411 results about "Plasma arc welding" patented technology

To protect the collimator of a transferred plasma arc torch from premature failure due to corrosion, an anti-corrosive covering is applied on the exposed face surface and a portion of the inner exit bore of the collimator. The specification describes several methods for producing the collimator for a plasma torch having an anti-corrosive coating or cladding on the exposed surfaces thereof, including electroplating, electroless plating, flame spraying, plasma spraying, plasma transferred arc, hot isostatic pressing and explosive cladding.

A method and apparatus for controlling a gas supply to a plasma arc torch uses a proportional control solenoid valve positioned adjacent the torch to manipulate the gas flow to the torch, thereby extending electrode life during arc transfer and shutdown. Swirl ring design can be simplified and gas supply and distribution systems become less complicated. The invention also allows manipulation of shield gas flow to reduce divot formation when making interior cuts. The system can be controlled with a digital signal processor utilizing a feedback loop from a sensor.

A series of replacement parts for use in a plasma arc torch is provided, wherein the parts have a color indicia and are adapted for use at different operating parameter values. Each part in the series has a color indicia formed on the part with a different color identifying the particular value of the operating parameter at which the part is adapted to operate. In another form, each part in the series is packaged in a package with a different color indicia identifying the particular value of the operating parameter at which the part is adapted to operate. Additionally, methods of packaging, applying the color indicia, selecting a package or part, and specifying a package or part are provided by the present invention.

A plasma arc torch that includes a torch body having a nozzle mounted relative to a composite electrode in the body to define a plasma chamber. The torch body includes a plasma flow path for directing a plasma gas to the plasma chamber in which a plasma arc is formed. The nozzle includes a hollow, body portion and a substantially solid, head portion defining an exit orifice. The composite electrode can be made of a metallic material (e.g., silver) with high thermal conductivity in the forward portion electrode body adjacent the emitting surface, and the aft portion of the electrode body is made of a second low cost, metallic material with good thermal and electrical conductivity. This composite electrode configuration produces an electrode with reduced electrode wear or pitting comparable to a silver electrode, for a price comparable to that of a copper electrode.

A first connector is disposed on a first end of a lead in a lead set for use with a plasma arc torch. The first connector is capable of engaging a second connector by causing a compression force in a second connector. The second connector compression force is caused by application of a translational force along a longitudinal axis. The second connector causes, upon application of a depression force along the longitudinal axis, disengagement of the first connector. The second causes disengagement of the first connector upon application of a linear force applied along the longitudinal axis to at least one of the first connector and the second connector. The second end of the lead may also be connected to a power supply. Methods for connecting and disconnecting a lead are also disclosed.

A threaded connection for an electrode holder and an electrode in a plasma arc torch is provided. The threaded connection has relatively low height, and the engaged portion of a male threaded portion of the electrode and a female threaded portion of the electrode holder are positioned at least partially within a nozzle chamber. In one inventive aspect, the nominal pitch diameter of the electrode is less than the minor diameter of the electrode. In another, the width of the root area of the electrode thread is wider than the width of the root area of the electrode holder thread by at least about 35%. The width of the root area of the electrode is at least about 15% wider than the width of the crest portion of the electrode. As such, the less consumable of the two parts, the electrode holder, is provided with a thread that is less likely to be worn and damaged. In one particular embodiment, the crest profile of the electrode is that of a Stub Acme thread separated by a larger root profile.

An electrode for a plasma arc cutting torch which minimizes the deposition of high emissivity material on the nozzle, reduces electrode wear, and improves cut quality. The electrode has a body having a first end, a second end in a spaced relationship relative to the first end, and an outer surface extending from the first end to the second end. The body has an end face disposed at the second end. The electrode also includes at least one passage extending from a first opening in the body to a second opening in the end face. A controller can control the electrode gas flow through the passages as a function of a plasma arc torch parameter. Methods for operating the plasma arc cutting torch with the electrode are disclosed.

An electrode-supporting assembly for a contact-start plasma arc torch has an insulator that partially houses an electrode, and employs a spring-loaded plunger to bias the electrode to a forward position. The spring is engaged between the plunger and a contact element attached to the insulator, and may conduct electrical current to the electrode. The plunger, spring, and contact element are retained in the insulator when the torch is opened to replace the electrode, which is a consumable part. The electrode and the plunger have axially-engagable mating surfaces to assure good thermal and electrical conductivity therebetween. Conductivity can be further enhanced by forming the plunger of silver or a silver-bearing alloy. In some embodiments, a passage through the insulator is partitioned into forward and rear chambers, with the plunger, spring, and contact element trapped in the rear chamber.

