Patent Description:
Many welding and cutting torches, such as plasma cutting torches, can receive a variety of consumable components, such as tips/nozzles, electrodes, shields, etc. One example prior art consumable stack <NUM> is illustrated in <FIG>. Consumable stack <NUM> includes an electrode <NUM>, a nozzle <NUM>, a swirl ring <NUM>, and a shield <NUM>. The electrode <NUM> includes a main body <NUM> that terminates in a distal end face <NUM> that defines a cavity <NUM> for an emissive insert (e.g., a hafnium emissive insert). Additionally, the electrode <NUM> includes an external surface <NUM> that faces an inner surface <NUM> of the nozzle <NUM> to define a plasma channel <NUM>. The external surface <NUM> includes a longitudinal portion <NUM> and a tapered portion <NUM> that is tapered at an angle A1 of approximately <NUM>° with respect to the longitudinal portion <NUM>. Notably, an upstream edge <NUM> of the tapered portion defines a hard edge with the longitudinal portion <NUM> and a downstream edge <NUM> defines a hard edge with the distal end face <NUM>, at least in between grooves <NUM> formed thereon.

Meanwhile, the nozzle <NUM> includes a main body <NUM> that defines an inner surface <NUM> with a longitudinal section <NUM> and a tapered section <NUM> that are connected by a rounded section <NUM>. The rounded section <NUM> has a non-constant curvature and extends around and above the tapered portion <NUM> of the electrode <NUM> (insofar as "above" refers to an upstream direction along a longitudinal axis of consumable stack <NUM>). That is, an upstream edge <NUM> of the rounded section <NUM> of the nozzle <NUM> is disposed above the upstream edge <NUM> of the tapered portion <NUM> of the electrode <NUM>. This creates a hard corner in the plasma channel <NUM>. Additionally, since the rounded section <NUM> faces a linear, angled tapered portion <NUM>, the plasma gas channel <NUM> diverges after the hard edge defined by the upstream edge <NUM> of the tapered portion <NUM> of the electrode <NUM>. Then, the plasma gas channel <NUM> converges at or near a downstream edge <NUM> of the rounded section <NUM> of the nozzle <NUM>. These convergent and divergent areas, as well as the corner, may cause flow of the plasma gas to separate. That is, these sections and/or the corners in the plasma gas channel <NUM> may create turbulent flow.

For the purposes of this application, a "plasma gas channel" is defined between a nozzle and an electrode and terminates in a plasma chamber. Thus, in <FIG>, plasma gas channel <NUM> terminates at the downstream edge <NUM> of the rounded section <NUM> of the nozzle <NUM> and feeds into plasma chamber <NUM>. The plasma chamber <NUM> is defined beneath the distal end face <NUM> of the electrode <NUM>, above an orifice <NUM> of the nozzle <NUM>, and interiorly of the tapered section <NUM> of the nozzle <NUM>. In the prior art consumable stack <NUM> depicted in <FIG>, the plasma chamber <NUM> includes an emissive insert catcher <NUM> defined by a stepped portion <NUM> of the inner surface <NUM> of the nozzle <NUM>. As can be seen, the tapered section <NUM> has a relatively shallow slope defined by taper angle A2, which may measure approximately <NUM>° with respect to a longitudinal axis (i.e., <NUM>° when measured between opposing surfaces of the annular interior surface) so that the emissive insert catcher <NUM> has a height H2 that spans approximately half of the overall height H1 of the plasma chamber <NUM>. Height H1 may be in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches).

The plasma chamber <NUM> terminates at an orifice <NUM>, which extends from the plasma chamber <NUM> to a distal end <NUM> of the nozzle <NUM>. Due to the compact height H1 of the plasma chamber <NUM>, the orifice <NUM> is elongated and has a height H3 of approximately <NUM> (<NUM> inches). In consumable stack <NUM>, plasma gas exiting the orifice <NUM> is constricted by an axial flow of shield gas that exits the consumable stack <NUM> via a shield gas path <NUM> defined between the shield <NUM> and an outer surface <NUM> of the nozzle <NUM>.

Generally, consumables, such as the electrode <NUM> and nozzle <NUM> included in stack <NUM>, have a limited lifespan and only last for a certain amount of cuts or welds before a user must replace them. Thus, consumables with longer lifespans may save time for a user since a user can continue cutting or welding operations without changing consumables. Additionally, consumables with longer lifespans may provide costs savings for users since a user will not need to purchase replacement consumables as frequently. Thus, consumables with improved lifespans are continuously desired.

<CIT> aims to prolong the electrode lifetime of plasma machining electrodes having a hafnium or zirconium insert. <CIT> discloses an electrode for a contact start plasma arc torch which includes an elongated electrode body formed of an electrically conductive material. <CIT> discloses an arc plasma torch with the same cooling means for electrodes. <CIT> discloses an electrode for use in a plasma arc torch. <CIT> discloses an air cooled, retract-start plasma cutting torch. <CIT> discloses an electrode for a plasma arc torch, the electrode including a conductive body, a plurality of deformed emissive inserts, and a dimple. <CIT> discloses a plasma torch having an electrode with a frustoconical end portion. The electrode is received by a plunger during a contact start sequence of the plasma torch and is self-releasing from the torch.

The present disclosure is directed towards consumables for cutting torches. The consumables presented herein define a parallel plasma channel and a steep, elongated plasma chamber. Additionally, the consumables may define smooth, rounded edges between different geometries of the plasma channel (e.g., at transitions between straight and angles sections) and/or between the plasma channel and the plasma chamber. That is, the consumables may provide a plasma channel that does not converge, diverge, or define any corners and/or a plasma channel that transitions to the plasma chamber without defining any corners.

