Patent Application
20080169277
The invention relates generally to the field of welding systems, and particularly to welding systems that require alignment of a torch and/or electrode to a desired weld location.
A number of forms of welding are known and are generally used in the art. These include metal inert gas (MIG) welding, tungsten inert gas (TIG) welding, and stick welding systems. In MIG systems, electrical current is applied to a wire electrode and an arc is established between a grounded work piece and the electrode. The wire electrode is advanced through a welding torch and is generally consumed as the work piece is melted due to heat released by a sustained arc, while a shielding gas surrounds the progressing weld. A variant of MIG welding is flux core arc welding (FCAW), in which a flux is integrated into welding wire and no shielding gas is required. Stick welding involves establishing an arc between a stick electrode which is often surrounded by a flux material. The stick electrode is generally consumed and its metal is fused with melted metal of the work piece as the welding operation continues under the heat of an established arc. In TIG welding, on the contrary, a non-consumable tungsten electrode is used to establish an arc with a work piece, causing the work piece material to melt and fuse to form a weld, often with the addition of consumable material which is melted and added to weld under the heat of the arc. These welding techniques may be used on different types of material or for different applications, but multiple techniques are often used by a welding operator depending upon the particular needs of an application.
One difficulty in welding applications is positioning and aligning the electrode with respect to a desired weld location. This concern is prevalent in TIG welding systems (also known as gas tungsten arc welding, or, GTAW), because the electrode is suspended above the work piece. In a TIG welding system, prior to and during the welding process, the weld area is protected from atmospheric contamination by a shielding gas (typically an inert gas) expelled from the tip of the welding torch to encapsulate the electrode, the weld location and the tip of a filler material. As briefly mentioned above, a non-consumable tungsten electrode is contained in a torch to provide a path for current flow to a work piece. When the energized electrode is positioned close to the grounded work piece, an electric arc is formed. The arc provides an intense heat that melts the work piece and surrounding metals to create a weld. In general, the arc is struck when the distance between the tip of the electrode and the work piece is approximately 1.5-3 mm (0.06-0.12 in), depending upon the electrical control regime and its parameters. Once the arc is struck, the welder moves the torch in small circles to create a weld pool, the size of which depends on the size of the electrode and the current level provide by the power source. While maintaining a constant distance between the electrode and the work piece, the torch may be titled at a slight angle to allow for a filler material to be manually added to the front end of the weld pool as is needed to fill any gaps or voids in the weld. This technique may be continued over a distance until the desired weld is complete.
While MIG or FCAW (Metal Inert Gas or Flux Core Arc Welding) maybe less sensitive to positioning the electrode than TIG welding, the distance from the torch and the length of the arc are still of concern. For example, when welding with a consumable electrode (e.g., MIG or FCAW) the arc and the filler material are both supplied via the consumable electrode which is positioned above the work piece. The distance between the electrode and work piece may affect the weld penetration as well as how the filler material is deposited. Thus, the distance between the electrode and the work piece is crucial to making a quality weld.
Properly aligning the electrode may include the positioning the electrode relative to the desired weld location on the work piece, as well as maintaining a proper distance between the tip of the electrode and the work piece. If the electrode is not aligned properly, the weld may be formed in the wrong location, the weld may have an inconsistent cross section, or the arc may be extinguished during the welding process. At present, the alignment of the electrode to the work piece is generally accomplished by an operator holding a torch or gun with an electrode, estimating the resulting arc location (i.e., weld location) on the work piece and estimating the proper distance from the tip of the electrode to the work piece, or simply touching the work piece to initiate the arc. During welding, proper distancing of the electrode from the work piece typically relies upon the skill and experience of the operator. This method of alignment is not precise and may lead to a weld in the wrong location, or a weld of low quality due to the electrode arcing at an improper distance from the work piece.
Moreover, most welding applications provide little or insufficient light to allow the welder to see any of the work piece or components once the arc is struck. That is, while work lamps may be used to illuminate a work area, once the welding operator lowers his welding shield, or transitions an autodarkening shield to a dark shade, the operator will have little or no visual feedback of the location of the electrode tip or its distance from the work piece other than the light provided by the arc.
