Inert gas welding torch head with adjustable electrode receiving section

Abstract

The removable arc welding torch head has a variable electrode receiving opening that includes multiple separate, slidable wedges guided within a conical interior surface, allowing the head to be used with multiple electrodes of varying diameters without changing the configuration of the torch head. The removable nature of the torch provides an adjustment collar that engages the multiple wedges and forms an adjustable opening for the electrode to be inserted, while providing for proper flow of inert gas.

Description

Technical Field

[0001] Priority Claim and Cross - Reference

[0002] This application claims priority under 35 U.S.C. § 119(e) from U.S. Provisional Patent Application No. 62 / 882,700, filed Aug. 5, 2019 by Jesro Jars, which is hereby incorporated by reference in its entirety.

[0003] This application cross - references U.S. Patent No. 9,789,560 B2, issued Oct. 17, 2017, to Jesro Jars, regarding an arc welding torch having a variable electrode receiver, which is hereby incorporated by reference in its entirety.

[0004] Technical Field

[0005] A self - centering adjustable electrode receptacle may be provided for a gas - shielded welding torch, but in order to facilitate the use of such a device, it is essential that the user (e.g., welder) be able to easily replace or switch the head used in a conventional welding torch. For example, it is costly to replace or swap out an entire inert gas welding torch to accommodate different electrode sizes. The disclosed welding torch head is suitable for use with multiple torch types and thus provides an additional advantage of an adjustable electrode receptacle in a replaceable inert gas welding torch head. Thus, a welder can enjoy the benefits of an adjustable electrode receptacle without replacing the entire welding torch - to use a wide range of electrode sizes, the welder only needs to install an improved torch head. The removable torch head includes an electrode - fixing wedge that uniformly contacts electrodes of various shapes, diameters, lengths, and inclinations. The adjustable electrode - fixing wedge provides a firm and uniform contact with the electrode, thus reducing the risk of resistive heating in the contact area.

Background Art

[0006] Background Technology and Summary

[0007] Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an electric welding process that uses an arc from a tungsten electrode to provide enough heat to create a "paddle," which is a molten material or plasma for welding or fusing a workpiece. Inert gas welding can be used on many metals and their alloys, making it a very versatile welding process. However, welding parameters and electrode sizes often need to be adjusted based on the material being welded and the welding conditions. For example, the diameter of a non-consumable tungsten electrode can vary between approximately 0.5 mm and 6.4 mm (0.020 inches to 0.25 inches), depending on the material of the workpiece and the type of welding, and the electrode length can vary between approximately 75 mm and 610 mm (3 inches to 24 inches). Conventional inert gas welding torches typically use a variety of collets, allowing the user to disassemble the welding head and use different collets for each electrode size—a time-consuming process, especially if the user needs to regularly switch electrode sizes.

[0008] In inert gas welding processes, the welding area is protected from air pollution by an inert shielding gas such as argon. The welding power source generates an electric current, which concentrates enough thermal energy to weld the parts when creating an arc between the electrode and the material being welded. The concentrated heat is sufficient to create a plasma state in the contact area and additional filler rod. Heat is generated by the welding operation, and as a result, the welding torch may require a cooling system. Air cooling systems are most commonly used for low-current operations, but water cooling may be required within the torch of a TIG welding system to dissipate heat in high-current applications or applications requiring long duty cycles.

[0009] As described above, tungsten arc welding gas shielded torches employ a dedicated collet and collet body for holding an electrode of a specific diameter within the torch head. The electrode collet is typically made of tubular copper and has at least two longitudinal gaps or slots that allow the diameter of the collet to be radially compressed when it moves relative to the internal conical shape of the adjacent collet body. This compression of the collet minimizes the opening within it, engaging and securing the electrode within the nominal internal radial area of ​​the collet. Because the collet is compressed relative to the electrode over a relatively small area, the current density per unit area is high, which can generate considerable heat due to the electrical resistance connection to the electrode and can perpetuate the peripheral arc discharge within the collet. Therefore, due to the effects of repeated expansion and contraction caused by both resistive and conductive heating and subsequent cooling, the electrode and collet tend to corrode over time. The coefficient of thermal expansion of copper collets is 9.8 × 10⁻⁶. -6 While the expansion coefficient is in / in / 0F, the expansion coefficient of the tungsten electrode is approximately half (3.9 × 10⁻⁶). -6 Because it is in / in / 0F, the situation worsens further, potentially causing the electrode fitting to loosen during welding, in which case the electrical resistance increases further and / or the electrode becomes unstable and moves within the torch head. [Overview of the project] [Problems that the invention aims to solve]

