Abstract:
The invention provides a high flow power cable for a welding system designed for effective cooling of the power cable while maintaining maneuverability of the cable. Provided is a power cable having two segments, the first segment being larger in diameter than the second segment. The first segment is generally coupled to the power source and the second segment is coupled to the welding torch. The first segment includes a thicker wire, which has less resistance and dissipates less heat while the second segment includes a thinner wire, allowing for easier handling. Additionally, cooling fluid is conducted through the first segment and the second segment, further cooling the cable.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Non-Provisional patent application of U.S. Provisional Patent Application No. 61/423,860 entitled “High Flow Power Cable for Small Welding Torch”, filed Dec. 16, 2010, which is herein incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The invention relates generally to cooling power cables for welding systems, and specifically those having small welding torches. 
         [0003]    In welding applications, power cables are generally used to carry current from the welding power supply to a welding torch. These high currents may cause the power cable to increase in temperature, often becoming quite hot. Hence, welding torch power cables are often cooled by gas, water or a coolant. Typically, such power cables consist of a copper conductor or conductors inside a rubber or vinyl hose or insulative jacket, through which the cooling fluid flows. 
         [0004]    Oftentimes, small welding torches may be used for welding projects having small work pieces and fine or complex weld joints. Small welding torches provide the fine welding needed for such projects. Additionally, small welding torches also provide the user with a greater degree of maneuverability. Ideally, power cables for small welding torches should also be smaller and more maneuverable as well, as having a bulky power cable attached to a small welding torch may minimize the advantages of using a small welding torch. However, a smaller power cable generally includes a smaller conductor wire as well. As the diameter of a wire decreases, its resistance increases, causing the temperature of the wire to increase as well. Additionally, the decreased cable size may restrict the flow of gas, water, or coolant through the cable. As such, the cable is cooled less effectively. 
       BRIEF DESCRIPTION 
       [0005]    In certain embodiments, a welding cable system includes a conduit for cooling fluid and electrical power. The conduit includes a first segment, a second segment, which is smaller in diameter than the first segment, and a coupler which connects the first segment and the second segment. 
         [0006]    In accordance with another embodiment of the present disclosure, a welding torch is coupled to a welding cable system that includes a conduit for cooling fluid and electrical power. The conduit includes a first segment, a second segment which is smaller in diameter than the first segment, and a coupler which connects the first segment and the second segment. 
         [0007]    Another embodiment includes a welding cable cooling method. The welding cable cooling method includes conducting cooling fluid through a first segment of a welding cable, conducting cooling fluid through a coupler; and conducting cooling fluid through a second segment of the welding cable. The coupler is coupled to the first segment and the second segment, and the second segment of the welding cable is configured to be smaller in diameter than the first segment of the welding cable. The method also includes conducting electrical power through a segment of welding cable having a large conductive wire, and conducting the same electrical power through a segment of welding cable having a small conductive wire, such that the large conductive wire and the small conductive wire are coupled together. 
     
    
     
       DRAWINGS 
         [0008]    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: 
           [0009]      FIG. 1  is a diagrammatical view of an exemplary welding system to be used with a high flow power cable, in accordance with embodiments of the present disclosure; 
           [0010]      FIG. 2  is an illustration of a high flow power cable as used in an exemplary welding system, in accordance with embodiments of the present disclosure; 
           [0011]      FIG. 3  is sectional view of a high flow power cable, in accordance with embodiments of the present disclosure; 
           [0012]      FIG. 4  is an exploded view of a high flow power cable, in accordance with embodiments of the present disclosure; 
           [0013]      FIG. 5  is a partially exploded view of a high flow power cable, in accordance with embodiments of the present disclosure; and 
           [0014]      FIG. 6  is a cross-sectional view of a high flow power cable, in accordance with embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The following discloses a novel high flow power cable for a welding system. The high flow power cable provides the benefits of a maneuverable power cable while having a means for effective cooling. Embodiments of the high flow power cable may be used in a Tungsten Inert Gas (TIG) welding system, the details of which are described below. 
