CN106180996B - High accessibility consumables for plasma arc cutting systems - Google Patents

Abstract

The invention discloses a high accessibility consumable for a plasma arc cutting system. A nozzle for a plasma arc torch is provided. The nozzle includes a substantially hollow elongate nozzle body configured to receive an electrode, the body defining a longitudinal axis, a distal end, and a proximal end. The nozzle also includes a vortex sleeve attachable to an inner surface of the nozzle body, the vortex sleeve configured to impart a vortex motion to gas introduced to the nozzle. The nozzle additionally includes a nozzle tip connected to the proximal end of the nozzle body, a nozzle shroud, and insulation configured to connect the nozzle tip and the nozzle shroud so as to electrically insulate the nozzle shroud and the nozzle tip from one another while transferring thermal energy between the nozzle shroud and the nozzle tip.

Description

High accessibility consumables for plasma arc cutting systems

Cross Reference to Related Applications

This application claims the benefit and priority of U.S. provisional patent application No.62/063,703 filed on day 10/14 of 2014 and U.S. provisional patent application No.61/949,609 filed on day 3/7 of 2014. This application is a partial continuation of U.S. patent application serial No. 14/610,011 filed on 30/1/2015, U.S. patent application serial No. 14/610,011 is a partial continuation of U.S. patent application serial No. 14/513,878 filed on 14/10/2014, U.S. patent application serial No. 14/513,878 is a partial continuation of U.S. patent application serial No. 13/570,526 filed on 9/8/2012, and U.S. patent application serial No. 13/570,526 is a partial continuation of U.S. patent application serial No. 13/553,273 filed on 19/7/2012. This application is also a partial continuation of U.S. patent application serial No. 13/229,105 ('105 application) (now U.S. patent 8,981,253) filed 9/2011, and the' 105 application is a partial continuation of U.S. patent application serial No. 12/878,512 (now U.S. patent No.8,624,150) filed 9/2010. The' 105 application is also a partial continuation of U.S. patent application serial No. 13/169,534 (now U.S. patent No.8,153,927) filed on 27.6.2011, the U.S. patent application serial No. 13/169,534 is a continuation of U.S. patent application serial No. 11/611,625 (now U.S. patent No.7,989,727) filed on 15.12.2006, and the U.S. patent application serial No. 11/611,625 claims the benefit and priority of U.S. provisional patent application No.60/825,453 filed on 13.9.2006. The' 105 application is a partial continuation of U.S. patent application serial No. 12/032,630 (now U.S. patent No.8,089,025) filed on 15/2/2008, and U.S. patent application serial No. 12/032,630 claims the benefit and priority of U.S. provisional patent application No.60/901,804 filed on 16/2/2007. The present application further claims the benefit and priority of U.S. patent application serial No. 61/991,114 filed 5,9, 2014. The contents of all of these applications are owned by the assignee of the present application and are incorporated herein by reference in their entirety.

Technical Field

The present disclosure relates generally to thermal cutting torches (e.g., plasma arc torches), and more particularly to plasma torch components and related systems and methods.

Background

Thermal processing torches, such as plasma arc torches, are widely used for high temperature processing (e.g., heating, cutting, gouging, and marking) of materials. A plasma arc torch generally includes a torch body, an electrode mounted within the torch body, an emissive plug disposed within a bore of the electrode, a nozzle mounted within the torch body provided with a central outlet orifice, a shield, electrical connections, passageways for cooling, passageways for an arc control fluid (e.g., plasma gas), and a power supply. A swirl ring can be used to control the pattern of fluid flow in a plasma chamber formed between the electrode and the nozzle. In some torches, a retaining cap is used to retain the nozzle and/or swirl ring in the plasma arc torch. In operation, the torch produces a plasma arc, which is a constricted stream of ionized gas having a high temperature and sufficient momentum to assist in the removal of molten metal. The gas used in the torch can be a non-reactive gas (e.g., argon or nitrogen) or a reactive gas (e.g., oxygen or air).

In cutting or marking a metal workpiece with a plasma arc, a pilot arc is first generated within a torch between an electrode (cathode) and a nozzle (anode). When operating in this pilot arc mode, the electrode may be separated from the nozzle, forming an arc between the electrode and the nozzle, for example, as described in U.S. Pat. No.4,791,268, the contents of which are incorporated herein by reference. The gas passing between the nozzle and the electrode is ionized to form a plasma, which then exits the outlet orifice of the nozzle. The gas can be passed through a swirl ring to impart a tangential motion to the gas as it passes through the torch, thereby improving torch performance. As the torch moves near the workpiece, the arc contacts the workpiece, and the current return path is then diverted from the nozzle to the workpiece. Generally, the torch operates in a transferred plasma arc mode, which is characterized by ionized plasma gas flowing from the electrode to the workpiece, while the current return path is from the workpiece back to the power supply. The plasma so generated may be used to cut, weld, work or imprint a work piece.

In addition to the post-spray operation described above, alternative known techniques include a pre-spray technique, wherein the nozzle is separate from the stationary nozzle. For example, reference is made to U.S. patent No.5,994,663, the contents of which are incorporated herein by reference.

The dimensions of the torch depend on the size and configuration of the consumables (e.g., electrode, swirl ring, nozzle, and shield) described above. The design of these consumables is very technical and has a great impact on torch life and performance. The electrode is generally surrounded by a swirl ring, a nozzle, and in some configurations by a shroud. All of these components, and the manner in which they are designed and combined, can affect the size, configuration, weight, cost, and other parameters of the overall torch.

In addition, the consumable components of the torch (e.g., the electrode, the nozzle, the swirl ring, and the shield) are exposed to high temperatures. Standard torches operate at a high percentage duty cycle without melting torch components and causing other temperature related problems in the torch. Various techniques may be utilized to cool the torch consumables, such as using water spray cooling to cool the nozzle and/or shield, liquid cooling in and/or around the electrode, or vent cooling to cool the shield, as illustrated in U.S. patent No.5,132,512, the contents of which are incorporated herein in their entirety. Plasma arc torch consumables may be even more difficult to cool when the plasma arc torch is operated at high currents (e.g., greater than about 15 amps), and/or when the plasma arc torch is completely gas cooled.

In addition, existing plasma cutting systems include a wide variety of consumables for use with different cutting currents and/or modes of operation. The large number of consumable choices may be confusing to the user and increase the likelihood of using an incorrect consumable. The large number of consumable choices may also result in lengthy setup times for the torch and make it difficult to transition between cutting processes with different requirements for the consumable arrangements.

Plasma arc torches are widely used for processing (e.g., cutting and imprinting) metallic materials. A plasma arc torch generally comprises a torch body, an electrode mounted within the body, a nozzle provided with a central exit orifice, passageways for electrical connections, cooling and arc control fluids, a swirl ring for controlling the fluid flow pattern, and a power supply. The torch produces a plasma arc, which is a constricted stream of plasma gas having high temperature and high momentum. The gas may be a non-reactive gas (e.g., nitrogen or argon), or a reactive gas (e.g., oxygen or air).

When cutting or marking a metal workpiece with a plasma arc, a pilot arc is usually first generated between an electrode (cathode) and a nozzle (anode). The pilot arc ionizes the gas passing through the nozzle exit orifice. After the ionized gas reduces the electrical resistance between the electrode and the workpiece, the arc is then transferred from the nozzle to the workpiece. The torch operates in this transferred plasma arc mode and is characterized by the flow of electronically and electrically conductive ionized gas from the electrode to the workpiece to cut or imprint the workpiece.

Disclosure of Invention

A cartridge-type compound nozzle for a plasma arc cutting system is provided that includes a nozzle body, a swirl sleeve, insulation, a nozzle tip, and a nozzle shield. The composite nozzle may combine and/or eliminate other torch components used in existing plasma torch consumables. For example, a conventional swirl ring may not be required because the composite nozzle may impart a swirl to the gas flow within the torch body.

The cooling capacity of the compound nozzle may be enhanced, manufacturing and material costs may be reduced, and/or the recirculation capacity, durability, and performance may be improved. The compound nozzle may be operated in both a handheld plasma cutting system and a mechanized plasma cutting system. The composite nozzle provides multiple consumable parts in one structure, thus enabling significant reduction in assembly time (e.g., to 1/5-1/10). This integrated design also ensures that the mating parts are properly selected and oriented (e.g., aligned) for a given cutting task, and makes it easier to recognize a set of appropriate consumable components for a given cutting task.

In one aspect, the invention features a nozzle for a plasma arc cutting torch. The nozzle comprises a substantially hollow elongate body capable of receiving an electrode. The nozzle body defines a longitudinal axis and has a length (L) along the axis from a first end of the nozzle body to a second end of the nozzle body. The nozzle also includes a plasma outlet orifice disposed at the first end of the body. The first end of the nozzle body has a width (W), and a ratio of the length of the nozzle body to the width of the nozzle body (L/W) is greater than about 3.

In another aspect, the invention comprises a method of cutting a workpiece. A plasma arc torch is provided having a body containing a flow path for directing a plasma gas through a swirl ring to a plasma chamber where a plasma arc is formed. A nozzle is also provided that is mounted relative to the electrode at the distal end of the torch body so as to define a plasma chamber. The nozzle comprises a substantially hollow elongate body capable of receiving an electrode. The nozzle body defines a longitudinal axis and has a length along the axis from a first end of the nozzle body to a second end of the nozzle body. The nozzle also includes a plasma outlet orifice disposed at the first end of the nozzle body. The first end of the nozzle body has a width, and a ratio of the length of the nozzle body to the width of the nozzle body is greater than about 3. The nozzle also includes at least one supplemental orifice disposed through at least one of an end face or a sidewall of the nozzle. The at least one supplemental orifice is relative to the plasma exit orifice. The plasma arc cutting torch operates at an amperage level of greater than about 15 amps. Substantially all of the cooling gas flows through the at least one supplemental orifice at the distal end of the torch body.

In another aspect, the invention features a nozzle assembly for a plasma arc cutting torch. The nozzle assembly includes a substantially hollow elongated body defining a longitudinal axis and having a length along the axis from a first end of the body to a second end of the body. The nozzle assembly also includes a plasma outlet orifice disposed at the first end of the body. A structure is configured to translatably receive the electrode and is integrally formed with the nozzle body. The structure includes a body having a beveled gas port for providing a swirling plasma gas during operation of the plasma arc cutting torch.

In another aspect, the invention features a method of cutting a workpiece. A nozzle assembly is also provided that is mounted relative to an electrode at a distal end of the torch body so as to define a plasma chamber. The nozzle assembly includes a substantially hollow elongated body defining a longitudinal axis and having a length along the axis from a first end of the body to a second end of the body. The nozzle assembly also includes a plasma outlet orifice disposed at the first end of the nozzle body. The nozzle assembly also includes at least one supplemental orifice disposed through an end face of the nozzle assembly relative to the plasma exit orifice. A structure is configured to translatably receive the electrode and is integrally formed with the nozzle body. The structure includes a body having a beveled gas port for providing a swirling plasma gas during operation of the plasma arc cutting torch. The plasma arc cutting torch operates at an amperage level of at least about 15 amps. Substantially all of the cooling gas flows through the at least one gas outlet.

In another aspect, the invention features an electrode for a high visibility plasma arc cutting torch. The electrode includes an elongated electrode body having a first end and a second end. The electrode body defines a bore in the first end for receiving a plug, and the electrode body includes (i) a first body portion extending from the first end; (ii) a second body portion extending to a second end; and (iii) a heat transfer region positioned relative to the first body portion at the first end of the electrode body. The heat transfer region is in thermal communication with the cooling gas during operation of the plasma torch at a current greater than about 15 amps and is configured to remove a majority of heat generated during operation of the plasma torch from the heat transfer region.

In another aspect, the invention features an electrode for a high visibility plasma arc cutting torch. The electrode includes an elongated electrode body having a first end and a second end. The body defines a bore in the first end for receiving a plug. The electrode body includes: (i) a first body portion extending from the first end; (ii) a second body portion extending to a second end; and (iii) a heat transfer region positioned relative to the first body portion at the first end of the electrode body. The heat transfer area is greater than about 1 square inch.

In another aspect, the invention features a torch tip for a handheld plasma torch. The hand-held plasma torch is provided with a trigger and a torch tip seat. The torch tip includes a substantially hollow nozzle and an electrode positioned relative to the nozzle. A housing is positioned relative to the nozzle and the electrode. The nozzle, electrode, and housing form an assembled torch tip having a distal end and a proximal end. The proximal end of the assembled torch tip is configured to be coupled to a torch tip seat. The distance from the distal end to the proximal end of the assembled torch tip is greater than about 3 inches.

In another aspect, the invention features a torch tip for a handheld plasma torch. The hand-held plasma torch is provided with a trigger and a torch tip seat. The torch tip includes a substantially hollow nozzle and an electrode positioned relative to the nozzle. A housing is positioned relative to the nozzle and the electrode. The nozzle, electrode, and housing form an assembled torch tip having a distal end and a proximal end. The proximal end of the assembled torch tip is configured to be coupled to a torch tip seat. The assembled torch tip defines a longitudinal axis and has a length along the axis from the proximal end to the distal end. The ratio of the length of the assembled torch tip to the width of the assembled torch tip is greater than about 3.

In another aspect, the invention features a method of aligning an electrode in a plasma arc torch. A nozzle assembly is provided. The nozzle assembly includes a substantially hollow elongated body capable of receiving an electrode. The body defines a longitudinal axis and has a length along the axis from a first end of the body to a second end of the body. The nozzle assembly also includes a plasma outlet orifice disposed at the first end of the body. One structure is integrally formed with the nozzle body. The structure includes a body having a beveled gas port for providing a swirling plasma gas during operation of the plasma arc cutting torch. An elongated electrode is disposed within the body of the nozzle. The electrode has a first end and a second end. The electrode body defines a bore in a first end of the electrode for receiving a plug. The bore of the electrode is aligned with the plasma outlet orifice of the nozzle via the structure.

In another aspect, the invention features a method for extending the life of a plasma arc torch. A torch body is provided that includes a plasma gas flow path for directing plasma gas to circulate through a vortex to a plasma chamber to form a plasma arc in the plasma chamber. A nozzle is provided that is mounted relative to an electrode at a distal end of a torch body to define a plasma chamber. The nozzle comprises a substantially hollow elongate body capable of receiving an electrode. The nozzle body has a first end and a second end. The nozzle body also includes a plasma outlet orifice disposed at the first end of the nozzle body, wherein a length of the nozzle body from the first end to the second end is greater than about 2 inches. At least one supplemental orifice is disposed through at least one of an end face or a sidewall of the nozzle. The at least one supplemental orifice is relative to the plasma exit orifice. The plasma arc torch operates at an amperage level of at least about 15 amps. Substantially all of the cooling gas flows through the at least one gas outlet.

