Inert gas torch head with adjustable electrode receiver

Abstract

A removable electric arc welding torch head having a variable electrode receiving aperture including a plurality of discrete, slidable wedges guided within a conical inner surface to enable the torch head to be used with electrodes of various diameters without changing components of the torch head. The removable nature of the torch, while providing adequate inert gas flow, provides an adjustment ring that engages the wedges and forms an adjustable opening for insertion of the electrode therein.

Description

[0001] Priority Claims and Cross-References

[0002] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 62 / 882,700, filed by Jesse Rogers on August 5, 2019, entitled “INERT GAS WELDING TORCH HEAD WITH ADJUSTABLE ELECTRODE RECEIVER,” the entire contents of which are incorporated herein by reference.

[0003] This application cross-references U.S. Patent 9,789,560 B2, issued to Jesse Rogers on October 17, 2017, and entitled “ARC WELDING TORCH HAVING A VARIABLE ELECTRODE RECEIVER,” the entire contents of which are incorporated herein by reference. Technical Field

[0004] While self-centering adjustable electrode receivers may be provided for gas shielded welding torches, in order to facilitate the use of such devices, it is critical to enable users (e.g., welders) to easily replace or switch the heads used on conventional torches. For example, it is expensive to replace or change an entire inert gas welding torch in order to accommodate different electrode sizes. The disclosed torch head is suitable for use with a variety of torch types, and thus provides the added advantage of an adjustable electrode receiver in a replaceable inert gas torch head. Thus, welders can now enjoy the advantages of an adjustable electrode receiver without having to replace the entire welding torch—they only need to install an improved torch head in order to use a wide range of electrode sizes. The removable torch head includes an electrode retaining wedge that uniformly contacts a variety of shapes, diameters, lengths, and orientations. The adjustable electrode retaining wedge provides a robust and uniform contact with the electrode, and thus reduces the likelihood of resistive heating in the contact area.

[0005] Background and Summary of the Invention

[0006] Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an electric welding process that uses an arc generated by a tungsten electrode to generate sufficient heat to produce a molten or plasma "weld pool" to weld or fuse the workpieces together. Inert gas welding can be used for a variety of metals and their alloys, making it a very versatile welding process. However, welding parameters and electrode size generally need to be adjusted based on the materials being welded and the welding conditions. For example, the diameter of a non-consumable tungsten electrode can vary between about 0.5 mm and about 6.4 mm (0.020 inches to 0.25 inches) depending on the workpiece material and the type of weld, and the length of the electrode can range from about 75 mm to about 610 mm (3 inches to 24 inches). Conventional inert gas welding torches typically use a series of chucks to allow the user to remove the welding tip, and use a different chuck for each electrode size - a time-consuming process, especially when the user needs to switch electrode sizes regularly.

[0007] In an inert gas welding process, the welding area is protected from atmospheric contaminants by an inert shielding gas, such as argon. A welding power source provides an electric current that, when an arc is created between the electrode and the material being welded, generates concentrated heat energy sufficient to weld the workpieces. The focused heat is sufficient to place the contact area and optional filler rod into a plasma state. Heat is generated by the welding operation, and therefore, the welding torch may require a cooling system. Air cooling systems are most commonly used for low current operations, however, water cooling is sometimes required within the welding torch for TIG welding systems to dissipate heat in higher current applications or in applications requiring longer duty cycles.