A shield for a plasma arc torch that pierces and cuts a metallic workpiece producing a splattering of molten metal directed at the torch, the shield protecting consumable components of the plasma arc torch from the splattering molten metal. The shield can include a body, a first surface of the body configured to be contact-cooled by a gas flow, a second surface of the body configured to be contact-cooled by a liquid flow, and a seal assembly configured to be secured to the body and disposed relative to the second surface configured to retain the liquid flow contact-cooling the second surface.

A coolant tube and electrode are adapted to mate with each other to align the tube relative to the electrode during operation of the torch. Improved alignment ensures an adequate flow of coolant along an interior surface of the electrode. In one aspect, an elongated body of the coolant tube has a surface adapted to mate with the electrode. In another aspect, an elongated body of the electrode has a surface adapted to mate with the coolant tube. The surfaces of the tube and electrode may, for example, be flanges, tapered surfaces, contours, or steps.

A method of determining a failure event of consumable for a plasma torch is provided. The method includes monitoring at least one of an operating current or an operating voltage during a transfer arc mode of the plasma arc torch. The method also includes determining when at least one parameter associated with the operating current or the operating voltage exceeds a tolerance threshold for a time period indicative of the failure event. The method further includes shutting off at least one of the operating current or the operating voltage of the plasma arc torch when the at least one parameter exceeds the tolerance threshold for the time period.

Apparatus and methods for thermally processing a workpiece include directing a plasma arc to the workpiece and using a dielectric shield or dielectric coating to protect a forward portion (e.g., a torch head) of a plasma arc torch. The dielectric shield or dielectric coating covers a nozzle disposed within the torch head and protects the nozzle from the effects of slag and double arcing. The shield also improves operator visibility due to the spatial relationship between the dielectric shield and the nozzle.

Apparatus and methods for thermally processing a workpiece include directing a plasma arc to the workpiece and using a dielectric shield or dielectric coating to protect a forward portion (e.g., a torch head) of a plasma arc torch. The dielectric shield or dielectric coating covers a nozzle disposed within the torch head and protects the nozzle from the effects of slag and double arcing. The shield also improves operator visibility due to the spatial relationship between the dielectric shield and the nozzle.

A nozzle for use in a plasma arc torch is provided. The nozzle includes an aft portion comprising a conductive first material with a first density. The aft portion defines a proximal end and a distal end. The nozzle includes a substantially hollow forward portion including 1) a tip section comprising a conductive second material with a second density, and 2) a rear section configured to couple the forward portion to the proximal end of the aft portion. The second density is at least two times greater than the first density. The nozzle further includes a plasma exit orifice disposed in the tip section of the forward portion.

A plasma torch is provided having a tubular member defining a bore extending axially between first and second ends, and nozzle engaged with the first end. A movable member is engaged in the tubular member bore, and includes a first end disposed toward the nozzle and a second end, with a piston member engaged therewith away from the first end. An electrode has a first portion defining a bore and is received by the movable member first end. The electrode has a second portion extending outwardly from the movable member first end toward the nozzle, and a radially outward-extending medial flange between the first and second portions axially outward of the movable member first end. The electrode is movable between an inoperable position in contact with the nozzle and an operable position separated from the nozzle and the medial flange in contact with the tubular member first end.

A system for controlling gas flow from a gas source, through a gas conduit, and to a plasma arc torch during a transition from a cold flow when no arc is present to a hot flow when an arc is provided by the present invention. The system comprises a first solenoid in communication with the gas source, a second solenoid disposed proximate the plasma arc torch, and a bypass circuit in communication with the gas source and the second solenoid. The bypass circuit comprises a bypass solenoid that controls the gas pressure within the gas conduit to reduce gas flow fluctuations when transitioning from cold flow to hot flow. Additional gas control systems and methods are also provided that cause the gas pressure to be higher during cold flow, prior to arc ignition, which overcomes the rapid drop in flow that typically occurs during the transition to hot flow.