         [0016]    Referring now to  FIG. 1 , a welding system  10  in accordance with one embodiment of the present technique is illustrated with both an electrode  44  and a filler material  62  in an independent arrangement. For example, as discussed in detail below, the filler material  62  may be thermally shielded and/or disposed away from the electrode  44 , which generates a significant amount of heat during a welding process. In other words, the electrode  44  and the filler material  62  may be kept apart from one another to reduce the possibility of the filler material  62  corrupting the electrode  44 , or the electrode  44  prematurely melting the filler material  62 , or both. In the illustrated embodiment, the welding system  10  includes a tungsten inert gas (TIG) welding system, and thus the electrode  44  is a non-consumable tungsten electrode. However, other embodiments may include other types of consumable or non-consumable electrodes. 
         [0017]    As depicted, the TIG welding system  10  includes a power source  12 , a shielding gas source  14 , a cooling system  16 , and a torch  18 . In the illustrated embodiment, the power source  12  provides power to the welding torch  18  via a conduit cable  34 . The power source  12  may supply a DC current or AC current to the torch  18  depending on the desired application. For example, an AC current may be suited for welding aluminum or magnesium, and a DC current may be suited for welding stainless steels, nickel or titanium. In addition to matching the current to the material selection, the output of the power source  12  may be varied to obtain desired weld characteristics. For example, a low AC frequency (e.g., 60 Hz) current may generate a wide arc with shallow penetration of a work piece  22 , while a high AC frequency (e.g., 200 Hz) current may generate a focused arc with deeper penetration into the work piece  22 . 
         [0018]    In addition to the frequency of the current, the power source  12  may vary the amperage of the current output to the torch  18 . The setting for the amperage output by the power source  12  may be adjusted by setting a knob or button or other input or interface device on the power source  12 , or may be set by a remote control  24 . For example, a welding system  10  may include a foot pedal remote control  24  that allows the operator to make current adjustments during welding by either holding down the foot pedal or feathering the foot pedal remote control  24  to vary the amperage. The remote control  24  may also include a finger tip control, audible command, or other form of input to signal the power source  12  to output a corresponding current. 
         [0019]    In addition, the torch  18  may be supplied with a shielding gas from a supply  14 . In general, the shielding gas may be supplied to the torch  18  and expelled from the torch at the location of the weld. The shielding gas may be expelled immediately prior to striking the welding arc and throughout welding until shortly after the welding arc is extinguished. The shielding gas protects the welding area from atmospheric gases such as nitrogen and oxygen, which can cause fusion defects, porosity, and weld metal embrittlement. The shielding gas may also transfer heat from the welding electrode to the metal and helps to start and maintain a stable arc. 
         [0020]    As depicted in  FIG. 1 , the shielding gas may be provided in a container and delivered to the torch  18  via a regulator  26 , a conduit  28 , a gas valve  30 , and the supply conduit  20 . The regulator  26  may allow an operator to limit the pressure of the gas delivered to the gas valve  30  to obtain a desired flow rate. Further, the gas valve  30  may provide for stopping and starting the flow of the shielding gas to the torch  18  in coordination with other welding operations. In certain embodiments, the gas valve  30  may not be present on the power supply. Rather, the gas valve  30  may be a part of the torch  18 . 
         [0021]    The TIG welding system  10  may be provided with a cooling system  16  to reduce heat build-up. The cooling system may take various forms including gas cooled and liquid cooled systems. The cooling system  16  may provide for circulation of the coolant via a coolant supply conduit  36  and conduit cables  32  and  34 , wherein supply conduit  36  provides coolant to the torch  18 , and conduit cables  32  and  34  return the coolant from the torch  18  to the cooling system  16 . The cooling system may be powered from the power supply  12  via a coolant system power cord  38 . 
         [0022]    In general, the welding system  10  may provide for current flow via a work piece  22  to the power source  12 . For example, as depicted in  FIG. 1 , the welding system  10  may include a cable  40  that is secured to the work piece  22  via a work clamp  42 . In this configuration, the current provided by the power source  12  flows through the supply conduit to the torch  18 , flows across an arc from an electrode  44  to the work piece  22 , and returns to the power source  12  via the work clamp  42  and the cable  40 . 