Accordingly, there is a need for an improved welding system that provides for proper alignment of a torch and/or an electrode prior to and during the welding process. There is also a need for a technique for lighting welding locations, particularly to provide an indication of the position and orientation of a welding electrode and/or general lighting in the workplace.
The invention provides a welding arrangement designed to respond to such needs. In accordance with one aspect of the present invention, a welding system includes a welding device, and a guide light coupled to the welding device. The guide light is configured to illuminate a location at or near a weld location. In a particular embodiment, the device is the welding torch/gun itself, and the guide light is supported on the torch/gun or the torch/gun handle.
In accordance with another aspect of the present invention, a TIG welding torch or MIG welding gun system is provided that includes a TIG welding torch or MIG welding gun and a guide light coupled to the TIG welding torch or MIG welding gun. The guide light is configured to illuminate a location at or near a weld location.
In accordance with yet another aspect of the present technique, a welding lighting system includes a guide light and an enclosure configured to encompass the guide light and configured to couple the guide light to a welding device.
In all of these configurations, the guide light or lighting system may actually include more than one light source. Thus, a single laser or LED, for example, may serve to illuminate a weld area, while more than one laser or LED may provide particular functionality, such as focusing, general illumination, distance indication, and so forth.
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:
Referring now to
In the illustrated embodiment, the power source 12 provides power to the welding torch 24 via a supply conduit 22. The power source 12 may supply a DC current or AC current to the torch 24 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 42, while a high AC frequency (e.g., 200 Hz) current may generate a focused arc with deeper penetration of the work piece.
In addition to the frequency of the current, the power source 12 may vary the amperage of the current output to the torch 24. The setting for the amperage output by the power source 12 may be adjusted by a setting a knob or button on the power source 12, or may be set by a remote control 44. For example, a welding system 10 may include a foot pedal remote control 44 that allows the operator to make current adjustments during welding by either holding down the foot pedal or feathering the foot pedal remote control 44 to vary the amperage. As will be appreciated, the remote control 44 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.
In addition to providing power to the torch 24, in a TIG welding system 10 the torch 24 may be supplied with a shielding gas from a supply 14. In general, the shielding gas may be supplied to the torch 24 and expelled from the torch at the location of the weld. The shielding gas may be expelled immediately prior to striking the welding arc, during welding, and continue until shortly after the welding arc is extinguished. The shielding gas may be used to protect 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, discussed below to the metal, and helps to start and maintain a stable arc.
As depicted in
The TIG welding systems 10 may be provided with a cooling system 26 to reduce heat build-up. The cooling system may take various forms including gas cooled and liquid cooled systems. The cooling system 26 may provide for circulation of the coolant via conduits 30 and 34. The cooling system may be powered from the power supply 12 via a coolant system power cord 36.
In general, a welding system 10 may provide for current flow by grounding a work piece 42 to the power source 12. For example, as depicted in
As will be appreciated by those skilled in the art, regardless of the type of welding system used, the operator typically relies upon skill to maintain the proper current and arc to provide a sufficient weld. For example, low heat at the weld caused by a low welding current or high welding speed, can limit the penetration of the weld into the work piece and cause the weld bead to lift away from the weld surface. In contrast, excess heat may allow the weld to grow in size, leading to excessive weld penetration and the potential for splattering of the weld or burning through the work piece. The heat at the weld may be controlled by the distance between the welding torch 24 electrode 60 and the work piece 42 (see
In addition to the problems associated with heat at the weld location, if the electrode 60 is not well protected by the shielding gas 14, or the operator accidentally allows the electrode 60 to contact the molten metal, the weld pool or the electrode 60 may be come dirty or contaminated. This may cause the weld arc to become unstable, and require the electrode 60 to be reground to remove the impurity. In conventional welding systems, the operator must approximate the distance between the electrode 60 and the work piece 42. Thus, the quality of the weld, and the efficient operation of the welding torch 24 relies on the skill of the operator to maintain a proper distance between the electrode 60 and the work piece 42. Further, prior to starting the weld, the operator may have to estimate the location of the arc due to the distance that may be required between the electrode 60 and the work piece 42. For example, to strike an arc with the aid of a “high frequency” current, the operator may have to initiate the current while suspending the electrode 60 above the work piece 42. Further, in other systems, a “lift-arc start” may require touching the electrode to the work piece 42 and slowly moving the electrode away from the work piece 42 until an arc is struck. If the operator does not estimate the correct position of the arc with either of the above techniques, the weld may be started in an undesired location.