[0008] As mentioned above, gas tungsten arc welding torches employ a specialized chuck and chuck body for holding an electrode of a specific diameter within the torch head. The electrode chuck is typically made of copper in a tubular shape and has at least two longitudinal gaps or slots to allow the diameter of the chuck to be radially compressed as it moves relative to the inner cone of the adjacent chuck body. This compression of the chuck minimizes the opening therein to engage and secure the electrode within the nominal inner radial area of ​​the chuck. Since the chuck is pressed against the electrode over a relatively small area, the current density per unit area is significant, and a large amount of heat may be generated due to the resistive connection to the electrode, which may also cause the peripheral arc within the chuck to persist. Therefore, the electrode, as well as the chuck, has a tendency to corrode over time due to the effects of repeated expansion and contraction caused by resistive heating and conductive heating and subsequent cooling. Since the copper chuck has a 9.8×10 -6 in / in / 0F, while the tungsten electrode expands only about half (3.9×10 -6in / in / 0F), thus further exacerbating the situation, potentially causing a poorly fitted electrode when welding, and further increasing resistance and / or causing the electrode to become unstable and move within the torch head.

[0009] The chuck and chuck body are typically provided in at least six hole sizes to accommodate the different diameters of the particular electrode being worked on. Therefore, a significant limitation of existing chucks is that each electrode size requires a specific corresponding chuck and chuck body. Therefore, the chuck assembly must also be interchanged whenever an alternate electrode diameter is needed. For example, it is necessary to have at least one 1 / 16 inch chuck and chuck body on hand to match a 1 / 16 inch tungsten electrode, as well as a 1 / 8 inch chuck and chuck body for a 1 / 8 inch electrode, and so on. Unfortunately, this becomes a logistical challenge and a time-consuming exercise each time an electrode is interchanged for another size. In addition, the use of a chuck also prevents the reversal of the electrode (end-to-end swap), which may form a bead or enlarged tip that prevents it from passing through the chuck opening.

[0010] When the electrode is in direct contact with a workpiece or fill line, the tip can become contaminated with "foreign" metal that is transferred and adhered to the tip of the tungsten electrode. This added material can cause the tip to mushroom and require regrinding or replacement of the electrode. However, as disclosed herein, the use of a removable welding head with an adjustable electrode receiver provides sufficient opening or adjustability for the mushroom-shaped end of the electrode so that when the enlarged and contaminated end passes through the adjustable opening, the end is flipped, end-to-end, and reinserted. Thus, the electrode can be used twice between regrinding or replacement. Therefore, another object is to provide an electrode receiver that will allow the enlarged / contaminated end of the electrode to be inserted therethrough and avoid the problem of using a certain size chuck to hold the electrode.

[0011] In one disclosed embodiment, the internal metal parts of the welding torch are preferably made of a conductive metal such as copper or brass to conduct current and transfer heat with minimal resistance over a relatively small contact area. The body of the welding torch is made of heat-resistant, insulating ceramics, plastics, and similar materials to cover the metal parts and provide thermal and electrical insulation to protect the welder. In addition, provisions may be provided to allow a constant flow of shielding gas through the welding torch handle and electrode receptacle to the workpiece area to provide an inert gas area or atmosphere near the weld.

[0012] For reasons of versatility and convenience, a welder should be able to select and use any size electrode at any time to achieve the best weld without having to reconfigure the electrode receptacle within the torch head. In other words, the configuration of the torch head and associated housing should not dictate the size or shape of the electrode. Thus, an adjustable electrode receptacle that can be changed as needed to accommodate a variety of different sized electrodes provides a distinct advantage when using an electric welding torch, such as is the case with TIG welding.

[0013] Embodiments disclosed herein relate to a removable torch head with an adjustable or variable electrode receptacle that replaces a conventional head and eliminates a conventional collet to allow for the use of a variety of electrode sizes.