In another aspect, the invention features a method for extending the life of a plasma arc torch. A torch body is provided that includes a plasma gas flow path for directing plasma gas to circulate through a vortex to a plasma chamber to form a plasma arc in the plasma chamber. A nozzle is also provided that is mounted relative to the electrode at the distal end of the torch body to define a plasma chamber. The nozzle comprises a substantially hollow elongate body capable of receiving an electrode. The nozzle body defines a longitudinal axis and has a length along the axis from a first end of the nozzle body to a second end of the nozzle body. A plasma outlet orifice is disposed at a first end of the nozzle body. The nozzle body has a length from the first end to the second end greater than about 2 inches. The plasma arc torch operates at an amperage level of at least about 15 amps. Substantially all of the cooling gas flows out of the distal end of the torch body.

In some embodiments, the nozzle further comprises an end face at the first end of the body through which the plasma outlet orifice is disposed, and through which at least one supplemental orifice is disposed relative to the plasma outlet orifice. The at least one supplemental orifice may be chamfered, or the at least one supplemental orifice may be linear/straight. Substantially all of the cooling gas can exit through the at least one supplemental orifice.

The nozzle may also include at least one orifice disposed through the body of the nozzle. The at least one aperture may be chamfered or the at least one aperture may be linear/straight. In some embodiments, the plasma arc torch is air cooled. Substantially all of the cooling gas exits through the at least one orifice.

In some embodiments, the nozzle body comprises at least one supplemental orifice disposed through an end face of the nozzle. The nozzle body may include at least one orifice disposed through the body of the nozzle. In some embodiments, the nozzle body includes at least one supplemental orifice disposed through an end face of the nozzle, and at least one orifice disposed through the body of the nozzle.

The nozzle may also include at least one heat exchange element disposed on the nozzle body and in thermal communication with the cooling gas. The at least one heat exchange element may be disposed on an outer surface of the nozzle body. The at least one heat exchange element may be disposed on an inner surface of the nozzle body.

The length of the nozzle may be greater than about 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inches. In some embodiments, the length of the nozzle is greater than about 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5 inches.

The length to width ratio of the nozzle may be greater than about 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, the nozzle has a length to width ratio greater than about 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5.

In some embodiments, any of the nozzles described herein are used in a plasma arc cutting torch. The plasma arc cutting torch can be a handheld plasma arc cutting torch.

The nozzle assembly may have a length greater than about 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inches. In some embodiments, the length of the nozzle assembly is greater than approximately 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5 inches.

In some embodiments, the nozzle assembly further includes an end face at the first end of the body through which the plasma outlet orifice is disposed, and at least one supplemental orifice disposed through at least one of the end face or the sidewall relative to the plasma outlet orifice. The at least one supplemental aperture may be chamfered. Substantially all of the cooling gas can exit through the at least one supplemental orifice. Structures within the nozzle assembly may be capable of translatably receiving the electrode.

The nozzle assembly may also include at least one heat exchange element disposed on the nozzle body and in thermal communication with the cooling gas. The at least one heat exchange element may be disposed on an outer surface of the nozzle body. The at least one heat exchange element may be disposed on an inner surface of the nozzle body.

The nozzle assembly may also include at least one orifice disposed through the nozzle body. In some embodiments, the nozzle body comprises at least one supplemental orifice disposed through an end face of the nozzle. The nozzle body may include at least one orifice disposed through the body of the nozzle. In some embodiments, the nozzle body includes at least one supplemental orifice disposed through an end face of the nozzle, and at least one orifice disposed through the body of the nozzle.

In some embodiments, any of the nozzle assemblies described herein are used in a plasma arc cutting torch. The plasma arc cutting torch can be a handheld plasma arc cutting torch.

The heat transfer area of the electrode may be greater than about 1 square inch. The heat transfer area may be between about 1 square inch and about 3 square inches.

In some embodiments, any of the electrodes described herein are used in a plasma arc cutting torch. The plasma arc cutting torch can be a handheld plasma arc cutting torch.

In some embodiments, the nozzle and/or the electrode are elongate. The nozzle may have a length along a longitudinal axis extending from a first end of the nozzle and a second end of the nozzle. The length from the first end to the second end of the nozzle may be greater than about 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inches. In some embodiments, the length of the nozzle is greater than about 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5 inches.

The housing can contain an adapter that can extend the distance from the distal end to the proximal end of the assembled torch tip. The distance from the distal end to the proximal end of the assembled torch tip can be greater than about 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inches. In some embodiments, the distance from the distal end to the proximal end of the assembled torch tip can be greater than about 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5 inches.

In some embodiments, the torch tip further comprises at least one heat exchange element disposed on the nozzle and in thermal communication with the cooling gas. The at least one heat exchange element may be disposed on an outer surface of the nozzle. The at least one heat exchange element may be disposed on an inner surface of the nozzle.

In another aspect, the invention features a nozzle for a plasma arc torch. The nozzle comprises a substantially hollow elongate nozzle body capable of receiving an electrode. The body defines a longitudinal axis, a distal end, and a proximal end. The nozzle additionally includes a swirl sleeve that may be attached to the inner surface of the nozzle body. The swirl sleeve is configured to impart a swirling motion to gas introduced to the nozzle. The nozzle also includes a nozzle tip connected to the proximal end of the nozzle body. The nozzle tip includes a nozzle exit orifice for introducing a plasma arc to the workpiece. The nozzle also includes a nozzle shroud and insulation configured to connect the nozzle tip and the nozzle shroud so as to electrically insulate the nozzle shroud and the nozzle tip from one another while still transferring thermal energy between the nozzle shroud and the nozzle tip.

In some embodiments, the nozzle body, swirl sleeve, nozzle tip, nozzle shroud, and insulator are connected via a press fit. In some embodiments, the nozzle comprises a single consumable component of a plasma arc torch. In some embodiments, at least one of the nozzle body, the swirl sleeve, the nozzle tip, or the nozzle shroud comprises a conductive material.

In some embodiments, the nozzle body comprises aluminum. The nozzle body may have a length along the longitudinal axis of about 2.5 to about 3 inches, and a cross-sectional width of about 0.4 to about 0.5 inches.

In some embodiments, the vortex sleeve is slidably attached to the inner surface of the nozzle body from the proximal end. The swirl sleeve may form an interference fit with the nozzle body at a stepped region that is seated on an inner surface of the nozzle body. The vortex sleeve may comprise copper. The vortex sleeve may have a length along the longitudinal axis of about 0.11 to about 0.12 inches.

In some embodiments, the nozzle tip comprises copper. The nozzle tip may occupy approximately 1/2, 1/3, or 1/4 of the length of the nozzle body along the longitudinal axis. The nozzle tip may comprise about 20%, 30% or 40% of the length of the nozzle along the longitudinal axis. The nozzle tip may have a length along the longitudinal axis of about 0.9 to about 1 inch, and a cross-sectional width of about 0.37 to about 0.4 inch.

In some embodiments, the insulation comprises at least one of anodized aluminum or plastic. The insulation may have a length along the longitudinal axis of about 0.3 to about 0.4 inches, and a maximum cross-sectional width of about 0.4 to about 0.5 inches.

In some embodiments, the nozzle shield comprises copper. The nozzle shroud may have a length along the longitudinal axis of about 0.25 to about 0.35 inches, and a maximum cross-sectional width of about 0.4 to about 0.5 inches.

In accordance with another aspect, a plasma arc torch assembly is provided that includes an electrode, a composite nozzle, and a retaining cap. The compound nozzle is configured to substantially surround the electrode. The composite nozzle includes a nozzle body, a swirl sleeve, a nozzle tip, a nozzle shroud, and insulation, which are interconnected by a press fit. The retaining cap is configured to substantially surround the composite nozzle to retain the composite nozzle in the plasma arc torch assembly.

In some embodiments, the swirl sleeve comprises at least one swirl hole configured to introduce a swirl to a gas in the plasma arc torch assembly.

In some embodiments, the nozzle tip includes a discharge orifice that fluidly connects the interior of the nozzle to the ambient environment via a retaining cap. The discharge orifice is configured to direct a first gas flow from an interior of the nozzle to an ambient environment to perform at least one of cooling the nozzle, cooling the nozzle shield, providing stability to the plasma arc, or removing debris. The nozzle tip may also contain a discharge passage fluidly connecting the interior of the nozzle to the nozzle shroud. The discharge passage is configured to direct the second gas flow from an interior of the nozzle to the nozzle shroud for use as a shielding gas. In some embodiments, at least one of the first gas flow or the second gas flow slows the swirling motion of the gas in the nozzle tip.

In some embodiments, the plasma arc torch assembly can further comprise a swirl ring coupled to the distal end of the electrode, substantially surrounding an outer surface of the electrode.

In some embodiments, the locking cap defines a longitudinal axis and has a length along the longitudinal axis from a distal end to a proximal end of the locking cap, the length being about 4.5 to about 5.5 inches, a first width of the distal end being about 1 inch, and a second width of the proximal end being about 0.5 inch. The first width may define a widest cross-sectional width of the distal end, and a ratio of the length to the first width may be greater than 3 or 4. The second width may define a cross-sectional width of the proximal end, and a ratio of the length to the second width may be greater than 5, 6, 7, 8, or 9.

In accordance with another aspect, a method for forming a plasma arc torch assembly is provided. The method includes attaching a swirl ring to the electrode to form the first portion, wherein the swirl ring substantially surrounds an outer surface of the electrode. The method also includes inserting the first portion into a compound nozzle to form a second portion. The composite nozzle includes a nozzle body, a swirl sleeve, a nozzle tip, a nozzle shroud, and insulation, which are interconnected by a press fit. The method also includes inserting the second portion into the retaining cap to form a plasma arc torch assembly. The retaining cap is configured to substantially surround the second portion to retain the second portion within the plasma arc torch assembly.

In some embodiments, the method further comprises sliding the vortex sleeve into the nozzle body from the proximal end of the nozzle body so as to form an interference fit between the vortex sleeve and the stepped region of the inner surface of the nozzle body.

In some aspects, the systems and methods for connecting consumable components to a plasma torch described herein can help make the plasma arc torch easier or more effective for a user. For example, while the basic operation of most plasma arc torches is the same, the consumables used to operate the plasma arc torch can vary widely. Moreover, torches are now used in more complex environments (e.g., handheld torches, mechanized torches, robotic arm torches, etc.), including environments where portions of a workpiece are difficult to access. The systems and methods described herein can be used to produce plasma torches that are more adaptable to different applications.

In particular, the systems and methods described herein (such as systems and methods utilizing consumable mounting equipment capable of flexibly positioning consumables relative to a plasma torch) can help make consumables more accessible to blocked or hard-to-reach areas that are to be cut or otherwise processed. That is, most handheld plasma cutting torches are provided with a torch head that is fixed at an angle between about 90 ° and about 115 ° relative to the handle. While this configuration is well suited for many cutting applications, it is not ideal for performing cuts in tight areas (e.g., in narrow corners, between machine parts, in pockets, etc.) or for many planing applications. While straight torches provided with a trigger may be easy to manufacture, such torches will be limited to these relatively rare applications.

The flexible, and in some cases relatively long, consumable mounting devices described herein (or torches having a flexible long portion within the torch) may provide a moveable arm that may be used to position the consumable so as to reach areas that are blocked or have limited access, such as around corners, or through curved areas.

Additionally, these flexible torch devices can also be used for mechanized cutting (e.g., robotic arm cutting). For example, rather than using a bevel head, the flexible torch device can simply be angled in a desired orientation (e.g., by hand, or with machine assistance), and a cut can be performed. The flexible torch device can also be used to perform cuts with high access requirements when machine cutting, such as when processing structural steel or cutting formed stock material.

In one aspect, a plasma torch extender for a plasma arc cutting system is described. The plasma torch extender comprises an elongate, substantially dielectric body comprising a first end and a second end. The elongate, substantially dielectric body includes a flexible section adapted to be capable of setting a configuration across a plurality of orientations. The plasma torch extender further comprises: a first connector at a first end of the elongated substantially dielectric body adapted to mate with a consumable set; a second connector at a second end of the elongated substantially dielectric body adapted to mate with the torch block; and a consumable detection medium adapted to communicate the presence of the consumable set. The consumable detection media may be disposed within the elongated substantially dielectric body and extend between the first end and the second end of the elongated substantially dielectric body.

According to another aspect, a plasma torch extender for a plasma arc cutting system comprises an elongate, substantially dielectric body having a first end and a second end. A first end of the elongated substantially dielectric body is configured to mate with a consumable set and a second end of the elongated substantially dielectric body is configured to mate with a torch handle. The plasma torch extender may also contain a transmission medium for communicating information indicative of the presence of the consumable set. The transmission medium may be disposed relative to the elongate body such that the transmission medium provides a transmission path between the first end and the second end of the elongate body.

In yet another aspect, a plasma arc cutting system includes a plasma arc torch including a torch base and a torch extension member connected to the torch base. The extension member has a first end and a second end and includes a flexible section. The flexible section of the extension member is configured to be settable over a range of angles. The plasma arc cutting system further comprises: a first connector at a first end of the extension member arranged to mate with a torch tip, the torch tip comprising an electrode and a nozzle; a second connector at a second end for mating with the torch mount; and a transmission medium for communicating information indicative of the presence of the torch tip. The transmission medium can be disposed within the torch extension member such that the transmission medium extends between the first end and the second end.

In other examples, any of the above aspects or any apparatus or method described herein may include one or more of the following features.

The plurality of orientations spanned by the flexible region when in the set configuration may include at least one movement to at least one of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 degrees.

The flexible section of the elongate body of substantially dielectric may be arranged such that the flexible section can be manipulated to position the first end of the elongate body of substantially dielectric at a compound angle relative to the second end of the elongate body of substantially dielectric. The flexible section of the elongate body of substantially dielectric may be configured such that the flexible section can be manipulated to position the first end of the elongate body of substantially dielectric across an angular range from 0 degrees to 360 degrees relative to the second end of the elongate body of substantially dielectric.

The first end of the elongate substantially dielectric body may remain fixed relative to the second end of the elongate substantially dielectric body after the body is manipulated by a user to assume a desired configuration. The second end of the elongate substantially dielectric body can mate with a motorized torch body or handle of a plasma arc torch. The elongate, substantially dielectric body can comprise at least one of a gas passage for providing plasma gas to the plasma arc torch or an electrical conductor for providing cutting current to the plasma arc torch.

The consumable detection medium may be adapted to detect the presence of the consumable set based on converting at least one of a mechanical, pneumatic, or electrical signal received from the first end of the elongate substantially dielectric body. A consumable detection medium for communicating the presence of a consumable set may contain a consumable sensor that detects the presence of the consumable set. The consumable sensor may comprise at least one of a mechanical sensor, a pneumatic sensor, or an electrical sensor.

The plasma torch extender can contain a transmission medium that repositions the functionality of the consumable sensor from a first end of the elongate substantially dielectric body to a torch sensor located at a second end of the elongate substantially dielectric body.

