Patent Publication Number: US-2012024823-A1

Title: Collet assembly with a universal collet

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Non-Provisional Patent Application of U.S. Provisional Patent Application No. 61/368,377 entitled “Universal Collet Assembly”, filed Jul. 28, 2010, which is herein incorporated by reference. 
    
    
     BACKGROUND 
     The invention relates generally to welding torches and, more particularly, to a universal collet of a collet assembly for a welding torch. 
     Welding is a process that has become increasingly ubiquitous in various industries and applications. Such processes may be automated in certain contexts, although a large number of applications continue to exist for manual welding operations. In both cases, such welding operations rely on a variety of types of equipment to ensure that the supply of welding consumables (e.g., wire feed, shielding gas, etc.) and welding power are provided to the weld in an appropriate amount at the desired time. 
     Tungsten inert gas (TIG) welding, also known as gas tungsten arc welding (GTAW), is a type of welding process in which an electric arc is maintained between a metal electrode and a metal object. The heat generated by the arc produces localized melting of the metal object. The electrode, typically tungsten, is secured to a welding torch to enable a user to direct the electrode and establish the point of contact between the electrode and the object. Typically, the weld puddle and the area surrounding the weld puddle are protected from the atmosphere by a shielding gas. The shielding gas may prevent rapid oxidation of the weld and the surrounding metal. 
     A welding electrode may be secured to a TIG welding torch by a collet, a backcap, and a collet body, for example. To secure the electrode to the welding torch, the electrode is inserted through the collet and collet body. The collet body is attached to a front portion of a torch head disposed within the torch body. The backcap is attached to the rear portion of the torch head. As the backcap is coupled to the torch body, the backcap drives the collet against the interior of the collet body. The collet is adapted to pinch down on the electrode as the collet is driven against an interior surface of the collet body, thereby securing the electrode to the torch. Unfortunately, a unique collet size and shape may be needed for different types of welding torches. Therefore, there is a need in the field that provides alternatives to unique collet configurations for different types of welding torches. 
     BRIEF DESCRIPTION 
     In one embodiment, a collet assembly of a welding torch includes a collet having an outer diameter and an inner diameter. The inner diameter of the collet is configured to contact a welding electrode disposed through the collet. The welding torch also includes a spacer configured to be disposed in a welding torch head and to compress the collet against the welding electrode to secure the welding electrode in the torch. 
     In another embodiment, a TIG welding torch includes a collet assembly including a collet and a spacer. The collet has an outer diameter and an inner diameter. The inner diameter of the collet is configured to contact a welding electrode disposed through the collet. The spacer is configured to be disposed in a welding torch head and to compress the collet against the welding electrode to secure the welding electrode in the torch. 
     In another embodiment, a TIG welding torch includes a welding electrode, a torch head coupled to a torch handle, and a collet assembly disposed in the torch head and configured to secure the welding electrode. 
    
    
     
       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 with a welding torch employing a collet assembly with a universal collet; 
         FIG. 2  is an exploded view of an embodiment of the welding torch assembly of  FIG. 1 ; 
         FIG. 3  is an exploded view of another embodiment of the welding torch assembly of  FIG. 1 ; 
         FIG. 4  is a side view of an embodiment of the collet assembly of the welding torch assembly of  FIG. 2 ; 
         FIG. 5  is a side view of an embodiment of the collet assembly of the welding torch assembly of  FIG. 3 ; 
         FIG. 6  is a perspective view of an embodiment of the collet of the collet assembly of  FIG. 4 ; and 
         FIG. 7  is a perspective view of an embodiment of the collet of the collet assembly of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of an exemplary welding system  10  employing a collet assembly with a universal collet. As appreciated, the welding system  10  may be utilized in a TIG welding process. 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. 
     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, touch screens, user interfaces, etc.). 