[0014] According to one aspect of the disclosed embodiment, a removable arc welding torch head having an adjustable electrode receiver is provided, comprising: a hollow plunger having a first end for being threadably connected to a welding torch; a nozzle seat (e.g., a high temperature plastic such as ), the nozzle seat surrounds and is operably connected to the first end of the plunger; a welding torch body, which includes a tapered inner region, a plurality of holes allowing gas flow, and a threaded inner diameter allowing a chuck back plate to be operably engaged thereon (e.g., threaded engagement), the chuck back plate having an outer diameter for engaging the inner diameter of the welding torch body; a plurality of radially positioned electrode fixing wedges (claws) forming an electrode hole therebetween within the tapered inner region of the welding torch body, so that each fixing wedge can uniformly pass through the conical inner surface of the tapered region in the longitudinal direction to form a variable hole (claw) therebetween, one end of the fixing wedge also contacts the plunger thrust cup, and the thrust cup also contacts the plunger and a backing plate, converting the rotation of the plunger relative to the backing plate into linear motion of the thrust cup in contact with the electrode fixing wedge, and further providing clamping motion of the electrode fixing wedge due to the contact of the electrode fixing wedge with the conical surface, each of the electrode fixing wedges being biased away from each other (and toward the conical inner surface of the tapered region) by at least one biasing member therebetween, and an inner conical surface in contact with each fixing wedge, the fixing wedge also providing electrical contact between the electrode and the conical surface of the welding torch body; and a nozzle, which surrounds the welding torch body and is operably attached to the nozzle seat at one end thereof.

[0015] Other and further objects, features and advantages will become apparent from a reading of the following description and from reference to the accompanying drawings which form a part hereof, and in which for the purpose of disclosure are shown by way of example presently preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1is a perspective view of a TIG welding torch according to a disclosed embodiment showing two welding torches to which replaceable heads may be attached, and a plurality of plunger members adapted to adapt the removable heads to various welding torch types;

[0017] Figure 2 is a perspective view of one embodiment of an inert gas welding torch head having an adjustable electrode receiver connected to a conventional welding torch handle;

[0018] Figure 3 yes Figure 2 A perspective view of an embodiment of the invention wherein the gas nozzle is removed and welding electrodes of different diameters are inserted into the adjustable electrode receiver;

[0019] Figure 4 is an enlarged perspective view of a welding torch according to a disclosed embodiment with a plunger and a nozzle holder assembly mounted on the welding torch;

[0020] Figure 5-7 is an example of a replaceable inert gas welding head having a torch head body and associated components according to the disclosed embodiments;

[0021] Figure 8-16 According to the disclosed embodiment Figure 1-7 detailed views of the various components shown; and

[0022] Fig.17 is a cross-sectional view of a removable torch head including a torch head body with an adjustable electrode receptacle according to a disclosed embodiment.

[0023] The various embodiments described herein are not intended to limit the invention to those described. Rather, the invention is intended to cover all alternatives, modifications and equivalents that may be included within the spirit and scope of the welding torch and adjustable electrode receptacle as defined by the appended claims. DETAILED DESCRIPTION

[0024] Reference is now made to the drawings, which are shown for the purpose of illustrating a preferred embodiment of a removable welding torch head having an adjustable electrode receiver. As will be appreciated, the disclosed welding torch head is part of a gas tungsten arc welding system. In one embodiment, such a welding system includes a power source, an inert gas source, a water / liquid cooler, and a welding torch assembly, which includes, for example, Figure 2. In practice, the workpiece (not shown) is electrically connected to a power source to provide -DC, +DC or AC through a clamp and a return cable electrically connected to the workpiece (not shown). The welding torch 100 provides a mechanism for delivering an inert gas and an arc formed in an air gap between the tip of the tungsten electrode 120 and the workpiece, wherein the arc is sufficient to generate the heat required to fuse the workpieces together. The welding torch 100 can also be connected to a water or cooling liquid source to cool the welding torch when performing high current and / or long time welding operations.