Each conduit may be a generally longitudinal cylindrical body. The longitudinal axis of each conduit may be arranged to be movable to a plurality of predetermined orientations about the connection point relative to the longitudinal axis of adjacent conduits. The plurality of predetermined orientations may include at least one movement to at least one of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 degree angles.

At least one end of each conduit may contain a motion limiter which limits movement of the conduit relative to its point of connection with its adjacent conduit. The motion limiter may be arranged to allow movement of the conduit relative to the connection point to a predetermined range of movement. The motion limiter may be arranged to limit pivoting of the first end of the elongate substantially dielectric body relative to the second end of the elongate substantially dielectric body in accordance with limiting movement of the catheter contained in the flexible region of the elongate substantially dielectric body.

The plurality of series-connected conduits may be located substantially inside an elongate substantially dielectric body. The flexible section of the elongated substantially dielectric body may be at least 6 inches long. The flexible section may be configured to form a compound angle. The compound angle may be obtained by moving the series connected conduits relative to their connection points for a plurality of predetermined movements. The series-connected conduits of the flexible sections may be connected by at least three connection points.

The flexible section of the elongated substantially dielectric body is movable between the first end and the second end of the elongated substantially dielectric body across a range of orientations, including at least one movement from 0 degrees to 180 degrees. The plurality of series-connected conduits may contain at least one of a gas passage for providing plasma gas to the plasma arc torch or an electrical conductor for providing a cutting current to the plasma arc torch, the cutting current passing through the plurality of series-connected conduits. The first end of the elongate body of substantially dielectric may remain stationary relative to the second end of the elongate body of substantially dielectric after the user positions the elongate body of substantially dielectric.

The elongate body of substantially electrical dielectric may be arranged to electrically insulate the first end of the elongate body of substantially electrical dielectric from the second end of the elongate body of substantially electrical dielectric.

The second end of the elongate substantially dielectric body is further arranged to connect to at least one of a camera or a bore finder disposed proximal to the elongate substantially flexible body.

The transmission medium for communicating information indicative of the presence of the consumable set may comprise a consumable sensor that detects the presence of the consumable set. The consumable sensor may comprise at least one of a mechanical sensor, a pneumatic sensor, or an electrical sensor. The transmission medium can reposition functionality of the consumable sensor from the first end of the elongate substantially dielectric body to a torch sensor located at the second end of the elongate substantially dielectric body.

The flexible zone of the torch extension member can be arranged such that the flexible zone can be manipulated to position the first end of the torch extension member at a predetermined range of angles relative to the second end of the torch extension member.

A transmission medium for communicating information indicative of the presence of the torch tip can be coupled with a torch tip sensor that detects the presence of the torch tip. The torch tip sensor can comprise at least one of a mechanical sensor, a pneumatic sensor, or an electrical sensor. A transmission medium for communicating information indicative of the presence of the torch tip can reposition the functionality of the torch tip sensor from a first end of the torch extension member to a torch sensor located at a second end of the torch extension member.

The second tip of the torch extension member can be connected to a motorized torch body or handle of the plasma arc torch. The extension member can comprise at least one of a gas passage for providing plasma gas to the plasma arc torch or an electrical conductor for providing cutting current to the plasma arc torch.

Drawings

The advantages of the invention described above, as well as others, will be better understood by reference to the following description taken in conjunction with the accompanying drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

Fig. 1 is a cross-sectional view of a plasma arc torch tip.

FIG. 2 is a cross-sectional view of a nozzle according to an illustrative embodiment of the invention.

Fig. 3 is a perspective view of an electrode according to an illustrative embodiment of the invention.

Fig. 4 is a cross-sectional view of a torch tip containing a nozzle, an electrode, and a swirl ring according to an illustrative embodiment of the invention.

FIG. 5 is a perspective view of a nozzle according to an illustrative embodiment of the invention.

FIG. 6 is a cross-sectional view of a nozzle assembly according to an illustrative embodiment of the invention.

Fig. 7 is a side view of a plasma arc torch adapter for an extended plasma arc torch in accordance with an illustrative embodiment of the invention.

Fig. 8 is a cross-sectional view of a torch tip according to an illustrative embodiment of the invention.

Fig. 9 is a diagrammatic illustration of a torch tip in accordance with an illustrative embodiment of the invention.

Fig. 10 is a graph showing torch body temperature versus time in accordance with an illustrative embodiment of the invention.

Fig. 11 is a graph showing cathode temperature versus time according to an illustrative embodiment of the invention.

Fig. 12 is a cross-sectional view of a torch tip according to an illustrative embodiment of the invention, showing gas flow.

Fig. 13 is a cross-sectional view of a torch tip according to an illustrative embodiment of the invention, showing the diameter and length of the nozzle and electrode.

Fig. 14 is a cross-sectional view of a torch tip according to an illustrative embodiment of the invention.

Fig. 15 is a cross-sectional view of a torch tip according to an illustrative embodiment of the invention.

Fig. 16 illustrates an exemplary consumable composite nozzle incorporating at least five different torch components.

FIG. 17 illustrates an embodiment of a nozzle body of the composite nozzle of FIG. 16.

FIG. 18 illustrates an embodiment of a swirl sleeve of the composite nozzle of FIG. 16.

FIG. 19 illustrates an embodiment of a nozzle tip of the composite nozzle of FIG. 16.

FIG. 20 illustrates another embodiment of a nozzle tip.

FIG. 21 illustrates an embodiment of the insulation of the composite spout of FIG. 16.

FIG. 22 illustrates an embodiment of a nozzle shroud of the composite nozzle of FIG. 16.

Fig. 23 illustrates an exemplary plasma arc torch assembly incorporating the composite nozzle of fig. 16.

Fig. 24 illustrates an exemplary gas flow pattern through the plasma arc torch assembly of fig. 23.

Fig. 25 illustrates an exploded view of consumable parts of another exemplary plasma arc torch assembly.

Fig. 26 illustrates an exemplary view of the locking cap of fig. 25.

Fig. 27 is a side view of a plasma arc torch provided with an extender member.

Fig. 28 is a perspective view of a partially disassembled plasma arc torch provided with an extender component.

Fig. 29A is a schematic side view of a plasma arc torch provided with an extender member in a straight configuration.

Fig. 29B is a schematic side view of a plasma arc torch provided with an extender member in a curved configuration.

Fig. 29C, 29D, 29E, 29F, 29G, 29H, and 29I are schematic side views of plasma arc torches provided with extender members of various example configurations.

30A, 30B, 30C, 30D, and 30E illustrate an example plasma arc torch provided with an extender with a flexible region that positions a consumable component relative to a handle region of the torch.

Fig. 31A is a schematic side view of a plasma arc torch provided with an extender member in a straight configuration.

Fig. 31B is a schematic side view of a plasma arc torch provided with an extender member in a curved configuration.

Fig. 32A is a schematic side view of a plasma arc torch provided with an extender member in a straight configuration.

Fig. 32B illustrates a schematic side view of a plasma arc torch provided with an extender member in a curved configuration.

Fig. 32C illustrates a schematic cross-section of a plasma arc torch provided with an extender member in a curved configuration.

FIG. 33 is a schematic view of a cathode nozzle that may be used with embodiments described herein.

Detailed Description

Fig. 1 shows a cross-sectional view of a plasma arc torch 100. The plasma torch tip is made up of a number of different consumables, such as the electrode 105, the nozzle 110, the retaining cap 115, the swirl ring 117, or the shield 125. The nozzle 110 is provided with a central outlet orifice mounted within the torch body. The torch and torch tip can contain electrical connections, passages for cooling, and passages for an arc control fluid (e.g., plasma gas). The shield 125 can be used to prevent molten splatter from damaging other components of the torch, such as the electrode 105, the nozzle 110, the retaining cap 115, or the swirl ring 120. The electrode 105 may include a heat exchanger 120 located at a proximal end 127 of the electrode 105.

Plasma arc torches that can reach into difficult to access areas (e.g., trenches or corners) may have consumables that: these consumables are elongated to provide the additional contact range necessary to access these types of locations. These longer length consumables (e.g., "tipped" consumables) may also increase visibility for an operator using the plasma arc torch. This increased visibility allows the operator to see the cut being made because the torch handle is located further from the cut, which provides an obstruction to the operator's view of the cut.

However, the presence of longer consumables can result in insufficient cooling of the plasma arc torch and in overheating and melting of consumable parts. Overheating may be at least partially due to the fact that existing cooling techniques utilize heat exchangers at the rear end of the electrodes, away from the plug. When the consumable is extended, this heat exchanger is moved further away from the heat source (e.g., the plug of the electrode). The further the cooling mechanism is from the heat source, the lower the cooling efficiency becomes. As a result, the extended consumable will overheat and melt early. This overheating phenomenon is particularly pronounced when the plasma arc torch is operated at currents above about 15 amps, or more particularly at currents above about 60 amps. Overheating is also particularly pronounced when the plasma arc torch is completely gas cooled (e.g., by air cooling).

In some embodiments, the consumable (e.g., nozzle, electrode, retaining cap, shield, and/or swirl ring) is longer than about 2 inches. Fig. 2 shows a cross-sectional view of the nozzle 200. The nozzle 200 includes a body 205, the body 205 being substantially hollow having a first end 206 and a second end 207. The hollow nozzle body 205 can receive an electrode (e.g., the electrode 105 of fig. 1). The plasma exit orifice 208 is disposed through an end face 209 at the first end 206 of the body 205.

The nozzle body 205 defines a longitudinal axis 210. The nozzle body 205 has a length L along a longitudinal axis 210 from a first end 206 to a second end 207 of the nozzle body 205. The first end 206 of the nozzle body has a width W. The ratio of the length L of the nozzle body 205 to the width W of the nozzle body 205 is greater than about 3.

For example, to provide an L/W ratio greater than about 3, the length of the nozzle body 205 may be about 3.5 inches and the width of the nozzle body may be about 0.5 inches. The ratio L/W thus obtained is equal to 3.5 inches/0.5 inches, or the ratio L/W is 7.

In some embodiments, the length of the nozzle may be greater than about 2 inches. The length of the nozzle may be greater than about 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inches. In some embodiments, the length of the nozzle is greater than about 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5 inches. Although specific values are listed herein for the length and/or width of the nozzle, one of ordinary skill in the art will readily recognize that other lengths and widths may be used without departing from the scope of the present invention. For example, the nozzle may have a length greater than about 21 inches without departing from the scope of the present invention.

The length to width ratio of the nozzle may be greater than about 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, the nozzle has a length to width ratio greater than about 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5. Although specific ratios of L/W are listed herein, one of ordinary skill in the art will readily recognize that other lengths and widths may be used without departing from the scope of the present invention. For example, the nozzles may have a ratio of greater than about 21 inches without departing from the scope of the present invention.

Similarly, an electrode (e.g., electrode 105 of fig. 1) can be designed to enable the plasma arc torch to reach areas that are difficult to access. To achieve a torch stack with high access and high visibility features, proper design of the electrode is a critical requirement. Reliable high access and high visibility torches require correct ratios and tolerances of the electrodes. Fig. 3 shows an electrode 300, the electrode 300 being provided with an elongated body 305, the elongated body 305 being capable of achieving the high access and high visibility requirements mentioned herein. The electrode body 305 has a first end 307 and a second end 308. The electrode body 305 also defines a bore 310 in the first end 307 for receiving a plug (e.g., hafnium). The electrode has a first body portion 315 extending from the first end 307 and a second body portion 320 extending to the second end 308. The first body portion 315 and the second body portion 320, respectively, may be formed as a unitary component, e.g., from a single piece of metal (such as copper).

While making consumable long versions (e.g., making the nozzle 200 of fig. 2 and/or the electrode 300 of fig. 3 long) possible to extend reach, visibility, and sharpness of a plasma arc torch, the life of the consumable is severely shortened due to overheating when using prior art cooling techniques. The prior art cooling techniques typically provide a heat exchanger on the end of the electrode opposite the hafnium plug. The cooling fluid performs most of its cooling function at the location of the heat exchanger. However, when a hafnium plug (e.g., a location where a large amount of heat is generated), a heat exchanger located at a distance from the plug is insufficient for cooling purposes.

For example, referring to FIG. 1, making the electrodes 105 elongated may cause the hafnium plug 130 to be farther from the heat exchanger 120. The heat exchanger 120 is configured to remove heat from the electrodes and other consumables when in communication with the cooling fluid, such heat exchanger 120 no longer being able to effectively remove sufficient heat from the distal end 135 of the electrode 105, thereby causing the consumable part to overheat and melt. This overheating phenomenon is particularly pronounced when the plasma arc torch is operated at currents above about 15 amps, or more particularly at currents above about 60 amps. Overheating is also particularly pronounced when the plasma arc torch is completely gas cooled (e.g., by air cooling). In some embodiments, the torch is cooled by various ratios of oxygen and/or nitrogen.

To compensate for inefficient cooling of the consumable, the consumable and the cooling path may be designed such that substantially all cooling occurs at the forward end of the torch tip, near the plug of the electrode. For example, the cooling gas may flow between the electrode and the nozzle, through the swirl ring and through the plasma chamber, and out the end face of the nozzle. A small portion of this gas may be carried to the nozzle orifice as a vortex cutting gas. By performing the cooling in this manner, the distance from the nozzle tip to the torch can be greatly extended. This combination of long consumables and forward flow cooling can achieve the advantages described herein without compromising consumable life.

In some embodiments, substantially all of the cooling gas (e.g., a majority of the cooling gas, greater than 75% of the cooling gas, greater than about 80% of the cooling gas, greater than about 95% of the cooling gas, or about 99% of the cooling gas) flows out through the front face or tip of the plasma arc torch while hardly allowing the cooling gas to flow back into the torch (however, the pressure in the plenum can still post-blow this electrode to the cutting location). This new "forward flow" cooling design cools the consumables at the location where most of the heat of the plasma arc torch is generated (e.g., at the plug of the electrode). Thus, the electrode of the present invention does not require a heat exchanger located at the proximal end of the electrode as shown in FIG. 1.

The electrode (e.g., electrode 300 of fig. 3) may be provided with a solid base provided with an internal bore to reduce temperature conduction within the electrode. A large temperature difference is formed between the electrode and the cooling gas, so that heat is driven into the cooling gas at the electrode head. This dramatically reduces the heat flow into the electrode body, thereby extending the life of the electrode and other consumables. In addition, the plasma arc torch can operate at lower temperatures for any given gas flow, and very high gas flows are no longer required to adequately cool the consumables. Also, since the degree of cooling of the consumables is drastically increased, higher operating currents (e.g., greater than 150 amps) can be achieved.