[0010] Collets and collet bodies are typically supplied in at least six opening sizes to accommodate the various diameters of job-specific electrodes. Therefore, a significant limitation of existing collets is that a specific collet and collet body are required for each electrode size. Thus, whenever an alternative electrode diameter is needed, the collet assembly must also be replaced. For example, a 1 / 16-inch tungsten electrode requires at least one 1 / 16-inch collet and collet body, and similarly, a 1 / 8-inch electrode requires an 1 / 8-inch collet and collet body, and so on. Unfortunately, this not only becomes a logistical challenge but also a time-consuming task each time the electrode is changed to a different size. Furthermore, the use of multiple collets can also hinder electrode reversal (swapping end to end) and potentially lead to the development of beads or enlarged tips that prevent them from passing through the collet opening.

[0011] If the electrode comes into direct contact with the workpiece or filler wire, the tip of the tungsten electrode will be contaminated by "foreign" metal that moves to and adheres to the tip. This added material creates a mushroom at the tip, necessitating the resharpening 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 to allow the mushroom-shaped end of the electrode to be inverted from end to end and to be reinserted as the enlarged and contaminated end passes through the adjustable opening. As a result, the electrode may be used twice between resharpening or replacement. Therefore, a further objective is to provide an electrode receiver that allows the enlarged / contaminated end of the electrode to be inserted through it, thereby avoiding the problems associated with using a collet of a certain size to hold the electrode. [Means for solving the problem]

[0012] In one disclosed embodiment, the internal metal portion of the torch is preferably made of a conductive metal such as copper or brass to conduct electric current and transfer heat with minimal resistance over a relatively small contact area. The torch body is made of a heat-resistant insulating ceramic, plastic, and similar material to cover the metal portion and provide thermal and electrical insulation to protect the welding machine. Furthermore, equipment may be provided to allow a constant flow of shielding gas to pass through the torch handle and electrode receiving section and reach the workpiece area in order to provide an inert gas area or atmosphere near the weld.

[0013] For versatility and convenience, welding machines must enable optimal welding by allowing the selection and use of electrodes of any size at any time without the need to reconfigure the electrode receiver 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. Therefore, an adjustable electrode receiver that can be modified as needed to accommodate various electrode sizes offers a clear advantage when using electric welding torches, such as when employing TIG welding.

[0014] Embodiments disclosed herein are directed toward a removable torch head having an adjustable or variable electrode receiving section, which replaces a conventional head and eliminates the conventional collet in order to allow the use of multiple electrode sizes.

[0015] According to one aspect of the disclosed embodiment, a removable arc welding torch head is provided having an adjustable electrode receiving section, the arc welding torch head comprising a hollow plunger having a first end for enabling screw connection to a welding torch, a nozzle seat (e.g., a high-temperature plastic such as Teflon®) surrounding the first end of the plunger and operably connected to the first end of the plunger, and a torch head body, the torch head body including an inner diameter having a tapered internal region, a plurality of openings for enabling gas flow through therein, and threads for operable engagement (e.g., threadable engagement) with a chuck back plate thereon, the chuck back plate having an outer diameter for engaging with the inner diameter of the torch body, the arc welding torch head further comprising a plurality of radially arranged electrode fixing wedges (a plurality of jaw pieces), the plurality of electrode fixing wedges forming electrode openings between the plurality of electrode fixing wedges within the tapered internal region of the torch body, and electrode openings The mouth is formed such that each fixed wedge simultaneously passes longitudinally through the conical inner surface of a tapered region, forming a variable opening (jaw) between them, the plurality of fixed wedges further contact a plunger thrust cup at their ends, the thrust cup further combines with the plunger and backplate to convert the rotation of the plunger relative to the backplate into linear motion of the thrust cup in contact with the plurality of electrode fixed wedges, and further provides clamping action of the plurality of electrode fixed wedges as a result of their contact with the tapered surface, each of the plurality of electrode fixed wedges is biased away from each other (and toward the conical inner surface of the tapered region) by at least one biasing member between them and further includes an inner conical surface in contact with each fixed wedge, the plurality of fixed wedges further provide electrical contact between the electrode and the conical surface of the torch body, the arc welding torch head further comprises a nozzle, the nozzle encircles the torch body and is operably attached at one end to a nozzle seat.