The parallel plasma channel smooths the flow of gas through the plasma channel. Consequently, the plasma gas can be supplied to the consumables at lower pressures than it would otherwise be provided to consumables without these features (e.g., as compared to consumables that defines corners or edges in a plasma channel). Lower gas pressures may create less wear on the consumables, for example by slowing depletion of an emissive insert included in an electrode, and thus, may increase the lifespan of the consumables. Additionally, the lower pressure may decrease gas consumption during cutting, providing further cost savings for a user, among other advantages. Still further, a steeper and/or elongated plasma chamber may encourage plasma gas to flow downwards to the orifice to assist with shielding and constricting an arc, providing further efficiency and cut quality enhancements.

According to a first embodiment of the present invention there is provided a set of consumables for a plasma arc torch assembly as recited in claim <NUM>.

Other systems, methods, features and advantages will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. All such additional systems, methods, features and advantages are included within this description, are within the scope of the claimed subject matter.

The consumables for a plasma arc torch presented herein may be better understood with reference to the following drawings and description. It should be understood that the elements in the figures are not necessarily to scale and that emphasis has been placed upon illustrating the principles of the consumables. In the figures, like-referenced numerals designate corresponding parts throughout the different views.

A consumable stack for cutting torches and/or individual consumables for a consumable stack intended for cutting torches are presented herein. The consumables presented herein define a parallel plasma channel and a steep, elongated plasma chamber. Additionally, the consumables may define smooth, rounded edges between different geometries of the plasma channel (e.g., at transitions between straight and angles sections) and/or between the plasma channel and the plasma chamber. That is, the consumables may provide a plasma channel that does not converge, diverge, or define any corners and/or a plasma channel that transitions to the plasma chamber without defining any corners (i.e., a plasma channel with a constant width).

<FIG> illustrates an example embodiment of a manual cutting system <NUM> that may utilize the consumable components presented herein. At a high-level, the manual cutting system <NUM> includes a power supply <NUM> and a torch assembly <NUM>. The power supply <NUM> is configured to supply (or at least control the supply of) power and gas to a torch <NUM> included in the torch assembly <NUM> via torch lead <NUM> (also referred to as cable hose <NUM>). For example, the power supply <NUM> may meter a flow of gas received from a gas supply <NUM>, which the power supply <NUM> receives via cable hose <NUM>, before or as the power supply <NUM> supplies gas to the torch <NUM> via cable hose <NUM>.

The manual cutting system <NUM> also includes a working lead assembly <NUM> with a grounding clamp <NUM> that is connected to the power supply by a work lead <NUM> (also referred to as cable hose <NUM>). As illustrated, cable hose <NUM>, cable hose <NUM>, and cable hose <NUM> may each be any length. Moreover, each end of cable hose <NUM>, cable hose <NUM>, and cable hose <NUM> may be connected to components of the manual cutting system <NUM> via any connectors now known or developed hereafter (e.g., via releasable connectors). For example, torch <NUM> may be connected to a distal end of cable hose <NUM> via a quick disconnect connector <NUM> and power supply <NUM> may be connected to a proximal end of cable hose <NUM> via a quick disconnect connector <NUM>.

<FIG> illustrates the torch assembly <NUM> of <FIG> independently from the power supply <NUM>. As can be seen, the torch <NUM> includes a torch body <NUM> that extends from a first end <NUM> (e.g., a connection end <NUM>) to a second end <NUM> (e.g., an operating or operative end <NUM>). The torch body <NUM> may also include a trigger <NUM> that allows a user to initiate cutting operations in any manner now known or developed hereafter (e.g., in a 2T or 4T mode). As mentioned above, the connection end <NUM> of the torch body <NUM> may be coupled (in any manner now known or developed hereafter) to one end of lead <NUM> Meanwhile, the operative end <NUM> of the torch body <NUM> may receive interchangeable components, such as consumable components that facilitate cutting operations. The consumable stack presented herein, which is depicted installed on torch <NUM> in <FIG>, is generally referred to as consumable stack <NUM> in <FIG>; however, this is merely representative of a consumable stack that includes the features presented herein (which are also shown in consumable stack <NUM> and consumable stack <NUM>).

<FIG> illustrates an example embodiment of an automated cutting head <NUM> that may utilize the consumable components presented herein. As can be seen, the cutting head <NUM> includes a body <NUM> that extends from a first end <NUM> (e.g., a connection end <NUM>) to a second end <NUM> (e.g., an operating or operative end <NUM>). The connection end <NUM> of the body <NUM> may be coupled (in any manner now known or developed hereafter) to an automation support structure (e.g., a cutting table, robot, gantry, etc.) and conduits <NUM> extending therefrom may be coupled to like conduits in the automation support structure to connect the automated cutting head <NUM> to a power supply, a gas supply, a coolant supply, and/or any other components supporting automated cutting operations. Meanwhile, the operative end <NUM> of the body <NUM> may receive interchangeable components, such as consumable components that facilitate cutting operations. The consumable stack presented herein, which is depicted installed on automated cutting head <NUM> in <FIG>, is generally referred to as consumable stack <NUM> in <FIG> (like in <FIG>); however, again, this is merely representative of a consumable stack that includes the features presented herein (which are also shown in consumable stack <NUM> and consumable stack <NUM>).