The forward flow cooling design also allows the torch body and handle to be substantially free of heat while cutting a workpiece. During cooling, the heat generated by the plasma arc torch at the plug near the electrode tip moves forward, rather than rearward toward the torch body and handle. This not only enables more efficient cooling, but also increases operator safety because the locations (e.g., the handle and torch body) where the operator is most likely to contact the plasma arc torch are not as hot as prior art plasma arc torches. In addition, the handle of the plasma arc torch can be smaller because the handle does not have to absorb as much heat as in prior art plasma arc torches. Also, less copper may be used to manufacture the consumable, as the cooling efficiency becomes higher. For example, the rear end of the electrode closest to the handle can be made of less copper than prior art electrodes because the heat generated by the plasma arc torch on the plug near the electrode tip moves forward during cooling rather than back toward the torch body and handle. Thus, less copper may be used to manufacture the consumable, and the cost of the consumable is lower than that of the consumables of the prior art.

In addition, the extended consumable of the present invention also has a forward flow design, reducing the need for very high gas flows. With this new forward flow design, less gas is used than was previously necessary with the prior art consumable design, yet the same heat can be removed from the electrode head. This is partly because the cooling gas is moved in a single direction (forward, or towards the electrode plug), rather than flowing in both the forward and backward directions to cool the consumable.

Fig. 4 shows a torch tip 400 that can be used in a plasma arc torch operating at high current and cooled entirely by gas, the torch tip 400 being provided with an elongated consumable comprising a nozzle 405, an electrode 410, and a swirl ring 415. The nozzle 405 has an end face 420, and a plasma outlet aperture 425 is disposed through the end face 420. The end face 420 may also be provided with at least one supplemental orifice 427, the supplemental orifice 427 being disposed relative to the plasma exit orifice 425. The supplemental apertures 427 may be located beyond the end face 430 of the electrode 410.

The supplemental apertures 427 may be chamfered or the supplemental apertures 427 may be straight or linear. The chamfered supplemental apertures can provide a swirl member to the cooling gas flowing from the nozzle to direct the cooling gas away from the cutting zone. Fig. 5 shows a nozzle 500, the nozzle 500 being provided with chamfered or angled complementary orifices 505. As shown in fig. 5, the supplemental orifice 505 is disposed relative to the plasma exit orifice 510. A plasma arc is emitted from the plasma arc torch through the plasma exit orifice 510 when the torch is operating. The cooling gas can flow out through the supplemental orifice 505 to provide cooling at the tip of the consumable set. In some embodiments, substantially all of the cooling gas (e.g., greater than about 95% of the cooling gas) flows out through the supplemental orifice 505.

Referring back to fig. 4, the body of the nozzle 405 may be provided with at least one aperture 435 disposed through the body of the nozzle 405. The nozzle 405 may be provided with a supplemental orifice 427 or an orifice 435. In some embodiments, nozzle 405 is provided with both supplemental apertures 427 and 435. The aperture 435 may be chamfered/angled or straight/linear.

Substantially all of the cooling gas may be used to cool the consumables at the tip of the plasma arc cutting torch and substantially all of the cooling gas may flow out through the supplemental apertures 427 and/or apertures 435. In this manner, all of the cooling gas flows along the exterior of the electrode and/or the exterior of the nozzle to cool the consumable at the site where the majority of the heat in the plasma arc torch is generated (e.g., on or near the plug of the electrode). This forward flow approach allows the plasma arc torch to be fully gas cooled and to operate at currents greater than 15 amps (or greater than 45 amps or greater than 60 amps or greater than 90 amps or greater than 150 amps) without premature failure of the consumable.

The supplemental apertures 427 and apertures 435 may be sized such that substantially all of the cooling gas flows through the supplemental apertures 427 and/or apertures 435.

To further cool the consumables, a heat exchange element 437 may be disposed on the nozzle body. Heat exchange elements 437 may be bumps, grooves, channels, textures, protrusions, projections, and/or fins. The heat exchange element 437 is in thermal communication with the cooling gas and provides additional surface area to increase the heat transfer coefficient and rate. In some embodiments, as shown in FIG. 4, a heat exchange element 437 is disposed on an outer surface 438 of the nozzle 405. In some embodiments, the heat exchange element 437 is disposed on an inner surface 439 of the nozzle 405. The heat exchange element 437 may be disposed on both the outer surface 438 and the inner surface 439 of the nozzle 405.

In some embodiments, the nozzle may comprise an integrally formed structure, thereby forming the nozzle assembly 600 of fig. 6. The nozzle assembly 600 may comprise a substantially hollow elongate body 605. The elongate body 605 defines a longitudinal axis 610. The assembly body 605 has only a length L along the axis from the first end 612 to the second end 613 of the body 605. Nozzle assembly 600 is provided with a plasma outlet orifice 615 disposed at a first end 612 of body 605.

The nozzle assembly includes a structure 620, the structure 620 being integrally formed with the nozzle body 605. In some embodiments, the structure 620 is removable from the nozzle body 605. The structure 620 may be, for example, a swirl ring that can control the orientation of the cooling gas flow. The structure 620 is configured to translatably receive the electrode such that a post-torch technique can be used. For example, the inner surface of structure 620 may be a bearing surface that may allow the electrode to slide within structure 620. The structure 620 comprises a body 625, the body 625 being provided with chamfered gas ports 630 for providing a swirling plasma gas during operation of the plasma arc cutting torch.

The structure 620 may be embedded in the nozzle body 605 such that the structure 620 is not removable. The inner diameter of the nozzle body 605 may be substantially the same as the outer diameter of the structure 620. Structure 620 may be used to align the bore of the electrode with the plasma exit aperture 615. The structure 620 may be sized such that when the electrode is disposed within the hollow body of the nozzle, the bore of the electrode is axially aligned with the plasma outlet orifice. For example, the outer diameter of the electrode is substantially the same as the inner diameter of the structure 620, thus aligning the electrode bore with the plasma exit orifice.

The alignment feature of the structure 620 is particularly useful when using long, pointed consumables within a plasma arc torch. Because of the length of the consumable, the electrodes may be tilted or angled relative to the longitudinal axis 610. This tilting or angling of the electrode within the nozzle is particularly evident when the alignment of the electrode occurs at the rear or proximal end of the torch tip. When the electrode bore and the plasma exit orifice of the nozzle are misaligned, a double arc phenomenon or poor torch performance may occur.

To ensure that the electrode bore is properly aligned with the plasma exit orifice, the structure 620 of fig. 6 may be used to align the electrode with the nozzle. As shown in fig. 6, alignment occurs near the tip of the nozzle/electrode, ensuring that the electrode is aligned with the nozzle. Moreover, the alignment of the electrode with the nozzle at the tip of the torch can align the electrode along the longitudinal axis 610 of the nozzle, thereby reducing or eliminating any tilting or angling of the electrode.

In addition to the alignment features of structure 620, structure 620 also isolates the electrodes from the nozzle. For example, the structure electrically isolates the electrode from the nozzle. Structure 620 may be, for example, non-conductive (e.g., made of a non-conductive material) so as to electrically isolate the electrode from the nozzle.

In some embodiments, the length of the nozzle assembly may be greater than about 2 inches. The nozzle assembly may have a length greater than about 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inches. In some embodiments, the length of the nozzle assembly is greater than approximately 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5 inches. Although specific values are listed herein for the length and/or width of the nozzle, one of ordinary skill in the art will readily recognize that other lengths and widths may be used without departing from the scope of the present invention. For example, the nozzle assembly may have a length greater than about 21 inches without departing from the scope of the present invention.

The nozzle assembly may have a ratio or L/W of at least about 2. The nozzle assembly may have a length to width ratio of greater than about 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, the nozzle assembly has a length to width ratio greater than about 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5. Although specific L/W ratios are listed herein, one of ordinary skill in the art will readily recognize that other lengths and widths may be used without departing from the scope of the present invention. For example, the nozzle assembly may have a ratio of greater than about 21 inches without departing from the scope of the present invention.

Similar to nozzle 405 of fig. 4, nozzle assembly 600 may be provided with at least one supplemental orifice (not shown) disposed through at least one of end face 635 or side wall 640 of nozzle assembly 600 relative to plasma outlet orifice 615. The supplemental orifice may be chamfered and substantially all of the cooling gas can flow out through the at least one supplemental orifice (in the end face and/or sidewall of the nozzle).

The nozzle assembly 600 may be provided with at least one heat exchange element (not shown) disposed on the nozzle body 605 and in thermal communication with the cooling gas. The heat exchange elements may be disposed on an outer surface and/or an inner surface of the nozzle body 605.

Referring to fig. 3, the electrode 300 may include a heat transfer region Z positioned relative to the first body portion 315 at the first end 307 of the electrode body 305. The heat transfer zone Z may be a region of the outer surface of the electrode 300 from which heat is transferred from the electrode to the cooling gas. The zone or heat transfer zone Z may comprise a region of any heat exchange element (e.g., similar to the heat exchange element described with respect to the nozzle) that may be disposed on the outer surface of the electrode 300. The heat transfer region Z is in thermal communication with the cooling gas during operation of the plasma torch (e.g., at a current greater than about 15 amps) and is configured to remove a majority of heat generated during operation of the plasma torch from the heat transfer region Z. The specific amount of heat removed may depend on the specific operating parameters of the plasma arc torch. For example, a torch operating at a current of about 15 amps will have to remove less heat from the heat transfer region than a torch operating at a current of about 60 amps. This is because a torch operating at a higher current generates more heat than a torch operating at a lower current. The heat removed from the heat transfer region should be sufficient to prevent premature failure (e.g., melting) of the consumable. Those skilled in the art will readily appreciate the heat that must be removed from the heat transfer area to prevent premature failure of the consumable.

The heat transfer zone Z may be greater than about 1 square inch. In some embodiments, the heat transfer zone Z may be between about 1 square inch and about 3 square inches. For example, the heat transfer zone Z can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, or 2.9 square inches. Although specific values are listed herein for the heat transfer region of the electrode, one of ordinary skill in the art will readily recognize that other areas may be used without departing from the scope of the present invention. For example, the electrode may have a heat transfer area greater than about 3 square inches or greater than about 3.5 inches without departing from the scope of the present invention. In some embodiments, the heat transfer area is less than about 1 square inch, for example, the heat transfer area may be about 0.75 or 0.5 square inches.

Fig. 7 illustrates a plasma arc torch system 700 comprising a housing 705 positioned relative to a consumable set 707, the consumable set 707 comprising a nozzle (not shown) and an electrode (not shown) of a plasma arc torch 710. Housing 705 and consumable set 707 form an assembled torch tip having a distal end 708 and a proximal end 709. The proximal end 709 of the torch tip is configured to couple to a torch tip seat 715. For example, the proximal end 709 of the torch tip can be coupled to the torch tip seat 715 via threads.

The nozzle of the torch tip/consumable set 707 can be any of the nozzle embodiments described herein. The electrode of the torch tip/consumable set 707 can be any of the electrode embodiments described herein.

In some embodiments, as shown in fig. 7, the housing 705 is an adapter or extender that can be used with prior art consumables 707 to extend the torch tip to areas that are difficult to access. For example, housing 705 can extend the distance from distal end 708 to proximal end 709 of the assembled torch tip. In other embodiments, as shown in fig. 8, an elongated consumable is used and a housing 805 is used to condition the consumable.

Fig. 8 illustrates a torch tip 800 for a handheld plasma arc torch that includes a substantially hollow nozzle 810, an electrode 815 positioned relative to the nozzle, and a housing 805 positioned relative to the nozzle 810 and the electrode 815. Nozzle 810, electrode 815, and housing 805 form an assembled torch tip having a distal end 820 and a proximal end 825. The proximal end 825 is configured to couple to a torch tip seat (not shown) of a plasma arc torch (not shown).

As shown in fig. 8, the nozzle 810 and/or electrode 815 may be elongate. The nozzle 810 may be any of the nozzle embodiments described herein. Electrode 815 may be any of the electrode embodiments described herein. The electrode 815 may be designed such that there is no heat exchanger at the proximal end 825 of the electrode 815. The sharpness of the electrode 815 is further increased by the absence of a heat exchanger at the proximal end 825 of the electrode 815.

The distance D from the distal end to the proximal end of the assembled torch tip of either fig. 7 or 8 can be greater than about 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 inches. In some embodiments, the distance D from the distal end to the proximal end of the assembled torch tip of either fig. 7 or 8 is greater than about 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5 inches. Although specific values are listed herein for the distance from the distal end to the proximal end of the assembled torch tip, one of ordinary skill in the art will readily recognize that other lengths may be used without departing from the scope of the present invention. For example, the torch tip may have a length greater than about 21 inches without departing from the scope of the invention.

In some embodiments, the ratio of the length D of the assembled torch tip of any of fig. 7 or 8 to the width W of the assembled torch tip can be greater than about 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. The ratio of the length D of the assembled torch tip of either fig. 7 or fig. 8 to the width W of the assembled torch tip can be greater than about 4.5, 5.5, 6.5, 7.5, 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5, 16.5, 17.5, 18.5, 19.5, or 20.5. Although specific values are listed herein for the ratio, one of ordinary skill in the art will readily recognize that other ratios may be used without departing from the scope of the present invention. For example, the torch tip may have a ratio of greater than about 21 inches without departing from the scope of the invention.

In addition to the elongated shape of nozzle 810 and electrode 815, retaining cap 830 may also be extended to accommodate the extended nozzle 810 and electrode 815. The additional length of the locking cap 830 can protect the consumables and/or the operator. Compared with the consumable material in the prior art, the consumable material is longer, and the body of the operator can be farther away from the plasma arc, so that the operator is safer. The retaining cap 830 may also allow shielding of the cooling flow for the consumable, as the inner surface of the retaining cap 830 may serve as part of the gas channel, allowing gas to flow down the shroud. The retaining cap may have a plastic sheath that extends over almost the entire length of the nozzle. An anodized aluminum head may be added at the capped end of the retaining cap (e.g., the end near the electrode tip and closest to the location of heat generation during operation of the plasma arc torch) for thermal protection. The entire outer surface of the retaining cap may then be electrically floated from the electrode and the nozzle.

Fig. 9 shows a torch tip 900. Torch tip 900 includes an extended/elongated electrode, nozzle, and retaining cap. These extended consumables increase the length of the torch tip 900. For example, the extended consumable can add about 2.5 inches to a standard prior art consumable. Thus, the distance D from the proximal end 905 to the distal end 910 of the torch tip 900 can be about 4.75 inches. The width W of the torch tip 900 can be about 0.56 inches. The smaller outer diameter W may allow the torch tip to extend into tight spaces. The ratio of distance D to width W of torch tip 900 (4.75/0.56) is about 8.48.

The thinner outer diameter or width W also allows the strike angle R of the plasma arc torch to be increased as compared to prior art torches. The strike angle R is the angle formed by the widest width of the consumable and the length of the consumable, as measured from the longitudinal axis of the consumable. The touch angle may be less than about 20 °, less than about 15 °, less than about 10 °, or less than about 6 °.