A plasma arc torch is provided that comprises torch head connections that are made between consumable components and a torch head independent of rotational alignment of the consumable components. Accordingly, connections for the flow of a cooling fluid, plasma gas, and / or a secondary gas are made independent of rotational alignment. Additionally, electrical connections are also provided that are independent of rotational alignment of the various plasma arc torch components.

The invention relates to a nozzle for a plasma arc torch and methods of manufacturing the nozzle. The nozzle includes a nozzle body and a nozzle liner. The nozzle body has a cylindrical portion and the nozzle liner has a cylindrical section in close thermal contact with a majority of an interior surface of a cylindrical portion of the nozzle body.

The invention aims to provide an aluminum alloy direct current plasma-tungsten electrode argon arc hybrid welding method based on pulse coordination control. A tungsten electrode argon arc welding gun is exerted on one side of a plasma arc welding gun, in the welding process, the tungsten electrode argon arc welding gun is utilized to remove oxidation films on the surface of aluminum alloy in front of the direct current plasma welding gun, and the direct current plasma welding gun is utilized to conduct welding behind the tungsten electrode argon arc welding gun. In order to avoid electromagnetic interference between plasma arcs and tungsten electrode argon arcs in the welding process, when a plasma arc current is in a pulse basic value pilot arc stage, a pulse signal controller is triggered, and a tungsten electrode argon arc current is adjusted to be in a negative half wave crest value for removing the oxidation films on the surface of the aluminum alloy; when the plasma arc current is in a pulse crest value welding stage, the pulse signal controller is utilized to adjust the tungsten electrode argon arc current to be in pulse basic value output, and the steps are repeatedly executed in this way. According to the method, the current pulse wave form of the tungsten electrode argon arcs and the current pulse wave form of a plasma arc power supply are reasonably adjusted, the effect of cleaning the oxidation films on the surface of the aluminum alloy and weld penetration are controlled, and therefore weld formation is guaranteed, tungsten electrode burning losses are reduced, and welding efficiency is improved.

Controlling the flow of a secondary gas reduces entrainment of the secondary gas and a plasma gas that forms a plasma arc in a plasma arc torch system. Reducing entrainment of the secondary gas and the plasma gas that forms the plasma arc improves the quality of cuts made with the plasma arc torch.

An improved torch providing high visibility of the work zone to the operator, an increased viewing angle, and a reduced obstruction angle. The high visibility torch includes consumables adapted to maintain torch and consumables performance while reducing visual obstruction to the user, by coordinating, balancing, and optimizing design requirements and stack up tolerances. The invention also includes a related low-profile safety switch that promotes workpiece visibility and minimizes view obstruction.

An electrode is provided for use in a plasma arc torch. The electrode includes a body having a forward portion, a middle portion and an aft portion. The forward portion includes an electrode tip comprising a conductive first material, wherein the electrode tip includes: 1) a pilot contact region for initiating a pilot arc across the nozzle and 2) an emitter. The middle portion comprises a second material and defines a proximal end for mating with the forward portion and a distal end for mating with the aft portion. The material density of the second material is at least half of the material density of the first material. The electrode also includes an electrically conductive path extending from the forward portion to the aft portion of the body.

A plasma torch is provided having a movable member carrying an electrode and movable along a tubular member bore having a nozzle at one end. A piston member engaged with the movable member moves the electrode between inoperable and operable positions within the bore, the movable member being biased outwardly of the one end of the bore. A first sealing member engaged with the piston member allows a fluid flow into the bore to act on the piston member to move the electrode to the operable position when the nozzle / electrode is engaged with the tubular member. A second sealing member, engaged with the bore, engages the piston member when the nozzle / electrode is removed. The fluid flow enters the bore between the sealing members, the second sealing member thus preventing torch operation when the nozzle / electrode is removed by preventing the fluid flow from acting on the piston.

A portable plasma arc torch system can be used for processing materials. The system includes a replaceable or rechargeable power source and replaceable or rechargeable gas source. A controller communicates with at least one of the power source or the gas source. A plasma delivery device received via the controller current from the power source and gas from the gas source to generate a plasma arc at an output of the plasma delivery device. The plasma arc can be used to process materials such as metallic workpieces. The plasma arc torch can include a wearable portable assembly which includes the replaceable or rechargeable power and gas source. A plasma delivery device receives current from the power source in the assembly and gas from the gas source in the assembly to generate a plasma arc.