For simplicity, <FIG>, <FIG>,and <FIG> do not illustrate an interior of torch body <NUM> or body <NUM>. However, it is to be understood that any unillustrated components that are typically included in a torch, such as components that facilitate welding or cutting operations, may (and, in fact, should) be included in a torch configured in accordance with an example embodiment of the present invention. Additionally, none of <FIG>, <FIG>, and <FIG>, nor the remaining figures, illustrate connections between the bodies <NUM>/<NUM> and the consumable stack <NUM> in detail; however, it should be understood that a consumable stack including the features or components presented therein, or components thereof, may be secured or affixed to the torch body <NUM> and/or body <NUM> in any desirable manner. For example, the consumable stack, or components thereof, could be coupled to a torch by mating threaded sections included on the torch body <NUM> or body <NUM> with corresponding threads included on one or more components of the consumable stack <NUM> (or of consumable stack <NUM>, consumable stack <NUM>, or another embodiment).

Now turning to <FIG>, this Figure illustrates a first example embodiment of a consumable stack <NUM> including the features presented herein. As can be seen in <FIG>, which is juxtaposed with the prior art consumable stack <NUM> illustrated in <FIG>, consumable stack <NUM> includes a similar overall structure to the prior art consumable stack <NUM>, but a number of different features (e.g., different geometries). For example, consumable stack <NUM> includes an electrode <NUM>, a nozzle <NUM>, a shield swirl ring <NUM>, and a shield <NUM> that define a plasma gas channel <NUM>, an elongated plasma chamber <NUM>, and a shield gas channel <NUM>. However, and perhaps most notably, the plasma gas channel <NUM> and the elongated plasma chamber <NUM> are geometrically different from the plasma gas channel <NUM> and the plasma chamber <NUM> of the prior art consumable stack <NUM>. This is, the electrode <NUM> and the nozzle <NUM> including different geometries than electrode <NUM> and nozzle <NUM> and, thus, define a plasma gas channel <NUM> and an elongated plasma chamber <NUM> that are geometrically different from the plasma gas channel <NUM> and the plasma chamber <NUM>.

More specifically, and now referring to <FIG> in combination with <FIG>, in consumable stack <NUM>, the electrode <NUM> includes a main body <NUM> that includes an internal surface <NUM> and an external surface <NUM>. The internal surface <NUM> defines an internal chamber <NUM> that may receive and circulate coolant to cool the electrode <NUM> (see <FIG>). The external surface <NUM> extends from a proximal end <NUM> of the electrode <NUM> to a distal end <NUM> of the electrode <NUM> (see <FIG>). A flange <NUM> extends from the proximal end <NUM> and facilitates attachment of the electrode <NUM> to torch <NUM> and/or other consumables in any manner now known or developed hereafter. The flange <NUM> may also define, or at least partially define, gas channels within the consumable stack <NUM> in any manner now known or developed hereafter. Meanwhile, a distal end portion <NUM> extends from the distal end <NUM> of the electrode <NUM> and cooperates with the nozzle <NUM> to define the plasma gas channel <NUM> and the elongated plasma chamber <NUM> (see <FIG>).

First, and now turning back to <FIG>, but with continued reference to <FIG>, the external surface <NUM> of the distal end portion <NUM> cooperates with the nozzle <NUM> to define the plasma gas channel <NUM>. The external surface <NUM> of electrode <NUM> is similar to the external surface <NUM> of the electrode <NUM> from the prior art consumable stack <NUM> in that it includes a longitudinal portion <NUM> and a tapered portion <NUM>. In fact, in the depicted embodiment, the tapered portion <NUM> is a truncated cone with a taper angle A3 in the range of <NUM>° to <NUM>°, <NUM>° to <NUM>°, or even <NUM>° to <NUM>° with respect to the longitudinal portion <NUM> (like tapered portion <NUM>). For example, the tapered portion <NUM> may have a taper angle A3 of approximately <NUM>°. Consequently, the exterior surface of the tapered portion <NUM> is a linear, but angled, surface. However, in other embodiments, the tapering might include multiple taper angles, curvature, or any desired tapering (i.e., narrowing) from its upstream edge (the edge adjacent transition portion <NUM>) to its downstream edge (the edge adjacent distal end face <NUM>).

However, and in contrast with tapered portion <NUM>, the tapered portion <NUM> is not connected to the longitudinal portion <NUM> at a hard edge. Instead, a transition portion <NUM> connects the longitudinal portion <NUM> to the tapered portion <NUM> and forms a smooth, rounded transition therebetween. That is, the transition portion <NUM> has an upstream edge <NUM> that provides a tangential transition (i.e., connects tangentially) to the longitudinal portion <NUM> and a downstream edge <NUM> that provides a tangential transition (i.e., connects tangentially) to the tapered portion <NUM>.

As is illustrated in <FIG>, in at least some embodiments, the transition portion <NUM> has a constant radius R1 in the range of <NUM> to <NUM> (<NUM> inches (in. ) to <NUM> in. ), the range of <NUM> tp <NUM> (<NUM> in. to <NUM> in. ), or the range of <NUM> to <NUM> (<NUM> in to <NUM> in. For example, transition portion <NUM> may have a constant radius R1 of approximately <NUM> (<NUM> inches). However, in other embodiments, the transition portion <NUM> may be a portion of an ellipse or otherwise have a changing radius of curvature, provided it provides a smooth, rounded transition between the longitudinal portion <NUM> and the tapered portion <NUM>. That is, the transition portion <NUM> may have any desirable convex curvature to provide a smooth, rounded transition between the longitudinal portion <NUM> and the tapered portion <NUM>. The smooth, rounded transition to the tapered portion <NUM> may reduce turbulence in a boundary layer of gas flowing along the plasma gas channel <NUM> from the longitudinal portion <NUM> to the tapered portion <NUM>. The reduced turbulence improves flow and allows the gas pressure of the plasma gas to be reduced as compared to the pressure of gas used with consumables that define a plasma gas channel that generates a turbulent boundary layer. This will increase the lifespan of the consumables while also reducing gas consumption.