As illustrated in
Other components of the welding torch 24 coupled to the torch body 48 may include an insulator 54, a nozzle 56, a collet 58, an electrode 60, and a back cap 62. The insulator 54 may be positioned on the interior of the torch body 48 to prevent 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 60, while providing a path for the shielding gas to pass between an interior surface of the nozzle 56 and the collet 58.
In the embodiment illustrated in
Further, the light assembly 64 may include an area light. For example, as depicted in
Turning now to
In another embodiment, multiple light sources may be provided. For example, as depicted in
In the various embodiments described herein, the light sources themselves may be of various types. For example, currently contemplated embodiments would make use of light emitting diodes (LED's) for area lighting, or even certain of the directed lighting. Small lasers may also be used, particularly for more directed or narrowly targeted lighting. These may provide both white light and light in various colors or wavelength bands, as described herein.
A multi-light embodiment may be configured to provide a visual indication of the arc location 68 as well as the proper arc distance 88, as illustrated generally in
As will be appreciated by those skilled in the art, two or more light sources may be combined to triangulate a visual indication of the proper arc distance 88 to an arc location 68. For example, as depicted in
To distinguish the light sources, and provide for various indicators, the color of the light projected may be varied. In one embodiment, a light source may project a color (e.g., red) when the distance between the electrode 60 and the work piece is incorrect, and a light source may project another color (e.g., green) when the distance is within an acceptable range. For example, as depicted in
In another embodiment, a third light source may be included to provide additional visual indicators. For example, as depicted in
The assembly 64 may incorporate other devices for providing feedback to the operator, in addition to the light sources. In on embodiment, the light assembly 64 may include a proximity sensor 82, as depicted in
To provide visual indication to the operator, the light source may also generate an indicator of a given shape or size on the work piece 42. Such size and shape may allow the operator to determine when the arc location and the arc distance are correct. For example, as depicted in
As will be appreciated by a person of ordinary skill in the art, although all possible combinations of light sources and sensors have not been discussed, any combination of light sources and sensors may be possible to meet the requirements of a given system. For example, a single light source may be combined with multiple sensors, or a colored area light may be combined with multiple laser diodes that triangulate position. The above discussion is not intended to limit the potential embodiments of the disclosed system.
Each of the previously described embodiments may require power to be supplied to the devices contained within the light assembly 64. In one embodiment, the power supplied to light assembly 64 and the light sources 74, 76, 78 and 80, may be remote controlled. For example as depicted in
Power supplied to the devices within the assembly 64 may be routed from the power source 12 to the assembly 64 in various manners. In one embodiment, as depicted in
Although previous discussion has included the assembly 64 mounted to the torch head 52, an embodiment may include the assembly 64 mounted to other portions of the torch 24 relative to the electrode 60 and/or weld location. For example, as depicted in
Further, as will be appreciated by those skilled in the art, the present invention may be adapted to other welding techniques. For example, the assembly 64 may be adapted for use on a MIG welding gun, a FCAW welding gun or on torches/guns of similar welding techniques. In one embodiment, the assembly may be coupled to a cutting torch (e.g., a plasma cutter) or similar device to aid the operator in cutting operations. A focused beam of light can illuminate a particular location on a work piece to enable the operator to predict and identify the cutting location. These additional techniques of welding may derive similar benefits from the invention, including alignment of an electrode to a work piece, and general lighting of the work area.
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.
This application claims priority to U.S. Provisional Patent Application No. 60/880,865, entitled “Lighted Welding Torch”, filed on Jan. 16, 2007, which is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60880865 | Jan 2007 | US |