         [0023]    As illustrated in  FIG. 1 , one embodiment of the TIG welding torch  18  includes a handle  46  that is attached to a torch body  48 . The handle  46  has a hollow interior to allow for routing power, shielding gas, and coolant to the welding torch  18 . The torch body  48  may include a torch neck  50  and a torch head  52 . The torch body  48  may provide a central-rigid support to mount all of the desired hardware of the TIG welding torch  18 . For example, the torch neck  50  provides for securing the handle  46  to other components, and enables an operator to hold and manipulate the welding torch  18  and its components via the handle  46 . 
         [0024]    Other components of the welding torch  18  coupled to the torch body  48  may include an insulator  54 , a nozzle  56 , a collet  58 , the electrode  44 , and a back cap  60 . The insulator  54  may be positioned on the interior of the torch body  48  to block heat produced by the welding current from passing into the torch body  48  and/or the handle  46 . The nozzle  56  may be attached to the insulator  54  or the torch head  52  of the torch body  48 . The nozzle  56  may include a hollow tubular shaped piece that encloses the collet  58  and the electrode  44 , and provides a path for the shielding gas to pass between an interior surface of the nozzle  56  and the collet  58 . 
         [0025]    Generally, a cable may be used to contain the conduits, such that the cable carries cooling fluid and electrical power from the cooling system  16  and welder power supply  12 , respectively, to the welding torch. In some embodiments of the welding system  10 , a small torch may be used. Using a small torch may be advantageous for some welding applications as a small torch may provide finer weld lines and increased maneuverability. Such an embodiment is illustrated in  FIG. 2 . 
         [0026]      FIG. 2  further illustrates a novel high flow power cable  64 . The high flow power cable  64  connects the welding torch  18  (generally a small welding torch) to a welder power source  12  and a cooling system  16 , wherein the welder power source  12  provides welding power to the torch  18  and the cooling system  16  provides cooling fluid for the cable  64 . The high flow power cable  64  includes a first segment  66 , which is connected to the cooling system  16  and the welder power supply  12 , a second segment  68 , which is connected to the welding torch  18 , and a coupler segment  70 , which couples the first segment  66  to the second segment  68  as shown in  FIG. 2 . In one or more embodiments, welding power and cooling fluid may be provided by the same system, and the first segment  66  of the high flow power cable  64  may be connected to such a system. 
         [0027]    A portion of the high flow power cable  64  is shown in detail in  FIG. 3 . The first segment  66  of the high flow power cable  64  includes a first hose  72  and a first conductive core  74 . In the present embodiment, the first conductive core  74  is a round wire or conductor disposed inside the first hose  72 , generally sharing the same center line. Likewise, the second segment  68  includes a second hose  76  and a second conductive core  78 , in which the second conductive core  78  may be a wire or conductor disposed inside the second hose  76 , generally sharing the same center line. The first hose  72  and the second hose  76  may be made of rubber, vinyl, or another suitable insulating material. The conductive cores  74 ,  78  may be a single wire, multiple wires twisted together, or another configuration of conductive material. The conductive cores  74 ,  78  may be made of copper or another conductive material. In the present embodiment, the first hose  72  may be a larger in diameter than the second hose  76 , and the first conductive core  74  may be larger in diameter than the second conductive core  78 . The electrical power enters the cable  64  through the first conductive core  74 , and flows to the second conductive core  78 , where it is delivered to the welding torch  18 . The cooling fluid generally enters the cable  64  through the second hose  76 , wherein the cooling fluid fills up the second hose  76 , surrounding the second conductive core  78 . As the cooling fluid flows to the first hose  72 , the cooling fluid fills up the second hose  72 , surrounding the second conductive core  74 . The cooling fluid may be coolant, water, or another suitable cooling fluid. 