Still referring to <FIG> in combination with <FIG>, as mentioned, the distal end portion <NUM> also cooperates with the nozzle <NUM> to define the elongated plasma chamber <NUM>. Specifically, the distal end portion <NUM> includes a distal end face <NUM> that cooperates with the nozzle <NUM> to define the elongated plasma chamber <NUM>. The distal end face <NUM> is centered on an emissive insert cavity <NUM> that is sized and shaped to receive an emissive insert (e.g., hafnium or tungsten) in any manner now known or developed hereafter. Additionally, the distal end face <NUM> is bounded by a hard edge <NUM>, which has an angle defined by the taper angle A3 of the tapered portion <NUM> (since the distal end face <NUM> is a substantially flat face that extends perpendicular to the longitudinal axis of the consumable stack <NUM>). For example, if measured interiorly (e.g., within the electrode <NUM>), an angle between the tapered portion <NUM> and the distal end face <NUM> may be the taper angle A3 plus <NUM>°, so that, for example, if taper angle A3 measures <NUM>°, the hard edge may have an interior angle of <NUM>°. Thus, based on the ranges of the taper angle A3 laid out above, the hard edge <NUM> may have an interior angle in the range in the range of <NUM>° to <NUM>°, the range of <NUM>° to <NUM>°, or even the range of <NUM>° to <NUM>°.

The hard edge <NUM> generally defines a circumference C1 of the distal end face <NUM>; however, the hard edge <NUM> need not define a complete or continuous circumference. For example, in the depicted embodiment, grooves <NUM> extend through the hard edge <NUM> so that the hard edge <NUM> defines a number of arc portions of the circumference C1 of the distal end face <NUM>. Nevertheless, the hard edge <NUM> generally defines the bounds of the distal end face <NUM>, which may have a diameter in the range of <NUM> in. to <NUM> in. (<NUM> to <NUM>), the range of <NUM> in. to <NUM> in. (<NUM> to <NUM>), or the range of <NUM> in to in. (<NUM> to <NUM>), such as approximately <NUM>. In the depicted embodiments, four grooves <NUM> are shown spaced around circumference C1; however, in other embodiments, any number of grooves <NUM> might be spaced around circumference C1.

As can be seen in <FIG>, which is a sectional view taken through two of grooves <NUM>, each of the grooves <NUM> provides a break in the hard edge <NUM> and a bottom of each of the grooves <NUM> provides a secondary tapered section <NUM> between the tapered portion <NUM> and the distal end face <NUM>. The secondary tapered section <NUM> extends radially inwardly of the hard edge <NUM> and, thus, in the sectional view of <FIG>, the distal end face <NUM> appears smaller than its circumference C1. The second tapered section <NUM> may have a taper angle A5 that is shallower (e.g., less than) the taper angle A3 of the tapered portion <NUM>. For example, taper angle A5 may be in the range of <NUM>° to <NUM>°, the range of <NUM>° to <NUM>°, or even the range of <NUM>° to <NUM>°, such as approximately <NUM>°. The shallow taper angle A5 may serve to, in essence, meter plasma gas towards an emissive insert disposed in emissive insert cavity <NUM> and generate a high-quality arc while preserving the life of the electrode <NUM>.

Still referring to <FIG>, but now in combination with <FIG>, the nozzle <NUM>, which may also referred to as tip <NUM>, has a main body <NUM> that extends from a proximal end <NUM> to a distal end <NUM>. The proximal end <NUM> has a flange <NUM> that facilitates attachment of the nozzle <NUM> to torch <NUM> and/or other consumables in any manner now known or developed hereafter. The flange <NUM> may also define, or at least partially define, gas channels within the consumable stack <NUM> in any manner now known or developed hereafter. The main body <NUM> also includes an outer surface <NUM> and an inner surface <NUM>, as shown in at least <FIG>. The inner surface <NUM> defines an interior chamber <NUM> that is sized to receive the electrode <NUM>. In particular, the interior chamber <NUM> is sized to receive the electrode <NUM> while maintaining spacing between the main body <NUM> of the electrode <NUM> and the main body <NUM> of the nozzle <NUM> so that the plasma gas channel <NUM> and the elongated plasma chamber <NUM> can be formed or defined therebetween.

Generally, the inner surface <NUM> of the nozzle <NUM> mirrors or mimics the shape of the external surface <NUM> of the electrode <NUM>. That is, at least a portion of the inner surface <NUM> of the nozzle <NUM> is contoured to be parallel to the external surface <NUM> of the electrode <NUM>. To that end, the inner surface <NUM> includes a longitudinal section <NUM>, a rounded section <NUM>, and a tapered section <NUM>. As is shown in <FIG>, installing the nozzle <NUM> around the electrode <NUM> causes: (<NUM>) the longitudinal section <NUM> of the nozzle <NUM> to mirror at least a portion of the longitudinal portion <NUM> of the electrode <NUM>; (<NUM>) the rounded section <NUM> of the nozzle <NUM> to mirror the transition portion <NUM> of the electrode <NUM>; and (<NUM>) at least a portion of the tapered section <NUM> of the nozzle <NUM> to mirror the tapered portion <NUM> of the electrode <NUM>. This creates a plasma gas channel <NUM> with parallel walls and a constant width perpendicular to those walls.

Notably, the rounded section <NUM> of the nozzle <NUM> does not extend above or below the transition portion <NUM> of the electrode <NUM> and, thus, no corners are formed or defined along the boundaries of the plasma gas channel <NUM>. Instead, an upstream edge <NUM> of the rounded section <NUM> is longitudinally aligned with the upstream edge <NUM> of the transition portion <NUM> of the electrode <NUM> and a downstream edge <NUM> of the rounded section <NUM> is longitudinally aligned with the downstream edge <NUM> of the transition portion <NUM> of the electrode <NUM>. In turn, this alignment aligns the longitudinal section <NUM>, the rounded section <NUM>, and the tapered section <NUM> of the nozzle <NUM> with the longitudinal portion <NUM>, the transition portion <NUM>, and the tapered portion <NUM> of the electrode <NUM>, respectively.