     The front of the welding power supply  12  also includes welding terminals  20  and  22 . A work cable  24  terminating in a clamp  26  is attached to terminal  20  of the welding power supply  12 . The clamp  26  is adapted to be clamped to a workpiece  28  during a welding operation. A weld 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 clamp  26  is secured 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 a torch handle  34  coupled to a torch head  36 . The torch head  36  has a front section  38  and a back section  40  that together contain a welding electrode (e.g., tungsten electrode), a collet assembly, a collet body, and a backcap. As will be described in more detail below, the collet assembly includes a collet and a spacer. The collet is designed to be used in a variety of welding torch assemblies and with various sizes of welding electrodes. Shielding gas for the welding operation is supplied by a gas supply  42 , such as a tank. The gas supply  42  may be coupled to the welding power supply  14  via a cable or hose  44  that directs shielding gas to the welding torch assembly  32 . 
       FIG. 2  is an exploded view of an embodiment of the welding torch assembly  32  of  FIG. 1 . The welding torch assembly  32  includes a welding electrode  52  that is used to establish a welding arc. In certain embodiments, the diameter of the welding electrode  52  may be approximately ⅛ inch. However, in other embodiments, the diameter of the welding electrode  52  may be in the range of approximately 1/50 inch to approximately 5/32 inch. The torch assembly  32  also includes a collet body  54 , a collet  56 , a spacer  58 , and a backcap portion  60 . In particular, the collet  56  includes a first end  62  that has a locking mechanism  64 . The locking mechanism  64  is constructed so that the collet  56  can be inserted into the collet body  54  and locked in place within the collet body  54 . In some embodiments, the collet  56  may not include the locking mechanism  64  so that the collet is not locked in place after being inserted into the collet body  54 . A second end  66  of the collet  56  has a first tapered surface  68  as well as slits that divide the second end  66  into extensions, as illustrated in more detail in  FIG. 4 . 
     To assemble the welding torch assembly, the welding electrode  52  is inserted through the collet body  54 , the collet  56 , the spacer  58 , the torch head  36 , and the backcap portion  60 . Further, the first tapered surface  68  of the collet  56  is inserted into a first end  70  of the spacer  58 . When inserted into the spacer  58 , the first tapered surface  68  of the collet  56  contacts a second tapered surface  72  of the spacer  58 . The second tapered surface  72  of the spacer  58  compresses the first tapered surface  68  of the collet  56  against the welding electrode  52  to secure the collet  56  to the welding electrode  52  (e.g., to secure the welding electrode  52  in the torch). 
     The spacer  58  is disposed in the torch head  36  by inserting a second end  74  of the spacer  58  into a first end  76  of the torch head  36 . In certain embodiments, the spacer  58  is inserted into the torch head  36  so that a portion of the spacer  58  and the collet  56  extend out of the first end  76  of the torch head  36 , while the spacer  58  does not extend out of a second end  78  of the torch head  36 . The backcap portion  60  is inserted into the second end  78  of the torch head  36 . The backcap portion  60  in conjunction with the back section  40  form the backcap. As may be appreciated, the backcap may be formed by overmolding the back section  40  over the backcap portion  60 . The backcap keeps the spacer  58  from exiting the torch head  36  via the second end  78  of the torch head  36 . The backcap portion  60  is secured to the torch head  36  by pressing the backcap portion  60  into the second end  78  of the torch head  36 . In certain embodiments, the backcap portion  60  and the torch head  36  may include threaded ends so that the backcap portion  60  is attached to the torch head  36  via rotating threads of the backcap portion  60  into threads of the torch head  36 . 
     The collet body  54  is positioned around the collet  56  and a portion of the spacer  58 , including the first end  70  of the spacer. The collet body  54  is inserted into the first end  76  of the torch head  36  and holds the collet  56  and spacer  58  (i.e., collet assembly) inside the torch head  36 . The collet body  54  is secured to the torch head  36  by pressing the collet body  54  into the first end  76  of the torch head  36 . In certain embodiments, the collet body  54  and the torch head  36  may include threaded ends so that the collet body  54  is attached to the torch head  36  via rotating threads of the collet body  54  into threads of the torch head  36 . To finish assembling the torch assembly  32 , the front section  38  is inserted into the first end  76  of the torch head  36  and secured to the torch head  36  by pressing the front section  38  into the first end  76  of the torch head  36 . Likewise, the back section  40  is inserted into the second end  78  of the torch head  36  and secured to the torch head  36  by pressing the back section  40  into the second end  78  of the torch head  36 . As may be appreciated, in certain embodiments, the front section  38 , the back section  40 , and the torch head  36  may also include threaded ends so that the front and back sections  38  and  40  are attached to the torch head  36  via rotating threads of the front and back sections  38  and  40  into threads of the torch head  36 . 