[0016] Other and further objectives, features, and advantages will become apparent by reading the following specification and referring to the attached drawings which form part thereof, and examples of currently preferred embodiments are given for disclosure purposes. [Brief explanation of the drawing]

[0017] Brief explanation of the drawing [Figure 1] This is a perspective view of a TIG welding torch according to the disclosed embodiment, showing two welding torches to which a removable head can be attached along multiple plunger pieces suitable for adapting the removable head to various torch types. [Figure 2] This is a perspective view of an embodiment of an inert gas welding torch head having an adjustable electrode receiving section attached to a conventional torch handle. [Figure 3] Figure 2 is a perspective view of the embodiment in which the gas nozzle has been removed and welding electrodes of different diameters have been inserted into the adjustable electrode receiving section. [Figure 4] This is an enlarged perspective view of a torch having a plunger and nozzle seat component mounted on the torch, according to a disclosed embodiment. [Figure 5] This is an exemplary example of a replaceable inert gas welding head having a torch head body and associated components according to the disclosed embodiments. [Figure 6] This is an exemplary example of a replaceable inert gas welding head having a torch head body and associated components according to the disclosed embodiments. [Figure 7] This is an exemplary example of a replaceable inert gas welding head having a torch head body and associated components according to the disclosed embodiments. [Figure 8] Figures 1-7 are detail diagrams of various components shown according to the disclosed embodiments. [Figure 9] Figures 1-7 are detail diagrams of various components shown according to the disclosed embodiments. [Figure 10]Detailed views of various components shown in FIGS. 1-7 according to the disclosed embodiments. [Figure 11] Detailed views of various components shown in FIGS. 1-7 according to the disclosed embodiments. [Figure 12] Detailed views of various components shown in FIGS. 1-7 according to the disclosed embodiments. [Figure 13] Detailed views of various components shown in FIGS. 1-7 according to the disclosed embodiments. [Figure 14] Detailed views of various components shown in FIGS. 1-7 according to the disclosed embodiments. [Figure 15] Detailed views of various components shown in FIGS. 1-7 according to the disclosed embodiments. [Figure 16] Detailed views of various components shown in FIGS. 1-7 according to the disclosed embodiments. [Figure 17] Cross-sectional view of a removable torch head according to the disclosed embodiments, including a torch head body having an adjustable electrode receiving portion.

Best Mode for Carrying Out the Invention

[0018] The various embodiments described herein are not intended to limit the invention to those described embodiments. On the contrary, the intention is to cover all alternatives, modifications, and equivalents that may be included within the spirit and scope of the welding torch and adjustable electrode receiving portion defined in the appended claims.

[0019] Detailed Description

[0020] Referencing the drawings, the depiction in the drawings is intended to illustrate a preferred embodiment of a removable torch head having an adjustable electrode receiving section. As understood, the disclosed welding torch head is part of a gas tungsten arc welding system. In one embodiment, such a welding system includes a power supply, an inert gas supply source, a water / liquid cooling section, and a torch assembly including a torch head 100, as shown, for example, in Figure 2. In practice, a workpiece (not shown) is electrically connected to the power supply, which provides either -DC, +DC, or AC via clamp and return cables electrically connected to the workpiece (not shown). The torch 100 provides means of carrying an inert gas, along with an arc formed in the air gap between the tip of a tungsten electrode 120 and the workpiece, and this arc is sufficient to generate the heat necessary to melt multiple workpieces together. The torch 100 may be further connected to a supply of water or a cooling liquid to cool the torch when high-current and / or extended-time welding operations are performed.