[0025] The operating mechanical elements of the adjustable electrode receiver reside within the housing of the welding torch 100, specifically the torch handle 108 to which the removable torch head 110 is attached. As shown in the figure, the removable torch head 110 includes a hollow plunger 114, which is adapted to mate with the welding torch body (e.g., see Figure 1 ), and has a first end 116 for threaded connection to the welding torch 100. The second threaded end 118 of the plunger is used to couple to and interact with the welding torch head body 130. When attached to the welding torch, for example, Figure 1 and 5 As shown, the hollow plunger 114 extends outwardly and provides a stem on which a surrounding nozzle holder 126 can be operatively connected around the exposed threaded end 118 of the plunger. In order to allow the use of the removable torch head 110, the end 116 of the hollow plunger 114 must be adapted to be threadedly connected to a conventional welding torch. Figure 1 At least two different torch types are shown in the figure, such as the HW20 torch and the WP20 torch, but it will be understood that the removable torch head disclosed herein may also be adapted for use with other torches. Although not specifically shown, it will be understood that the rear end of the torch generally includes an end piece that surrounds the portion of the electrode that extends through the removable head.

[0026] The nozzle holder 126 and nozzle 128 may be made of a variety of materials suitable for high temperature use, such as machinable or moldable ceramic or materials or high temperature plastics such as glass-filled polytetrafluoroethylene (PTFE) or Inert gas supplied to the torch and entering the removable torch head 110 flows through the hollow interior of the plunger 114, the gas is then directed into the torch head body 130 and nozzle 128, and then out around the electrode in the area of ​​the arc extending between the workpiece and the electrode.

[0027] For example Figure 3-4As depicted in , the nozzle 128 is associated with the torch body and the nozzle holder 126 and is removably secured to the nozzle holder and the torch head body 130 by a friction fit. As an alternative to the friction fit between the nozzle holder and the nozzle, a threaded connection or a bayonet-type connection therebetween is also contemplated. Furthermore, in one embodiment, the friction fit with the torch body can be achieved via an O-ring 124 or similar element surrounding the torch body (e.g., such as Fig. 9 122 as depicted in the O-ring retaining recess 122).

[0028] Referring also to FIG. 18 , the removable torch 110 head also includes a torch head body 130 including a tapered interior region 134, a plurality of holes 138 to allow gas flow therethrough, and a threaded inner diameter 142 to allow a chuck backing plate 146 to be operably engaged (e.g., threadably connected) thereto. In one embodiment, the chuck backing plate 146 has a threaded outer diameter for engaging the threaded inner diameter of the torch body. Also within the removable head 130 are at least two and typically at least three or more radially positioned electrode retaining wedges (claws) 154 that form an electrode aperture therebetween within the tapered interior region of the torch body such that each retaining wedge can be uniformly transversely or slid in a longitudinal direction along the conical inner surface of the tapered region 134 to form a variable aperture (jaw) therebetween. The retaining wedges 154 are further contacted on their ends by a plunger thrust cup 160. The thrust cup 160 is further combined with the plunger 114 and the back plate 146 to convert the rotation of the plunger relative to the back plate into linear motion of the thrust cup in contact with the electrode fixing wedge, and due to the sliding contact between the electrode fixing wedge and the conical surface, further provides a clamping motion of the electrode fixing wedge against the electrode 120.

[0029] In operation, the electrode 120 is inserted along the inner surface of the wedge 154 and clamped therein by the force applied to the inner end of the wedge by the plunger thrust cup 160. In the illustrated embodiment, a compressive force is provided to the thrust cup 160 by the rotation of the plunger 114 relative to the torch head body 130, thereby advancing the wedge 154 in response to the rotation of the head and closing the jaws formed by the wedge around the electrode. When the plunger is rotated in the opposite direction, the plunger is retracted relative to the head body 130, and thus, the pressure applied to the wedge is removed. In the absence of pressure from the plunger 114, the electrode wedge 120 slides upward along the jaws under the force of the biasing member (spring) 164 to expand or open the jaws. In other words, when the plunger 114 returns away from the thrust cup, the biasing spring 164 forces the electrode wedges apart so that the wedges slide the jaws upward and outward along the inner cone head and hold them against the thrust cup. There is no pulling action of the plunger or thrust cup, but the biasing force moves the wedges to the position of maximum diameter. The springs simply keep all components under tension and moving in the cone during retraction. In the unlikely event that the wedges temporarily "stick" in one position, a light tap with a tungsten electrode causes them to snap back and continue moving for retraction, but usually they slide back.