Fig. 10 and 11 are graphs showing how the forward flow method described herein reduces the temperature of a plasma arc torch during operation using an extended consumable. For example, fig. 10 shows torch temperature in degrees celsius versus time during operation of the plasma arc torch at 45 amps. The plasma arc torch was operated for 20 seconds and then turned off for five seconds. This process was repeated 222 times. A large vertical gap indicates a change in the consumable set. As shown on the graph, the maximum temperature induced by the torch body and consumable is 41 ℃. The prior art consumables typically reach temperatures in excess of 120 ℃.

FIG. 11 is a graph comparing the temperature of standard consumables to extended consumables used with the forward flow method described herein for a plasma arc torch operating at 30 amps. Standard consumables reach temperatures in excess of 120 ℃. The maximum temperature reached by the extension consumables was 54 ℃.

The heat transfer of a forward flow design of consumables that provide such dramatic temperature reduction of a plasma arc torch can be expressed as equations 1-3, where Q is the heat induced into the electrode and nozzle by the arc, A is the total (electrode and nozzle) heat transfer surface, h_AVGIs the heat transfer coefficient, T, of the heat exchange surfaces of the electrode and the nozzle_{Surface of}Is the local surface temperature of the heat exchange surface, and T_bIs the local spherical temperature of the gas (air).

Q = Ah_AVGΔ T equation 1

A = A_{Electrode for electrochemical cell}+ A_{Nozzle with a nozzle body} Equation 2

ΔT = T_{Surface of}- T_bEquation 3.

Fig. 12 shows a torch tip containing an electrode 1205, a nozzle 1210, a shield 1215, and a swirl ring 1220. The electrode 1205 is provided with a plug 1225, for example a hafnium plug. Nozzle 1210 includes a gas outlet 1230. A cooling gas (e.g., air) 1235 may flow between the electrode 1205 and the nozzle 1210, and a shielding gas 1240 may flow between the nozzle 1210 and the shroud 1215. The cooling gas 1235 and the shroud gas 1240 in combination cool the consumables at the torch tip.

Referring to fig. 13, the total area of the electrode and the nozzle as the heat transfer area may be calculated based on equations 4-7, where d is the diameter and l is the length.

A₁= πd₁l₁= A_{Electrode surface}Equation 4

A₂= πd₂l₂= A_{Nozzle bore surface} Equation 5

A₃= πd₃l₃= A_{Nozzle outer diameter surface}Equation 6

A = A₁+ A₂+ A₃Equation 7.

Referring to fig. 14 and equation 1, several factors should be considered in calculating hAVG. First is the size of the gap 1405 between the nozzle inner diameter and the electrode. For example, if the diameter of the small nozzle inside diameter minus the diameter of the electrode is smaller than the diameter of the large nozzle inside diameter minus the diameter of the electrode (e.g., see equation 8 in conjunction with FIG. 14), then a pressure drop will develop across the swirl ring, which may affect the velocity and pressure of the cooling gas.

(D_{Small nozzle bore}– D_{Electrode for electrochemical cell})<(D_{Large nozzle bore diameter}– D_{Electrode for electrochemical cell}) Equation 8.

Additionally, the size of the gap 1410 between the outer diameter of the nozzle and the shroud may affect the velocity and pressure of the shielding gas. Any heat exchange features on any of the heat exchange surfaces (the outer surface of the electrode 1415, the corresponding inner or outer surface of the nozzles 1420, 1425, or the inner surface of the shroud 1430) can create turbulence and contract the boundary layer to increase the cooling airflow and/or shield convection in the airflow. Moreover, the outlet aperture 1435 may affect the boundary layer and turbulence of the cooling gas based on the diameter and location of the outlet aperture 1435. In calculating h_AVGThe gravity and gas properties of the cooling and shielding gas may also be taken into account.

Referring to fig. 15, the heat entering the electrode and nozzle caused by the arc can also be calculated by equation 9.

Q = A₁h₁(T_{Electrode for electrochemical cell}– T_{Bulk electrode}) + A₂h₂(T_{Nozzle with a nozzle body}– T_{Bulk electrode}) + A₃h₃(T_{Nozzle with a nozzle body}– T_{Body shield}) Equation 9.

While embodiments of the present invention are described with respect to a handheld plasma arc torch, the embodiments are equally applicable to mechanized torches. Those of ordinary skill in the art will readily appreciate that the design of consumables and flow characteristics can be applied to both hand-held and mechanized torches.

Methods of cutting a workpiece and extending the life of a plasma arc torch can be performed using any of the consumables (e.g., at least one of the nozzle or electrode embodiments) and the forward flow cooling methods described herein. The method can be performed by providing a plasma arc torch having a body. The body contains a flow path for directing plasma gas through the swirl ring to the plasma chamber to form a plasma arc. Any one or more of the consumable embodiments described herein may be provided. For example, the nozzle of fig. 2 may be provided, the nozzle assembly of fig. 6 may be provided, or the electrode of fig. 3 may be provided. In some embodiments, both the nozzle of fig. 2 and the electrode of fig. 3 may be provided, or the nozzle assembly of fig. 6 and the electrode of fig. 3 may be provided.

The plasma arc torch can be operated at an amperage level of at least about 15 amps. In some embodiments, the plasma arc torch operates at an amperage level of at least about 30 amps, at least about 45 amps, at least about 60 amps, at least about 80 amps, at least about 100 amps, at least about 120 amps, at least about 150 amps, or at least about 200 amps.

The method also includes flowing a majority (e.g., greater than about 95%) of the cooling gas through at least one supplemental orifice at the distal end of the torch body (e.g., a supplemental orifice of the nozzle).

In accordance with another aspect of the present technique, several conventional torch components can be redesigned, combined, and/or eliminated to form one or more cartridge-type consumables for a plasma arc cutting system. FIG. 16 illustrates an exemplary consumable composite nozzle 1600 that incorporates at least five different torch components, including a nozzle body 1602, a vortex sleeve 1604, insulation 1606, a nozzle tip 1608, and a nozzle shroud 1610.

In some embodiments, the five components of the nozzle 1600 are press fit together to form the nozzle 1600. This allows for efficient manufacturing and assembly of these components, improves the durability of the nozzle 1600 via a press-fit connection, and facilitates proper orientation of the components relative to each other. Using a press-fit arrangement, greater cooling of the nozzle 1600 can also be achieved. The press fit arrangement may provide an improved airflow surface. The press-fit arrangement may also simplify manufacturing and/or assembly of the components (e.g., because many features are not required for implementation, as would be required for a threaded connection). The press-fit arrangement may provide an improved thermal conduction path between the various components of the nozzle 1600 due to the relatively small tolerances of these components and/or the proximity of the interfering surfaces to one another. The press fit arrangement may include an interference fit or a tabbed/interlocking fit, including a stepped feature. The press-fit arrangement is small in size, which may reduce manufacturing and/or material costs. In some embodiments, at least one of the components of nozzle 1600 is molded or formed via a molding process. In some embodiments, the components of the nozzle 1600 are threaded to allow an operator to connect them together. In some embodiments, the nozzle 1600 is configured as a heat sink for a plasma arc torch.

FIG. 17 illustrates an embodiment of a nozzle body 1602 of the composite nozzle 1600 of FIG. 16. The nozzle body 1602 may include a body of conductive material, such as copper or aluminum. In some embodiments, using aluminum for the nozzle body 1602 can enhance cooling performance relative to conventional materials because aluminum has a higher thermal conductivity than conventional materials (e.g., Vespel). By flowing cold gas through aluminum nozzle body 1602, significantly better cooling of nozzle tip 1608 and the attached electrode (not shown) may be achieved. Additionally, since Vespel may be much more expensive than aluminum, replacing Vespel with aluminum may reduce the manufacturing cost of the nozzle 1600. In some embodiments, aluminum is a better choice than copper for the nozzle body 1602 because copper is a more expensive material than aluminum, although copper is more thermally conductive. Thus, to reduce costs, a highly thermally conductive material may be used only in areas that are most exposed to heat during torch operation (such as in the nozzle tip 1608 or nozzle shield 1610). Thus, the use of aluminum for the nozzle body 1602 represents a desirable balance between cost and function.

As shown in FIG. 17, the nozzle body 1602 defines a longitudinal axis 1601 from a proximal end 1603 (i.e., the end closest to the nozzle shield 1610 after assembly) to a distal end 1605 opposite the proximal end 1603. The nozzle body 1602 has a length (L) along the longitudinal axis 1601 of about 2.5 to about 3 inches, and a cross-sectional width (W) of about 0.4 to about 0.5 inches. Vortex sleeve 1604 may be attached to an inner surface of nozzle body 1602. For example, vortex sleeve 1604 may be slid into nozzle body 1602 from proximal end 1603 and form an interference fit with nozzle body 1602 at stepped region 1616 disposed on an inner surface of nozzle body 1602. As shown in fig. 17, the stepped region 1616 may include three portions: a first portion 1616a closest to the distal end 1605, a third portion 1616c closest to the proximal end 1603, and a second portion 1616b between the first portion 1616a and the third portion 1616 c. The cross-sectional width of the second portion 1616b may be greater than the cross-sectional width of the first portion 1616 a. The cross-sectional width of the third portion 1616c may be substantially the same as the cross-sectional width of the second portion 1616b or greater than the cross-sectional width of the second portion 1616 b. During assembly, vortex sleeve 1604 may be slid through third portion 1616c from proximal end 1603 and form an interference fit with second portion 1616 b. Because of the narrow cross-sectional width of first portion 1616a, further axial advancement of vortex sleeve 1604 toward distal end 1605 is prevented.

FIG. 18 illustrates an embodiment of vortex sleeve 1604 of composite nozzle 1600 of FIG. 16. Vortex sleeve 1604 may contain a set of one or more vortex holes 1604a (e.g., six vortex holes), which are radially offset to impart a vortex motion (e.g., radial and tangential velocity components) to the gas (e.g., shield gas, plasma gas, and/or pressurized gas) flowing therethrough. Vortex sleeve 1604 may perform the vortex function previously provided by a separate vortex ring. Thus, a separate swirl ring is no longer required. Eddy current sleeve 1604 may be made of a conductive material such as copper. The length of vortex sleeve 1604 along longitudinal axis 1601 may be about 0.11 to about 0.12 inches, and the cross-sectional diameter of vortex sleeve 1604 may be substantially the same as the cross-sectional width of second portion 1616b of stepped region 1616 of nozzle body 1602.

FIG. 19 illustrates an embodiment of a nozzle tip 1608 of the composite nozzle 1600 of FIG. 16. Nozzle tip 1608 may be made of a conductive material (e.g., copper) because nozzle tip 1608 is exposed to a large thermal gradient during torch operation. As shown in fig. 19, nozzle tip 1608 may be shorter than nozzle body 1602 in order to minimize the use of copper in nozzle tip 1608 and/or to increase the use of less expensive materials (e.g., aluminum) in elongated nozzle body 1602. For example, the length of nozzle tip 1608 may be approximately 1/2, 1/3, or 1/4 of the length of nozzle body 1602. In general, composite nozzle 1600 functions similarly to prior art nozzles that include primarily copper, but composite nozzle 1600 is more cost effective to manufacture and lighter in weight, which allows for easier manipulation of the torch tip.

FIG. 20 shows another embodiment of a nozzle tip 1608. As shown, nozzle tip 1608 includes a set of one or more discharge holes 1612 and/or a set of one or more discharge passages 1618 that fluidly connect the interior of nozzle 1600 to the exterior of nozzle 1600. The exterior of the nozzle 1600 may be the ambient environment and the interior of the nozzle 1600 may be the interior of the shield 1610. The function of the drain holes 1612 and the drain passages 1618 is described below with respect to fig. 23. In addition, the nozzle tip 1608 includes a nozzle exit orifice 1614 for introducing a plasma arc to the workpiece. As shown in fig. 20, the nozzle tip 1608 may have a length (L) along the longitudinal axis 1601 of about 0.9 to about 1 inch and a cross-sectional width (W) of about 0.37 to about 0.4 inch.

FIG. 21 illustrates an embodiment of an insulator 1606 of the composite nozzle 1600 of FIG. 16. The insulation 1606 may be an electrically insulating ring configured to connect the nozzle shield 1610 to the nozzle tip 1608. The electrically insulating ring may include a set of press-fit surfaces (e.g., one for the nozzle tip 1608 and one for the nozzle shield 1610). Thus, the shield 1610 may be press-fit onto the insulation 1606 and the insulation 1606 may be press-fit onto the nozzle tip 1608. An electrical insulation ring 1606 may connect the nozzle tip 1608 to the shield 1610 such that the nozzle tip 1608 and the shield 1610 are electrically insulated from each other while still transferring thermal energy to each other. In some embodiments, insulation 1606 is a two-piece insulation (not shown) that can increase (e.g., double) the electrical insulation capacity due to the increased contact surface. In some embodiments, insulation 1606 is made of anodized aluminum and/or plastic. As shown in fig. 21, insulation 1606 may have a length (L) along longitudinal axis 1601 of about 0.3 to about 0.4 inches, and a maximum cross-sectional width (W) of about 0.4 to about 0.5 inches.

In some embodiments, the anodized layer of insulation 1606 can be formed using hard anodization techniques. For example, the anodization layer may be formed using a sulfuric acid hard anodization process based on an electrolytic solution of sulfuric acid maintained at approximately 32 degrees Fahrenheit and a current density of about 23 to 37 amperes per square foot. The process may last for about 20 to 120 minutes, depending on the alloy used and the desired coating thickness. Coatings of about 10 to 50 microns in thickness can be produced. This hard anodized coating can provide high corrosion resistance (e.g., 336+ hour salt spray resistance), high durability (e.g., 60-70 rockwell C scale rating), and electrical insulation (e.g., 800V/mil thickness). The hard anodize coating may be dyed, the dyeing process not necessarily producing the bright color produced by sulfuric acid anodize.

The anodization process may provide aluminum to the Al₂O₃Surface conversion of (1). The anodization process may provide a dielectric crust of approximately 0.003 inches thick (containing 50% buildup (e.g., deposits on the part)) and 50% permeability (e.g., material variation of the exposed surface of the part). The dielectric crust may provide good resistance to atmospheric corrosion. In extreme environments, a 5% dichromate solution seal is recommended, which can result in good wear resistance. In some embodiments, a plurality of anodized disks may be pressed or heat shrunk together. Using multiple disks, adjustable electrical isolation can be created, for example, because each disk linearly increases electrical isolation (per coating/per layer introduced via the new surface of each disk). By using multiple layers, the electrical isolation capability can be made very strong. For example, by using insulation 1606, a safety factor of 4 may be used to make copper parts (e.g., nozzle tip 1608 and/or nozzle shroud)1610) And (4) electrically isolating. In some embodiments, plastic, ceramic, lava, or Vespel may be used instead of any or all of the anodized parts/components.