[0021] The operable mechanical elements of the adjustable electrode receiver are located within the torch 100, and in particular, on the torch handle 108 to which the removable torch head 110 is attached. As shown in the drawings, the removable torch head 110 includes a hollow plunger 114, which is fitted to fit onto the torch body (see, for example, Figure 1) and has a first end 116 for enabling a threaded connection to the welding torch 100. A second threaded end 118 of the plunger is for coupling to the torch head body 130 and for interacting with the torch head body 130. When mounted on the welding torch, for example as shown in Figures 1 and 5, the hollow plunger 114 extends outward and provides a stem, on which a peripheral nozzle seat 126 can be operablely connected around the exposed threaded end 118 of the plunger. To allow the use of the removable torch head 110, the end 116 of the hollow plunger 114 must be suitable for screw connection to a conventional torch. While at least two different torch types, such as the HW20 torch and the WP20 torch, are shown in Figure 1, it will be understood that the removable torch head disclosed herein may also be suitable for use with other torches. Although not specifically shown, it will be understood that the rear end of the torch typically includes a tailpiece surrounding the portion of the electrode that extends through the removable head.

[0022] The nozzle seat 126 and nozzle 128 may be made of many materials suitable for high-temperature use, such as machinable or molded ceramics, Pyrex®, or high-temperature plastics such as glass-filled polytetrafluoroethylene (PTFE) or Teflon®. The inert gas supplied into the torch and removable torch head 110 flows through the hollow interior of the plunger 114, where the gas is directed towards the torch head body 130 and nozzle 128, and then flows out around the electrode in the region of the arc extending between the workpiece and the electrode.

[0023] For example, as shown in Figures 3-4, the nozzle 128 is associated with the torch body and nozzle seat 126 and is removably attached to the nozzle seat and torch head body 130 by friction fitting. Instead of friction fitting between the nozzle seat and the nozzle, a threaded connection or a bayonet-type connection between them is also possible. Furthermore, in one embodiment, the friction fitting with the torch body may be provided via an O-ring 124 or a similar element surrounding the torch body, for example, an O-ring in an O-ring retaining groove 122 as shown in Figure 9.

[0024] See also Figure 18, the removable torch head 110 also includes a torch head body 130, which includes a tapered internal region 134, a plurality of openings 138 that allow gas to flow through it, and an inner diameter 142 having threads that allow for operational engagement (e.g., screw connection) of a chuck back plate 146 thereon. In one embodiment, the chuck back plate 146 has a threaded outer diameter for engaging with the threaded inner diameter of the torch body. Also within the removable head 130 are at least two, typically at least three or more radially arranged electrode fixing wedges (jaw pieces) 154, which form electrode openings between them within the tapered internal region of the torch body, and the electrode openings are formed such that each fixing wedge can simultaneously traverse or slide longitudinally along the conical inner surface of the tapered region 134 to form a variable opening (jaw) between them. The fixing wedge 154 has its end in further contact with the plunger thrust cup 160. The thrust cup 160, in combination with the plunger 114 and backplate 146, converts the rotation of the plunger relative to the backplate into linear motion of the thrust cup in contact with the electrode fixing wedge, and further provides clamping motion of the electrode fixing wedge against the electrode 120 as a result of sliding contact between the tapered surface and them.