This alignment ensures that the plasma gas channel <NUM> does not include or define any corners or irregular boundaries that might create turbulence (i.e., separate flow). By comparison, in the prior art consumable stack <NUM> of <FIG>, the rounded section <NUM> of the nozzle <NUM> of extends above the tapered portion <NUM> of the electrode <NUM>, which creates a corner in the plasma channel <NUM>. Moreover, the rounded section <NUM> of the nozzle <NUM> is similar to the transition portion <NUM> of the electrode <NUM> in that in provides a smooth, rounded transition. That is, the upstream edge <NUM> of the rounded section <NUM> provides a tangential transition (i.e., connects tangentially) to the longitudinal section <NUM> of the inner surface <NUM> of the nozzle <NUM> and the downstream edge <NUM> of the rounded section <NUM> provides a tangential transition (i.e., connects tangentially) to the tapered section <NUM>.

The rounded section <NUM> may have a radius R2 that matches the radius R1 of the transition portion <NUM> of the electrode <NUM>. Thus, in at least some embodiments, R2 may be a constant radius in the range of <NUM> in. to <NUM> in. (<NUM> to <NUM>), the range of <NUM>. to <NUM> in. (<NUM> to <NUM>), or the range of <NUM> in to in. (<NUM> to <NUM>), such as a constant radius of approximately <NUM> in. Alternatively, in other embodiments, the rounded section <NUM> may be a portion of an ellipse or otherwise have a changing radius of curvature, provided it provides a smooth, rounded transition between the longitudinal section <NUM> and the tapered section <NUM> that matches or mirrors the transition portion <NUM> of the electrode <NUM>. That is, the rounded section <NUM> may have any desirable convex curvature to provide a smooth, rounded transition between the longitudinal section <NUM> and the tapered section <NUM> that matches or mirrors the transition portion <NUM> of the electrode <NUM>. The smooth, rounded transition may cooperate with the transition portion <NUM> of the electrode <NUM> to reduce turbulence gas flowing along the plasma gas channel <NUM>. As mentioned above, a reduction in turbulence may improve flow and allow the gas pressure of the plasma gas to be reduced as compared to the pressure of gas used with consumables that define a plasma gas channel that generates a turbulent boundary layer. This will increase the lifespan of the consumables while also reducing gas consumption.

Still referring to <FIG> in combination with <FIG>, as mentioned, the tapered section <NUM> of the nozzle <NUM> may define a truncated cone with a cone angle that matches a truncated cone shape of the tapered portion <NUM> of the electrode <NUM>. For example, if the tapered portion <NUM> has a taper angle A3 of approximately <NUM>°, the tapered section <NUM> may define an edge-to-edge interior angle A4 of approximately <NUM>°, so that each face of the tapered section <NUM> is sloped approximately <NUM>° with respect to a longitudinal axis. Consequently, an edge-to-edge interior angle A4 may be in the range of <NUM>° to <NUM>°, the range of <NUM>° to <NUM>°, or even the range of <NUM>° to <NUM>° to define sloped surfaces in the range of <NUM>° to <NUM>°, the range of <NUM>° to <NUM>°, or even the range of <NUM>° to <NUM>° to match the angle of the tapered portion <NUM> of the electrode <NUM> (which, as mentioned above, may have a taper angle A3 in the range of <NUM>° to <NUM>°, the range of <NUM>° to <NUM>°, or even the range of <NUM>° to <NUM>° with respect to the longitudinal portion <NUM>). Moreover, although the tapered portion <NUM> and the tapered section <NUM> are illustrated as linear, angled surfaces; both surfaces might include multiple taper angles, curvature, or any other desired tapering (i.e., narrowing) from their upstream edges to their downstream edges, provided that the tapered section <NUM> of the nozzle <NUM> matches (e.g., mirrors or mimics) the tapered portion <NUM> of the electrode <NUM>.

Still referring to <FIG> and <FIG>, the tapered section <NUM> of the nozzle <NUM> may lead to or terminate at an orifice <NUM> defined by a distal end portion <NUM> of the main body <NUM>. In at least some embodiments, such as the embodiments depicted in <FIG>, the tapered section <NUM> is connected to the orifice <NUM> via a stepped portion <NUM> that defines an emissive insert catcher <NUM>. An angled bottom surface <NUM> of the stepped portion <NUM> may have an edge-to-edge interior angle A6 that defines a second taper that is shallower (i.e., less steep) than the taper angle defined by the edge-to-edge interior angle A4 (i.e., angle A6 may be greater than angle A4, creating less slope). For example, interior angle A6 may be in the range of <NUM>° to <NUM>°, the range of <NUM>° to <NUM>°, or even the range of <NUM>° to <NUM>° to define sloped surfaces in the range of <NUM>° to <NUM>°, the range of <NUM>° to <NUM>°, or even the range of <NUM>° to <NUM>°, provided A6 is larger than A4. As a specific example, if edge-to-edge interior angle A4 is approximately <NUM>°, edge-to-edge interior angle A6 may be approximately <NUM>°.