FIG. 22 illustrates an embodiment of a nozzle shroud 1610 of the composite nozzle 1600 of FIG. 16. The nozzle shield 1610 may be made of a conductive material such as copper. The nozzle shroud 1610 may be much smaller than previous shrouds. For example, for a 45 amp system, a prior art inventory shield may have a diameter of about one inch (e.g., about 0.990 inch) and a mass of about 0.036 pounds; while a nozzle shield 1610 in accordance with the teachings of the present invention may have a diameter of about one-half inch (e.g., 0.496 inches) and a mass of about 0.007 pounds. For a 105 amp system, a prior art inventory shield may have a diameter of about one inch (e.g., about 1.00 inch) and a mass of about 0.047 pounds; while a nozzle shield 1610 according to the current technique may have a diameter of about one-half inch (e.g., 0.58 inch) and a mass of about 0.013 pounds. In general, the smaller size of the nozzle shield 1610 may reduce the overall mass, and thus the thermal capacity of the part, allowing for rapid cooling during post flow and/or allowing for more heat transfer to the cooling gas during operation. The nozzle shield 1610 may be exposed to cold gas (via exhaust holes 1612) flowing from the torch around the exterior of the shield 1610, which can further reduce the temperature. The shroud is smaller, can achieve higher temperatures during operation, and can transfer more heat to the cooling gas (e.g., create a larger temperature gradient). As shown in FIG. 22, the nozzle shroud 1610 may have a length (L) along the longitudinal axis 1601 of about 0.25 to about 0.35 inches and a maximum cross-sectional width (W) of about 0.4 to about 0.5 inches.

In general, the cartridge-mounted composite nozzle 1600 may have enhanced cooling and insulating capabilities (e.g., by increasing heat transfer away from the consumable components of the torch), reduced manufacturing and material costs, and/or improved recirculation capabilities, durability, and performance. The nozzle 1600 may be cost effective for both hand-held plasma cutting systems and mechanized plasma cutting systems. The nozzle 1600 combines many consumable components into one piece, thus enabling significant reduction in assembly time (e.g., to 1/5-1/10 (by a factor of 5-10)), thereby ensuring proper selection of mating parts for a given cutting task and/or easier recognition of the appropriate consumable component for a given cutting task.

In some embodiments, the nozzle 1600 is elongated to reach difficult to access locations. The nozzle 1600 may have a length (L) along the longitudinal axis 1601 and a cross-sectional width (W) along the axial direction such that the L/W ratio is greater than or equal to about 3. In some embodiments, the length L of the nozzle tip 1608 along the longitudinal axis₁Is about 25% of the overall length L of the nozzle 1600. Alternatively, length L of nozzle tip 1608₁Including about 20%, 30%, or 40% of the overall length L of the nozzle 1600. In some embodiments, the length L of the nozzle body 1602₂Is the length L of nozzle tip 1608₁About 2-3 times higher. In general, the nozzle 1600 may be cartridge-style, in that the nozzle 1600 may be constructed of five components that are separate to be unusable, but replaceable as a whole. Nozzle 1600 may include a nozzle body 1602, a nozzle tip 1608, a swirl sleeve 1604, a nozzle shroud 1610, and insulation 1606.

Fig. 23 illustrates an exemplary plasma arc torch assembly 2300 comprising the composite nozzle 1600 of fig. 16. When fully assembled, the nozzle 1600 substantially surrounds the electrode 2302. A retaining cap 2304 can substantially surround nozzle 1600 to retain nozzle 1600 in torch assembly 2300. Part 2310, for example made of brass, may be coupled with securing cap 2304 via a threaded connection. A retaining cap 2304 coupled to the part 2310 is configured to receive the electrode 2302, the composite nozzle 1600, and an optional trailing insulation member 2320 (e.g., an optional swirl ring). Additionally, a threaded portion (not shown) can be disposed on the assembly 2300 to couple the assembly 2300 (representative of a torch tip) to a plasma arc torch. In a "post-spray" contact start mode of operation of the torch, the gas pressure can cause the electrode 2302 to move within the nozzle 1600, away from the nozzle tip 1608. This separation causes an arc to form between the electrode 2302 and the nozzle tip 1608. The arc ionizes the incoming gas, thereby generating a plasma jet that can be delivered to a workpiece for material processing. The walls of the nozzle 1600 (about which the electrode 2302 moves) may remain cool during operation because the gas flow passes over both the interior of the nozzle 1600 and the exterior surface of the nozzle 1600. The material selection (e.g., aluminum in copper composite) of the nozzle 1600 provides a better conduction path/heat sink than previously used materials (e.g., Vespel). These effects help cool the electrode 2302 and allow the electrode 2302 to function even after a pit is formed in the emissive element 2308 because of the use of the electrode.

Fig. 24 illustrates an exemplary gas flow pattern through the plasma arc torch assembly 2300 of fig. 23. As shown, the airflow generally may travel from the distal end 2314 toward the proximal end 2316 of the assembly 2300, with the emitting element 2308 located at the proximal end 2316. The gas flow may serve multiple functions and may serve as a shield gas and/or a plasma gas. Vortex holes 1604a of vortex sleeve 1604 are configured to introduce additional vortices into the airflow. A portion 2402 of the airflow may be discharged from the interior of nozzle 1600 to the ambient environment through retaining cap 2304 via discharge holes 1612 of nozzle tip 1608. This gas portion 2402 may cool the nozzle 1600 and the exterior of the shield 1610, provide stability to the resulting plasma arc, and remove debris from the workpiece. Another portion 2404 of the gas flow may be directed from the interior of the nozzle 1600 to the nozzle shield 1610 via discharge passages 1618 of the nozzle tip 1608, serving as a shielding gas. Yet another portion of the gas flow (not shown) may be used as a plasma gas and may be ionized by an electric current to produce a plasma arc via the nozzle outlet orifice 1614 for processing the workpiece. In some embodiments, the gas flow portions 2402 and 2404 slow the swirling motion of the gas in the nozzle tip 1608.

Fig. 25 illustrates an exploded view of consumable parts of another exemplary plasma arc torch assembly 2500. To configure the plasma arc torch assembly 2500, an optional insulating member or swirl ring 2502 (similar to the insulating member 2320 of fig. 23) can be fitted through the electrode 2504 (similar to the electrode 2302 of fig. 23) to substantially surround an outer surface portion of the electrode 2504. The resulting combination of these two components may be inserted into nozzle 2506 (similar to nozzle 1600 of fig. 16 and 23). The resulting combination of these three components may be further inserted into retaining cap 2508 (similar to retaining cap 2304 of fig. 23) to complete assembly 2500.

Fig. 26 illustrates an exemplary view of retaining cap 2508 of fig. 25. Retaining cap 2508 may be substantially similar to retaining cap 2304 of fig. 23. The retaining cap 2508 can have a length (L) of about 4.5-5.5 inches, a first cross-sectional width (W1) of about 1 inch (as measured at a distal portion 2510 (i.e., the portion configured to be attached to a plasma arc torch) of the retaining cap 2508), and a second cross-sectional width (W2) of 0.5 inches (as measured at a proximal portion 2512 (i.e., the portion opposite the distal portion 2510) of the retaining cap 2508). The retaining cap 2508 may have a length to first width ratio (L/W1) of greater than 3 or greater than 4 (e.g., 4.5) when the first width is measured at the widest point of the cross-sectional width near the distal portion 2510 of the retaining cap 2508. The retaining cap 2508 may have a length to second width ratio (L/W2) greater than 5, 6, 7, 8, or 9 when the second width is measured at the proximal portion 2512. In some embodiments, retaining cap 2508 is relatively elongated and/or small in cross-section to reach difficult to access locations.

Fig. 27 is a side view of a plasma arc torch 2700 provided with an extender member 2706, the extender member 2706 including a flexible zone. The plasma arc torch 2700 may include a handle device (e.g., handle) 2702, the handle device (e.g., handle) 2702 being connected to a power supply (not shown). The handle 2702 houses electrical and gas connections that can provide one or more of electrical circuitry and cutting gas to a set of consumables 2704, which consumables 2704 can be connected to the handle 2702 through an extender member 2706 to generate a plasma arc. The handle 2702 also typically contains a switch (e.g., trigger) 2708 that, when depressed, can enable gas and electrical energy to flow to the consumable 2704 and trigger a pilot arc to create a plasma cutting arc.

In some aspects, the plasma arc torch can include an elongate extender 2706, the elongate extender 2706 including a flexible section. The elongate extender 2706 can be a substantially dielectric body and/or spacer member. The flexible region can be a flexible (e.g., semi-rigid but configurable or positionable) region of the elongate extender 2706 that can be configured (e.g., can have and maintain a configuration) that can be used to move and reliably position the plasma arc emission consumable in any of a variety of positions, distances, and configurations relative to the plasma arc torch handle.

The flexible region (e.g., flexible consumable connection or flexible extension member) of the elongate extender 2706 is generally configured to remain in a positioned configuration (i.e., a configuration manipulated by a user) during use until it is manipulated into a different configuration.

During use, a user may grip the plasma arc torch with a handle to move the torch and reorient a plasma cutting arc emitted from the plasma arc torch. While the examples illustrated and described herein generally involve a handheld torch, other embodiments are possible. For example, a mechanized torch (e.g., a machine torch or a robotic torch) can include the flexible zone described herein to position the consumable relative to the torch. In addition, the flex zone can be used with a high frequency torch or a water cooled torch. Thus, in some embodiments, the flexible zone may be configured to deliver water or high frequency electricity to the consumable.

As illustrated, extender member 2706 positions consumable 2704 apart from handle 2702 so that a user can access difficult to reach areas that handle 2702 may not access (e.g., because of size limitations). Also, as described above, the extender member 2706 can be temporarily manipulated (e.g., set configuration, bent, positioned, angled, adjusted, or otherwise moved) to arrange consumables in a wide variety of configurations and distances relative to the handle.

For example, prior to performing a treatment operation, an operator may check the location to be treated (e.g., cut or marked) and manually position the consumable 2704 relative to the handle 2702, e.g., by grasping a flexible section of the extender member 2706 and bending the flexible section of the extender member 2706 into a desired shape in order to perform the operation (e.g., cutting, gouging, etc.).

In some aspects, the consumable 104 may be moved during a processing operation. As a non-limiting example, if the operator determines that the surface to be cut is around a tight corner, the operator may bend the flexible section of the extender component 106 into a curved shape (e.g., as depicted in fig. 27) so that the consumable 104 may be inserted into the tight corner to reach the surface to be cut. Once the consumable 104 and extender component 106 are removed from the cutting zone, the operator can reposition the consumable 104 relative to the handle, for example, by re-bending the flexible section of the extender component 106 to the next configuration desired for cutting.

In addition to being able to position the consumable relative to the handle, the flexible section of the extender member 2706 can also be manipulated into a desired shape to conform to the layout of obstacles around the section to be cut. For example, in examples where the consumable needs to be bent around one or more bends to access the cutting surface, the flexible section of the extender member 2706 may be bent into an "S-shape. The flexible section of the extender member 2706 can be configured across a range of orientations and/or can be configured to have any orientation by moving the flexible member to have a desired angle. The desired angle may be any angle ranging from 0 degrees to 360 degrees.

The flexible section of the extender member 2706 can contain any of a variety of types of flexible, repositionable tubing configured to deliver gas and electricity to a consumable. In some embodiments, the flexible section of the extender member 2706 can be manipulated to position the consumables at a predetermined range of angles relative to the handle. For example, the extender member 2706 may position the consumables at an orientation of at least one of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 degrees relative to the handle.

The flexible section of the extender member 2706 can be manipulated and configured such that it has two or more angles that together position the consumable at a compound angle relative to the handle 2702. The extender member 2706 and flexible sections are arranged such that once the configuration is set in the desired configuration, the extender member 2706 retains its set shape until the extender member 2706 is further manipulated or set. The position of the consumable 2704 remains fixed relative to the handle 2702 while the extender member 2706 and/or the flexible section retain their shape.

The extender member 2706 can be coupled to the handle 2702 or torch base of the plasma arc torch using a connector located at one end of the extender member. However, the embodiments described herein are not limited to use with a handheld plasma arc torch. In some embodiments, the extender member 2706 can be coupled, connected, or configured to mate with a motorized torch body. The extender member 2706 can contain a gas passage for providing plasma gas to the plasma arc torch. Alternatively and/or additionally, the extender member 2706 can comprise an electrical conductor for providing cutting current to the plasma arc torch.

The torch handle/hub tip of extender member 2706 can be connected to a camera (shown in fig. 29A) or a bore finder disposed proximal to extender member 2706.

Extender member 2706 can also include connectors at its consumable end that are arranged to mate with a consumable set. Although shown as an elongate body having two ends, in some embodiments, the extender member 2706 can have more than two ends.

The extender member 2706 can take the form of an accessory that can be detached from the torch (e.g., an extension that fits on a conventional torch) and/or include one or more features to interface with one or more switches on the torch (e.g., a consumable sensing switch, a lid sensing switch, etc.). In some embodiments, the extender member 2707 can include features that connect to and/or communicate with switches, sensors, and/or other features included on the torch.

For example, for safety reasons, some torches may include switches that detect consumables installed on the torch to limit torch ignition (e.g., ignition) when certain consumables (e.g., a cap) are not installed on the torch. Extenders for use with such torches may be configured such that the extenders contain communication/transmission media and/or detection media (e.g., switches and/or sensors) that communicate with (e.g., work with) the sensors and switches mounted on the torch. The communication medium or detection medium on the extender communicates with sensors and switches on the torch to ensure that the torch does not ignite unless one or more particular consumables are mounted on the flex connector (i.e., at the end opposite the torch) to close the switches on the torch.

The sensors and switches used with the extender may be mechanical, pneumatic, and/or electrical. The sensor and/or switch is arranged such that it relocates the functionality of the consumable sensor from the consumable end of the extender to the switch or sensor located at the torch end of the extender. For example, the cap sensing switch can be open when the extender is attached to the torch at the torch tip without the cap. At this point, one or more consumables (e.g., caps) may be attached to the consumable tip of the flexible accessory (e.g., by threading the caps onto the torch), and movement of the caps relative to the consumable seats (or consumable stops) of the flexible accessory may move an element (e.g., a piston) along the accessory. The piston may be attached to a translating element that extends along the length of the extender and translates the mechanical action of the piston along the length of the flexible accessory from the consumable seat to the torch tip. At the torch tip of the flexible accessory, the translation element can activate (e.g., push) a lid sensing switch on the torch to a closed position (thereby permitting torch operation).

As described above, the extender member 2706 may contain or be coupled with a consumable detection medium (not shown) that can detect and/or communicate the presence of a consumable set at a tip of the extender member 2706 that is configured to mate with the consumable set. The consumable detection medium can be disposed within extension member 2706 and/or extend between a consumable end and a handle end of extension member 2706.

