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AssigneeHypertherm, Inc.
InventorsRichard W. Couch, Jr., Nicholas A. Sanders, Lifeng Luo, John Sobr, Patrik Backander
Estimating the term…
In a plasma arc cutting torch a flow of plasma gas is bypassed out of a plasma chamber, preferably at an annular gap between a pre-orifice in an inner nozzle piece and an exit nozzle orifice in an outer nozzle piece. A bypass channel formed between the inner and outer nozzle pieces directs the bypass flow to atmosphere. A metering valve or restricting orifice remote from the gap controls the amount of the bypass flow and delays the response of changes in the flow parameters in the plasma chamber to changes in the bypass flow. The pre-orifice and nozzle orifice are positioned and dimensioned to optimize the mass flow velocity and the strength of a vortex-type flow at the pre-orifice, thereby creating a virtual nozzle immediately below the electrode. The gas flow in the plasma chamber is highly uniform and very steady.
In a transferred arc plasma torch having a torch body mounting an electrode and a nozzle closely spaced from the electrode at a lower end of the torch to define a plasma chamber therebetween, said nozzle having a central orifice with an upstream entrance end adjacent the electrode and a downstream exit end adjacent and spaced from a workpiece with a high current density plasma jet exiting the torch from the central nozzle orifice and a plasma gas inlet passage formed in said torch body to direct plasma gas to the plasma chamber via a swirl ring, the improvement comprising
A nozzle for a high current density plasma arc torch having a torch body, an electrode mounted in the body in a spaced relationship with respect to the nozzle to define a plasma chamber therebetween with a nozzle orifice at one end of the nozzle providing an exit for the plasma arc from the torch to a workpiece when the arc is transferred, and a plasma gas inlet passage that directs plasma gas to the plasma arc chamber at its upper end opposite the nozzle orifice, comprising
The method of operating a high current density, transferred arc plasma cutting torch having an electrode and a nozzle mounted in a mutually closely spaced relationship at a lower end of a torch body with a plasma chamber defined between the electrode and the nozzle, a swirling flow of plasma gas to the plasma chamber at an upper end thereof, and a nozzle orifice that guides a transferred plasma arc to a workpiece from an orifice entrance end to an exit orifice end, comprising,
Dependencies are inferred from the claim text.