Precision Wire Guide For A Welding Consumable

A wire guide including a bracket for securing the wire guide to an external support, a housing, a holder for holding a nozzle extension, a main spring and an adjustment mechanism, and wherein the main spring is configured to allow the holder to float within the housing whilst a first end of the holder extends through an aperture formed in the housing and has a position adjustable with reference to the housing by the adjustment mechanism.

TECHNICAL FIELD OF INVENTION

The present invention relates to a wire guide fora welding consumable.

BACKGROUND OF INVENTION

During a TIG welding operation, a welding consumable (filler) is often fed into the molten welding pool that is created by an electric arc. The welding consumable or filler wire is added to the weld pool to provide additional material to flow into any space between the two surfaces being joined.

Although manual feed of the consumable into the molten weld pool is possible in some situations, the weld location may not always allow for it. Accordingly, it is more preferable to make use of a feeding device that winds the consumable off a reel and feeds it to the welding pool via a wire guide.

FIG. 1 of E P patent application 0194045 (E P0194045) illustrates a TIG welding arrangement that includes a feeding device6that feeds filler wire5(consumable) off a reel and into the molten weld pool. The filler wire5is passed through a conduit7and a wire guide9that includes a contact tip8. Contact tip8is shown connected to a power source10to enable current to be fed into the filler wire5to increase its melting rate (if required).

FIG. 2 of E P0194045 shows a semi-automatic TIG welding arrangement in which the wire guide9is secured to a torch body11and the filler wire5is automatically fed at a predetermined rate by a wire feeding device. To ensure that the filler wire5is fed to the proper position of the molten weld pool12, a manual adjustor13is provided for finely adjusting the filling position of the filler wire5. Adjustor13is connected to the contact tip8and is also mounted to the torch body11. Accordingly, the contact tip8and thus the wire5moves together with the torch body11.

The present invention seeks to provide a wire guide that includes an improved arrangement for adjusting the positioning of the filler wire with respect to the molten weld pool formed by a welding device.

The discussion of the background to the invention herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of this application.

SUMMARY OF INVENTION

According to the present invention there is provided a wire guide including a bracket for securing the wire guide to an external support, a housing, a holder for holding a nozzle extension, a main spring and an adjustment mechanism, and wherein the main spring is configured to allow the holder to float within the housing whilst a first end of the holder extends through an aperture formed in the housing and has a position adjustable with reference to the housing by the adjustment mechanism.

In accordance with an embodiment of the invention, the nozzle extension is configured to pass through the bracket and the holder, and a filler wire is configured to pass through the nozzle extension.

The main spring is preferably configured to bias the holder in a direction towards the bracket and preferably to hold a second end of the holder against the bracket whilst allowing the positioning of the first end of the holder to be adjusted using the adjustment mechanism.

The adjustment mechanism is configured to enable adjustment of the position of the first end of the holder relevant to a longitudinal centre line of the housing.

Preferably, adjustment is possible in the direction of both a notional X-axis and a notional Y-axis. The notional X-axis and notional Y-axis extend perpendicular to one another and perpendicular to a longitudinal centreline of the housing. Accordingly, such adjustment results in a substantially equivalent adjustment of the nozzle extension held by the holder along the notional X-axis and the notional Y-axis.

Preferably, the filler wire passes through the nozzle extension and the holder substantially coincident to the longitudinal centreline of the holder. However, the position of the longitudinal centreline of the filler wire relative to the housing will vary depending on the operation of the adjustment mechanism by a user.

The adjustment mechanism preferably includes a first and a second member each arranged to be located and moved each within an aperture in the housing. The apertures are preferably located substantially perpendicular to one another and substantially perpendicular to the longitudinal centre line of the housing. Each first and second member, which may be a threaded member such as a bolt, is arranged to move inwardly and outwardly of the aperture by a user so as to push against or retract from a respective part of the holder. The inward or outward path of travel of the first member is coincident with the notional X-axis and the inward or outward path of travel of the second member is coincident with the notional Y-axis. It will thus be appreciated that by adjusting the positioning of the first and second members within their respective apertures, it is possible to directly adjust the positioning of the holder within the housing. This in turn will cause an adjustment of the positioning of the free end of the filler wire.