     It should be noted that welding power flows through the collet  56  to the welding electrode  52 . For the welding power to flow to the welding electrode  52 , there is contact between the extensions of the collet  56  and the welding electrode  52 . The contact between the collet  56  and the welding electrode  52  results from the collet  56  being inserted into the first end  70  of the spacer  58 . The second tapered surface  72  of the spacer  58  makes contact with the first tapered surface  68  of the collet  56  and presses the extensions of the collet  56  against the welding electrode  52 . As may be appreciated, when contact area between the collet  56  and the welding electrode  52  increases, the electrical resistance between the collet  56  and the welding electrode  52  decreases. As the resistance decreases, less heat is present where the collet  56  contacts the welding electrode  52 . In certain embodiments, the heat present where the collet  56  contacts the welding electrode  52  is lower than in configurations without the universal collet  56  as disclosed herein. 
       FIG. 3  is an exploded view of another embodiment of the welding torch assembly  32  of  FIG. 1 . This embodiment of the welding torch assembly  32  is very similar to the torch assembly  32  of  FIG. 2 , but may be used in different applications, such as in welding applications that utilize a welding electrode with a different diameter than the welding electrode  52 . In particular, the welding torch assembly  32  includes a welding electrode  80  that is used to establish a welding arc. In certain embodiments, the diameter of the welding electrode  80  may be approximately 3/32 inch. However, in other embodiments, the diameter of the welding electrode  80  may be in the range of approximately 1/50 inch to approximately 5/32 inch. The torch assembly  32  also includes a front section  82 , a collet body  84 , a collet  86 , a spacer  88 , a torch head  90 , a torch handle  92 , a backcap portion  94 , and a back section  96 . Furthermore, the collet  86  includes a first end  98  that does not include a locking mechanism. A second end  100  of the collet  86  has a first tapered surface  102  as well as slits that divide the second end  100  into extensions, as illustrated in more detail in  FIG. 5 . 
     To assemble the welding torch assembly, the welding electrode  80  is inserted through the collet body  84 , the collet  86 , the spacer  88 , the torch head  90 , and the backcap portion  94 . Further, the first tapered surface  102  of the collet  86  is inserted into a first end  104  of the spacer  88 . When inserted into the spacer  88 , the first tapered surface  102  of the collet  86  contacts a second tapered surface  106  of the spacer  88 . The second tapered surface  106  of the spacer  88  compresses the first tapered surface  102  of the collet  86  against the welding electrode  80  to secure the collet  86  to the welding electrode  80 . 
     The spacer  88  is disposed in the torch head  90  by inserting a second end  108  of the spacer  88  into a first end  110  of the torch head  90 . In certain embodiments, the spacer  88  is inserted into the torch head  90  so that a portion of the spacer  88  and the collet  86  extend out of the first end  110  of the torch head  90 , while the spacer  88  does not extend out of a second end  112  of the torch head  90 . The backcap portion  94  is inserted into the second end  112  of the torch head  90 . The backcap portion  94  in conjunction with the back section  96  form the backcap. As may be appreciated, the backcap may be formed by overmolding the back section  96  over the backcap portion  94 . The backcap keeps the spacer  88  from exiting the torch head  90  via the second end  112  of the torch head  90 . The backcap portion  94  is secured to the torch head  90  by pressing the backcap portion  94  into the second end  112  of the torch head  90 . 
     The collet body  84  is positioned around the collet  86  and a portion of the spacer  88 , including the first end  104  of the spacer. The collet body  84  is inserted into the first end  110  of the torch head  90  and holds the collet  86  and spacer  88  (i.e., collet assembly) inside the torch head  90 . The collet body  84  is secured to the torch head  90  by pressing the collet body  84  into the first end  110  of the torch head  90 . To finish assembling the torch assembly  32 , the front section  82  is inserted into the first end  110  of the torch head  90  and secured to the torch head  90  by pressing the front section  82  into the first end  110 . Likewise, the back section  96  is inserted into the second end  112  of the torch head  90  and secured to the torch head  90  by pressing the back section  96  into the second end  112 . 
