Hypertherm, Inc.

Commonwealth Scientific and Industrial Research Organisation

Other

Synergy Innovations, Inc.

Richard W Couch, Jr

Nicholas A Sanders

Jon W Lindsay

Zheng Duan

Zhipeng Lu

Lifeng Luo

John Sobr

Charles Marcou Hackett

David Jonathan Cook

Robert C Dean, Jr

Kirk H Ferland

Staffan C Stenfelt

Ashley Grant Doolette

Brian J Currier

Aaron D Brandt

Kenneth J Woods

Richard Rox Anderson

Yong Yang

Subramania Ramakrishnan

Maciej Wlodzimierz Rogozinski

Patrik Backander

Jennifer L Freeman

Matthew L Brown

William J Connally

Jeffrey L Peterson

Edward M Shipulski

William V Bailey

David F Nelson

Timothy M Brewer

Elizabeth B Hackett

Mark W Blanchard

Young Yang

Nichols A Sanders

Roger L Kenyon

Casey Jones

Charles M Hackett

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.

Composite electrode for a plasma arc torch

A method and apparatus for forming high-speed water droplets takes advantage on a synergy of features disclosed by the present invention including a low Weber number in a chamber in which a liquid stream breaks up into droplets; a reduced break up distance for forming the water droplets by introducing turbulence into the liquid source, thereby providing a unit or tool that is of practical size; accomplishing the generation of high-speed water droplets without using a complex driver; reducing the liquid's surface tension thereby facilitating the creating of near spherical droplets; and maintaining the droplets in form until they strike the surface of a workpiece.

Method and apparatus for forming high-speed liquid

A metal jet cutting system, which includes a jetting heat, a heater and a power source, is used for modifying a workpiece. The jetting head includes a crucible and an inlet for receiving a feed stock of a conductive material. The heater melts the conductive material in the crucible to provide a conductive fluid, which exits the jetting head via an outlet. The power source, which is in electrical communication with the conductive fluid, increases the temperature of the conductive fluid. The conductive fluid is applied to the workpiece to modify the workpiece.

Process and apparatus for cutting or welding a workpiece

An electrode for use in a plasma arc torch has an insert designed to improve the service life of the electrode, particularly for high current processes. The electrode comprises an elongated electrode body formed of a high thermal conductivity material and having a bore disposed in a bottom end of the electrode body. The bore can be cylindrical or ring-shaped. An insert comprising a high thermionic emissivity material, and in some embodiments, a high thermal conductivity material, is disposed in the bore. The insert can be ringed-shaped or cylindrical.

Electrode for a plasma arc torch having an improved insert configuration

Disclosed is a novel method and structure for contact starting a plasma arc torch. A translatable, electrically conductive component such as a nozzle or swirl ring is biased into contact with an electrode by a compliant spring element. A pilot arc is formed by first passing current through the electrode/component interface. Thereafter, the component is translated under the influence of gas pressure in a plasma chamber formed between the electrode and component, compressing the compliant element and initiating the pilot arc. The spring element may be maintained integrally with the nozzle, swirl ring, or a retaining cap, facilitating removal and replacement of the spring element with consumable components of the torch. Exemplary spring elements include wave spring washers, finger spring washers, curved spring washers, helical compression springs, flat wire compression springs, and slotted conical discs.

Integral spring consumables for plasma arc torch using blow forward

Disclosed is a method and structure for improving alignment of a plasma arc with an axial centerline of a plasma arc torch. At least one of an electrode and nozzle are mounted in respective bores of a cathode block and torch body using a radial spring element. By concentrically machining the bores along an axial centerline of the torch and centering the consumable components within the bores using the spring elements, an insert disposed in a tip of the electrode is axially aligned with an orifice formed in a tip of the nozzle. Asymmetric wear of the nozzle orifice due to a skewed arc path is markedly reduced or eliminated. The torch may be employed in computer controlled cutting and marking systems to produce components or workpieces with reduced dimensional and angular errors.