Contact between each of the first and second members with the respective parts of the holder is maintained in use by respective biasing means. Each biasing means is preferably a spring and grub screw combination located in an aperture positioned opposite the aperture of the respective first or second member. The biasing means is provided and set to ensure that the holder will return to a centrally located position within the housing under the bias of the spring when both the first and second members are set to a zero position. In this position, in accordance with the preferred embodiment, the longitudinal centreline of the holder is coincident with the longitudinal centreline of the housing.

DETAILED DESCRIPTION OF DRAWINGS

Wire guide100shown inFIGS. 1 and 2includes bracket110, holder120, main spring130, housing140, and a nozzle extension150. Preferably, a wire feed tip160is further included. InFIG. 1, a filler wire200is shown being fed from the rear of the wire guide100, that is the side adjacent to the bracket110, through the housing140of the wire guide100, and exiting through the feed tip160. The filler wire200is normally contained within a sheath210until about the point at which the filler wire200enters the nozzle extension150.

The wire guide100is typically arranged in use to be connected via the bracket100to an external support or other element not illustrated. The bracket100may for example be connected to a part of a welding apparatus (not shown). To this end, and as shown inFIG. 3, a link170may be provided and arranged for pivotal connection via pivot pin172to the upper part of the bracket110. The pivotal connection of the link170to the bracket110enables the angular positioning of the wire guide100to be adjusted relative to the external support (not shown). The link170may be directly connected to the external support or a connector180may be attached between the link170and the external support.

FIG. 3shows one example of a connector180. However, a person skilled in the art will appreciate that both the configuration of the link170and the connector180may be varied to suit the particular application and the configuration of the external support to which the wire guide100is to be connected.

FIG. 4further illustrates the holder120. Holder120includes a body122with a through hole124formed therein through which the nozzle extension150may be passed. The through hole124is preferably dimensioned relative to the external diameter of the nozzle extension150to allow the nozzle extension150to be passed through the through hole124whilst limiting any potential side to side movement of the nozzle extension150therewithin.

Holder120has an enlarged trailing end (second end) formed by flange126and a leading end (first end)128. The flange126has a generally planar first end face126aand second end face126b.

Flange126is dimensioned to snugly fit within the housing140whilst still allowing adjustment of the position of the leading end128of the holder120relative to the housing140. This adjustment will be explained in more detail later.

As best shown inFIG. 4, the leading end128of the holder120includes a threaded hole128a.In use, a fastener, such as a bolt300is arranged to be screwed into the hole128aso that the innermost end thereof presses against a part of the nozzle extension150and in this way locates and secures the nozzle extension150within the holder120. This prevents the nozzle extension150from moving side to side or longitudinally within the holder120. The longitudinal axis of hole128ais located perpendicular to the longitudinal axis of the through hole124of the holder120.

FIG. 5best illustrates the housing140. As shown, housing140includes a through opening which includes a major bore142and a minor bore144. The housing140and major and minor bores142,144are sized so that when the holder120is properly positioned within the housing140with bracket110secured thereto, the leading end128of the holder120passes through the minor bore142and is positioned as shown inFIG. 1. In this position, bolt300can be screwed into the hole128awhich is located externally of the housing140.

The major bore142of the housing140is sized relative to the flange126of the holder120so that there is some limited ability for the holder120to move or float within the housing140. However, that movement or float, as will be explained, is controllable by the main spring300and an adjustment mechanism.

Main spring130is arranged to sit over the holder120with one end located against the second end face126bof the flange126of the holder120and the other end located against the bottom face142aof the major bore142. When the holder120is located within the major bore142of the housing140and the bracket110secured thereto, the main spring130is held under compression. Accordingly, the main spring130acts to push the holder120in the direction of the bracket110so that the first end face126aof the flange126of the holder120is normally held in contact with the bracket110. However, it should be appreciated that the holder120is not fixedly secured to any part of the housing140and thus it can “float” within the housing140.

As shown, four screws350are used to secure the bracket110to the body of the housing140. However, any suitable means for securing the bracket110to the housing140may be adopted.

The nozzle extension150is a tubular member, for example a length of copper tube. In accordance with the illustrated embodiment, the tubular member includes at one end, an enlarged external diameter portion152which is threaded internally. Such an arrangement is provided to enable the sheath210surrounding the filler wire200to connect thereto. The other end154of the tubular member is arranged, in accordance with the illustrated embodiment, for connection to the feed tip160. To this end, the external periphery of the other end154is also threaded.