Still referring to <FIG> and <FIG>, as mentioned, the distal end face <NUM> of the electrode <NUM> and the tapered section <NUM> of the nozzle <NUM> define or bound, at least in part, the elongated plasma chamber <NUM>. Specifically, a portion of the tapered section <NUM> of the nozzle <NUM> (e.g., a second portion of the tapered section <NUM>) may extend beyond the distal end face <NUM> of the electrode <NUM> to define at least a portion of the lateral boundaries of the elongated plasma chamber <NUM>. Meanwhile, the distal end face <NUM> of the electrode <NUM> may define a top of the elongated plasma chamber <NUM>.

As mentioned, the emissive insert catcher <NUM> may, at least for the purposes of this application, be considered part of the elongated plasma chamber <NUM>. Thus, a height H4 of the elongated plasma chamber <NUM> may be measured as the distance between the distal end face <NUM> of the electrode <NUM> and a bottom <NUM> of the emissive insert catcher <NUM>. The height H4 of the elongated plasma chamber <NUM> may be in the range of <NUM> in. to <NUM> in. , such as approximately <NUM> in. , and may be elongated as compared to the height H1 of the plasma chamber <NUM> of the prior art consumable stack <NUM> shown in <FIG>, which may be in the range of <NUM> in. to <NUM> in. , such as approximately <NUM> in.

The steep angle of the tapered section <NUM> (defined by angle A4) may be the primary driver of the elongation of the elongated plasma chamber <NUM>, but the tapered section <NUM> does not only elongate the elongated plasma chamber <NUM>. Due to its steep angle, the tapered section <NUM> also reduces the amount of plasma gas that is diverted axially as it enters the plasma chamber <NUM>. That is, since the tapered section <NUM> is steep, plasma gas moving from the plasma gas channel <NUM> to the plasma chamber <NUM> can continue flowing primarily longitudinally and only a minimal portion of the plasma gas will be diverted axially, which will smooth the flow of plasma gas.

By comparison, when a plasma chamber has a lateral wall with a shallow angle, like the tapered section <NUM> of the nozzle <NUM> from the prior art consumable stack <NUM>, which has a taper angle A2 of approximately <NUM> degrees, approximately half of the plasma gas flow is diverted axially, creating turbulence in the plasma gas that reduces consumable lifespan. Moreover, a tapered section <NUM> with a steep, constant taper angle does not create any boundary irregularities (e.g., corners) that might generate turbulence. That is, since the tapered section <NUM> of the nozzle <NUM> is, in at least some embodiments, linear with a steep taper angle, it will encourage or funnel plasma gas towards the orifice <NUM>. Generally, a smaller taper angle might allow flow to converge slower than the flow would converge with a larger taper angle that might abruptly alter a direction of flow.

Still referring to <FIG> and <FIG>, the consumables included in stack <NUM> may also elongate the emissive insert catcher <NUM> and shorten the orifice, at least as compared to the prior art consumable stack <NUM> shown in <FIG>. That is, the emissive insert catcher <NUM> may have a height H5, measured from a bottom <NUM> of the emissive insert catcher <NUM> to a top <NUM> of the emissive insert catcher <NUM>, that is longer than the height H2 of the emissive insert catcher <NUM> of the prior art consumable stack <NUM> shown in <FIG>. The height H5 may be in the range of <NUM> in. to <NUM> in. (<NUM> to <NUM>), such as approximately <NUM> in. Meanwhile, the orifice <NUM> may have a height H6, measured from a distal end surface <NUM> of the distal end portion <NUM> of the nozzle <NUM> to the bottom <NUM> of the emissive insert catcher <NUM>, that is shorter than the height H3 of the orifice <NUM> of the prior art consumable stack <NUM> shown in <FIG>. The height H6 may be in the range of <NUM> in. to <NUM> in. (<NUM> to <NUM>), such as approximately <NUM> in. (<NUM> to <NUM>.

Among other advantages, lengthening the emissive insert catcher <NUM> may smooth flow approaching the orifice <NUM>. This is because the lengthened emissive catcher <NUM> elongates the space in which air flow may merge or condense before flowing through the orifice <NUM>, which defines a smaller, more restrictive passageway than areas above the orifice <NUM>. Increasing the space for convergence may smooth the flow. Meanwhile, shortening the orifice <NUM> may provide improved thermal management because a smaller surface area is exposed to the arc; however, the decrease in surface area must also be balanced against heat resistance concerns.

Now turning back to <FIG> alone, in various embodiments, the depicted electrode <NUM> and nozzle <NUM>, as well as variations thereof, may be connected to, assembled with, or otherwise used with any number of other components. For example, the electrode <NUM> and/or the nozzle <NUM> may be included in a cartridge (e.g., a cartridge that cannot be disassembled) with other consumable components and/or non-consumable components. Alternatively, as another example, electrode <NUM> and/or the nozzle <NUM> could be sold and/or manufactured as individual components and could be installable onto torch <NUM> with any other consumable components and/or non-consumable components. In <FIG>, the electrode <NUM> and the nozzle <NUM> are shown with a shield swirl ring <NUM> and a shield <NUM>.

The shield swirl ring <NUM> includes an outer surface <NUM> that can be aligned with a shield gas supply and/or a shield gas passageway and an inner surface <NUM> that is connected to the outer surface <NUM> via swirl holes <NUM>. The shield <NUM> sits around the shield swirl ring <NUM> and the nozzle <NUM>, and has an inner surface <NUM> that is spaced from an outer guide surface <NUM> of the nozzle <NUM> to define a shield gas channel <NUM> that can receive gas from the shield swirl ring <NUM>. The shield <NUM> also defines an orifice <NUM> and an outer surface <NUM>. The outer surface <NUM> may protect the nozzle <NUM> from molten splatter during cutting and the orifice <NUM> may align, but be radially larger than, the orifice <NUM> of the nozzle <NUM> to allow plasma to exit the elongated plasma chamber <NUM> via the orifice <NUM> while protected and/or constricted by shield gas exiting shield gas channel <NUM>.