Apparatus and method for improved assembly concentricity in a plasma arc

A plasma arc torch apparatus and method for cutting or marking a workpiece includes a torch having an electrode and a nozzle coupled to a power supply, and a plasma gas source coupled to a fluid line for delivering plasma gas to the torch. A flow restriction member is disposed in the fluid line adjacent the torch and causes the pressure of the plasma gas in the torch to gradually increase during start up thus creating a stable plasma arc. A three-way valve is disposed in the fluid line downstream of the flow restriction member and has an inlet, a torch outlet, and a vent outlet. The inlet is in fluid communication with the torch outlet for delivering plasma gas to the torch when the valve is in the open position, and the torch outlet is in fluid communication with the vent outlet when the valve is in the vent position, for rapidly dissipating the gas in the plasma chamber of the torch to atmosphere after the arc has been extinguished. The rapid reduction of the gas pressure in the torch reduces the cycle time, enabling the torch to be restarted more quickly after completion of a prior cutting cycle.

Apparatus and method for starting and stopping a plasma arc torch used

A coolant tube for a liquid-cooled electrode disposed a plasma arc torch does not become damaged during an electrode blow-out condition. The coolant tube includes a hollow member and a substantially solid member. The hollow member has a first end, a second end and a coolant passage extending between the first and second ends. The first end can be secured within the torch such that the coolant tube is disposed adjacent the interior surface of the electrode and such that the coolant passage is in fluid communication with a coolant supply. The substantially solid member extends from the second end of the hollow member and has at least one flow restriction orifice extending therethrough. Each flow restriction orifice is fluid communication with the coolant passage for providing at least one high velocity jet of coolant to the interior surface of the electrode.

Coolant tube for use in a liquid-cooled electrode disposed in a plasma

Detecting non-symmetrical nozzle wear in a plasma arc torch

Plasma torch condition monitoring

A plasma arc torch has a secondary gas flow that is extremely large during piercing of a workpiece to keep splattered molten metal away from the torch and thereby prevent 'double arcing'. The secondary flow exits the torch immediately adjacent the transferred plasma arc and is an extremely uniform, swirling flow. A swirl ring is located in the secondary gas flow path at the exit point. A prechamber feeds gas to the swirl ring, which is in turn fed through a flow restricting orifice. For certain applications the secondary gas is a mixture of an oxidizing gas, preferably oxygen, and a non-oxidizing gas, preferably nitrogen, in a flow ratio of oxygen to nitrogen in the range of 2:3 to 9:1. Preferably the flow ratio is about 2:1. A network of conduits and solenoid valves operated under the control of a central microprocessor regulates the flows of plasma gas and secondary gas and mixes the secondary gas. The network includes valved parallel branches that provide a quick charge capability and a set of venting valves, also electrically actuated by the microprocessor, to provide a quick discharge. In a preferred high-definition embodiment, a nozzle with a cut back outer surface and a large, conical head allows a metal seal and enhanced cooling. A two-piece cap protects the nozzle during cutting.

Plasma arc cutting process and apparatus using an oxygen-rich gas shield

Plasma arc or laser cutting uses a mix of reactive and reducing gas flows to cut sheets of stainless steel, aluminum and other non-ferrous metals. The reducing gas flow to the cut varies as a percentage of the total gas flow to maintain a reducing atmosphere down through the cut, but to leave a predominantly oxidizing atmosphere at the intersection of the cut and the bottom surface of the sheet being cut. In plasma arc cutting these flows can also be characterized as either a plasma gas flow, one that forms the arc, or a shield gas flow that surrounds the arc. The reactive gas is preferably a flow of air, oxygen, nitrogen, carbon dioxide or a combination of these gases. The reducing gas is preferably hydrogen, hydrogen 35, methane, or a mixture of these gases. For aluminum, the reactive gas is preferably air or nitrogen and the reducing gas is preferably methane or a mixture of methane and air. In laser cutting the reducing gases such as methane can be used by mixing them with reactive assist gases.

Process for high quality plasma arc and laser cutting of stainless steel

Growing community of inventors

Hanover, NH, United States of America

Richard W Couch, Jr