     The collets  56  and  86  disclosed in  FIGS. 2 and 3  are constructed to be universal (i.e., work with a wide variety of welding torches rather than a single style of welding torch). As described in  FIG. 2 , collet  56  includes a locking mechanism  64 , while collet  86  of  FIG. 3  does not include a locking mechanism. However, it should be noted, that the remaining features of the collets  56  and  86  allow the collets to be interchangeable and to be used within either embodiment of the welding torch assembly  32 . For example, the collet  86  of  FIG. 3  may be used in the welding torch assembly  32  of  FIG. 2 . Furthermore, the collet  56  of  FIG. 2  may be used in the welding torch assembly  32  of  FIG. 3 . Likewise, collets  56  and  86  may be used in additional styles of welding torch assemblies. 
       FIG. 4  is a side view of an embodiment of a collet assembly  114  of the welding torch assembly  32  of  FIG. 2 . As previously described, the collet assembly  114  includes the collet  56  and the spacer  58 .  FIG. 4  depicts the welding electrode  52  extending through the collet assembly  114 . As illustrated, the first end  62  of the collet  56  includes the locking mechanism  64 . The locking mechanism  64  is formed by slits  116  that create extensions  117 . The extensions  117  form a locking edge  118  to lock the collet  56  inside of the collet body  54  of  FIG. 3  when the first end  62  of the collet  56  is inserted into the collet body  54 . As may be appreciated, the locking mechanism  64  may be constructed in another manner, such as with any type of press fit, snap, or other mechanism to lock together the collet  56  and the collet body  54 . Furthermore, as described in relation to the collet  86  of  FIG. 3 , the collet  56  may not include a locking mechanism  64 . 
     The second end  66  of the collet  56  has the first tapered surface  68  that is illustrated as extending within the second tapered surface  72  found on the first end  70  of the spacer  58 . The second end  66  of the collet  56  has slits  119  that form extensions  120 . As the extensions  120  are inserted into the first end  70  of the spacer  58 , the extensions  120  are pressed toward the welding electrode  52  and the extensions  120  are deformed by the spacer  58  to contact the welding electrode  52 . As may be appreciated, the slits  119  permit the extensions  120  to move and contact the welding electrode  52 . 
     As depicted, the second tapered surface  72  of the spacer  58  creates a flared edge on the first end  70 . As such, an outer diameter  122  of the first end  70  is greater than an outer diameter  124  of the spacer  58 . Furthermore, the change in the outer diameter from diameter  122  to diameter  124  also corresponds to an inner diameter change. In addition, the diameter change corresponds to a change in the diameter of the second tapered surface  72 . The collet  56  has a length  126 , while the slits  119  have a length  128 . Specifically, the length  126  of the collet  56  may be approximately 0.2 to 0.8 inches. In certain embodiments, the length  126  of the collet  56  may be approximately 0.5 inches. Further, the length  128  of the slits  119  may be approximately 0.1 to 0.6 inches. In certain embodiments, the length  128  of the slits  119  may be approximately 0.4 inches. 
     The collet  56  may be considerably shorter, such as by at least approximately  75  percent, than non-universal collets (e.g., collets that are not designed to be universal as disclosed). Furthermore, the slits  119  may be at least approximately  50  percent shorter than slits used in non-universal collets. As such, the extensions  120  have an increased resistance to breaking when compared to extensions that may be found in non-universal collets. As may be appreciated, the diameter of the welding electrode  52  may vary depending on the welding application. For example, in certain embodiments, the welding electrode  52  may have a diameter of approximately 3/32 inch to approximately 5/32 inch. It should be noted that the collet assembly  114  (i.e., the collet  56  and the spacer  58 ) may be formed using any variety of conductive materials, such as various metals including brass, copper, another metal or alloy, etc. For example, the collet  56  and the spacer  58  may be formed using brass. 