The consumable detection medium may detect the presence of a consumable set by: convert mechanical, pneumatic, or electrical signals received from the consumable end of extender member 2706. The consumable detection medium may be a consumable sensor that detects the presence of a consumable set. The sensor may be a mechanical sensor, a pneumatic sensor, an electrical sensor, or any other sensor known in the art.

The consumable detection media can be coupled or connected to a transmission medium that relocates functionality of the consumable sensor from the consumable end of the extender component 2706 to a torch sensor located at the handle or torch end of the extender component 2706. In some embodiments, the transmission medium may be a wire or cable. Where the consumable detection medium determines that one or more consumables are present at the consumable end of extender component 2706, a transmission medium can communicate information between the consumable end of extender component 2706 and the torch handle end of extender component 2706 indicating that a torch tip is present. The transmission medium may be disposed inside, near, or outside of the extender member 2706 and/or extend between the consumable end of the extender member 2706 and the torch handle end.

Fig. 28 is a perspective view of an example torch extension member 2800 including a partial disassembly of the flexible section. The torch extension member 2800 can include any of a variety of types of flexible, repositionable tubing configured to deliver gas and electricity to the consumable.

For example, in some embodiments, the torch extension member 2800 can include a central section 2802, the central section 2802 configured to contain and deliver gas to a set of consumable components. One or more components of the torch extension member 2800 (e.g., the central region 2802) can comprise a flexible region. For example, a portion of the torch extension member 2800 can be semi-rigid such that the portion can be bent into a desired shape (e.g., bent by hand, or automatically, such as using a robotic arm), and generally maintain the desired shape until bent into another desired shape. In some examples, the central section 2802 can be a length of conductive tubing (e.g., copper tubing) provided with conductive walls configured to deliver electrical current (e.g., a leading electrical current) to the consumable and define a channel configured to deliver gas (e.g., a plasma gas) to the consumable.

The flexible region of the torch extension member 2800 can be a kink resistant element 2804, the kink resistant element 2804 disposed around an outer surface of the conduit member along one or more regions of the torch extension member 2800. The kink-resistant element 2804 may limit (e.g., prevent) the torch extension member 2800 from kinking (e.g., over-bending, pinching, bending to an internal collapse point, deforming to a necking or breaking point, or otherwise bending or deforming beyond a desired amount). The kink-resisting element 2804 may comprise any of a variety of materials or components configured to help limit kinking, such as a restrictive tube or a coating of material having a desired stiffness and ductility surrounding the catheter member. In some embodiments, the kink-resisting element 2804 may comprise a length of tubing, such as plastic or rubber tubing (e.g., polyethylene tubing) that fits around the torch extension member 2800.

The torch extension component 2800 can also include a fluid channel and/or one or more additional conductive components (e.g., wires) 2806 to deliver electricity to consumables (e.g., signals, high frequency signals, cutting current, etc.). As illustrated in fig. 28, the conductive member 2806 may take the form of a wire (e.g., an insulated wire) disposed around the central section 2802 and the kink resisting element 2804. Additionally/alternatively, the conductive member 2806 can be configured to deliver a cutting current to the consumable. In some embodiments, the torch extension member 2800 may include two conductive wires for delivering the lead current and the cutting current to the consumable.

The torch extension member 2800 can incorporate any of a variety of structural components or features to help encapsulate various components (e.g., conduit members, kink-resisting elements, and/or conductive members) relative to one another to form a relatively compact device without the need to fully couple or bond these components to one another. That is, to permit the desired bending and repositioning, the internal components may generally move or slide relative to one another to accommodate the positioning of the flexible member and the associated adjustment of the internal components that may occur during bending. For example, as illustrated, the torch extension component 2800 can include a wrap (e.g., a coiled or coiled cable wrap) 2808 that can wrap around the internal components to bind the conductive component 2806 to the central region portion 2802 and/or the kink resistant element 2804. Alternatively or additionally, the flexible connector may include a sleeve or coating configured to protect and insulate the internal components of the flexible connector.

As described above, the flexible section of the torch extension member 2800 can be set in configuration across a range of angles such that the flexible section can be fully set in configuration to have and maintain a desired configuration. Once set, the flexible section of the torch extension member 2800 remains stationary (i.e., immobile) until the flexible section is again manipulated and/or reconfigured by the user. In some embodiments, the manipulation and or configuration of the flexible section may be performed automatically, such as by a pre-programmed robotic arm.

The torch extension component 2800 can contain or be coupled with a consumable detection medium (e.g., a lid sensing switch) (not shown) that can detect and/or communicate the presence of a consumable set at a tip of the extension component 2800 that is configured to mate with the consumable set. The consumable detection medium may be disposed within the extension member 2800 and/or extend between a consumable end and a handle end of the extension member 2800.

The consumable detection medium may detect the presence of the consumable set and convert mechanical, pneumatic, or electrical signals received from the consumable end of the extension member 2800. The consumable detection medium may be a consumable sensor that detects the presence of a consumable set. The sensor may be a mechanical sensor, a pneumatic sensor, an electrical sensor, or any other sensor known in the art.

Additionally or alternatively, the consumable detection media may be coupled or connected to a transmission medium that relocates functionality of the consumable sensor from the consumable tip of the extension component 2800 to a torch sensor located at the handle or torch tip of the extender component 2706.

While certain configurations of the torch extension member 2800 are illustrated, various other configurations are possible. For example, in some cases, the torch extension member 2800 can comprise one or more conduit members (e.g., coaxial conduit members) that define the gas flow channel and the positionable structural member. For example, the torch extension member 2800 can comprise one or more lengths of metal jacketed tubing that can carry gas to the consumables. In some cases, the metal sleeve may serve as a conductive member configured to deliver electricity to the consumable. Other types of positionable tubular members may be implemented in accordance with the present disclosure.

Fig. 29A is a schematic side view of a plasma arc torch extender provided with a flexible zone positioned in a straight configuration. In the example shown in fig. 29A, the torch extender spans a length "L" when positioned in a straight configuration (e.g., prior to manipulation). As shown in fig. 29A, a camera (generally shown in box) may be disposed proximal to the elongated substantially flexible body. The line leading to the camera is shown in hatched lines, as this line may be external or internal to the flexible member. In some embodiments, the bore probe may be disposed proximal to the elongate substantially flexible body.

Fig. 29B is a schematic side view of a plasma arc torch extender provided with a flexible zone manipulated into a bent configuration. Fig. 29B illustrates how the consumable of a handheld torch provided with a plasma arc torch extender having a flexible zone can be bent away from the handle (e.g., due to the user manually deflecting the consumable or due to the user manually bending the flexible zone). As shown, these consumables can be bent away from the flex zone at an angle θ from a longitudinal axis of the zone (e.g., the torch body/flex zone connection axis) that extends away from the torch body. The flexible connector may have a length L (which may be relatively long (e.g., about 2 inches to about 5 feet or more)) such that the flexible connector may bend along a long, smooth arcuate path rather than just bending or kinking (e.g., pivoting) at a particular (e.g., predetermined) location or pivot point. The path may be defined by an L/theta ratio, where a longer length indicates that the transition arc of the flexible connection is smoother. Such longer L/theta ratios may be distinguished from plasma torches or other similar devices that merely incorporate a curved junction, as a simple junction does not readily allow the operating head to be fed or "snaked" into tight areas or crevices.

Fig. 29C, 29D, 29E, 29F, 29G, 29H, and 29I are schematic side views of a plasma arc torch provided with a torch extender having a flexible region that sets configurations across various example orientations.

As illustrated in fig. 29C, the flexible section of the torch extender can be used to form bends, for example, to form a compound angle that positions the consumables around obstacles. In addition to guiding around multiple obstructions, forming multiple bends (e.g., around different axes) can also help offset the longitudinal axis of the consumable away from the longitudinal axis of the consumable connector of the torch. That is, the example illustrated in fig. 29C displaces or offsets the longitudinal axis of the consumable from the longitudinal axis of the torch connector and effectively shortens the longitudinal distance between the torch handle and the consumable, rather than merely bending away from the torch on a consistent bending axis.

Referring to fig. 29D and 29E, the flexible section of the torch extender can also be used to articulate the consumable set along a variety of positions relative to the handle. For example, fig. 29D illustrates an example in which the consumable may be oriented generally toward the handle, but spaced from the handle by a gap S. Such a configuration may be used, for example, to cut around a blind corner. FIG. 29E further illustrates the various motions that can be used when the consumable is moved relative to the handle. As illustrated, the consumable may be moved over a range of 360 degrees relative to the handle.

The flexible connector may be bent in two different directions (e.g., along two different planes) to form a three-dimensional bending axis. For example, fig. 29F illustrates a top view of the torch in which the flexible section of the torch extender bends, laterally offsetting the consumable (by a distance Dz) in a first direction (e.g., along the z-axis). Fig. 29G illustrates a side view of the torch in which the flex connector is also bent, vertically offsetting the consumable (by a distance Dy) in a second direction (e.g., along the y-axis). Such bending in different directions is contemplated to be particularly useful in a series of paths for feeding consumables into a structure (e.g., a welded assembly, a series of connected pipes or tubes, a frame structure, or any of a variety of three-dimensional structures).

Fig. 29H and 29I further illustrate the ability of the flexible section to have full range of motion, and fig. 29H and 29I illustrate respective top and side views of the torch with the flexible section of the extender bent into a loop.

Fig. 30A, 30B, 30C, 30D, and 30E illustrate another example of a plasma arc torch 3000 provided with an extender with a flexible region (e.g., a flexible region portion) that positions a consumable component relative to a handle region of the torch. The extender 3002 may include a flexible section that surrounds or otherwise shrouds a non-metallic conduit configured to carry gas from the torch to the consumable. As illustrated, in some embodiments, extender 3002 may have a helical configuration of a metallic material (e.g., steel, aluminum, or another structurally suitable material). The extender 3002 can also include one or more consumable component connectors 3004, which consumable component connectors 3004 are configured to connect (e.g., fluidly and/or electrically connect) a set of consumable components to the extender 3002 and the torch.

Referring to fig. 30B and 30E, a set of consumable part connectors 3004 may comprise: a first component 3004A configured to connect to the extender 3002, and a second component 3004B configured to couple to one or more consumable components. As illustrated, in some embodiments, the second component 3004B can include a threaded region to which one or more consumable components can be coupled. The consumable connector component may be formed of one or more non-conductive materials, such as a polymer material, and thus be substantially dielectric, or electrically insulating.

The extender 3002 can be configured such that the extender 3002 can be attached to the torch, replacing typical consumables on the torch. That is, in some embodiments, the extender may include a torch connection area 3006, the torch connection area 3006 designed and/or configured to connect to a plasma arc torch, replacing a set of consumables that would otherwise connect to the torch.

The extender 3002 can be an integral component of the torch, and/or can be configured as a separate component that can be attached to or coupled with the torch. Other configurations are also possible. For example, in some embodiments, extender 3002 may take the form of an accessory to a torch. In some cases, extender 3002 may be an accessory to be connected to the torch to replace one or more consumables. Moreover, extender 3002 and/or flexible sections thereof may include various other features or components. For example, extender 3002 may be completely flexible and/or include one or more flexible sections.

Extender 3002 can be used with a contact start torch or can be configured to carry gas, power, pilot arc current, and/or other types of electronic signals to read information from (e.g., read information from) or write information to (e.g., write information to) a consumable mounted at an end of an accessory. Various media, such as antenna coils, may be configured to communicate with data tags disposed in or on consumables located at consumable ends of extenders. Additionally or alternatively, the extender may be configured to sense (e.g., for safety or regulatory purposes) the installed consumable (e.g., based on translation of the mechanical device), the arc voltage, or the current delivered to the consumable.

The flexible torch components described and illustrated herein can be used with mechanized (e.g., robotic) torch systems. The flexible connector can have multiple bending points or can bend at any location between the torch handle and the set of consumables.

The flexible portion of the extender member may be configured in various arrangements. For example, the flexible portion of the extender member may comprise a plurality of serially connected conduits that are movable relative to each other. This feature of relative movement of the catheter may allow flexibility of the flexible portion of the extension member.

Fig. 31A is a schematic side view of a plasma arc torch provided with an extender component 3100, the extender component 3100 having a flexible region comprising a plurality of conduits 3101 and 3102 connected in series. In the example shown in fig. 31A, the extender member is illustrated in a straight configuration.

As shown in fig. 31A, the plasma torch extender 3100 of the plasma arc cutting system can comprise an elongate extension member 3100, the elongate extension member 3100 having a first tip 3104 and a second tip 3105. The first tip 3104 may be compatible with a consumable set and the second tip 3105 may be compatible with a torch handle or with a mechanical torch. The exterior of the body of the elongate extension member 3100 may be substantially dielectric (electrically insulating). Also, the body of the elongate extension member 3100 may include a flexible section configured to include a set of series interconnected conduits 3101, 3102. Each catheter 3101 and its adjacent catheter 3102 may meet at a connection point 3103. Each catheter may be arranged such that the catheter 3101 may be moved completely in three dimensions relative to its adjacent catheter about its connection point 3103 with the adjacent catheter 3102.

The conduits may be arranged such that at least one conduit is a substantially cylindrical body. In some embodiments, each conduit may be a generally longitudinal cylindrical body. Also, each catheter may define a central axis and be arranged such that the catheter 3101 may be fully moved and/or pivoted relative to its central axis adjacent to the catheter 3102.

The catheters 3101, 3102 are moved relative to each other such that the flexible section can set a configuration across multiple orientations. Fig. 31B is a schematic side view of a plasma arc torch provided with an extender component 3100, the extender component 3100 having a flexible region comprising a plurality of conduits 3101 and 3102 connected in series. In the example shown in fig. 31B, the extender member is illustrated in a curved configuration.

Further, movement of the catheters 3101, 3102 may allow the flexible section to set a configuration, allowing the flexible section of the elongate extension member to move to have a desired configuration (e.g., the curved configuration shown in fig. 29B-29F).

Additionally, each catheter may contain a motion limiter (not shown) that limits movement of the catheter relative to its point of attachment to its adjacent catheter. The motion limiter may be arranged such that it allows the catheter 3101 to move within a predetermined range of movement relative to its connection point 3103 adjacent to the catheter 3102. For example, in one embodiment, the motion limiter may allow the catheter 3101 to move in 1 degree increments relative to its connection point 3103 with its adjacent catheter 3102. In some embodiments, the motion limiter may allow the catheter 3101 to move and change its orientation by at least one movement in an amount of at least one of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 degree angles.

The motion limiter may be arranged to limit movement of the catheter 3101, which, if the catheter 3101 were moved, may result in misalignment of the catheter 3101 relative to the connection point 3103. After the flexible section is manipulated and configured to have a desired shape, the motion limiter may be triggered to prevent further movement of the flexible section. In particular, the motion limiter may allow a predetermined movement of the catheter 3101 (e.g., 15 degrees relative to its point of attachment to the adjacent catheter 3102). Once this movement is complete, the motion limiter may be triggered to stop further movement of the catheter 3101 relative to the connection point 3103. This allows the flexible portion of the elongate extension member to be configured to have a desired configuration (i.e. the overall elongate body is configured as desired by moving the catheter contained in the flexible region), and also ensures that once configured, the flexible region of the elongate body retains its shape (by preventing further movement of the catheter) and does not deform when performing a cutting operation.