[0025] During operation, the electrode 120 is inserted along the inner surfaces of the plurality of wedges 154 and clamped within them by the force applied to the inner ends of the plurality of wedges by the plunger thrust cup 160. In the illustrated embodiment, a compressive force is applied to the thrust cup 160 by a plunger 114 that rotates relative to the torch head body 130, thereby advancing the plurality of wedges 154 in response to the rotation of the head and closing the jaws formed by the plurality of wedges around the electrode. When the plunger rotates in the opposite direction, the plunger retracts relative to the head body 130, and as a result the pressure applied to the plurality of wedges is relieved. In the absence of pressure from the plunger 114, the plurality of electrode wedges 120 slide their jaws upward under the force of the biasing member (spring) 164, thereby expanding or opening the jaws. In other words, as the plunger 114 moves away from the thrust cup, the biasing spring 164 pushes the plurality of electrode wedges apart, causing the plurality of wedges to slide their jaws upward and outward along the inner cone and hold them relative to the thrust cup. There is no pulling action from the plunger or thrust cup, but the biasing force moves the multiple wedges to their maximum diameter position. The spring keeps them all under tension and only moves within the cone when compressed. If, by any chance, the multiple wedges become temporarily "fixed" in one position, a light tap on the tungsten electrode will cause them to snap back and continue moving for compression, but normally they slide back.

[0026] The rate of change in the orifice diameter formed by the multiple wedges 154 is a function of the screw pitch or turns per inch (TPI) at the mating surface between the chuck backing plate 146 and the end 118 of the hollow plunger 114, as well as the angle θ or inclination of the rear surface 162 of the wedge 154. The corresponding internal conical surfaces 134 typically share a common inclination angle θ in the range of 15 to 20 degrees. Thus, the minimum and maximum opening diameters are sine functions of the angle θ.

[0027] Furthermore, in order to ensure that the electrode fixing wedges 154 remain spaced apart when not compressed relative to the electrodes, each electrode fixing wedge is biased toward the conical inner surface of the tapered region away from adjacent wedges and is biased by at least one biasing member 164 between a plurality of adjacent wedges. In one embodiment, the biasing member is a compression spring made of stainless steel and seated in each recess 142 of the plane 168 of the electrode fixing wedge 154. As understood, the elastic member 164 (e.g., a coil compression spring) associated with each electrode fixing wedge biases the plurality of wedges toward the conical inner surface of the tapered region 134. Furthermore, although the elastic member 164 is described as being located between a plurality of adjacent wedges 154, or more specifically between a plurality of recesses 142 on a plurality of wedges, it is also possible to provide other wedge and spring configurations that bias the plurality of wedges so that they move outward (and thus toward a larger diameter of the housing).

[0028] In summary, in the torch head body 130 of the adjustable electrode receiving section, each of the electrode fixing wedges 154 includes a plurality of adjacent planes that share a first end or a line of movement 156 between them, each having an opposing end 158 spaced apart and slightly inclined with respect to the first end, and further including a conical surface (162, behind the wedge in Figure 16) extending between the plurality of opposing ends of the plane 168, at least one of the plurality of planes including an opening therein (for receiving the end of the coil compression spring 164). To be further understood, the line of movement 156 between adjacent planes of the electrode fixing wedges provides a continuous region (e.g., along the line) for contact between the wedge and the electrode.

[0029] To ensure the flow of current through the torch head body 130 to the multiple wedges 154 and associated electrodes 129, the internal conical surface 134 remains in contact with each fixed wedge beyond at least some of the outer wedge surfaces, thereby reducing contact heating. In one embodiment, the multiple wedges are formed from a conductive material such as an alloy of steel, copper (e.g., brass, bronze), or nickel alloy. As shown in Figure 7, in one embodiment, three electrode fixed wedges 154 are employed in the head 130. The fixed wedges 154 electrically connect the electrodes 120 to the conical surface 134 of the torch body 130. In the embodiments shown in Figures 6, 7, and 18, for example, the electrode fixed wedges 154 arranged radially within the torch head body 130 can accommodate an electrode diameter of at least about 0.145 inches or more.

[0030] As described above, the nozzle 128 surrounding the torch body guides the inert gas along and through the torch head, and the nozzle is operationally attached to the nozzle seat 126 at one end.

[0031] In summary, as shown in the drawings, the removable torch head features a variable-sized electrode receiving section. Multiple electrode fixing wedges 154 are arranged radially within the torch head body 130, forming an opening between them, the size of which is adjustable based on the position of the multiple wedges relative to the internal conical surface 134 within the body. The use of the disclosed embodiment is expected to result in improved productivity by at least eliminating the need to change the collet when switching between various electrode diameters or shapes. Furthermore, the interchangeable head is easily mounted and compatible with use in conventional inert gas welding torches.