Now turning to <FIG> and <FIG>, the figures illustrate second and third example embodiments of consumable stacks incorporating the features described herein. In particular, <FIG> illustrates consumable stack <NUM> while <FIG> illustrates consumable stack <NUM>. Consumable stack <NUM> and consumable stack <NUM> are substantially similar to consumable stack <NUM> and, thus, for brevity, only differences between these embodiments are described in detail below (with different structural features being labeled with new part numbers or prime part numbers in the figures). However, any description consumable stack <NUM> should be understood to like aspects of consumable stacks <NUM> and <NUM> (e.g., parts labeled with the same part numbers) and the descriptions of consumable stacks <NUM>, <NUM>, and <NUM> are not intended to limit the consumables presented herein in any manner. Instead, consumable stacks <NUM>, <NUM>, and <NUM> are presented and described herein to provide non-limiting examples of consumables incorporating the features that are presented herein.

With that said, in <FIG>, the consumable stack <NUM> only includes an electrode <NUM>' and a nozzle <NUM>' that are largely similar to electrode <NUM> and nozzle <NUM>. Two of the main differences between these embodiments, if not the only differences, are the height of the emissive insert catcher and a length of a curved portion of the plasma channel. First, in consumable stack <NUM>, the elongated plasma chamber <NUM>' still has a height H4 (and, thus, orifice <NUM> still has a height H6), but the elongated plasma chamber <NUM>' of consumable stack <NUM> has an emissive insert catcher <NUM>' that is shorter that the emissive insert catcher <NUM> of consumable stack <NUM>. That is, the emissive insert catcher <NUM>' has a height H8 that is smaller than H5 (see <FIG>). For example, height H8 may be in the range of <NUM> in. to <NUM> in. (<NUM> to <NUM>), such as approximately <NUM> in.

Second, in consumable stack <NUM>, the transition portion <NUM>' of the external surface <NUM> of the electrode <NUM>' and the rounded section <NUM>' of the inner surface <NUM> of the nozzle <NUM>' have a radius R3 that is smaller than the radii R1 and R2 of the like portions depicted in <FIG>. For example, radius R3 may be in the range of <NUM> in. to <NUM> in. (<NUM> to <NUM>), such as approximately <NUM> in. This shortens the overall length of the curved portion of the plasma channel <NUM>' defined by transition portion <NUM>' and the rounded section <NUM>' (thereby lengthening the tapered portion of the plasma channel <NUM>' defined by the tapered portion <NUM> of the electrode <NUM> and the tapered section <NUM> of the nozzle <NUM>). However, with these dimensions, the plasma channel <NUM>' is still defined by parallel walls that define a constant width and encourage smooth flow along the length of the plasma channel <NUM>'. Put another way, the transition portion <NUM>' and the rounded section <NUM>' each still have upstream edges <NUM> and <NUM> that provides a tangential transition (i.e., connect tangentially) to longitudinal portion <NUM> and longitudinal section <NUM> , respectively. Additionally, the transition portion <NUM>' and the rounded section <NUM>' each still have downstream edges <NUM> and <NUM> that provide a tangential transition (i.e., connect tangentially) to tapered portion <NUM> and tapered section <NUM>, respectively.

Meanwhile, in <FIG>, the consumable stack <NUM> includes more components than are shown in consumable stack <NUM> or consumable stack <NUM>, but still includes at least a portion, if not all of, the advantageous features described herein. For example, consumable stack <NUM> includes the electrode <NUM>' from the embodiment illustrated in <FIG> and includes a nozzle <NUM>" with an inner surface <NUM> that mirrors (i.e., runs parallel to) to the external surface <NUM> of the electrode <NUM>' to define a parallel plasma chamber <NUM>' with a constant width. However, the main difference of this embodiment as compared to the embodiments described above, if not the only difference, is that nozzle <NUM>" does not include a stepped portion to define a emissive insert catcher (e.g., like the stepped portion <NUM> that defines emissive insert catcher <NUM>). Instead, the tapered section <NUM> of the inner surface <NUM> of the nozzle <NUM> extends directly from the rounded section <NUM>' to the orifice <NUM>.

Consequently, the elongated plasma chamber <NUM>" is defined within the tapered section <NUM>", above a top <NUM> of the orifice <NUM>, and beneath the distal end face <NUM> of the electrode <NUM>'. In the depicted embodiments, the elongated plasma chamber <NUM>" still has a height H4 that is identical to the heights of elongated plasma chambers <NUM> and <NUM>' and still has a steep lateral boundary wall defined by tapered section <NUM>. However, in other embodiments, the height can differ depending on the taper angle A3 of the tapered section <NUM>".

Typically, nozzles define an emissive insert catcher to limit the amount of an emissive insert that is secreted from the electrode; however, since the features presented herein (e.g., parallel plasma channel, rounded edges, etc.) allow for a reduction in plasma gas pressure through the plasma channel and plasma chamber, emissive insert secretion is reduced with the geometry of the consumables. Thus, this may eliminates the need for an emissive insert catcher, which may reduce the cost of manufacturing the nozzle (since the emissive insert catcher is typically formed with numerous, precise machining operations). Additionally, the elimination of the emissive insert catcher, as shown in <FIG>, may reduce the number of features on the nozzle that might wear or fail and, thus, may extend the lifespan of the nozzle.