[0030] The rate of change of the orifice diameter formed by the wedge 154 is a function of the thread pitch or turns per inch (TPI) on the mating surfaces of the chuck back plate 146 and the end 118 of the hollow plunger 114 and the included angle θ or slope of the rear surface 162 of the wedge 154. The corresponding internal conical surfaces 134 have a common slope angle θ, typically in the range of 15-20 degrees. Therefore, the minimum and maximum aperture diameters are sinusoidal functions of the angle θ.

[0031] In addition, to ensure that the electrode fixing wedges 154 remain spaced apart when not pressed against the electrode, each electrode fixing wedge is biased away from the adjacent wedges and toward the tapered inner surface of the tapered region by at least one biasing member 164 between adjacent wedges. In one embodiment, the biasing member is a compression spring made of stainless steel and is located in a recess 142 in each planar surface 168 of the electrode fixing wedge 154. As will be understood, the resilient member 164 (e.g., a helical compression spring) associated with each electrode fixing wedge biases the wedge toward the conical inner surface of the tapered region 134. It will also be understood that while the resilient member 164 is depicted as being located between adjacent wedges 154, or more specifically between the recesses 142 on the wedges, other wedge and spring configurations may also be provided that bias the wedges so that they tend to move outward (and therefore toward the larger diameter of the housing).

[0032] In summary, in the torch head body 130 of the adjustable electrode receiver, the electrode retaining wedges 154 each include adjacent planar surfaces that share a first edge or transition line 156 therebetween, and each have an opposing edge 158 that is spaced apart and slightly angled relative to the first edge, and a conical surface (162, Fig.16 The planar surfaces 156 of the electrode retaining wedge are arranged at the rear of the wedge and at least one of which includes a hole therein (to receive the end of the helical compression spring 164). As will be further understood, the transition line 156 between adjacent planar surfaces of the electrode retaining wedge provides a continuous area (e.g., along the line) for contact between the wedge and the electrode.

[0033] To ensure that current flows through the torch head body 130 and into the wedges 154 and associated electrodes 129, the inner conical surface 134 maintains contact with each fixed wedge over at least a portion, if not all, of the outer wedge surface to reduce contact heating. In one embodiment, the wedges are formed of a conductive metal, such as an alloy—for example, a steel alloy, a copper alloy (e.g., brass, bronze), or a nickel alloy. Figure 7 As shown in FIG. 1 , one embodiment employs three electrode fixing wedges 154 in the head 130. Furthermore, the fixing wedges 154 further provide electrical contact between the electrode 120 and the conical surface 134 of the torch body 130. Figure 6 , 7 In the embodiments depicted in FIGS. 1 and 18 , the radially positioned electrode retaining wedge 154 is capable of accommodating an electrode diameter of at least approximately 0.145 inches or greater within the torch head body 130 .

[0034] As previously described, the nozzle 128 surrounds the torch body to direct the inert gas along and through the torch head, and the nozzle is operably attached to the nozzle holder 126 at one end thereof.

[0035] In summary, as shown, a removable torch head having an electrode receiver of variable size is provided. A plurality of electrode retaining wedges 154 are radially positioned within the torch head body 130 and form a hole therebetween, wherein the size of the hole is adjustable based on the position of the wedge relative to the internal conical surface 134 within the body. The use of the disclosed embodiments is believed to increase productivity by at least eliminating the need to change the collet when switching between various electrode diameters or shapes. In addition, the replaceable head is easy to install and is suitable for use with conventional inert gas torches.

[0036] It should be understood that several of the above disclosed embodiments and other features and functions or their alternatives may be ideally combined into many other different systems or applications. In addition, various currently unforeseen or unanticipated substitutions, modifications, changes or improvements may be made subsequently by those skilled in the art, which are also intended to be encompassed by the above description and the following claims.