         [0028]    The first segment  66  of the high flow power cable  64  may be relatively cooler in temperature due to the larger diameter of the first conductive core  74 . The larger diameter of the first conductive core  74  generally gives the first conductive core  74  a lower resistance value, which following the equation: Power Dissipation=I 2 R, (where I is the current through the cores, and R is their respective resistance values) results in less power dissipation. Thus, less heat is produced by the first conductive core  74  due to its lower resistance. Additionally, not only is the first segment  66  consequently lower in temperature, but the cooling fluid may also absorb less heat as it travels through the first segment  66  owing to the flow rate and consequent residence time. As such, the cooling fluid enters the cooling system  18  at a lower temperature, further cooling the cooling system and thus the overall welding system  10 . This allows the cooling fluid to absorb more heat from the second conductive core  78  as it flows through the second segment  68 , lowering the temperature of the second segment  68  as well. Additionally, the temperature of the torch  18  is lowered, providing increased torch performance. 
         [0029]    Referring again to  FIG. 2 , the first segment  66  of the high flow power cable  64  is coupled to the welder power supply  12  and the cooling system  15 . The second segment  68  is coupled to the first segment  66  via the coupler segment  70  on one end, and coupled to the welding torch on the opposing end, as illustrated. The welding torch  18  being connected to the second segment  68 , which has a relatively smaller diameter, provides the user with better control of the welding torch  18  as there is less weight/resistance caused by the power cable  64 . This novel configuration allows for more effective cooling of the power cable  64 , while improving maneuverability of the power cable  64 , both of which are important factors in welding practice. 
         [0030]    An exploded view of the high flow power cable  64  is provided in  FIG. 4 . In addition to elements seen in  FIG. 3 , such as the first hose  72 , first conductive core  74 , second hose  76 , second conductive core  78 , and coupler hose  80 , the presently embodied high flow power cable  64  also includes a coupler  83 , a spacer  84 , and fasteners  86 . The coupler  83  may be configured to electrically and physically couple the first conductive core  74  and the second conductive core  78  such that electrical power can flow from the first conductive core  74  to the second conductive core  78 . In the present embodiment, the coupler  83  is tubular, having a first receptacle  87  and a second receptacle  88 . The first receptacle  87  has an inner diameter slightly larger than the diameter of the first conductive core  74 , such that the first conductive core  74  may fit inside the first receptacle  87 . In one or more embodiments, the inner diameter of the first receptacle  87  may be infinitesimally larger than the diameter of the first conductive core  74  such that the first conductive core  74  fits tightly inside the first receptacle  87  and such that the inner surface of the first receptacle  87  is generally in contact with the surface of the first conductive core  74 . Likewise, the second receptacle  88  of the coupler  83  has an inner diameter slightly larger than the diameter of the second conductive core  78 , such that the second conductive core  78  may fit inside the second receptacle  88 . In one or more embodiments, the inner diameter of the second receptacle  88  may be larger than the diameter of the second conductive core  78  such that the second conductive core  78  fits tightly inside the second receptacle  88  and such that the inner surface of the second receptacle  88  is generally in contact with the surface of the second conductive core  78 . 
         [0031]    In the high flow power cable  64 , the first conductive core  74  is generally disposed in the first receptacle  87  of the coupler  83 , and the second conductive core  78  is generally disposed in the second receptacle  88  of the coupler  83 . Typically, the conductive cores  74 ,  78  extend beyond the portion of the conductive cores  74 ,  78  that is disposed inside the respective receptacle  87 ,  88 . 
         [0032]    The outer diameter of the first and second receptacles  87 ,  88  may generally be similar to the inner diameter of the first and second hoses  72 ,  76 , respectively. The first receptacle  87  is disposed inside one end of the first hose  72 , and the second receptacle  88  is disposed inside one end of the second hose. Generally, the receptacles  87 ,  88  fit tightly inside the hoses  72 ,  76 , and may stretch the hose slightly when disposed in order to establish a tight fit. In the present embodiment, the receptacles  87 ,  88  may include ridges  89  on the outer surface. The ridges  89  may increase friction between the hoses  72 ,  76  and the receptacles  87 ,  88 , generally preventing the hoses from slipping off the receptacles  87 ,  88 . In the present embodiment, there may be a spacer  84  disposed on the coupler between the first receptacle  87  and the second receptacle  88 . In the present embodiment, the first and second hoses  72 ,  76  are fully disposed when one end of the first hose  72  and one end of second hose  76  make contact with the respective side of the spacer  84 . The spacer  84  prevents the first and second receptacles  87 ,  88  from being disposed too far into either one of the hoses. Typically, the first and second hoses  72 ,  76  extend beyond the portion of the first and second hoses, respectively, that hold the disposed coupler  83 . In the present embodiment, the coupler may have holes  90  on the sides of the first and second receptacles  87 ,  88 , as shown in  FIG. 4 . The holes  90  may facilitate the flow of cooling fluid through the high flow power cable  64 . 