[0032] It will be understood that the embodiments disclosed above, as well as some of the other features and functions, or their substitutes, can preferably be combined as needed for many other different systems or applications. Furthermore, various currently unforeseen or new substitutions, modifications, variations, or improvements therein can subsequently be made by those skilled in the art and are intended to be included in the above description and the following claims.

Claims

1. 1. A removable arc welding torch head having an adjustable electrode receiving portion, comprising: a hollow plunger having a first end for allowing a threaded connection to a welding torch; a nozzle sheet surrounding and connected to the first end of the hollow plunger; and a torch head body, the torch head body comprising: a tapered interior region, a plurality of openings therethrough to permit gas flow therethrough, and a threaded inner diameter to permit engagement of a chuck back plate thereon; the chuck backplate has an outer diameter for engaging a threaded inner diameter of the torch head body; a plurality of radially arranged electrode clamp wedges defining an electrode aperture therebetween within the tapered interior region of the torch head body such that each electrode clamp wedge passes longitudinally through a conically tapered inner surface of the tapered interior region to define a variable aperture therebetween, said plurality of electrode clamp wedges further contacting plunger thrust cups at their ends, said plunger thrust cups further combining with a hollow plunger and a chuck back plate to translate rotation of the hollow plunger relative to the chuck back plate into linear motion of the plunger thrust cups in contact with the plurality of electrode clamp wedges and further providing a clamping action of the plurality of electrode clamp wedges as a result of their contact with the tapered inner surface; each of the plurality of electrode securing wedges is biased away from one another by at least one biasing member therebetween; the tapered inner surface contacting a respective electrode clamping wedge, the plurality of electrode clamping wedges further providing electrical contact between an electrode and the tapered inner surface of a torch head body; The removable arc welding torch head further comprising a nozzle, the nozzle surrounding the torch head body and attached at one end to the nozzle seat.

2. The removable arc welding torch head of claim 1 , wherein each of the plurality of electrode clamping wedges further includes at least one surface feature for receiving a portion of the biasing member therein.

3. 10. The removable arc welding torch head of claim 1, wherein the hollow plunger is adapted for threaded connection to a conventional torch.

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

5. 2. The removable arc welding torch head of claim 1, wherein the combination of the torch head body and the plurality of radially disposed electrode clamping wedges is capable of accepting electrodes having a diameter of at least up to 0.145 inches.

6. The removable arc welding torch head of claim 1 , wherein each of said plurality of radially disposed electrode clamping wedges is formed from an alloy.

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

8. The removable arc welding torch head of claim 1 , wherein the nozzle is formed of a material suitable for use at high temperatures.

9. 9. The removable arc welding torch head of claim 8, wherein the material suitable for high temperature use is glass filled polytetrafluoroethylene (PTFE).

10. The removable arc welding torch head of claim 1 , wherein the nozzle seat is formed of a material suitable for use at high temperatures.

11. The removable arc welding torch head of claim 10, wherein the material suitable for high temperature use is glass filled polytetrafluoroethylene (PTFE).

12. The removable arc welding torch head of claim 1 , wherein the at least one biasing member is a coil spring disposed between adjacent electrode clamping wedges.

13. The removable arc welding torch head of claim 1 including at least three electrode clamping wedges.

14. 14. The removable arc welding torch head of claim 13, wherein each of the plurality of electrode clamping wedges includes adjacent planar surfaces, each sharing a first edge between adjacent planar surfaces, each having an opposing end spaced slightly angled relative to the first edge, and a conical surface spanning between the opposing ends of the planar surfaces.

15. The removable arc welding torch head of claim 14 , wherein a first end between adjacent planar surfaces of the electrode clamping wedge provides a continuous contact area for contacting the electrode.

16. 10. The removable arc welding torch head of claim 1, wherein the torch head body includes a plurality of openings therein for facilitating movement of inert gas through the torch head body and around the torch head body.

17. The removable arc welding torch head of claim 1 , wherein the nozzle is associated with a nozzle seat and is removably attached to the nozzle seat and torch head body by a friction fit.