Other than this difference, consumable stack <NUM> also includes additional components as compared to consumable stacks <NUM> and <NUM>. In particular, consumable stack <NUM> includes an insulator <NUM> disposed between the nozzle <NUM>' and the shield swirl ring <NUM>. Additionally, consumable stack <NUM> includes a nozzle swirl ring <NUM> disposed between the proximal end <NUM> of the nozzle <NUM>' and the proximal end <NUM> of the electrode <NUM>'. The nozzle swirl ring <NUM> includes an outer surface <NUM> can be aligned with a supply of plasma gas and/or a plasma gas passageway. Additionally, the nozzle swirl ring <NUM> includes swirl holes <NUM> that allow plasma gas to move through the nozzle swirl ring <NUM>, from the outer surface <NUM> to an inner surface <NUM> of the nozzle swirl ring <NUM>. Thus, the nozzle swirl ring <NUM> directs plasma gas into the plasma channel <NUM>' and towards plasma chamber <NUM>". However, as mentioned, these components are merely examples of additional components that could be connected to, assembled with, or otherwise used with the nozzles and electrodes presented herein. In other embodiments, any combination of components, whether consumable or non-consumable could be used on combination with the nozzles and electrodes presented herein (or other nozzles and/or electrodes including the features presented herein).

As demonstrated herein, the consumables presented herein provide a number of advantages. For example, since the consumable stack defines parallel plasma channel with the rounded transitions, the consumable stack may smooth gas flow through the plasma channel. Consequently, plasma gas can be supplied to the consumables at lower pressures than it might be provided to similar consumables without these features (e.g., as compared to consumables that defines corners or edges in a plasma channel). Lower gas pressures may create less wear on the consumables, for example by depleting an emissive insert included in an electrode at a slower rate, and, thus, may increase the lifespan of the consumables. For example, the consumables presented herein may allow for <NUM> amps (A) cutting at a pressure of <NUM> pounds per square inch (psi) while many known consumables cutting at <NUM> A require <NUM> psi.

Additionally, the lower pressure may decrease gas consumption during cutting, providing further cost savings for a user, among other advantages. Moreover, a steeper and/or elongated plasma chamber may encourage plasma gas to flow downwards to the orifice to assist with shielding and constricting an arc, providing further efficiency enhancements. Thus, the consumables may also improve cut quality and/or cut faster, each of which provides savings in terms of cost and time (cutting faster and/or at higher quality allows more cuts before expiration of the life of a consumable, thereby saving cost and/or time). For example, in at least some embodiments, the consumables presented herein may cut ¾ inch inch (<NUM>) mild steel at a rate in the range of <NUM> in. /minute(min. ) to <NUM> in. /min (<NUM>/min to <NUM>/min).

While the consumables presented herein have been illustrated and described in detail and with reference to specific embodiments thereof, it is nevertheless not intended to be limited to the details shown, since it will be apparent that various modifications and structural changes may be made therein without departing from the scope of the claims which define the invention. For example, as mentioned, the consumables presented herein may be modified to connect to or be used with any other desired consumable or non-consumable components, whether to build a unitary cartridge (i.e., a cartridge that cannot be disassembled) or to form a consumable stack from discrete components. Additionally, the consumables presented herein may be suitable for automated (e.g., mechanized) and/or manual (e.g., handheld) cutting.

In addition, various features from one of the embodiments may be incorporated into another of the embodiments. That is, it is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in a preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions, and/or properties disclosed herein. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure as set forth in the following claims.

It is also to be understood that terms such as "left," "right," "top," "bottom," "front," "rear," "side," "height," "length," "width," "upper," "lower," "interior," "exterior," "inner," "outer" and the like as may be used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration. Further, the term "exemplary" is used herein to describe an example or illustration. Any embodiment described herein as exemplary is not to be construed as a preferred or advantageous embodiment, but rather as one example or illustration of a possible embodiment of the invention. Additionally, it is also to be understood that the consumables described herein, or portions thereof may be fabricated from any suitable material or combination of materials, such as plastic or metals (e.g., copper, bronze, hafnium, etc.), as well as derivatives thereof, and combinations thereof.

Claim 1:
A set of consumables for a plasma arc torch assembly, comprising:
an electrode (<NUM>,<NUM>') including a main body (<NUM>) that extends between a proximal end (<NUM>) and a distal end (<NUM>) with a distal end face (<NUM>), the distal end face (<NUM>) being substantially flat and perpendicular to a longitudinal axis of the electrode (<NUM>,<NUM>'), the main body including an external surface (<NUM>), comprising:
a longitudinal portion (<NUM>) that is substantially parallel to the longitudinal axis of the electrode (<NUM>,<NUM>');
a tapered portion (<NUM>) that has a constant interior taper angle (A3) in the range of <NUM>° to <NUM>° and extends between the longitudinal portion (<NUM>) and the distal end face (<NUM>); and
a transition portion (<NUM>,<NUM>') that connects the tapered portion (<NUM>) to the longitudinal portion (<NUM>); and
a nozzle (<NUM>,<NUM>') that is installable around the electrode (<NUM>,<NUM>'), the nozzle including a main body (<NUM>) defined, at least in part, by an outer surface (<NUM>) and an inner surface (<NUM>),
wherein:
the transition portion defines a smooth, rounded transition between the longitudinal portion and the tapered portion; and
the inner surface (<NUM>) of the nozzle (<NUM>,<NUM>') is disposed opposite to and mirroring the tapered portion (<NUM>) of the electrode (<NUM>,<NUM>'), opposite to and mirroring the transition portion (<NUM>,<NUM>') of the electrode, and opposite to and mirroring at least a portion of the longitudinal portion (<NUM>) of the electrode (<NUM>, <NUM>') so that the external surface (<NUM>) of the electrode (<NUM>, <NUM>') and the inner surface (<NUM>) of the nozzle (<NUM>, <NUM>') define a plasma gas channel (<NUM>,<NUM>') therebetween having a constant width perpendicular to the external and inner surfaces.