nickel, and other metals, for example. Next, at step  170 , the metal rod is coated with flux. The flux may protect a weld area from oxidation and contamination by producing CO 2  during the welding process. The flux may be made from rutile, potassium silicate, sodium silicate, quartz, calcite, mica, iron alloys, or other materials, for example. 
     During step  170 , the metal rod may be coated with flux by various methods including dipping the metal rod in a molten flux, through extrusion, and so forth. When dipping the metal rod in a molten flux, a clamped central portion may enable individual sides (i.e., the first and second sides) of the metal rod to be dipped while the clamped central portion may prevent flux from coating the clamped central portion. In another embodiment, the whole metal rod may be dipped into a flux. When coating the metal rod with flux through extrusion, the flux may be made into a paste and shaped into a cylindrical shape. The paste and metal rod may be passed through a die where the flux coats the metal rod. As such, the size of the die opening may alter the thickness of the flux coating. 
     At step  172 , flux may be removed from the central portion of the metal rod to create an area where a welding torch may be secured to the metal rod. The flux may be removed using any available method, in order to expose the metal rod. For example, the flux may be removed by using a grinder or a rotating wire brush. Next, at step  173 , flux on both ends of the metal rod may be beveled, thereby removing flux from the ends to create a contact surface for initiating a welding arc. Again, the flux may be removed by using a grinder or a rotating wire brush. After the flux is removed from the central portion and the ends of the metal rod, the coated metal rod with flux is dried, at step  174 , to remove excess moisture from the flux. The coated metal rod may be dried in an oven, air dried, or the coated metal rod may be dried in any other manner. 
     Next, at step  176 , if the metal rod was clamped at the central portion of the metal rod, the metal rod may be unclamped. By using a clamp over the central portion, not only can the metal rod be moved through the manufacturing process via the clamp, but also the clamp may inhibit flux from covering the central portion of the metal rod, thereby maintaining an exposed central portion of the metal rod. Although specific steps for manufacturing the electrode have been described, the steps may be altered or varied to achieve the same end result. Likewise, the steps may be performed in any suitable order. 
     While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.