FIG. 6clearly illustrates the through hole156within the nozzle extension150. The filler wire200is arranged to be pushed through the through hole156during use of the wire guide100.

Feed tip160includes a through hole through which the filler wire200passes. Different sized feed tips160may be provided to ensure a tight fit with different feed wire diameters. For example, the diameter of the through hole156of the nozzle extension150is typically set at 2 mm, whereas feed tips160with internal diameters of 1.1, 1.3 and 1.7 mm may be adopted for use with filler wire diameters of 0.9, 1.2 and 1.6 mm.

As best shown inFIGS. 2 and 5, the wire guide100includes an adjustment mechanism for adjusting the relative positioning of the free end200aof the filler wire200relative to the housing140. To this end, the housing140also includes two internally threaded thumb screw apertures146a,146bwhich are aligned with respective opposed grub screw apertures148a,148b.The two thumb screw apertures146a,146beach have a central axis which extends substantially perpendicularly to the longitudinal centreline through the housing140and perpendicularly to one another. In this way, the central axis of thumb screw aperture146adefines a notional X-axis and the central axis of thumb screw aperture146bdefines a notional Y-axis. Each thumb screw aperture146a,146bis arranged to receive a screw400a,400bwhich can be rotated so as to be driven inwardly and outwardly of the respective apertures146a,146b.

Each grub screw aperture148a,148bis configured to receive a spring500and grub screw600combination. Each spring500and grub screw600combination is set within the respective grub screw aperture148a,148bso that in use the inner most end of the spring500contacts against a part of the periphery of the holder120. Each spring500is held under compression. It will thus be appreciated that when the thumb screw400awithin the thumb screw aperture146ais rotated to move inwardly of the aperture146a,the distal end of the screw400awill press against one side of the periphery of the holder120, whilst the opposed side of the holder120will in turn press against the inner most end of the paired spring500to compress the same. Accordingly, the holder120will be pushed by the screw400aalong the notional X-axis and towards the grub screw600. When the screw400awithin the thumb screw aperture146ais rotated outwardly, the holder120will move back along the X-axis towards the screw400a.In this way, the positioning of the holder120with the respect to the longitudinal centreline through the housing140can be adjusted in the direction of the notional X-axis. Similarly, adjustment in the direction of the notional Y-axis can be achieved by rotating the thumb screw400binwardly or outwardly of the aperture146b.This fine adjustment of the positioning of the holder120within the housing140is possible because the holder120effectively “floats” within the housing140under the influence of the main spring300and any pressure applied to the holder120by the thumb screws400a,400band springs500.

It will thus be appreciated by a person skilled in the art that fine adjustment in the positioning of the holder120relative to the longitudinal centreline through the housing140can be achieved in both the X and Y axis direction. In turn, such an adjustment results in a corresponding or related adjustment in the positioning of the connected nozzle extension150and thus the filler wire200held within the nozzle extension150. Thus, such fine positioning adjustment of the holder120within the housing140can be used to vary the position of the free end200aof the filler wire200relative to the housing140. Consequently, this fine adjustment can be used to vary the point at which the free end200aof the filler wire200is located relative to the external support and in this way vary the position at which, for example, the filler wire would enter a weld pool.

The adjustment of the position of the free end200aof the filler wire200can be quickly and easily made by a user simply by rotating one or both of the thumb screws400a,400b.Further, given the selected orientation of the thumb screws400a,400band associated apertures146a,146bof the illustrated embodiment, the required adjustment of the positioning of the free end200aof the filler wire200is directly translatable to the screws400a,400b.For example, when the free end200aof the filler wire200needs to be moved forward in a direction parallel to the X-axis, then the X-axis screw400ais simply rotated to move in the required direction. Similarly, when the free end200aof the filler wire200needs to be moved rearward in a direction parallel to the Y-axis, then the Y-axis screw400bis simply rotated to move in the required direction. In this way, the adjustment is deemed directed translatable which is intuitive for the user, thus making operation of the adjustment mechanism easier to learn and master.

The embodiments have been described by way of example only and modifications within the spirit and scope of the invention are envisaged.