Claims

1. A removable arc welding torch head with an adjustable electrode receiver, comprising: a hollow plunger having a first end for threadably connecting to a welding torch; a nozzle seat surrounding and operably connected to the first end of the hollow plunger; Torch head body, including: a tapered interior area, multiple holes to allow gas flow, and a threaded inner diameter to allow the chuck backing plate to operatively engage thereon, The chuck back plate has an outer diameter for engaging the threaded inner diameter of the torch head body, a plurality of radially positioned electrode fixing wedges, wherein the electrode fixing wedges form electrode holes between the electrode fixing wedges within the conical inner region of the welding torch head body, so that each of the electrode fixing wedges can uniformly pass through the conical inner surface of the conical inner region in the longitudinal direction to form a variable hole therebetween, one end of the electrode fixing wedge is also in contact with a plunger thrust cup, and the plunger thrust cup is also combined with the hollow plunger and the chuck back plate to convert the rotation of the hollow plunger relative to the chuck back plate into a linear movement of the plunger thrust cup contacting the electrode fixing wedge, and the clamping movement of the electrode fixing wedge is further provided due to the contact of the electrode fixing wedge with the conical inner surface, Each of the electrode retaining wedges is biased away from each other by at least one biasing member therebetween, and the conical inner surface in contact with each of the electrode retaining wedges, the electrode retaining wedges also providing electrical contact between the electrode and the conical inner surface of the torch head body; as well as A nozzle surrounds the torch head body and is operably attached to the nozzle holder at one end thereof.

2. The removable arc welding torch head of claim 1, wherein: Each of the electrode retaining wedges also includes at least one surface feature to receive a portion of the biasing member therein.

3. The removable arc welding torch head of claim 1 , wherein: The hollow plunger is adapted to be threadedly connected to a conventional welding torch.

4. The removable arc welding torch head of claim 3, wherein: The conventional welding torch is selected from the group consisting of a HW20 welding torch and a WP20 welding torch.

5. The removable arc welding torch head of claim 1, wherein: The combination of the torch head body and the plurality of radially positioned electrode retaining wedges is capable of receiving an electrode having a diameter of up to at least 0.145 inches.

6. The removable arc welding torch head of claim 1, wherein: The plurality of radially positioned electrode retaining wedges are each formed of an alloy.

7. The removable arc welding torch head of claim 1, wherein: The nozzle is formed from a machinable ceramic material.

8. The removable arc welding torch head of claim 1, wherein: The nozzle is formed from glass-filled polytetrafluoroethylene (PTFE).

9. The removable arc welding torch head of claim 1, wherein: The nozzle holder is formed from a machinable ceramic material.

10. The removable arc torch head of claim 1, wherein: The nozzle holder is formed from glass-filled polytetrafluoroethylene (PTFE).

11. The removable arc torch head of claim 1 , wherein: The at least one biasing member is a coil spring positioned between adjacent electrode retaining wedges.

12. The removable electric arc torch head of claim 1, comprising at least three electrode retaining wedges.

13. The removable arc torch head of claim 12, wherein: Each of the electrode fixing wedges includes: adjacent planar surfaces, each of the planar surfaces sharing a first edge or a transition therebetween, and each planar surface having an opposite edge spaced apart and slightly angled relative to the first edge; and a tapered surface spanning between the opposite edges of the planar surfaces.

14. The removable arc welding torch head of claim 13, wherein: The first edge or transition between adjacent planar surfaces of the electrode retaining wedge provides a continuous area of ​​contact with the electrode.

15. The removable arc torch head of claim 1, wherein: The torch head body includes holes therein to facilitate movement of an inert gas through and around the torch head body.

16. The removable arc torch head of claim 1, wherein: The nozzle is associated with the torch head body and the nozzle holder, and the nozzle is removably secured to the nozzle holder and the torch head body by a friction fit.

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