       FIG. 5  is a side view of an embodiment of a collet assembly  130  of the welding torch assembly  32  of  FIG. 3 . As previously described, the collet assembly  130  includes the collet  86  and the spacer  88 . The welding electrode  80  is illustrated extending through the collet assembly  130 . The second end  100  of the collet  86  has the first tapered surface  102  that is illustrated as extending within the second tapered surface  106  found on the first end  104  of the spacer  88 . The second end  100  of the collet  86  has slits  132  that form extensions  134 . As the extensions  134  are inserted into the first end  104  of the spacer  88 , the extensions  134  are pressed toward the welding electrode  80  and the extensions  134  are deformed by the spacer  88  to contact the welding electrode  80 . As may be appreciated, the slits  132  permit the extensions  134  to move and contact the welding electrode  80 . 
     As depicted, the second tapered surface  106  of the spacer  88  creates a flared edge on the first end  104 . As such, an outer diameter  136  of the first end  104  is greater than an outer diameter  138  of the spacer  88 . Furthermore, the change in the outer diameter from diameter  136  to diameter  138  also corresponds to an inner diameter change. The diameter change also corresponds to a change in the diameter of the second tapered surface  106 . The collet  86  has a length  140 , while the slits  132  have a length  142 . Specifically, the length  140  of the collet  86  may be approximately 0.2 to 0.8 inches. In certain embodiments, the length  142  of the collet  86  may be approximately 0.5 inches. Further, the length  142  of the slits  132  may be approximately 0.1 to 0.6 inches. In certain embodiments, the length  142  of the slits  132  may be approximately 0.4 inches. 
     As may be appreciated, the diameter of the welding electrode  80  may vary depending on the welding application. For example, in certain embodiments, the welding electrode  80  may have a diameter of approximately 3/32 inch to approximately 5/32 inch. Similar to the collet assembly  114  of  FIG. 4 , the collet assembly  130  (i.e., the collet  86  and the spacer  88 ) may be formed using any variety of conductive materials, such as various metals including brass, copper, another metal or alloy, etc. For example, the collet  86  and the spacer  88  may be formed using brass. 
       FIG. 6  is a perspective view of an embodiment of the collet  56  of the collet assembly  114  of  FIG. 4 . As illustrated, the collet  56  includes four slits  119  that divide the second end  66  into four extensions  120 . Likewise, there are four slits  116  that divide the first end  62  into four extensions  117 , although only two slits  116  are visible in  FIG. 4 . The first tapered surface  68  extends from the second end  66  toward the first end  62 . As the first tapered surface  68  moves away from the second end  66 , the outside diameter increases until the tapered surface  68  ends at a ridge  148 . Further, at the second end  66 , the collet  56  has an inner diameter  150 . The inner diameter  150  is sufficient to enable the welding electrode  52 , which may have a range of diameters, to be disposed therein. As such, the inner diameter  150  may be within the range of approximately 3/32 inch to approximately 7/32 inch. In addition, the inner diameter  150  is configured to contact the welding electrode  52  disposed through the collet  56 . An outer diameter of the collet  56  at the second end  66  is the sum of the inner diameter  150  and a thickness  152  of the material at the second end  66  of the extensions  120 . As previously discussed, the outer diameter increases along the first tapered surface  68  from the second end  66  to the ridge  148  which has a diameter  154 . 
       FIG. 7  is a perspective view of an embodiment of the collet  86  of the collet assembly  130  of  FIG. 5 . Similar to collet  56  of  FIG. 6 , the collet  86  includes four slits  132  that divide the second end  100  into four extensions  134 . The first tapered surface  102  extends from the second end  100  toward the first end  98 . As the first tapered surface  102  moves away from the second end  100 , the outside diameter increases until the tapered surface  102  ends at a ridge  160 . Further, at the second end  100 , the collet  86  has an inner diameter  162 . The inner diameter  162  is sufficient to enable the welding electrode  80 , which may have a range of diameters, to be disposed therein. As such, the inner diameter  162  may be within the range of approximately 3/32 inch to approximately 7/32 inch. In addition, the inner diameter  162  is configured to contact the welding electrode  80  disposed through the collet  86 . An outer diameter of the collet  86  at the second end  100  is the sum of the inner diameter  162  and a thickness  164  of the material at the second end  100  of the extensions  134 . The outer diameter increases along the first tapered surface  102  from the second end  100  to the ridge  160  which has a diameter  166 . 
     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.