Thus, by limiting movement of the catheter relative to its point of attachment to adjacent catheters, the motion limiter ensures that once configured to have the desired shape, the first end 3104 of the elongate member remains stationary relative to the second end 3105. The flexible portion may be configured by a user and/or automatically (e.g., via a robotic arm). Given the flexibility provided by serially connected catheters, a user can easily manipulate the catheters relative to each other to create compound angles within the flexible section.

The catheter may be located within the elongate member such that the catheter is an integral part of the elongate member. In some embodiments, the flexible portion of the elongate member may be at least 6 inches long. The elongate member may be entirely flexible and/or comprise one or more flexible individual portions. In some embodiments, the elongate member may be coupled or arranged to connect to at least one of a camera or a bore probe disposed proximal to the elongate substantially flexible body.

The series connected conduits may contain or surround a gas passage for providing plasma gas to the plasma arc torch. Additionally or alternatively, the series-connected conduits may contain or surround an electrical conductor that provides cutting current to the plasma arc torch, the cutting current passing through the plurality of series-connected conduits.

Fig. 32A is a schematic side view of a plasma arc torch provided with an extender member 3200 in a straight configuration. The plasma arc torch comprises an elongate, substantially dielectric extender member 3200, the extender member 3200 having a first end 3202 and a second end 3201. First end 3202 of extender member 3200 is arranged such that first end 3202 mates with a set of consumables 3204. Second end 3201 is configured such that second end 3201 mates with torch handle 3209 and or a mechanized torch.

The elongated, substantially dielectric extension member 3200 also includes a flexible section 3203. The flexible zone 3203 may be included in the extension member 3200 such that the flexible zone 3203 is an integral part of the extension member 3200. In some embodiments, the extension member 3200 may be completely flexible. Alternatively, extension member 3200 may contain one or more flexible sections 3203.

The flexible section 3203 of the extension member 3200 may comprise a set of series interconnected conduits 3203-C1, 3203-C2 that are interconnected at a plurality of connection points 3206. Each conduit 3203-C1 is arranged such that it can move in three dimensions relative to its neighboring conduit 3203-C2 about its connection point 3206 with the neighboring conduit 3203-C2. Movement of the conduits 3203-C1, 3203-C2 relative to one another may enable the flexible section 3203 to set a configuration across multiple orientations.

Fig. 32B is a schematic side view of a plasma arc torch provided with an extender member in a curved configuration. As shown in fig. 32B, the conduits 3203-C1, 3203-C2 of the flexible section 3203 of the extension member 3200 may be manipulated such that the flexible section 3203 may be configured to have a desired configuration (e.g., the curved configuration shown in fig. 31B). Extension member 3200 may be configured in a variety of orientations depending on how catheters 3203-C1, 3203-C2 are manipulated. For example, the extension member 3200 may be configured to have compound angles.

Each conduit 3203-C1, 3203-C2 may be a generally longitudinal cylindrical body that may be moved about a connection point 3206 into a plurality of predetermined orientations relative to a longitudinal axis of an adjacent conduit.

As described with respect to fig. 31A and 31B, at least one end of each conduit 3203-C1 may include a motion limiter 3232 (shown later in connection with fig. 32C), the motion limiter 3232 limiting movement of the conduit with respect to its connection point with its adjacent conduit 3203-C2. Motion limiter 3232 is arranged such that motion limiter 3232 allows a predetermined range of movement of conduit 3203-C1 relative to connection point 3206. For example, a user (not shown) may move the flexible section conduits 3203-C1, 3203-C2 relative to one another to set the flexible section 3203 into a desired configuration. Motion limiter 3232 allows a user to configure flexible section 3203 by permitting the catheters to move relative to one another within a predetermined range. Once flexible section 3203 is set to the configuration, motion limiter 3232 prevents further movement of conduits 3203-C1, 3203-C2, thereby ensuring that flexible section 3203 maintains the configuration set by the user. In some embodiments, motion limiter 3232 may be a junction that allows a predetermined movement of the catheter only until the catheter meets motion limiter 3232. Once the catheter meets motion limiter 3232, motion limiter 3232 triggers and prevents further movement and/or pivoting of the catheter.

Fig. 32C illustrates a schematic cross-section of a plasma arc torch provided with an extender member in a curved configuration. As previously described, for safety reasons, some torches may include switches that detect consumables installed on the torch to limit torch ignition (e.g., ignition) when certain consumables (e.g., a cap) are not installed on the torch. Extenders 3200 used with such torches can be configured such that the extenders contain communication/transmission media and/or detection media (e.g., switches and/or sensors) that communicate with (e.g., work with) the sensors and switches mounted on the torch. The communication medium or detection medium on the extender communicates with sensors and switches on the torch to ensure that the torch does not ignite unless one or more particular consumables are mounted on the flex connector (i.e., at the end opposite the torch) to close the switches on the torch.

Fig. 32C illustrates an example in which switches and sensors 3210, 3220 contained in extender component 3200 are used to communicate with switches and sensors contained on the torch handle and/or on the torch body 3202 and/or consumable set 3204.

As shown in fig. 32C, the first end 3202 of the extender member 3200 may contain a transmission/detection medium 3220 (e.g., a sensor, switch, etc., hereinafter collectively referred to as "consumable end sensor 3220"), the transmission/detection medium 3220 being in communication with the consumable set 3204. Similarly, the second end 3201 of the extender member 3200 may contain transmission/detection media 3210 (e.g., sensors, switches, etc., hereinafter collectively referred to as "torch handle sensors 3210"), the transmission/detection media 3210 meeting with corresponding sensors contained in the handle or body of the torch 3209.

The sensors and switches used with the extender may be mechanical, pneumatic, and/or electrical. The sensors and/or switches 3210, 3220 are arranged such that a functional signal emitted by the consumable sensor 3220 is transmitted from the consumable end of the flexible section 3203 to the torch end 3201 of the extender. As shown in fig. 32C, sensors and switches 3220 on the consumable end 3210 of the extender member may be arranged such that these sensors and switches 3220 communicate with sensors and/or switches coupled with the consumable set 3204. Similarly, sensors and switches 3210 on the torch handle end 3201 of the extender member can be arranged such that these sensors and switches 3210 communicate with sensors and/or switches coupled with the torch handle.

FIG. 33 is an example of a cathode nozzle 3300 that may be used with embodiments described herein. Cathode nozzle 3300 may be positioned proximal to the torch body/handle and shaped to support and/or connect to extender member 3200. In one embodiment, the cathode nozzle 3300 may be shaped to capture fluids flowing from the torch and redirect and/or concentrate the fluids (e.g., plasma gases) to flow through the extension member 3200 (shown in fig. 32A-32C) to the torch tip 3204 (shown in fig. 32A-32C). In contrast to conventional torch designs, which disperse the plasma gas as it exits the extension member 3200, the cathode nozzle 3300 redirects the gas flow inward toward the torch tip 3204, thereby concentrating the gas flow before it is dispersed proximally of the consumable set. In one embodiment, the cathode nozzle 3300 can be used as an electrical connection between the torch and the consumable set.

It should also be appreciated that the various aspects and embodiments of the technology may be combined in a variety of ways. Based on the teachings of this specification, one of ordinary skill in the art can readily determine how to combine these various embodiments. In addition, modifications (e.g., flexible single torch, flexible attachment, etc.) will occur to those skilled in the art upon reading the specification.

Claims (31)

1. A nozzle for a plasma arc torch, the nozzle comprising:

a substantially hollow elongate nozzle body capable of receiving an electrode, the body defining a longitudinal axis, a distal end, and a proximal end;

a vortex sleeve attachable to an inner surface of the nozzle body, the vortex sleeve configured to impart a vortex motion to gas introduced to the nozzle;

a nozzle tip connected to the proximal end of the nozzle body, the nozzle tip including a nozzle outlet orifice for introducing a plasma arc to a workpiece;

a nozzle shroud; and

an insulator configured to connect the nozzle tip and the nozzle shroud so as to electrically insulate the nozzle shroud and the nozzle tip from one another while transferring thermal energy between the nozzle shroud and the nozzle tip,

wherein the swirl sleeve is slidably attached to the inner surface of the nozzle body from the proximal end, and

wherein the swirl sleeve forms an interference fit with the nozzle body at a stepped region disposed on the inner surface of the nozzle body to prevent further axial advancement of the swirl sleeve toward the distal end of the nozzle body.

2. The nozzle of claim 1 wherein said nozzle body, said swirl sleeve, said nozzle tip, said nozzle shroud, and said insulator are connected via a press fit.

3. The nozzle of claim 1, wherein the nozzle comprises a single consumable component of a plasma arc torch.

4. The nozzle of claim 1 wherein at least one of said nozzle body, said swirl sleeve, said nozzle tip, or said nozzle shroud comprises a conductive material.

5. The nozzle of claim 1, wherein the nozzle body comprises aluminum.

6. The nozzle of claim 1, wherein the nozzle body has a length along the longitudinal axis of about 2.5 to 3 inches and a cross-sectional width of about 0.4 to about 0.5 inches.

7. The nozzle of claim 1 wherein said swirl sleeve comprises copper.

8. The nozzle of claim 1 wherein said swirl sleeve has a length along said longitudinal axis of about 0.11 to about 0.12 inches.

9. The nozzle of claim 1, wherein the nozzle tip comprises copper.

10. The nozzle of claim 1 wherein said nozzle tip occupies about 1/2, 1/3, or 1/4 of a length of said nozzle body along said longitudinal axis.

11. The nozzle of claim 1, wherein the nozzle tip comprises approximately 20%, 30%, or 40% of the length of the nozzle along the longitudinal axis.

12. The nozzle of claim 1, wherein the nozzle tip has a length along the longitudinal axis of about 0.9 to about 1 inch and a cross-sectional width of about 0.37 to about 0.4 inch.

13. The nozzle of claim 1, wherein the insulation comprises at least one of anodized aluminum or plastic.

14. The nozzle of claim 1, wherein the insulation has a length along the longitudinal axis of about 0.3 to about 0.4 inches and a maximum cross-sectional width of about 0.4 to about 0.5 inches.

15. The nozzle of claim 1, wherein the nozzle shroud comprises copper.

16. The nozzle of claim 1 wherein said nozzle shroud has a length along said longitudinal axis of about 0.25 to about 0.35 inches and a maximum cross-sectional width of about 0.4 to about 0.5 inches.

17. A plasma arc torch assembly, comprising:

an electrode;

a compound nozzle configured to substantially surround the electrode, the compound nozzle comprising a nozzle body, a swirl sleeve, a nozzle tip, a nozzle shroud, and an insulator interconnected by a press fit, the insulator configured to connect the nozzle tip and the nozzle shroud so as to electrically insulate the nozzle shroud and the nozzle tip from one another; and

a retaining cap configured to substantially surround the compound nozzle to retain the compound nozzle in the plasma arc torch assembly,

wherein the nozzle tip is connected to the proximal end of the nozzle body,

wherein the swirl sleeve is slidably attached to an inner surface of the nozzle body from the proximal end of the nozzle body, and

wherein the swirl sleeve forms an interference fit with the nozzle body at a stepped region disposed on the inner surface of the nozzle body to prevent further axial advancement of the swirl sleeve toward the distal end of the nozzle body.

18. The plasma arc torch assembly of claim 17, wherein the swirl sleeve comprises at least one swirl hole configured to introduce swirl to gas in the plasma arc torch assembly.

19. The plasma arc torch assembly of claim 17, wherein the nozzle tip comprises a vent hole fluidly connecting an interior of the nozzle to ambient via the retaining cap, the vent hole configured to direct a first gas flow from the interior of the nozzle to ambient to at least one of cool the nozzle, cool the nozzle shield, provide stability to a plasma arc, or remove debris.

20. The plasma arc torch assembly of claim 19, wherein the nozzle tip comprises a vent channel fluidly connecting an interior of the nozzle to the nozzle shield, the vent channel configured to direct a second gas flow from the interior of the nozzle to the nozzle shield for use as a shielding gas.

21. The plasma arc torch assembly of claim 20, wherein at least one of the first gas flow or the second gas flow slows a swirling motion of the gas in the nozzle tip.

22. The plasma arc torch assembly of claim 17, further comprising a swirl ring coupled to an end of the electrode distal from the workpiece to substantially surround an outer surface of the electrode.

23. The plasma arc torch assembly of claim 17, wherein the retaining cap defines a longitudinal axis and has a length along the longitudinal axis from an end of the retaining cap distal to the workpiece to an end proximal to the workpiece, the length being about 4.5 to about 5.5 inches, the first width of the end distal to the workpiece being about 1 inch, and the second width of the end proximal to the workpiece being about 0.5 inch.

24. The plasma arc torch assembly of claim 23, wherein the first width defines a widest cross-sectional width of the end distal to the workpiece, and a ratio of the length to the first width is greater than 3.

25. The plasma arc torch assembly of claim 24, wherein a ratio of the length to the first width is greater than 4.

26. The plasma arc torch assembly of claim 23, wherein the second width defines a cross-sectional width of the end proximate the workpiece, and a ratio of the length to the second width is greater than 5.

27. The plasma arc torch assembly of claim 26, wherein a ratio of the length to the second width is greater than 6.

28. The plasma arc torch assembly of claim 27, wherein a ratio of the length to the second width is greater than 7.

29. The plasma arc torch assembly of claim 28, wherein a ratio of the length to the second width is greater than 8.

30. The plasma arc torch assembly of claim 29, wherein a ratio of the length to the second width is greater than 9.

31. A method for forming a plasma arc torch assembly, the method comprising:

attaching a swirl ring to an electrode to form a first portion, wherein the swirl ring substantially surrounds an outer surface of the electrode;

inserting the first portion into a compound nozzle to form a second portion, the compound nozzle comprising a nozzle body, a swirl sleeve, a nozzle tip, a nozzle shroud, and an insulator interconnected by a press fit, the insulator configured to connect the nozzle tip and the nozzle shroud so as to electrically insulate the nozzle shroud and the nozzle tip from one another; and

inserting the second portion into a retaining cap configured to substantially surround the second portion to retain the second portion in the plasma arc torch assembly to form the plasma arc torch assembly,

wherein the nozzle tip is connected to the proximal end of the nozzle body,

wherein the swirl sleeve is slidably attached to an inner surface of the nozzle body from the proximal end of the nozzle body, and

wherein the swirl sleeve forms an interference fit with the nozzle body at a stepped region disposed on the inner surface of the nozzle body to prevent further axial advancement of the swirl sleeve toward the distal end of the nozzle body.

Images