         [0033]    The exploded view of  FIG. 4  exemplifies the fasteners  86  as a twist tie and a ferrule.  FIG. 5  illustrates the fasteners in their assembled position as described below. The fastener  86  is generally fastened around the part of the hose that holds a disposed receptacle, such that when the fastener  86  is fully fastened, the hose is further tightly held onto the receptacle. Specifically, the fastener  86  may fasten the hose onto the ridges of the receptacle ( FIG. 4 ). There may be a fastener  86  on each of the first and second hoses  72 ,  76  as shown in the present embodiment, or there may be a fastener on only one of the hoses  72 ,  76 . The fastener  86  may a type of clamp, strap, ring, or another suitable fastening device. The fastener may be fastened by pulling, twisting, tying, pressing, clamping, and so forth. 
         [0034]    The coupler hose  80  is configured to cover the coupler  83  as well as the ends of the first hose  72  and second hose  76  that contain the coupler  83 . The coupler hose  80  includes a first end and a second end, wherein the first end covers the disposed first hose  72  and the second end covers the disposed second hose. The coupler hose  80  may be a heat shrink material such as polyolefin, which when heated, shrinks onto the ends of the first and second hoses  72 ,  76 , the spacer  84 , and any exposed part of the coupler  83 . When shrunk, the coupler hose  80  may generally conform to the outer contours of the coupler  83  and the first and second hoses  72 ,  76 , further holding these parts in place. In some embodiments, the coupler hose  80  may have a tubular shape wherein the first end and the second end have the same shape and size prior to heating, the inner diameter of the coupler hose  80  being at least as large as the outer diameter of the first hose  72 . In some embodiments, the first end of the coupler hose  80  may have an inner diameter larger than the inner diameter of the second hose  76  prior to heating, wherein the inner diameter of the first end of the coupler hose  80  may be at least as large as the outer diameter of the first hose  72 , and the inner diameter of the second end of the coupler hose  80  may be at least as large as the outer diameter of the second hose  74 . The coupler hose  80  may cover a small section of the high flow power cable  64  as shown, or it may cover a larger portion of the high flow power cable  64 , generally covering the section of the high flow power cable  64  having the coupler  83 . In one or more embodiments, the coupler hose may be made of elastic material. 
         [0035]    The length of the entire high flow power cable  64  ( FIG. 2 ) may generally be about 12.5 feet to 25 feet, but may be longer or shorter depending on the embodiment or application. The second segment  68 , which eventually couples to the welding torch  18 , may generally be about 5 feet, but may also be longer or shorter depending on the embodiment or application. The first segment  66  of the high flow power cable  64  may generally be approximately 0.400″ in diameter or larger, while the second segment  68  of the high flow power cable  64  may be approximately 0.400″ or smaller in diameter. The dimensions disclosed above are exemplary, and certain embodiments may include a first segment  66  smaller than 0.400″ in diameter and/or a second segment  68  larger than 0.400″ in diameter. 
         [0036]    A cross-sectional view of a high flow power cable  64  is provided in  FIG. 6 . As shown in the present embodiment, one end of the first conductive core  74  is disposed inside the first receptacle  87  of the coupler  83 , and one end of the second conductive core  78  is disposed inside the second receptacle  88 . The first receptacle  87  is disposed inside one end of the first hose  72  and the second receptacle  88  is disposed inside one end of the second hose  76 , such that the spacer  84  is in between the first hose  72  and the second hose  76 . The coupler hose  80  is disposed over and around the coupler  83  via the ends of the first hose  72  and second hose  76 , as shown in  FIG. 6 . 
         [0037]    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.